U.S. patent application number 15/861561 was filed with the patent office on 2018-07-05 for optics in three-dimensional printing.
The applicant listed for this patent is Velo3D, Inc.. Invention is credited to Jatinder RANDHAWA.
Application Number | 20180186082 15/861561 |
Document ID | / |
Family ID | 62708322 |
Filed Date | 2018-07-05 |
United States Patent
Application |
20180186082 |
Kind Code |
A1 |
RANDHAWA; Jatinder |
July 5, 2018 |
OPTICS IN THREE-DIMENSIONAL PRINTING
Abstract
The present disclosure provides various apparatuses, systems,
software, and methods for three-dimensional (3D) printing. The
disclosure delineates various optical components of the 3D printing
system, their usage, and their optional calibration. The disclosure
delineates calibration of one or more components of the 3D printer
(e.g., the energy beam).
Inventors: |
RANDHAWA; Jatinder;
(Milpitas, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Velo3D, Inc. |
Campbell |
CA |
US |
|
|
Family ID: |
62708322 |
Appl. No.: |
15/861561 |
Filed: |
January 3, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62442896 |
Jan 5, 2017 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B33Y 50/02 20141201;
B23K 26/342 20151001; B29C 64/153 20170801; B23K 26/125 20130101;
B33Y 10/00 20141201; B29C 64/268 20170801; B23K 26/127 20130101;
B33Y 30/00 20141201; B29C 64/35 20170801; B23K 26/0604 20130101;
B23K 26/032 20130101; B22F 2999/00 20130101; B23K 26/354 20151001;
B23K 26/0608 20130101; B29C 64/393 20170801; B23K 26/34 20130101;
B23K 26/703 20151001; B28B 1/001 20130101; B22F 3/1055 20130101;
B22F 2003/1057 20130101; B29C 64/135 20170801; B28B 17/0081
20130101; B23K 26/062 20151001; B22F 2999/00 20130101; B22F 2203/03
20130101; B22F 2203/11 20130101 |
International
Class: |
B29C 64/393 20060101
B29C064/393; B29C 64/153 20060101 B29C064/153; B29C 64/268 20060101
B29C064/268; B29C 64/35 20060101 B29C064/35; B22F 3/105 20060101
B22F003/105; B28B 17/00 20060101 B28B017/00; B28B 1/00 20060101
B28B001/00; B33Y 10/00 20060101 B33Y010/00; B33Y 30/00 20060101
B33Y030/00; B33Y 50/02 20060101 B33Y050/02; B23K 26/354 20060101
B23K026/354; B23K 26/34 20060101 B23K026/34; B23K 26/062 20060101
B23K026/062 |
Claims
1. An apparatus for printing at least one three-dimensional object,
comprising at least one controller that is programmed to: (a)
direct an energy source to generate an energy beam to a test
calibration structure through an optical arrangement comprising one
or more optical elements, which energy beam is configured to
transform a pre-transformed material to a transformed material for
printing the at least one three-dimensional object in an enclosure,
which optical arrangement is configured to provide a requested
footprint of the energy beam at least on an exposed surface of the
test calibration structure, which test calibration structure is
disposed in the enclosure, wherein the at least one controller is
operatively coupled to the energy source and to the optical
arrangement; (b) direct a detector to detect a returning radiation
from the test calibration structure and generate an associated test
signal; and (c) direct evaluation of a thermal lensing of the
optical arrangement using the associated test signal.
2. The apparatus of claim 1, wherein one or more of (a), (b), and
(c) occur in real time during the printing of the three-dimensional
object.
3. The apparatus of claim 1, wherein the evaluation considers a
deviation between the associated test signal and an associated
benchmark signal.
4. The apparatus of claim 3, wherein the optical arrangement is in
non-thermal lensing conditions and/or varying thermal lensing
conditions during a generation of a returning benchmark
radiation.
5. The apparatus of claim 4, wherein the at least one controller is
configured to direct varying the thermal lensing conditions.
6. The apparatus of claim 5, wherein the at least one controller is
configured to direct an energy beam to irradiate a heat sink
through the optical arrangement to induce a variation in a thermal
condition of the optical arrangement.
7. The apparatus of claim 6, wherein the at least one controller is
configured to control a throughput of the energy beam for
irradiating the heat sink through the optical arrangement.
8. The apparatus of claim 6, wherein the at least one controller is
configured to control a temperature of at least one optical element
of the optical arrangement resulting from the variation in the
thermal condition.
9. The apparatus of claim 6, wherein the at least one controller is
configured to direct the energy beam that is configured to
transform the pre-transformed material to the transformed material
for irradiating energy through the optical arrangement.
10. The apparatus of claim 6, wherein the at least one controller
is configured to direct a different energy beam for irradiating
energy through the optical arrangement.
11. The apparatus of claim 3, wherein the associated benchmark
signal comprises a correlation between a set of requested
footprints on a benchmark calibration structure and an associated
set of benchmark signals generated from respective returning
radiations from the benchmark calibration structure, at (i) a given
energy throughput through the optical arrangement and/or (ii) a
given focal setup of the optical arrangement.
12. The apparatus of claim 11, wherein the evaluation considers a
deviation between the associated test signal and the associated
benchmark signal.
13. The apparatus of claim 11, wherein the at least one controller
is further programmed to control the focal setup of the optical
arrangement while considering a result of the evaluation.
14. The apparatus of claim 1, wherein the at least one controller
is further programmed to direct formation of a benchmark
calibration structure from a transformation of a portion of the
pre-transformed material.
15. The apparatus of claim 14, wherein the benchmark calibration
structure is printed in real time during printing of the
three-dimensional object.
16. The apparatus of claim 1, wherein the associated test signal
comprises a correlation between (I) an energy throughput that is
emitted through the optical arrangement by the energy beam at a
focal setting and (II) the associated test signal that is generated
from the returning radiation from the test calibration
structure.
17. The apparatus of claim 1, wherein the at least one controller
is configured to direct a cleaning process of at least one surface
of the test calibration structure.
18. A method of printing of at least one three-dimensional object,
comprising: (a) directing an energy beam to a test calibration
structure through an optical arrangement comprising one or more
optical elements, which energy beam is configured to transform a
pre-transformed material to a transformed material for printing the
at least one three-dimensional object in an enclosure, which
optical arrangement is configured to provide a requested footprint
of the energy beam at least on an exposed surface of the test
calibration structure, which test calibration structure is disposed
in the enclosure; (b) detecting a returning radiation from the test
calibration structure and generating an associated test signal; and
(c) evaluating a thermal lensing of the optical arrangement using
the associated test signal.
19. The method of claim 18, wherein evaluating the thermal lensing
further comprising considering a deviation between the associated
test signal and an associated benchmark signal of a benchmark
returning radiation from the test calibration structure or a
different calibration structure.
20. The method of claim 19, wherein the test calibration structure
or the different calibration structure comprises a benchmark
calibration structure.
21. The method of claim 20, wherein the optical arrangement is at
non-thermal lensing conditions or at various thermal lensing
conditions of the optical arrangement while generating the
benchmark returning radiation.
22. The method of claim 21, further comprising varying a thermal
condition of the optical arrangement by irradiating a heat
sink.
23. The method of claim 22, further comprising controlling the
irradiating the heat sink through the optical arrangement.
24. The method of claim 23, wherein controlling comprises
controlling a throughput of an energy irradiating through the
optical arrangement and/or controlling a temperature of the one or
more optical elements of the optical arrangement.
25. The method of claim 18, wherein the at least one
three-dimensional object is printed above a platform, and wherein
the test calibration structure is disposed adjacent to the
platform.
26. The method of claim 25, wherein adjacent comprises laterally
adjacent to the platform.
27. The method of claim 25, wherein adjacent comprises above the
platform.
28. The method of claim 20, further comprising forming the
benchmark calibration structure by transforming a portion of the
pre-transformed material.
29. The method of claim 28, wherein forming the test calibration
structure and/or the benchmark calibration structure is performed
in real time during the printing.
30. The method of claim 20, wherein the associated benchmark signal
comprises correlating the requested footprint on the benchmark
calibration structure with the associated test signal generated
from a returning benchmark radiation from the benchmark calibration
structure.
31. The method of claim 30, wherein correlating comprises a set of
requested footprints on the benchmark calibration structure and an
associated set of associated benchmark signals generated from
respective returning benchmark radiations from the benchmark
calibration structure.
32. The method of claim 20, further comprising directing a cleaning
process of at least one surface of the benchmark calibration
structure.
33. The method of claim 18, wherein one or more of (a), (b), and
(c) are in real-time during the printing.
Description
CROSS-REFERENCE
[0001] This application claims benefit of prior-filed U.S.
Provisional Patent Application Ser. No. 62/442,896, filed Jan. 5,
2017, titled "OPTICAL CALIBRATION IN THREE-DIMENSIONAL PRINTING,"
which is entirely incorporated herein by reference.
BACKGROUND
[0002] Three-dimensional (3D) printing (e.g., additive
manufacturing) is a process for making a three-dimensional (3D)
object of any shape from a design. The design may be in the form of
a data source such as an electronic data source, or may be in the
form of a hard copy. The hard copy may be a two-dimensional
representation of a 3D object. The data source may be an electronic
3D model. 3D printing may be accomplished through an additive
process in which successive layers of material are laid down one on
top of each other. This process may be controlled (e.g., computer
controlled, manually controlled, or both). A 3D printer can be an
industrial robot.
[0003] 3D printing can generate custom parts quickly and
efficiently. A variety of materials can be used in a 3D printing
process including elemental metal, metal alloy, ceramic, elemental
carbon, or polymeric material. In a typical additive 3D printing
process, a first material-layer is formed, and thereafter,
successive material-layers (or parts thereof) are added one by one,
wherein each new material-layer is added on a pre-formed
material-layer, until the entire designed three-dimensional
structure (3D object) is materialized.
[0004] 3D models may be created utilizing a computer aided design
package or via 3D scanner. The manual modeling process of preparing
geometric data for 3D computer graphics may be similar to plastic
arts, such as sculpting or animating. 3D scanning is a process of
analyzing and collecting digital data on the shape and appearance
of a real object. Based on this data, 3D models of the scanned
object can be produced. The 3D models may include computer-aided
design (CAD).
[0005] Many additive processes are currently available. They may
differ in the manner layers are deposited to create the
materialized structure. They may vary in the material or materials
that are used to generate the designed structure. Some methods melt
or soften material to produce the layers. Examples for 3D printing
methods include selective laser melting (SLM), selective laser
sintering (SLS), direct metal laser sintering (DMLS), shape
deposition manufacturing (SDM) or fused deposition modeling (FDM).
Other methods cure liquid materials using different technologies
such as stereo lithography (SLA). In the method of laminated object
manufacturing (LOM), thin layers (made inter alia of paper,
polymer, metal) are cut to shape and joined together.
SUMMARY
[0006] In some instances, it may be desirable to calibrate at least
one characteristic of the energy beam that facilitates formation of
the three-dimensional object. For example, it may be desirable to
calibrate its location with respect to at least one component of
the 3D printer (e.g., target surface, a load lock shutter, and/or a
calibration mark). It may be desirable to calibrate the speed,
power density distribution, and/or focal point. The present
disclosure facilitates the calibration of the at least one
characteristic of the energy beam.
[0007] In some instances, it may be desirable to detect one or more
characteristics of the forming 3D object and/or its vicinity (e.g.,
in real-time during at least a portion of the 3D printing). For
example, it may be desirable to include a detection system that
facilitates contemporaneous focusing of a first energy beam on a
target surface, and a second (related) energy beam on the detector.
For example, it may be desirable to include a detection system that
facilitates contemporaneous focusing of an energy beam on a target
surface, and on the detector. For example, the detection system may
use achromatic optics.
[0008] At times, an optical system (e.g., comprising a detection
system) of the 3D printer may deviate from one or more of its
calibrated properties. It may be desirable to include a calibration
system that facilitates calibration of one or more elements of an
optical system. Calibrating the one or more elements of the optical
system may result in (e.g., substantially) accurate operation of
the optical system. For example, the one or more energy beams
within the optical system may require (e.g., periodical)
calibration. For example, the one or more lenses and/or one or more
detectors within the optical system may require (e.g., periodical)
calibration.
[0009] At times, detection speed and/or accuracy are important. The
present disclosure delineates various systems, apparatuses, and
methodologies of this regard. For example, the present disclosure
describes usage of at least one optical fiber that is connected to
a detector. For example, an optical fiber bundle having fibers of
identical and/or different cross sections. The present disclosure
delineates apparatuses, systems, software, and methods that
facilitates accomplishing these.
[0010] In an aspect described herein are methods, systems, and/or
apparatuses for detecting one or more characteristics of the
forming 3D object and/or its vicinity. Another aspect of the
present disclosure describes methods, systems, and/or apparatuses
for facilitating irradiation of an elongated energy beam. Another
aspect of the present disclosure describes methods, systems, and/or
apparatuses for facilitating contemporaneous focusing of the energy
beam.
[0011] In another aspect, a system for printing a three-dimensional
object comprises: a target surface; an energy source configured to
generate an energy beam that is directed towards the target surface
to print the three-dimensional object; at least one calibration
mark comprises at least one identifiable border, which at least one
calibration mark is disposed at or adjacent to the target surface;
and at least one controller that is operatively coupled to the
energy beam and to the at least one calibration mark and is
configured to direct the energy beam to travel from a first side of
the at least one identifiable border to a second side of the at
least one identifiable border, wherein the second side opposes the
first side.
[0012] In some embodiments, the target surface comprises an exposed
surface of a material bed. In some embodiments, the material bed
comprises a particulate material. In some embodiments, the
particulate material is a powder material. In some embodiments, the
powder material comprises at least one member from the group
consisting of an elemental metal, a metal alloy, a ceramic, an
allotrope of elemental carbon, a polymer, and a resin. In some
embodiments, the powder material comprises at least one member from
the group consisting of an elemental metal, a metal alloy, a
ceramic, and an allotrope of elemental carbon. In some embodiments,
the energy source comprises an electromagnetic energy source or a
charged particle energy source. In some embodiments, the
electromagnetic energy source comprises a laser. In some
embodiments, the at least one calibration mark comprises a first
calibration mark and a second calibration mark. In some
embodiments, the first calibration mark and the second calibration
mark are separated by the at least one identifiable border. In some
embodiments, the first calibration mark and the second calibration
mark are substantially similar. In some embodiments, the first
calibration mark and the second calibration mark are different by
at least one identifiable property. In some embodiments, the at
least one calibration mark comprises a first calibration mark type
and a second calibration mark type that is different by at least
one identifiable property from the first calibration mark type, and
wherein the first calibration mark type is arranged interchangeably
with the second calibration mark type. In some embodiments,
arranged interchangeably comprises a space filling polygon
arrangement in at least one direction. In some embodiments, the at
least one direction comprises a longitudinal direction. In some
embodiments, the space filling polygon arrangement is planar. In
some embodiments, the space filling polygon arrangement is
substantially horizontal. In some embodiments, the space filling
polygon arrangement comprises a tessellation. In some embodiments,
the tessellation comprises a symmetric polygon. In some
embodiments, the tessellation comprises an equilateral polygon. In
some embodiments, the tessellation comprises a triangle, a
tetragon, or a hexagon. In some embodiments, the tetragon comprises
a concave or a convex tetragon. In some embodiments, the tetragon
comprises a rectangle. In some embodiments, the rectangle comprises
a square. In some embodiments, the at least one calibration mark
comprises an oval. In some embodiments, the oval comprises a
circle. In some embodiments, adjacent to the target surface
comprises from a position that is separated from the target surface
by a gap comprising an atmosphere. In some embodiments, the at
least one calibration mark forms at least a portion of a
calibration structure. In some embodiments, the calibration
structure is configured for lateral movement. In some embodiments,
the at least one calibration mark forms at least a portion of a
calibration structure. In some embodiments, the calibration
structure is configured for horizontal movement. In some
embodiments, the at least one calibration mark forms at least a
portion of a calibration structure. In some embodiments, the
calibration structure is configured for vertical movement. In some
embodiments, the at least one calibration mark forms at least a
portion of a calibration structure. In some embodiments, the
calibration structure is configured for engagement with a stopper.
In some embodiments, the calibration structure is mounted on or
comprises a stage. In some embodiments, the stage is configured for
movement. In some embodiments, movement comprises horizontal or
vertical movement. In some embodiments, the stage is configured to
move towards a stopper. In some embodiments, the stopper is
disposed in a processing chamber, through at least a portion of
which the energy beam travels therethrough to the target surface to
print the three-dimensional object. In some embodiments, the
stopper is configured to reversibly engage with the stage. In some
embodiments, to reversibly engage comprises a complementary
engagement. In some embodiments, to reversibly engage comprises a
dove-tail engagement. In some embodiments, to reversibly engage
comprises fitting together. In some embodiments, to reversibly
engage comprises at least one protrusion that is adapted to fit at
least one complementary indentation. In some embodiments, the stage
comprises the at least one indentation or at least one protrusion.
In some embodiments, the at least one protrusion is a part of the
stage and its at least one complementary indentation is a part of
the stopper. In some embodiments, the at least one protrusion is a
part of the stopper and its at least one complementary indentation
is a part of the stage. In some embodiments, the stage is
positioned against a stopper. In some embodiments, at least one of
the stage and the stopper comprises a kinematic support. In some
embodiments, at least one of the stage and stopper comprises a
plurality of kinematic supports. In some embodiments, the stopper
is mounted on a wall of a processing chamber. In some embodiments,
the stopper is mounted on a floor of a processing chamber. In some
embodiments, the kinematic support includes one or more shafts. In
some embodiments, a chamber comprises a load lock shutter
configured to separate the processing chamber from a load lock
chamber. In some embodiments, the stopper is disposed in the load
lock chamber. In some embodiments, the stopper is mounted on a wall
of the load lock chamber. In some embodiments, the stopper is
mounted on a floor of the load lock chamber. In some embodiments, a
chamber comprises a load lock shutter configured to separate the
processing chamber from a build module. In some embodiments, the
stopper is disposed in the build module. In some embodiments, the
stopper is mounted on a wall of the build module. In some
embodiments, the stopper is mounted on a floor of the build module.
In some embodiments, the at least one calibration mark comprises a
border of a detector or a sensor that is configured to detect at
least one signal associated with the energy beam, from the at least
one calibration mark. In some embodiments, the at least one
calibration mark comprises a camera. In some embodiments, the at
least one mark is connected to an optical fiber. In some
embodiments, the at least one calibration mark comprises an array
of detectors or sensors. In some embodiments, the array of
detectors is connected to an optical fiber bundle. In some
embodiments, adjacent to the target surface comprises to a side of
the target surface. In some embodiments, to the side of the target
surface comprises on a floor of a processing chamber. In some
embodiments, the energy beam travels through at least a portion of
the processing chamber to the target surface to print the
three-dimensional object. In some embodiments, adjacent to the
target surface comprises below the target surface. In some
embodiments, below the target surface comprises on a platform,
above which platform the three-dimensional object is printed. In
some embodiments, below the target surface comprises below a
shutter that is configured to reversibly separate the target
surface from a processing chamber. In some embodiments, the energy
beam travels through at least a portion of the processing chamber
to the target surface to print the three-dimensional object. In
some embodiments, below the shutter is outside of the processing
chamber. In some embodiments, below the target surface comprises a
part of a shutter that is configured to reversibly separate the
target surface from a processing chamber. In some embodiments, the
energy beam travels through at least a portion of the processing
chamber to the target surface to print the three-dimensional
object. In some embodiments, the at least one controller is further
configured to direct measurement of at least one characteristic of
the energy beam to receive a measurement value during its travel
from the first side of the at least one identifiable border to the
second side of the at least one identifiable border. In some
embodiments, the energy beam has a footprint which comprises a
projection of the energy beam at least onto the at least one
calibration mark. In some embodiments, the at least one
characteristic comprises (i) a center position of the footprint,
(ii) a fundamental length scale of the footprint, (iii) a measure
of a power density distribution within the footprint, (iv) a focal
position of the footprint, or (v) a velocity of the footprint. In
some embodiments, the at least one controller is configured to
further direct calibration of the at least one characteristic of
the energy beam by using the measurement value. In some
embodiments, two or more of (i)-(v) are directed by different
controllers. In some embodiments, two or more of (i)-(v) are
directed by the same controller. In some embodiments, the measure
of the power density distribution within the footprint comprises an
integral of the power density distribution within the footprint. In
some embodiments, the center position is with respect to the at
least one identifiable border.
[0013] In another aspect, a system for printing a three-dimensional
object comprises: a target surface that comprises a particulate
material; an energy source configured to generate an energy beam
that is directed towards the target surface and to form a footprint
on the target surface that emits an associated signal; and at least
one controller that is operatively coupled to the energy beam, the
target surface, and the associated signal, which at least one
controller is configured to direct (i) the energy beam to irradiate
at least a portion of the target surface, (ii) separation of a
signal that is related to the target surface from the associated
signal to receive a cleaned signal, and (iii) processing of the
cleaned signal to obtain the at least one characteristic of the
energy beam that comprises (a) a center position of the footprint,
(b) a fundamental length scale of the footprint, (c) a measure of a
power density distribution within the footprint, (d) a focal
position of the footprint, or (e) a velocity of the footprint.
[0014] In some embodiments, the associated signal comprises an
optical signal. In some embodiments, separation of the signal
comprises optical filtering. In some embodiments, separation of the
signal comprises signal processing. In some embodiments, separation
of the signal comprises image processing. In some embodiments, the
signal processing utilizes a processor. In some embodiments, the
processing in (iii) utilizes a processor. In some embodiments, the
processing in (iii) comprises image processing. In some
embodiments, at least two of (i), (ii), and (iii) are directed by
different controllers. In some embodiments, at least two of (i),
(ii), and (iii) are directed by the same controller. In some
embodiments, the center position of the footprint is with respect
to the target surface.
[0015] In another aspect, a system for printing a three-dimensional
object comprises: a processing chamber; a platform above which the
three-dimensional object is printed, which platform is disposed
adjacent to the processing chamber; a load lock mechanism that is
configured to facilitate engagement of the platform with the
processing chamber by use of a shutter that is configured to
reversibly separate the processing chamber from the platform,
wherein the shutter (i) is configured for movement, and (ii)
comprises a top surface having at least one identifiable
calibration mark; an energy source configured to generate an energy
beam that travels in a first direction through at least a portion
of the processing chamber towards at least one of the platform and
the shutter, wherein above is in a second direction opposite to the
first direction, wherein top is towards the second direction
opposite to the first direction; and one or more controllers that
are operatively coupled to the energy beam and to the shutter and
are configured to direct: (a) the shutter to move to a position
that facilitates irradiation of the at least one identifiable
calibration mark by the energy beam, and (b) the energy beam to
irradiate the least one identifiable calibration mark.
[0016] In some embodiments, the shutter is configured for lateral
movement. In some embodiments, the shutter is configured for
substantially horizontal movement. In some embodiments, the load
lock mechanism is disposed below the processing chamber. In some
embodiments, below is in the first direction. In some embodiments,
(a) and (b) are directed by different controllers. In some
embodiments, (a) and (b) are directed by the same controller.
[0017] In another aspect, an apparatus for printing a
three-dimensional object comprises: a processing chamber; a
platform above which the three-dimensional object is printed, which
platform is engaged with the processing chamber, which platform is
disposed adjacent to the processing chamber; a load lock mechanism
that is configured to facilitate engagement of the platform with
the processing chamber by use of a shutter that is configured to
reversibly separate the processing chamber from the platform,
wherein the shutter (i) is configured for movement, and (ii)
comprises a top surface having at least one identifiable
calibration mark; and an energy source configured to generate an
energy beam that is directed through at least a portion of the
processing chamber in a first direction towards at least one of the
platform and the shutter, wherein above is in a second position
that is opposite to the first direction, wherein top is towards a
second direction.
[0018] In some embodiments, the platform is disposed below or at a
floor of the processing chamber. In some embodiments, below is in
the first direction. In some embodiments, the at least one
calibration mark comprises a first calibration mark and a second
calibration mark. In some embodiments, the first calibration mark
and the second calibration mark are separated by at least one
identifiable border. In some embodiments, the first calibration
mark and the second calibration mark are substantially similar. In
some embodiments, the first calibration mark and the second
calibration mark are different by at least one identifiable
property. In some embodiments, the at least one identifiable
calibration mark comprises a first calibration mark type and a
second calibration mark type that is different by at least one
identifiable property from the first calibration mark type, and
wherein the first calibration mark type is arranged interchangeably
with the second calibration mark type. In some embodiments,
arranged interchangeably comprises a space-filling polygon
arrangement in at least one direction. In some embodiments, the at
least one direction comprises a longitudinal direction. In some
embodiments, the space-filling polygon arrangement is planar. In
some embodiments, the space-filling polygon arrangement is
substantially horizontal. In some embodiments, the space-filling
polygon arrangement comprises a tessellation. In some embodiments,
the tessellation comprises a symmetric polygon. In some
embodiments, the tessellation comprises an equilateral polygon. In
some embodiments, the tessellation comprises a triangle, a
tetragon, or a hexagon. In some embodiments, the tetragon comprises
a concave or a convex tetragon. In some embodiments, the tetragon
comprises a rectangle. In some embodiments, the rectangle comprises
a square. In some embodiments, the at least one calibration mark
comprises an oval. In some embodiments, the oval comprises a
circle.
[0019] In another aspect, a method for printing a three-dimensional
object comprises: irradiating an energy beam on a first calibration
mark that is disposed on a shutter that separates a processing
chamber from a target surface above which the three-dimensional
object is printing; measuring at least one characteristic of the
energy beam during the irradiating to receive a measurement value,
wherein the energy beam has a footprint which comprises a
projection of the energy beam onto the shutter, wherein the at
least one characteristic comprises (i) a center position of the
footprint, (ii) a fundamental length scale of the footprint, (iii)
a measure of a power density distribution within the footprint,
(iv) a focal position of the footprint, or (v) a velocity of the
footprint; and calibrating the at least one characteristic of the
energy beam by using the measurement value.
[0020] In some embodiments, the method further comprises measuring
the fundamental length scale of the footprint. In some embodiments,
the fundamental length scale comprises a radius, a radius
equivalent, a diameter, a full width at half maximum of an
intensity, or a cross section. In some embodiments, the center
position of the footprint is with respect to a position on the
shutter. In some embodiments, the method further comprises before
(b), altering the focal position of the footprint. In some
embodiments, the altering comprises altering a position of at least
one optical element through which the energy beam travels to the
shutter. In some embodiments, the at least one optical element
comprises a lens. In some embodiments, the method further comprises
before (b) moving the energy beam with respect to the shutter. In
some embodiments, the method further comprises measuring the
velocity of the moving. In some embodiments, the method further
comprises moving the energy beam from a first side of a first
border to a second side of the first border. In some embodiments,
the first border is of the first calibration mark. In some
embodiments, the moving comprises circularly moving. In some
embodiments, the method further comprises before (b), moving the
energy beam from a first side of a second border to a second side
of the second border. In some embodiments, the second border is of
the first calibration mark. In some embodiments, the first border
opposes the second border. In some embodiments, the first border
contacts the second border. In some embodiments, the method further
comprises before (b), moving the energy beam from a first side of a
third border to a second side of the third border. In some
embodiments, the third border is of a second calibration mark that
borders the first calibration mark by the second border. In some
embodiments, the first border contacts the third border. In some
embodiments, the second border contacts the third border. In some
embodiments, the method further comprises before (b), moving the
energy beam from a first side of a fourth border to a second side
of the fourth border. In some embodiments, the third border is of a
third calibration mark that borders the second calibration mark by
the third border. In some embodiments, the first border contacts
the fourth border. In some embodiments, the second border contacts
the fourth border. In some embodiments, the third border contacts
the fourth border.
[0021] In another aspect, a method for printing a three-dimensional
object comprises: moving an energy beam across at least a portion
of a target surface that comprises a particulate material, wherein
the energy beam has a footprint which comprises a projection of the
energy beam onto the target surface; measuring a reflection of the
footprint from the at least a portion of the target surface during
the moving; separating a target surface signal from the reflection
of the footprint to obtain a clean reflection footprint signal;
extracting at least one characteristic of the energy beam from the
clean reflection footprint signal to obtain an extracted value,
wherein the at least one characteristic comprises (i) a center
position of the footprint, (ii) a fundamental length scale of the
footprint, (iii) a measure of a power density distribution within
the footprint, (iv) a focal position of the footprint, or (v) a
velocity of the footprint; and calibrating the at least one
characteristic of the energy beam by using the extracted value.
[0022] In some embodiments, the separating considers at least one
property of the particulate material. In some embodiments, the at
least one property comprises a material type. In some embodiments,
the at least one property comprises a fundamental length scale of
the particulate material. In some embodiments, the at least one
property comprises an average or a mean volume of the particulate
material. In some embodiments, the at least one property comprises
a reflective property of the particulate material. In some
embodiments, the at least one property comprises an absorptive
property of the particulate material. In some embodiments, the
center position of the footprint is with respect to a position on
the target surface.
[0023] In another aspect, a method for forming a three-dimensional
object comprises: irradiating a bitmap with an energy beam at or
adjacent to a target surface, the bitmap comprising one or more
bits, wherein an intersection of the bitmap with the energy beam is
a footprint of the energy beam on the bitmap, wherein the energy
beam is irradiating through an optical setup; detecting a position
of the footprint by a detector, wherein the position is detected
relative to the one or more bits of the bitmap; comparing the
position of the footprint to an expected position of the footprint
on the bitmap, the expected position of the footprint determined
based on a calibration relative to the one or more bits of the
bitmap; adjusting one or more optical elements of the optical setup
to coincide the position of the footprint with the expected
position of the footprint; and using the irradiating energy beam to
transform a portion of a pre-transformed material adjacent to the
target surface to form at least a portion of the three-dimensional
object.
[0024] In some embodiments, the bitmap comprises two or more
different mark types. In some embodiments, the two or more
different mark types differ in at least one detectable property. In
some embodiments, the at least one detectable property comprises a
reflective surface. In some embodiments, the at least one
detectable property comprises a diffusive and/or dispersive
surface. In some embodiments, the at least one detectable property
comprises an absorptive stain. In some embodiments, the at least
one detectable property comprises a reflective stain. In some
embodiments, the at least one detectable property comprises a
depression. In some embodiments, the at least one detectable
property comprises a protrusion. In some embodiments, a bit of the
one or more bits comprises a mark type. In some embodiments, a mark
type comprises a surface mark. In some embodiments, a mark type
comprises a surface roughness. In some embodiments, a mark type
comprises a surface reflectivity. In some embodiments, a mark type
comprises a surface absorption. In some embodiments, a mark type
comprises a surface color. In some embodiments, a mark type
comprises a material density. In some embodiments, a mark type
comprises a material composition. In some embodiments, adjusting
comprises adjusting a converging lens. In some embodiments,
adjusting comprises adjusting a diverging lens. In some
embodiments, adjusting comprises adjusting a beam splitter. In some
embodiments, adjusting comprises adjusting a mirror. In some
embodiments, adjusting comprises adjusting one or more elements of
an aberration-correcting optical setup. In some embodiments,
adjusting comprises adjusting a focus of the irradiating energy
beam. In some embodiments, adjusting comprises adjusting a speed of
the irradiating energy beam relative to the target surface. In some
embodiments, adjusting comprises adjusting a cross sectional area
of the irradiating energy beam. In some embodiments, adjusting
comprises adjusting a measure of a power density distribution of
the irradiating energy beam. In some embodiments, the measure of
the power density distribution is an integral over the footprint of
the energy beam on the bitmap.
[0025] In another aspect, an apparatus for detecting a
three-dimensional object comprises: (a) a platform configured to
support a material bed, which material bed comprises an exposed
surface having an average planarity and an average optical
characteristic, which material bed comprises a transformed
material; (b) an energy source configured to generate an energy
beam, which energy beam is operable to transform a pre-transformed
material to the transformed material as part of the
three-dimensional object, which three-dimensional object is
disposed in the material bed, wherein the three-dimensional object
causes at least a portion of the exposed surface to deviate from
(I) the average planarity and/or (II) the average optical
characteristic, wherein the energy source is disposed adjacent to
the platform; (c) a radiation source configured to generate a
structured radiation for projection onto the exposed surface to
form a detectable image, wherein the radiation source is disposed
adjacent to the energy source; and (d) a detector configured to
detect any deviation within the detectable image, which deviation
is indicative of (i) a composition of the three-dimensional object,
(ii) a position of the three-dimensional object, (iii) a shape of
the three-dimensional object, (iv) an average planarity of the
exposed surface, or (v) any combination of (i), (ii), (iii) and
(iv), wherein the detector is disposed adjacent to the radiation
source.
[0026] In some embodiments, the pre-transformed material is at
least 50 percent, or at least 80 percent diffusive relative to its
total reflection. In some embodiments, the transformed material is
at least 80 percent specular relative to its total reflection. In
some embodiments, the radiation source is configured to generate
the structured radiation in real time during the printing. In some
embodiments, the detector is configured to detect in real time
during the printing. In some embodiments, the apparatus further
comprises a filter operatively coupled with the radiation source
and/or the detector, which filter is configured to alter an
intensity of at least a portion of the detectable image received at
the detector. In some embodiments, the filter is operatively
coupled with the detector and is configured to alter a focus of the
detectable image detected by the detector. In some embodiments, the
filter is configured to lower the resolution of the detectable
image detected by the detector. In some embodiments, the filter is
a low pass filter. In some embodiments, the filter comprises a
polarizer. In some embodiments, the polarizer comprises a linear
polarizer. In some embodiments, the polarizer comprises a circular
polarizer. In some embodiments, the structured radiation that is
projected onto the exposed surface to form the detectable image
comprises a polarized radiation. In some embodiments, the filter is
configured to filter out at least part of the polarized radiation.
In some embodiments, the filter has a field of view configured to
receive a specular reflection of the structured radiation. In some
embodiments, the specular reflection is polarized, and wherein the
filter is configured to at least partially filter out the specular
reflection that is polarized. In some embodiments, the filter is a
first filter. In some embodiments, the apparatus further comprises
a second filter that is configured to generate a polarized
radiation of the structured radiation that is projected onto the
exposed surface to form the detectable image. In some embodiments,
the second filter is operatively coupled to the radiation source.
In some embodiments, the second filter comprises a polarizer. In
some embodiments, the polarizer comprises a linear polarizer. In
some embodiments, the polarizer comprises a circular polarizer. In
some embodiments, the second filter is configured to at least
partially cancel out the polarized radiation transmitted by the
first filter. In some embodiments, the polarized radiation
comprises a specular reflection from the exposed surface. In some
embodiments, the first filter and/or second filter is configured to
adjust a range of canceled out polarized radiation. In some
embodiments, adjustment of the range of canceled out polarized
radiation varies the amount of specular reflection that reaches the
detector. In some embodiments, the deviation in the average
planarity of the exposed surface comprises horizontal and/or
vertical deviation from planarity. In some embodiments, the
deviation in the position of the three-dimensional object comprises
horizontal and/or vertical position. In some embodiments, the
apparatus further comprises at least one controller operatively
coupled to at least one of the platform, the energy source, the
radiation source, the detector, and the filter, which at least one
controller is configured to: (I) direct the energy beam to generate
the three-dimensional object from the at least a portion of the
material bed, (II) direct the radiation source to generate the
structured radiation on the exposed surface, (III) direct
adjustment of the filter to alter the intensity of the detectable
image received at the detector, (IV) direct evaluation of the
deviation in the detectable image using image analysis of a
captured image, and/or (V) use (IV) to control at least one
characteristic of the energy beam to form the three-dimensional
object. In some embodiments, (III) is based upon the average
optical characteristic of the exposed surface. In some embodiments,
the controller is configured to make an adjustment to (I), (II)
and/or (III) based on the evaluation in (IV). In some embodiments,
the evaluation in (IV) comprises an adjustment to (A) a power
generated by the energy source, or (B) at least one characteristic
of the energy beam. In some embodiments, the at least one
characteristic of the energy beam comprises (a) a dwell time of the
energy beam at or adjacent to the exposed surface, or (b) a speed
of movement of the energy beam along a trajectory. In some
embodiments, the detectable image comprises a region having a first
intensity and a first shape and a region having a second intensity
and a second shape, and wherein the first intensity is higher than
the second intensity, which higher is detectable. In some
embodiments, the detector is configured to detect the deviation
over a measurement range, which measurement range is based on a
dimension of the region having the first intensity and the first
shape, a dimension of the region having the second intensity and
the second shape, or a combination thereof. In some embodiments,
the radiation source is configured to modify the structured
radiation dynamically. In some embodiments, dynamically is in real
time during the printing. In some embodiments, to modify comprises
alteration of a first structured radiation projecting a first
detectable image to a second structured radiation projecting a
second detectable image. In some embodiments, to modify comprises
an alteration of the first intensity and/or of the second
intensity. In some embodiments, to modify comprises an alteration
of a shape of the region having the first intensity and/or a shape
of the region having the second intensity. In some embodiments, to
modify comprises an alteration of a relative spacing between the
region having the first intensity and the region having the second
intensity. In some embodiments, the measurement range is modified
by the alteration. In some embodiments, the measurement range
comprises a vertical and/or horizontal measurement. In some
embodiments, a resolution of a detection of the deviation is
modified by the alteration. In some embodiments, to modify
comprises an alteration of the first shape and/or of the second
shape. In some embodiments, the measurement range is modified by
the alteration of the first shape and/or of the second shape. In
some embodiments, a resolution of a detection of the deviation is
modified by the alteration of the first shape and/or of the second
shape. In some embodiments, dynamically comprises during a
detection of the deviation. In some embodiments, dynamically
comprises between a first and a second detection of the deviation.
In some embodiments, the detector is disposed at a position outside
of the material bed. In some embodiments, the detector comprises an
optical detector. In some embodiments, to detect is configured to
capture an image by a plurality of sensors. In some embodiments, to
detect is configured to capture an image by a camera. In some
embodiments, the radiation source comprises a projector. In some
embodiments, the radiation source comprises an additional energy
beam. In some embodiments, the radiation source comprises a laser.
In some embodiments, the radiation source is configured to generate
the structured radiation in real time, during formation of the
three-dimensional object. In some embodiments, the detectable image
is a detectable pattern. In some embodiments, the pattern comprises
oscillations in an intensity of the structured radiation. In some
embodiments, the exposed surface comprises a kinematic support, or
is operatively coupled to a kinematic support. In some embodiments,
the evaluation comprises processing the detectable image captured
by the detector to eliminate or average pixels in the detectable
image captured by the detector, which pixels are attributed to an
edge. In some embodiments, the edge is between the pre-transformed
material to the transformed material. In some embodiments, the
detector is configured to filter an edge feature in the detectable
image. In some embodiments, the pre-transformed and/or transformed
material comprises an elemental metal, metal alloy, ceramic, or an
allotrope of elemental carbon.
[0027] In another aspect, a non-transitory computer-readable medium
comprises machine-executable code, in which program instructions
are stored, which instructions, when read by one or more computer
processors, cause the one or more computer processors to perform
operations for printing at least one three-dimensional object
comprising: (a) receiving an input signal from a detector that
corresponds to a detectable image from at least an exposed surface
of a material bed by projection of a structured radiation onto the
exposed surface of the material bed, wherein the non-transitory
computer-readable medium is operatively coupled to the detector;
and, (b) detecting any deviation within the detectable image,
wherein the deviation is indicative of (i) a composition of at
least a portion of the three-dimensional object that is printed in
the material bed, (ii) a position of at least a portion of the
three-dimensional object relative to a platform that supports the
material bed, (iii) a shape of at least a portion of the
three-dimensional object, (iv) an average planarity of the exposed
surface, or (v) any combination of (i), (ii), (iii), and (iv).
[0028] In some embodiments, the pre-transformed material is at
least 50 percent, or at least 80 percent diffusive relative to its
total reflection. In some embodiments, the transformed material is
at least 80 percent specular relative to its total reflection. In
some embodiments, the non-transitory computer-readable medium
further comprises instructions for directing an image modification
process to form a modified image based on a captured image
comprising the detectable image. In some embodiments, the image
modification process comprises identifying a plurality of pixels in
the captured image for modification. In some embodiments,
identifying is based on a gradient of pixel data values of the
captured image. In some embodiments, the plurality of pixels is
identified by image pixels that have a gradient value at or above a
threshold value. In some embodiments, the image modification
process comprises filtering. In some embodiments, filtering
comprises edge filtering. In some embodiments, edge filtering
includes filtering by a Canny edge detector, a Prewitt operator,
Sobel operator, Sobel-Feldman operator, Scharr operator, Log Gabor
filter, or any combination thereof. In some embodiments,
identifying the plurality of pixels comprises excluding the
plurality of pixels from consideration during an image analysis of
the captured image. In some embodiments, the identifying the
plurality of pixels comprises averaging values of the plurality of
pixels. In some embodiments, averaging the values of the plurality
of pixels is with values of a neighboring plurality of pixels. In
some embodiments, (b) comprises an image analysis. In some
embodiments, the image analysis comprises determining an image
contrast ratio. In some embodiments, the non-transitory
computer-readable medium is operatively coupled to a radiation
source configured to generate the structured radiation. In some
embodiments, the program instructions cause the one or more
computer processors to alter the structured radiation while
considering the image contrast ratio. In some embodiments, the
structured radiation comprises a region having a first intensity
and a first shape and a region having a second intensity and a
second shape, and wherein the first intensity is higher than the
second intensity, which higher is detectable. In some embodiments,
to alter comprises to modify the structured radiation dynamically.
In some embodiments, to modify comprises an alteration of the first
intensity and/or of the second intensity. In some embodiments, to
modify comprises an alteration of the first shape and/or of the
second shape. In some embodiments, the three-dimensional object is
generated according to a computer model of a requested
three-dimensional structure. In some embodiments, the computer
model comprises a model of a physical process of three-dimensional
printing the three-dimensional object. In some embodiments, the
computer model estimates a physical parameter of the physical
process of the three-dimensional printing. In some embodiments, the
non-transitory computer-readable medium further comprises
instructions to update the physical parameter while considering
(v). In some embodiments, to update is in real time during printing
of the at least one three-dimensional object. In some embodiments,
to update is before and/or after the forming the at least one
three-dimensional object. In some embodiments, the non-transitory
computer-readable medium is operatively coupled with an energy
source configured to generate an energy beam to transform a
pre-transformed material to a transformed material as part of the
at least one three-dimensional object. In some embodiments,
operations further comprise adjusting (A) a power generated by the
energy source, (B) at least one characteristic of the energy
beam.
[0029] In another aspect, a method for detecting a
three-dimensional object, comprises: (a) directing an energy beam
to an exposed surface of a material bed comprising a
pre-transformed material, the exposed surface having an average
planarity and an average optical characteristic; (b) transforming
the pre-transformed material to a transformed material as part of
the three-dimensional object that (I) is disposed in the material
bed, and (II) causes at least a portion of the exposed surface to
deviate from the average planarity and/or the average optical
characteristic; (c) projecting a detectable image on the exposed
surface; and (d) detecting any deviation within the detectable
image from the average planarity and/or from the average optical
characteristic, which deviation is indicative of (i) a composition
of at least a portion of the three-dimensional object, (ii) a
position of at least a portion of the three-dimensional object
relative to a platform supporting the material bed, (iii) a shape
of at least a portion of the three-dimensional object, (iv) an
average planarity of the exposed surface, or (v) any combination of
(i), (ii), (iii), and (iv).
[0030] In some embodiments, the pre-transformed material is at
least 50 percent, or at least 80 percent diffusive relative to its
total reflection. In some embodiments, the transformed material is
at least 80 percent specular relative to its total reflection. In
some embodiments, detecting any deviation comprises capturing an
image of the exposed surface. In some embodiments, detecting any
deviation comprises performing an image modification process on the
image that is captured. In some embodiments, the image modification
process comprises identifying a plurality of pixels for
modification. In some embodiments, identifying is based on a
gradient of pixel data values of the image. In some embodiments,
the plurality of pixels is identified by image pixels that have a
gradient value at or above a threshold value. In some embodiments,
the image modification process comprises filtering. In some
embodiments, filtering comprises edge filtering. In some
embodiments, edge filtering comprises filtering by a Canny edge
detector, a Prewitt operator, Sobel operator, Sobel-Feldman
operator, Scharr operator, Log Gabor filter, or any combination
thereof. In some embodiments, identifying the plurality of pixels
comprises excluding the plurality of pixels from consideration
during an image analysis of the image that is captured. In some
embodiments, the identifying the plurality of pixels comprises
averaging values of the plurality of pixels with values of a
neighboring plurality of pixels during an image analysis of the
image that is captured. In some embodiments, detecting any
deviation within the detectable image comprises performing an image
analysis of at least a portion of the detectable image. In some
embodiments, performing an image analysis of at least a portion of
the detectable image comprises determining an image contrast ratio.
In some embodiments, the method further comprises altering the
detectable image based on the image contrast ratio. In some
embodiments, the detectable image comprises a region having a first
intensity and a first shape and a region having a second intensity
and a second shape. In some embodiments, the first intensity is
higher than the second intensity, which higher is detectable. In
some embodiments, altering comprises modifying the detectable image
dynamically. In some embodiments, modifying comprises altering the
first intensity and/or of the second intensity. In some
embodiments, modifying comprises altering the first shape and/or of
the second shape. In some embodiments, the method further comprises
altering an intensity of at least part of the detectable image. In
some embodiments, altering at least part of the detectable image
comprises filtering a radiation used in projecting the detectable
image. In some embodiments, filtering comprises altering a polarity
of the radiation used in projecting the detectable image. In some
embodiments, altering the polarity comprises altering a linear
polarization of the radiation used in the projecting the detectable
image. In some embodiments, altering the polarity comprises
altering a circular polarization of the radiation used in the
projecting the detectable image. In some embodiments, the method
further comprises generating the three-dimensional object according
to a computer model of a desired three-dimensional structure. In
some embodiments, the method further comprises modelling a physical
process of three-dimensional printing the three-dimensional object.
In some embodiments, the method further comprises estimating a
physical parameter of the physical process of the three-dimensional
printing. In some embodiments, the method further comprises
updating the physical parameter based on (v). In some embodiments,
the updating is in real time during formation of the
three-dimensional object. In some embodiments, the updating is
before and/or after the forming the at least one three-dimensional
object. In some embodiments, the method further comprises adjusting
(A) a power generated by an energy source, (B) a dwell time of the
energy beam at or adjacent to the exposed surface, and/or (C) a
speed of movement of the energy beam, based on considering the
detecting any deviation. In some embodiments, altering at least
part of the detectable image comprises filtering a radiation of the
detectable image. In some embodiments, the method further comprises
using a detector to detect any deviation within the detectable
image, and wherein filtering comprises lowering a resolution of the
detectable image detected by the detector. In some embodiments, the
method further comprises using a detector to detect any deviation
within the detectable image, and altering a focus of the detectable
image detected by the detector to filter out an edge feature in the
detectable image (e.g., using an optical detector, e.g., a camera).
In some embodiments, the method further comprises using a detector
to detect any deviation within the detectable image, and averaging
at least part of the detectable image detected by the detector the
detector.
[0031] In another aspect, an apparatus for printing of at least one
three-dimensional object comprises: at least one controller that is
programmed to (a) direct an energy source to generate an energy
beam to irradiate a calibration structure and generate a returning
radiation from the calibration structure, which calibration
structure comprises an identifiable border, wherein the energy beam
forms a footprint on the calibration structure, wherein the
returning radiation is emanating from the footprint, which energy
beam is configured to transform a pre-transformed material to a
transformed material to print the three-dimensional object; (b)
direct the energy beam to translate across the identifiable border;
(c) direct a detector to detect the returning radiation from the
calibration structure; (e) direct evaluation of a deviation between
the returning radiation and a target returning radiation value; and
(f) use the deviation to control at least one characteristic of the
energy beam to transform the pre-transformed material to the
transformed material to print the three-dimensional object.
[0032] In some embodiments, at least two of (a), (b), (c), (d), (e)
and (f) are controlled by the same controller. In some embodiments,
at least two of (a), (b), (c), (d), (e) and (f) are controlled by
different controllers. In some embodiments, one or more of (a),
(b), (c), (d), (e) and (f) are in real-time during the printing. In
some embodiments, one or more of (a), (b), (c), (d), (e) and (f) is
before the printing. In some embodiments, to direct in (c)
comprises directing the energy beam from a first side of the
identifiable border to a second side of the identifiable border. In
some embodiments, the second side opposes the first side. In some
embodiments, in (f) the at least one characteristic of the energy
beam comprises (i) a center position of the footprint, (ii) a
fundamental length scale of the footprint, (iii) a measure of a
power density distribution within the footprint, (iv) a focal
position of the footprint, (v) a velocity of the footprint, or (vi)
a shape of the footprint. In some embodiments, the controller is
operatively coupled to one or more of: the detector, an optical
element configured for (b), and energy source. In some embodiments,
the shape of the footprint comprises astigmatism. In some
embodiments, the at least one controller is configured to direct,
prior to (c), a cleaning process of at least one surface of the
calibration structure. In some embodiments, the at least one
surface of the calibration structure is at least partially coated
by a coating material, the coating material comprising the
pre-transformed material, an oxide, soot, or a combination thereof,
and wherein the cleaning process is operable to substantially
remove the coating material. In some embodiments, the at least one
controller is configured to direct the energy beam over the at
least one surface to ablate the coating material. In some
embodiments, the at least one controller is configured to direct a
gas flow from a gas source over the at least one surface to
dislodge the coating material, the gas source disposed adjacent to
the calibration structure. In some embodiments, the at least one
controller is configured to direct a gas flow from a vacuum source
over the at least one surface to dislodge the coating material, the
vacuum source disposed adjacent to the calibration structure. In
some embodiments, the at least one controller is configured to
direct a movable member to move across the at least one surface to
dislodge the coating material, the movable member comprising a
translatable blade, a cylindrical wheel, or a combination thereof.
In some embodiments, the at least one controller is configured to
direct performing (e) by evaluating a deviation in an intensity of
the returning radiation. In some embodiments, the deviation in
intensity comprises a deviation in a slope of an intensity profile
of the returning radiation from (c). In some embodiments, the
deviation in the slope of the intensity profile comprises a
deviation in a maximum value of the slope. In some embodiments, the
identifiable border comprises an optically identifiable border. In
some embodiments, the identifiable border comprises a width of at
most 10 microns. In some embodiments, the calibration structure
comprises a first area having a first optical characteristic and a
second area having a second optical characteristic, which first
area borders the second area in a defined border that is the
identifiable border, which first optical characteristic is
detectably different than the second optical characteristic. In
some embodiments, detectably different comprises a differing
reflective surface. In some embodiments, detectably different
comprises a differing diffusive and/or dispersive surface. In some
embodiments, one of the first area and the second area comprises a
material having a high melting temperature. In some embodiments,
the high melting temperature is above 2000 degrees Celsius. In some
embodiments, the high melting temperature is above 3200 degrees
Celsius. In some embodiments, the material comprises elemental
metal, metal alloy, salt, oxide, ceramic, or an allotrope of
elemental carbon. In some embodiments, one of the first area and
the second area comprises tungsten. In some embodiments, another
one of the first area and the second area comprises an oxide or
ceramic. In some embodiments, another one of the first area and the
second area comprises alumina. In some embodiments, an exposed
surface of the first area differs from an exposed surface of the
second area in terms of absorption the energy beam. In some
embodiments, an exposed surface of the first area differs from an
exposed surface of the second area in terms of dispersing the
energy beam. In some embodiments, an exposed surface of the first
area differs from an exposed surface of the second area in terms of
diffusing the energy beam. In some embodiments, an exposed surface
of the first area differs from an exposed surface of the second
area in terms of reflecting the energy beam. In some embodiments,
an exposed surface of the first area and/or an exposed surface of
the second area comprises a stain. In some embodiments, the
apparatus further comprises the at least one controller directing
the energy beam to transform a portion of the pre-transformed
material to form the calibration structure. In some embodiments,
the portion of the pre-transformed material is transformed at a
pre-determined location of a material bed disposed above a
platform, the at least one controller operatively coupled with the
platform, the material bed comprising the pre-transformed material.
In some embodiments, the at least one controller causes at least
one of the one or more optical elements of an optical arrangement
to move to perform (c) and/or (f). In some embodiments, the at
least one controller is configured to direct the returning
radiation through a filter disposed along a radiation return path
to the detector, which radiation return path is from the
calibration structure to the detector. In some embodiments, the
detector is disposed to have an indirect view of the returning
radiation from the at least one calibration structure. In some
embodiments, the at least one controller is configured to direct a
calibration of the at least one characteristic of the energy beam
by using a value of the returning radiation. In some embodiments,
the at least one controller comprises a graphical processing unit
(GPU), system-on-chip (SOC), application specific integrated
circuit (ASIC), application specific instruction-set processor
(ASIPs), programmable logic device (PLD), or field programmable
gate array (FPGA). In some embodiments, the calibration structure
is mounted on or comprises a stage configured for movement. In some
embodiments, the at least one controller is configured to direct
movement of the stage. In some embodiments, the stage comprises a
kinematic support or is operatively coupled to a kinematic support.
In some embodiments, the calibration structure comprises a
kinematic support or is operatively coupled to a kinematic support.
In some embodiments, the calibration structure is configured to
accommodate at least a footprint of the energy beam on an exposed
surface of the calibration structure. In some embodiments, the
apparatus further comprises a converging lens that is configured to
capture the returning radiation on its preparation to the detector.
In some embodiments, the apparatus comprises a diffusive element
configured to capture the returning radiation on its preparation to
the detector. In some embodiments, the apparatus is configured to
capture the returning radiation from multiple directions, e.g., by
using a diffusing element (e.g., diffuser). In some embodiments,
the diffusing element is disposed in an optical path from the
calibration structure to the detector.
[0033] In another aspect, a method of printing of a
three-dimensional object, comprises: (a) directing an energy beam
to irradiate a calibration structure to generate a returning
radiation from the calibration structure that comprises an
identifiable border, wherein the energy beam forms a footprint on
the calibration structure, wherein the returning radiation is
emanating from the footprint, which energy beam is transforming a
pre-transformed material to a transformed material during the
printing of the three-dimensional object; (b) translating the
energy beam across the identifiable border; (c) detecting the
returning radiation from the calibration structure during
translation of the energy beam across the identifiable border; (d)
evaluating a deviation between the returning radiation and a target
returning radiation value; and (e) using the deviation to control
at least one characteristic of the energy beam for the
printing.
[0034] In some embodiments, translating comprises translating the
energy beam from a first side of the identifiable border to a
second side of the identifiable border. In some embodiments, the
second side opposes the first side. In some embodiments, the method
further comprises accommodating at least a footprint of the energy
beam on an exposed surface of the calibration structure. In some
embodiments, the at least one characteristic of the energy beam
comprises (i) a center position of the footprint, (ii) a
fundamental length scale of the footprint, (iii) a measure of a
power density distribution within the footprint, (iv) a focal
position of the footprint, (v) a velocity of the footprint, or (vi)
a shape of the footprint. In some embodiments, the method further
comprises performing a cleaning process of at least one surface of
the calibration structure, prior to translating the beam across the
identifiable border. In some embodiments, the at least one surface
of the calibration structure is at least partially coated by a
coating material, the coating material comprising the
pre-transformed material, an oxide, soot, or a combination thereof,
and wherein the cleaning process comprises substantially removing
the coating material. In some embodiments, the method further
comprises moving the energy beam over the at least one surface to
ablate the coating material. In some embodiments, the method
further comprises flowing a gas from a gas source over the at least
one surface to dislodge the coating material. In some embodiments,
the method further comprises suctioning over the at least one
surface to dislodge the coating material. In some embodiments, the
method further comprises moving a movable member across the at
least one surface to dislodge the coating material, the movable
member comprising a translatable blade, a cylindrical wheel, or a
combination thereof. In some embodiments, the method further
comprises evaluating a deviation in an intensity of the returning
radiation. In some embodiments, the deviation in intensity
comprises a deviation in a slope of an intensity profile of the
returning radiation from translating the energy beam across the
identifiable border. In some embodiments, the deviation in the
slope of the intensity profile comprises a deviation in a maximum
value of slope. In some embodiments, the method further comprises
continuously detecting the returning radiation. In some
embodiments, the method further comprises detecting the returning
radiation at one or more time intervals. In some embodiments, the
method further comprises detecting the returning radiation at
predetermined times. In some embodiments, the identifiable border
comprises an optically identifiable border. In some embodiments,
the identifiable border comprises a width of at most 10 microns. In
some embodiments, the calibration structure comprises a first area
having a first optical characteristic and a second area having a
second optical characteristic, which first area borders the second
area in a defined border, which first optical characteristic is
detectably different than the second optical characteristic. In
some embodiments, detectably different comprises a differing
reflective surface. In some embodiments, detectably different
comprises a differing dispersive surface. In some embodiments,
detectably different comprises a differing diffusive surface. In
some embodiments, detectably different comprises a differing
absorptive surface. In some embodiments, one of the first area and
the second area comprises a material having a high melting
temperature. In some embodiments, the high melting temperature is
above 2000 degrees Celsius. In some embodiments, the high melting
temperature is above 3200 degrees Celsius. In some embodiments, one
of the first area and the second area comprises tungsten. In some
embodiments, another one of the first area and the second area
comprises an oxide. In some embodiments, another one of the first
area and the second area comprises an elemental metal, a metal
alloy, a ceramic, a salt, or an allotrope of elemental carbon. In
some embodiments, another one of the first area and the second area
comprises alumina. In some embodiments, one of the first area and
the second area comprises an absorptive exposed surface. In some
embodiments, one of the first area and the second area comprises a
reflective exposed surface. In some embodiments, one of the first
area and the second area comprises a dispersive exposed surface. In
some embodiments, one of the first area and the second area
comprises a diffusive exposed surface. In some embodiments, the
method further comprises forming the calibration structure from the
pre-transformed material. In some embodiments, the method further
comprises forming the calibration structure from the
pre-transformed material in a material bed. In some embodiments,
the method further comprises filtering the returning radiation
prior to the detecting. In some embodiments, the method further
comprises directing a calibration of the at least one
characteristic of the energy beam by using a value of the returning
radiation. In some embodiments, the method further comprises
capturing the returning radiation on its preparation to the
detector by using at least one converging lens. In some
embodiments, the method further comprises capturing the returning
radiation on its preparation to the detector by using at least one
diffusive element. In some embodiments, the method further
comprises capturing the returning radiation from multiple
directions, e.g., by using a diffusing element (e.g., diffuser). In
some embodiments, the diffusing element is disposed in an optical
path from the calibration structure to the detector. In some
embodiments, the method further comprises capturing the returning
radiation from multiple directions for detection in operation (c),
which returning radiation is reflected from calibration
structure.
[0035] In another aspect, an apparatus for forming a
three-dimensional object, comprises: a target surface configured to
support the three-dimensional object during the printing; an energy
source configured to generate an energy beam, wherein the energy
source is disposed adjacent to the target surface; and an optical
arrangement comprising one or more optical elements, which optical
arrangement is operatively coupled with the energy source and
configured to direct the energy beam to irradiate a pre-transformed
material at or adjacent to the target surface to form a transformed
material as part of the three-dimensional object.
[0036] In some embodiments, the energy beam transforms a
pre-transformed material to a transformed material to print the
three-dimensional object. In some embodiments, the pre-transformed
material comprises elemental metal, metal alloy, ceramic, or an
allotrope of elemental carbon. In some embodiments, the one or more
optical elements are configured to experience insignificant thermal
lensing during formation of at least 1000 cubic centimeters of
transformed material. In some embodiments, the insignificant
thermal lensing comprises at least a 30 second irradiation of the
energy beam through the one or more optical elements, with a power
density of the energy beam (at a nominal power of the energy
source) that diminishes by at most about 10 percent relative to the
power density at a beginning of the 30 second irradiation, which
energy density is measured at the target surface. In some
embodiments, the energy beam is a laser. In some embodiments, the
peak power density changes by at most 20 percent, or 10 percent. In
some embodiments, the FLS of the spot size changes by at most 10%.
The FLS of the spot size may comprise the diameter of the spot
size. The FLS of the spot size (e.g., footprint) may be the full
width at half maximum of the spot size diameter, or the diameter of
about 90% of the energy irradiated to form the spot size. In some
embodiments, the focal point of the one or more optical elements
shifts by at most 10 mm, 1 mm or 0.2 mm, which shift is in the
direction along the propagation direction of the energy beam (e.g.,
in a direction normal to the target surface). In some embodiments,
a wave-front distortion of the energy beam at most: one tenth (
1/10), one fourth (1/4) or one wavelength of the energy beam. In
some embodiments, the energy beam has a selected focus. In some
embodiments, an associated focal length of the one or more optical
elements remains substantially constant during transformation of
the pre-transformed material to the transformed material. In some
embodiments, substantially constant comprises substantially free of
a change in an associated index of refraction of the one or more
optical elements. In some embodiments, the one or more optical
elements comprise a low optical absorption coefficient. In some
embodiments, the optical absorption coefficient is at most 250
parts per million (ppm) per centimeter at a wavelength of the
energy beam. In some embodiments, the one or more optical elements
comprise a low temperature coefficient of refractive index, at
ambient pressure and at a wavelength of the energy beam, of at most
20*10-6/Kelvin. In some embodiments, the one or more optical
elements comprises a Thermal Lensing Figure of Merits of at most
4*10.sup.-6 meters per Watts, at standard temperature and pressure,
and at an operating wavelength of the energy beam. In some
embodiments, substantially constant comprises at most a 10% change
in an associated index of refraction of the one or more optical
elements, with respect to the associated index of refraction at
ambient pressure and temperature. In some embodiments,
substantially constant comprises at most a 5% change in an
associated index of refraction of the one or more optical elements,
with respect to the associated index of refraction at ambient
pressure and temperature. In some embodiments, substantially
constant comprises at most a 2% change in an associated index of
refraction of the one or more optical elements, with respect to the
associated index of refraction at ambient pressure and temperature.
In some embodiments, substantially constant during transformation
comprises a throughput of the energy beam to form at least 1000
cubic centimeters (cm3) of transformed material. In some
embodiments, substantially constant during transformation comprises
a throughput of the energy beam to form at least about 50 cm3 and
at most 1000 cm3 of transformed material. In some embodiments,
substantially constant during transformation comprises a throughput
of the energy beam to form at least 2000 cm3 of transformed
material. In some embodiments, the energy source is operable to
controllably generate the energy beam having an average power
density of from 10000 Watts per square millimeter (W/mm2) (e.g., to
100000 Watts per square millimeter (W/mm2)) at the target surface.
In some embodiments, substantially constant during transformation
comprises directing the energy beam comprises energy of at least 3
kilowatt hours (kWh). In some embodiments, substantially constant
during transformation comprises directing the energy beam having an
energy of at least 0.5 kWh and at most 3 kWh. In some embodiments,
substantially constant during transformation comprises a throughput
of the energy beam comprising energy of at least 50 kWh. In some
embodiments, the one or more optical elements comprises a lens,
mirror, or a beam splitter. In some embodiments, the one or more
optical elements is movable. In some embodiments, the optical
arrangement comprises at least one high thermal conductivity
optical element. In some embodiments, the at least one high thermal
conductivity optical element comprises sapphire, crystal quartz,
zinc selenide (ZnSe), magnesium fluoride (MgF.sub.2), calcium
fluoride (CaF.sub.2), fused silica, borosilicate, silicon fluoride,
or Pyrex.RTM.. In some embodiments, the at least one high thermal
conductivity optical element comprises sapphire, zinc selenide
(ZnSe), magnesium fluoride (MgF2), calcium fluoride (CaF2), or
crystal quartz. In some embodiments, the at least one high thermal
conductivity optical element comprises zinc selenide (ZnSe), or
calcium fluoride (CaF2). In some embodiments, the at least one high
thermal conductivity optical element comprises sapphire, magnesium
fluoride (MgF2), or crystal quartz. In some embodiments, the at
least one high thermal conductivity optical element comprises a
birefringent material. In some embodiments, the one or more optical
elements are disposed in an optical chamber configured to
facilitate separation of the energy beam from an environment
external to the optical chamber. In some embodiments, the optical
chamber is configured to be maintained at a positive pressure with
respect to atmospheric pressure. In some embodiments, the optical
chamber is substantially sealed to prevent introduction of gases
from an exterior of the optical chamber. In some embodiments, the
optical chamber comprises one or more filters configured to filter
an inlet and/or an outlet gas composition. In some embodiments, the
apparatus further comprises one or more enclosure channels disposed
to encompass an optical path comprising a portion in which the
energy beam is introduced into the optical chamber, the one or more
optical elements of the optical arrangement, and a portion out of
which the energy beam exits the optical chamber. In some
embodiments, the one or more enclosure channels are covered
channels that are configured to enclose a positive pressure with
respect to an ambient atmosphere. In some embodiments, the one or
more enclosure channels are covered, and wherein the one or more
enclosure channels comprise one or more openings configured to
permit a gas flow from an interior of the one or more enclosure
channels to an exterior of the one or more enclosure channels. In
some embodiments, the one or more enclosure channels are covered.
In some embodiments, the one or more enclosure channels comprise
one or more segments joined together by at least one leaky seal,
which leaky seal is configured to permit a gas flow from an
interior of the one or more enclosure channels to an exterior of
the one or more enclosure channels. In some embodiments, the one or
more enclosure channels are one or more tubes. In some embodiments,
the apparatus further comprises a detector. In some embodiments,
the detector is configured to detect a temperature of a position of
(a) a footprint of the energy beam on the pre-transformed material
and/or the target surface, and/or a (b) vicinity of (a). In some
embodiments, the vicinity of (a) extends to at most six fundamental
length scales of the footprint of the energy beam in (a). In some
embodiments, the detector is configured for indirect view of the
target surface. In some embodiments, the detector is configured to
output a result, and at least one controller is configured to
direct adjusting at least one characteristic of the energy source
and/or energy beam considering the result. In some embodiments, the
apparatus further comprises the at least one controller
operationally coupled with one or more sensors, which at least one
controller is configured to direct the one or more sensors to
detect a presence of a contaminant, the one or more sensors
disposed at or adjacent to the target surface and/or the one or
more optical elements of the optical arrangement. In some
embodiments, the one or more sensors are configured to detect a
presence of a contaminant comprising a hydrocarbon, a silicon-based
compound, an oxide, a threshold humidity value, pre-transformed
material, soot, or a combination thereof. In some embodiments, the
one or more sensors are configured to detect a presence of a
contaminant along an optical path of the energy beam. In some
embodiments, the one or more sensors are configured to detect a
presence of a contaminant along the optical arrangement. In some
embodiments, the apparatus further comprises a processing chamber
comprising the target surface. In some embodiments, the one or more
sensors are configured to detect a presence of a contaminant. In
some embodiments, the one or more sensors comprise an optical
sensor, or a material sensor. In some embodiments, the optical
sensor comprises an optical density sensor or an IR/visible light
spectroscopy sensor. In some embodiments, the material sensor
comprises a humidity, oxygen, hydrocarbon, silicon sensor, a metal
sensor, or a debris sensor. In some embodiments, the material
sensor comprises a sensor configured to sense oil. In some
embodiments, the material sensor comprises a sensor configured to
sense the pre-transformed material. In some embodiments, the
apparatus further comprises a processing chamber in which the
target surface is disposed, which processing chamber is operatively
coupled to a gas flow system configured to generate a gas flow
through the processing chamber to reduce a presence of a
contaminant. In some embodiments, the one or more optical elements
comprises an optical window disposed between a remaining set of the
one or more optical elements and the processing chamber. In some
embodiments, the gas flow is operable to reduce an amount of the
contaminant within the processing chamber. In some embodiments, to
reduce is with respect to a lack of the gas flow. In some
embodiments, the gas flow is operable to reduce an amount of the
contaminant at a surface of the optical window. In some
embodiments, to reduce is with respect to a lack of the gas flow.
In some embodiments, the gas flow is configured to be directed away
from the surface of the optical window, which surface of the
optical window faces the processing chamber. In some embodiments,
the gas flow comprises an ionized gas directed toward at least one
of the one or more optical elements, which ionized gas is
configured to ionize a surface of the at least one or more optical
elements, the contaminant, or a combination thereof. In some
embodiments, an ultrasonic transducer is operatively coupled with
at least one of the one or more optical elements, which ultrasonic
transducer is configured to vibrate the at least one of the one or
more optical elements to reduce an amount of a contaminant at a
surface of the at least one of the one or more optical elements. In
some embodiments, to reduce is with respect to a lack of vibration.
In some embodiments, the apparatus further comprises a calibration
structure configured for calibration of the energy beam, which
calibration structure is mounted on or comprises a stage disposed
within the processing chamber and configured for movement. In some
embodiments, the stage comprises a kinematic support.
[0037] In another aspect, an apparatus for printing a
three-dimensional object comprises at least one controller that is
operatively coupled to one or more of: a target surface configured
to support the three-dimensional object, an energy source
configured to generate an energy beam to transform a
pre-transformed material to a transformed material to print the
three-dimensional object, and at least one optical element of an
optical arrangement, which at least one controller is programmed
to: (a) direct the energy source to generate the energy beam; and
(b) direct the energy beam through an optical path towards the
target surface.
[0038] In some embodiments, the one or more optical elements are
configured to experience insignificant thermal lensing during
formation of at least 1000 cubic centimeters of transformed
material. In some embodiments, the insignificant thermal lensing
comprises at least a 30 second irradiation of the energy beam
through the one or more optical elements, with a power density of
the energy beam at a nominal power, which power density diminishes
by at most about 10 percent relative to the power density at a
beginning of the 30 second irradiation. In some embodiments, the
energy density is measured at the target surface. In some
embodiments, the peak power density changes by at most 20 percent,
or 10 percent. In some embodiments, the FLS of the spot size
changes by at most 10%. The FLS of the spot size may comprise the
diameter of the spot size. The FLS of the spot size (e.g.,
footprint) may be the full width at half maximum of the spot size
diameter, or the diameter of about 90% of the energy irradiated to
form the spot size. In some embodiments, the focal point of the one
or more optical elements shifts by at most 10 mm, 1 mm or 0.2 mm,
which shift is in the direction along the propagation direction of
the energy beam (e.g., in a direction normal to the target
surface). In some embodiments, a wave-front distortion of the
energy beam at most: one tenth ( 1/10), one fourth (1/4) or one
wavelength of the energy beam. In some embodiments, an associated
focal length of the at least one optical element with respect to
the target surface remains substantially constant during
transformation of the pre-transformed material to the transformed
material. In some embodiments, wherein the at least one optical
element alters a focus of the energy beam to have an altered focus.
In some embodiments, the energy beam in (b) comprises an adjusted
beam spot size defined by an intersection of the energy beam with
the target surface, which adjusted beam spot size comprises an
associated area. In some embodiments, remains substantially
constant comprises the associated area of the adjusted beam spot
size varying by at most 10% during transformation of the
pre-transformed material to the transformed material at the altered
focus. In some embodiments, remains substantially constant
comprises the associated area of the adjusted beam spot size
varying by at most 5% during transformation of the pre-transformed
material to the transformed material at the altered focus. In some
embodiments, remains substantially constant comprises the
associated area of the adjusted beam spot size varying by at most
2% during transformation of the pre-transformed material to the
transformed material at the altered focus. In some embodiments,
remains substantially constant during transformation comprises the
at least one controller directing to the energy beam to form at
least 1000 cubic centimeters (cm3) of transformed material. In some
embodiments, remains substantially constant during transformation
comprises the at least one controller directing the energy beam to
form at least 50 cm3 at most 1000 cm3 of transformed material. In
some embodiments, remains substantially constant during
transformation comprises the at least one controller directing the
energy beam to form at least 2000 cm3 of transformed material. In
some embodiments, in (a) the at least one controller directs the
energy beam to comprise an average power density of from at least
10000 Watts per square millimeter (e.g., to at most 100000 Watts
per square millimeter (W/mm2)), at the target surface. In some
embodiments, remains substantially constant during transformation
comprises the at least one controller directing the energy beam
comprising an energy of at least 3 kilowatt hours (kWh). In some
embodiments, remains substantially constant during transformation
comprises the at least one controller directing the energy beam
comprising an energy of at least 50 kWh. In some embodiments, the
apparatus further comprises an optical chamber configured to
separate a portion of an optical path from an environment external
to the optical chamber. In some embodiments, the at least one
controller is operatively coupled to the optical chamber. In some
embodiments, the at least one controller is configured to maintain
the optical chamber at a positive pressure with respect to an
ambient pressure. In some embodiments, the at least one controller
is configured to substantially seal the optical chamber to prevent
introduction of gases and/or debris from an exterior of the optical
chamber. In some embodiments, the apparatus further comprises a gas
inlet and/or a gas outlet operatively coupled to the optical
chamber, and a filter operatively coupled to the gas inlet and/or
gas outlet, which filter is configured to filter a gas composition
of the optical chamber. In some embodiments, the at least one
controller is operatively coupled with one or more of the filter,
gas inlet, and gas outlet. In some embodiments, the apparatus
further comprises one or more enclosure channels configured to
encompass the optical path that comprises a portion in which the
energy beam is introduced into the optical chamber, the at least
one optical element, and a portion out of which the energy beam
exits the optical chamber. In some embodiments, the at least one
controller is configured to maintain a positive pressure in the one
or more enclosure channels with respect to an ambient atmosphere in
a remainder of the optical chamber. In some embodiments, the at
least one controller is configured to flow a gas from an interior
of the one or more enclosure channels to an exterior of the one or
more enclosure channels via one or more openings in the one or more
enclosure channels. In some embodiments, the at least one
controller is configured to flow a gas from an interior of the one
or more enclosure channels to an exterior of the one or more
enclosure channels via one or more segments joined together by at
least one leaky seal. In some embodiments, the at least one
controller is configured to flow a gas from an interior of the one
or more enclosure channels to an exterior of the one or more
enclosure channels via one or more segments thereof that are joined
together by at least one leaky seal. In some embodiments, the
apparatus further comprises one or more sensors, which at least one
controller is configured to direct the one or more sensors to
detect a presence of a contaminant at or adjacent to (i) the target
surface and/or (ii) the at least one optical element. In some
embodiments, the at least one controller is operatively coupled
with the one or more sensors. In some embodiments, the one or more
sensors are configured to detect a presence of a contaminant
comprising a hydrocarbon, a silicon-based compound, an oxide, a
threshold humidity value, pre-transformed material, soot, or a
combination thereof. In some embodiments, the one or more sensors
are configured to detect a presence of a contaminant along an
optical path of the energy beam. In some embodiments, the one or
more sensors are configured to detect a presence of a contaminant
along the optical arrangement. In some embodiments, the one or more
sensors comprise an optical sensor, or a material sensor. In some
embodiments, the optical sensor comprises an optical density sensor
or an IR/visible light spectroscopy sensor. In some embodiments,
the material sensor comprises a humidity, oxygen, hydrocarbon,
silicon sensor, a metal sensor, or a debris sensor. In some
embodiments, the material sensor comprises a sensor configured to
sense oil. In some embodiments, the material sensor comprises a
sensor configured to sense the pre-transformed material. In some
embodiments, the apparatus further comprises a processing chamber
comprising the target surface. In some embodiments, the one or more
sensors are configured to detect a presence of a contaminant. In
some embodiments, the at least one controller is configured to
direct a cleaning process based on a detection of the one or more
sensors. In some embodiments, the cleaning process comprises the at
least one controller configured to flow a gas to reduce an amount
of the contaminant within a processing chamber that comprises the
target surface. In some embodiments, to reduce is with respect to a
lack of flowing the gas. In some embodiments, the apparatus further
comprises a calibration structure configured for calibration of the
energy beam, which calibration structure is mounted on or comprises
a stage disposed within the processing chamber and configured for
movement. In some embodiments, the at least one controller is
configured to direct movement of the stage. In some embodiments,
the stage comprises a kinematic support. In some embodiments, the
cleaning process comprises the at least one controller configured
to flow a gas to reduce an amount of the contaminant at a surface
of an optical window, which optical window is an optical element of
the at least one optical element. In some embodiments, to reduce is
with respect to a lack of flowing the gas. In some embodiments, the
at least one controller is configured to direct the gas away from
the surface of the optical window. In some embodiments, the
cleaning process comprises the at least one controller configured
to direct an ionized gas toward the at least one optical element,
which ionized gas is operable to ionize a surface of the at least
one optical element, the contaminant, or a combination thereof. In
some embodiments, the cleaning process comprises the at least one
controller configured to cause an ultrasonic transducer to vibrate
the at least one optical element to reduce an amount of the
contaminant at a surface of the at least one optical element. In
some embodiments, to reduce is with respect to a lack of
vibration.
[0039] In another aspect, a method for printing a three-dimensional
object, comprises: (a) directing an energy beam through an optical
path towards a target surface, which optical path comprises one or
more optical elements; and (b) transforming a pre-transformed
material to a transformed material to print the three-dimensional
object.
[0040] In some embodiments, the method further comprises using an
energy source to generate the energy beam directed towards the
target surface, which energy source has a nominal power. In some
embodiments, the one or more optical elements are configured to
experience insignificant thermal lensing during formation of at
least 1000 cubic centimeters of transformed material. In some
embodiments, the insignificant thermal lensing comprises at least a
30 second irradiation of the energy beam through the one or more
optical elements, with a power density of the energy beam at the
nominal power that diminishes by at most about 10 percent relative
to the power density at a beginning of the 30 second irradiation.
In some embodiments, the energy density is measured at the target
surface. In some embodiments, the energy beam is directed through
an optical path to alter a focus of the energy beam to have an
altered focus. In some embodiments, the peak power density changes
by at most 20 percent, or 10 percent. In some embodiments, the FLS
of the spot size changes by at most 10%. The FLS of the spot size
may comprise the diameter of the spot size. The FLS of the spot
size (e.g., footprint) may be the full width at half maximum of the
spot size diameter, or the diameter of about 90% of the energy
irradiated to form the spot size. In some embodiments, the focal
point of the one or more optical elements shifts by at most 10 mm,
1 mm or 0.2 mm, which shift is in the direction along the
propagation direction of the energy beam (e.g., in a direction
normal to the target surface). In some embodiments, a wave-front
distortion of the energy beam at most: one tenth ( 1/10), one
fourth (1/4) or one wavelength of the energy beam. In some
embodiments, the one or more optical elements have an associated
focal length with respect to the target surface (e.g., a position
at a target surface). In some embodiments, the associated focal
length of the one or more optical elements (e.g., at the position)
remains substantially constant during transformation of the
pre-transformed material to the transformed material. In some
embodiments, the energy beam comprises an adjusted beam spot size
defined by an intersection of the energy beam with the target
surface, which adjusted beam spot size comprises an associated
area. In some embodiments, remains substantially constant comprises
the associated area of the adjusted beam spot size varying by at
most 10% during transformation of the pre-transformed material to
the transformed material at the altered focus. In some embodiments,
remains substantially constant comprises the associated area of the
adjusted beam spot size varying by at most 5% during transformation
of the pre-transformed material to the transformed material at the
altered focus. In some embodiments, remains substantially constant
comprises the associated area of the adjusted beam spot size
varying by at most 2% during transformation of the pre-transformed
material to the transformed material at the altered focus. In some
embodiments, remains substantially constant during transformation
comprises directing to the energy beam to form at least 225 cubic
centimeters (cm.sup.3) of transformed material. In some
embodiments, remains substantially constant during transformation
comprises directing the energy beam to form at least 2000 cm.sup.3
of transformed material. In some embodiments, the energy beam
comprises an average power density of at least 10000 Watts per
square millimeter (W/mm.sup.2). In some embodiments, remains
substantially constant during transformation comprises directing
the energy beam comprising energy of at least 3 kilowatt hours
(kWh). In some embodiments, remains substantially constant during
transformation comprises a throughput of the energy beam comprising
energy of at least 50 kWh. In some embodiments, the method further
comprises separating a portion of the optical path from an
environment external to an optical chamber that comprises the
portion of the optical path. In some embodiments, the method
further comprises maintaining the optical chamber at a positive
pressure with respect to an ambient pressure. In some embodiments,
above ambient pressure is at least about 0.5 pounds per square inch
(PSI) above ambient pressure. In some embodiments, the method
further comprises substantially sealing the optical chamber to
reduce introduction of gases from an exterior of the optical
chamber. In some embodiments, the method further comprises
filtering an inlet and/or outlet gas composition. In some
embodiments, the method further comprises encompassing the optical
path in one or more enclosure channels, the optical path comprising
a portion in which the energy beam is introduced into the optical
chamber, the one or more optical elements, and a portion out of
which the energy beam exits the optical chamber. In some
embodiments, the method further comprises maintaining a positive
pressure in the enclosure channels with respect to an ambient
atmosphere in a remainder of the optical chamber. In some
embodiments, the method further comprises flowing a gas from an
interior of the one or more enclosure channels to an exterior of
the one or more enclosure channels via one or more openings. In
some embodiments, the method further comprises flowing a gas from
an interior of the one or more enclosure channels to an exterior of
the one or more enclosure channels via one or more segments thereof
that are joined together by at least one leaky seal. In some
embodiments, the method further comprises detecting a presence of a
contaminant at or adjacent to (i) the target surface and/or (ii)
the one or more optical elements. In some embodiments, the
contaminant comprises a hydrocarbon, a silicon-based compound, an
oxide, a threshold humidity value, pre-transformed material, soot,
or a combination thereof. In some embodiments, the method further
comprises performing a cleaning process based on the detecting. In
some embodiments, the cleaning process comprises flowing a gas for
reducing an amount of the contaminant within a processing chamber
that comprises the target surface, which reducing is with respect
to a lack of flowing the gas. In some embodiments, the cleaning
process comprises flowing a gas for reducing an amount of the
contaminant at a surface of an optical window, which optical window
is an optical element of the one or more optical elements, which
reducing is with respect to a lack of flowing the gas. In some
embodiments, flowing the gas comprises directing the gas toward the
surface of the optical window. In some embodiments, the cleaning
process comprises directing an ionized gas toward at least one of
the one or more optical elements, which ionized gas ionizes a
surface of the at least one or more optical elements, the
contaminant, or a combination thereof. In some embodiments, the
cleaning process comprises vibrating the at least one of the one or
more optical elements to reduce an amount of the contaminant at a
surface of the at least one of the one or more optical elements. In
some embodiments, to reduce is with respect to a lack of
vibration.
[0041] In another aspect, an apparatus for printing at least one
three-dimensional object, comprises at least one controller that is
programmed to: (a) direct an energy source to generate an energy
beam to a test calibration structure through an optical arrangement
comprises one or more optical elements, which energy beam is
configured to transform a pre-transformed material to a transformed
material for printing the at least one three-dimensional object in
an enclosure, which optical arrangement is configured to provide a
requested footprint of the energy beam at least on an exposed
surface of the test calibration structure, which test calibration
structure is disposed in the enclosure, wherein the at least one
controller is operatively coupled to the energy source and to the
optical arrangement; (b) direct a detector to detect a returning
radiation from the test calibration structure and generate an
associated test signal; and (c) direct evaluation of a thermal
lensing of the optical arrangement using the associated test
signal.
[0042] In some embodiments, the evaluation considers a deviation
between the associated test signal and an associated benchmark
signal. In some embodiments, the associated benchmark signal is of
a returning benchmark radiation from the test calibration structure
or from a different calibration structure (e.g., having the same
optical characteristic as the test calibration structure). In some
embodiments, the test calibration structure or the different
calibration structure comprises a benchmark calibration structure
(e.g., that is at or above an ambient temperature). In some
embodiments, the optical arrangement is at and/or above an ambient
temperature during a generation of the benchmark returning
radiation. In some embodiments, the optical arrangement is at or
above an ambient pressure during a generation of the returning
benchmark radiation. In some embodiments, the optical arrangement
is in non-thermal lensing conditions and/or varying thermal lensing
conditions during a generation of a returning benchmark radiation.
In some embodiments, the at least one controller is configured to
direct varying the thermal lensing conditions. In some embodiments,
the at least one controller is configured to direct an energy beam
to irradiate a heat sink through the optical arrangement to induce
a variation in a thermal condition of the optical arrangement. In
some embodiments, the at least one controller is configured to
control a throughput of the energy beam for irradiating the heat
sink through the optical arrangement. In some embodiments, the at
least one controller is configured to control a temperature of at
least one optical element of the optical arrangement resulting from
the variation in the thermal condition. In some embodiments, the at
least one controller is configured to direct the energy beam that
is configured to transform the pre-transformed material to the
transformed material for irradiating energy through the optical
arrangement. In some embodiments, the at least one controller is
configured to direct a different energy beam for irradiating energy
through the optical arrangement. In some embodiments, the heat sink
comprises the test calibration structure, a benchmark calibrations
structure, or a different structure. In some embodiments, the heat
sink is disposed adjacent to the test calibrations structure. In
some embodiments, the heat sink is disposed adjacent to a platform
that is configured to support the three-dimensional object during
the printing. In some embodiments, adjacent is above and/or
laterally adjacent. In some embodiments, the heat sink comprises a
material having a high melting temperature. In some embodiments,
the high melting temperature is above 2000 degrees Celsius. In some
embodiments, the at least one controller is further programmed to
direct formation of a benchmark calibration structure from a
transformation of a portion of the pre-transformed material. In
some embodiments, the portion of the pre-transformed material is
transformed at a location of a material bed disposed above a
platform, the at least one controller operatively coupled with the
platform. In some embodiments, the benchmark calibration structure
is printed in real time during printing of the three-dimensional
object. In some embodiments, one or more of (a), (b), and (c) occur
in real time during the printing of the three-dimensional object.
In some embodiments, real time comprises during printing of the
three-dimensional object, during printing a plurality of layers as
part of the three-dimensional object, or during printing of a layer
of a three-dimensional object. In some embodiments, an associated
benchmark signal comprises a correlation between a set of requested
footprints on a benchmark calibration structure and an associated
set of benchmark signals generated from respective returning
radiations from the benchmark calibration structure, at (i) a given
energy throughput through the optical arrangement and/or (ii) a
given focal setup of the optical arrangement. In some embodiments,
the associated test signal comprises a correlation between (I) an
energy throughput that is emitted through the optical arrangement
by the energy beam at a focal setting and (II) the associated test
signal that is generated from the returning radiation from the test
calibration structure. In some embodiments, an estimated footprint
of the energy beam is determined while considering a deviation
between the associated test signal and the associated benchmark
signal. In some embodiments, the evaluation considers a deviation
between the associated test signal and the associated benchmark
signal. In some embodiments, the at least one controller is further
programmed to control the focal setup of the optical arrangement
while considering a result of the evaluation. In some embodiments,
the at least one controller is further programmed to control at
least one characteristic of the energy beam considering a result of
the evaluation. In some embodiments, the at least one
characteristic of the energy beam comprises (i) a center position
of the requested footprint, (ii) a fundamental length scale of the
requested footprint, (iii) a measure of a power density
distribution in the requested footprint, (iv) an average power
density in the requested footprint, or (iv) a focal position of the
requested footprint. In some embodiments, the at least one
controller is programmed to control the at least one characteristic
of the energy beam when the result of the evaluation comprises a
threshold of the thermal lensing being detected. In some
embodiments, the threshold is a threshold value or a threshold
range. In some embodiments, the threshold of the thermal lensing
comprises a threshold variation in the estimated footprint from the
requested footprint. In some embodiments, the threshold comprises a
change in the fundamental length scale of the requested footprint
of 10% or less. In some embodiments, the threshold comprises a
change in the measure of the power density distribution in the
requested footprint of 20% or less. In some embodiments, the
threshold comprises a change in the average power density in the
requested footprint of 20% or less. In some embodiments, the
threshold comprises a change in the focal position of the requested
footprint of 10 millimeters or less, which change is in an energy
beam propagation direction that is normal to a plane of the test
calibration structure. In some embodiments, the threshold comprises
a wave-front distortion of 25% or less of an energy beam
wavelength. In some embodiments, the at least one controller is
configured to direct (e.g., prior to (b)) a cleaning process of at
least one surface of the test calibration structure. In some
embodiments, the at least one surface of the test calibration
structure is at least partially coated by a coating material, the
coating material comprising the pre-transformed material, an oxide,
soot, or a combination thereof, and wherein the cleaning process is
operable to substantially remove the coating material. In some
embodiments, the at least one controller is configured to direct
the energy beam over the at least one surface to ablate the coating
material. In some embodiments, the at least one controller is
configured to direct a gas flow from a gas source over the at least
one surface to dislodge the coating material, the gas source
disposed adjacent to the test calibration structure. In some
embodiments, the at least one controller is configured to direct a
gas flow from a vacuum source over the at least one surface to
dislodge the coating material, the vacuum source disposed adjacent
to the test calibration structure. In some embodiments, the at
least one controller is configured to direct a movable member to
move across the at least one surface to dislodge the coating
material, the movable member comprising a blade, or a roller. In
some embodiments, the detector comprises a bore-sight view of the
test calibration structure, which bore-sight view comprises a
shared portion of an energy beam optical path. In some embodiments,
the detector comprises a non-direct view of the test calibration
structure. In some embodiments, the detector is configured to
detect a temperature of the requested footprint of the energy beam
on the test calibration structure, and/or a vicinity thereof. In
some embodiments, the detector is configured to detect the
temperature indirectly. In some embodiments, the detector is
configured to detect the temperature indirectly using spectroscopy,
photon count, and/or current measurement. In some embodiments, the
vicinity extends to at most six fundamental length scales of the
requested footprint of the energy beam. In some embodiments, the
test calibration structure is mounted on or comprises a stage
configured for movement. In some embodiments, the at least one
controller is configured to direct movement of the stage. In some
embodiments, the stage comprises a kinematic support or is
operatively coupled to a kinematic support. In some embodiments,
the test calibration structure is operatively coupled to a
kinematic support. In some embodiments, the one or more optical
elements comprises a high thermal conductivity optical element. In
some embodiments, the one or more optical elements comprises
sapphire, crystal quartz, Zinc sulfide (ZnS), zinc selenide (ZnSe),
magnesium fluoride (MgF2), calcium fluoride (CaF2), fused silica,
borosilicate, silicon fluoride, or Pyrex.RTM.. In some embodiments,
at least two of (a), (b), and (c) are controlled by the same
controller. In some embodiments, at least two of (a), (b), and (c)
are controlled by different controllers. In some embodiments, one
or more of (a), (b), and (c) are in real-time during the printing.
In some embodiments, one or more of (a), (b), and (c) is before the
printing. In some embodiments, the apparatus further comprises a
platform configured to support the three-dimensional object during
the printing. In some embodiments, the test calibration structure
is disposed adjacent to the platform. In some embodiments, adjacent
is laterally adjacent to the platform.
[0043] In another aspect, a method of printing of at least one
three-dimensional object, comprises: (a) directing an energy beam
to a test calibration structure through an optical arrangement
comprises one or more optical elements, which energy beam is
configured to transform a pre-transformed material to a transformed
material for printing the at least one three-dimensional object in
an enclosure, which optical arrangement is configured to provide a
requested footprint of the energy beam at least on an exposed
surface of the test calibration structure, which test calibration
structure is disposed in the enclosure; (b) detecting a returning
radiation from the test calibration structure and generating an
associated test signal; and (c) evaluating a thermal lensing of the
optical arrangement using the associated test signal.
[0044] In some embodiments, the method further comprises
maintaining a pressure at or above ambient pressure. In some
embodiments, evaluating the thermal lensing further comprises
considering a deviation between the associated test signal and an
associated benchmark signal of a benchmark returning radiation from
the test calibration structure or a different calibration
structure. In some embodiments, the test calibration structure or
the different calibration structure comprises a benchmark
calibration structure. In some embodiments, the optical arrangement
is at or above an ambient temperature while generating the
benchmark returning radiation. In some embodiments, the optical
arrangement is at or above an ambient pressure while generating the
benchmark returning radiation. In some embodiments, the optical
arrangement is at non-thermal lensing conditions or at various
thermal lensing conditions of the optical arrangement while
generating the benchmark returning radiation (e.g., which various
thermal lensing conditions are known and/or controlled). In some
embodiments, the method further comprises varying a thermal
condition of the optical arrangement by irradiating a heat sink. In
some embodiments, the method further comprises controlling the
irradiating the heat sink through the optical arrangement. In some
embodiments, controlling comprises controlling a throughput of an
energy irradiating through the optical arrangement and/or
controlling a temperature of the one or more optical elements of
the optical arrangement. In some embodiments, the irradiating is
using the energy beam. In some embodiments, the heat sink comprises
the test calibration structure, the benchmark calibration
structure, or a different structure. In some embodiments, the heat
sink is disposed adjacent to the test calibration structure. In
some embodiments, the heat sink comprises a material having a high
melting temperature. In some embodiments, the high melting
temperature is above 2000 degrees Celsius. In some embodiments, the
test calibration structure comprises a benchmark calibration
structure (e.g., that is at an ambient temperature). In some
embodiments, the at least one three-dimensional object is printed
above a platform, and wherein the test calibration structure is
disposed adjacent to the platform. In some embodiments, adjacent
comprises laterally adjacent to the platform. In some embodiments,
adjacent comprises above the platform. In some embodiments, the
method further comprises forming the benchmark calibration
structure by transforming a portion of the pre-transformed
material. In some embodiments, transforming the portion of the
pre-transformed material is in a material bed that comprises the
pre-transformed material. In some embodiments, forming the test
calibration structure and/or the benchmark calibration structure is
performed in real time during the printing. In some embodiments, in
real time comprises during printing of the three-dimensional
object, during printing a plurality of layers as part of the
three-dimensional object, or during printing of a layer of a
three-dimensional object. In some embodiments, the associated
benchmark signal comprises correlating the requested footprint on
the benchmark calibration structure with the associated test signal
generated from a returning benchmark radiation from the benchmark
calibration structure. In some embodiments, correlating comprises a
set of requested footprints on the benchmark calibration structure
and an associated set of associated benchmark signals generated
from respective returning benchmark radiations from the benchmark
calibration structure. In some embodiments, the method further
comprises determining an estimated footprint of the energy beam
while considering the deviation between the associated test signal
and the associated benchmark signal. In some embodiments, the
method further comprises controlling at least one characteristic of
the energy beam considering a result of evaluating the thermal
lensing of the optical arrangement. In some embodiments, the at
least one characteristic of the energy beam comprises (i) a center
position of the requested footprint, (ii) a fundamental length
scale of the requested footprint, (iii) a measure of a power
density distribution in the requested footprint, (iv) a measure of
an average power density in the requested footprint, or (iv) a
focal position of the requested footprint. In some embodiments, the
method further comprises controlling the at least one
characteristic of the energy beam when the result of evaluating the
thermal lensing of the optical arrangement comprises a threshold of
the thermal lensing being detected. In some embodiments, the
threshold is a threshold value or a threshold range. In some
embodiments, the threshold of the thermal lensing comprises a
threshold variation in the estimated footprint from the requested
footprint. In some embodiments, the threshold comprises a change in
(ii) of 10% or less. In some embodiments, the threshold comprises a
change in (iii) of 20% or less. In some embodiments, the threshold
comprises a change in (iv) of 10 millimeters or less, which change
is in an energy beam propagation direction that is normal to a
plane of the test calibration structure. In some embodiments, the
threshold comprises a wave-front distortion of 25% or less of an
energy beam wavelength. In some embodiments, the method further
comprises directing a cleaning process of at least one surface of
the benchmark calibration structure. In some embodiments, the
cleaning is prior to directing the energy beam to the test
calibration structure, and/or prior to detecting the returning
radiation from the test calibration structure. In some embodiments,
the at least one surface of the benchmark calibration structure is
at least partially coated by a coating material, the coating
material comprising the pre-transformed material, an oxide, soot,
or a combination thereof, and wherein the cleaning process is
operable to substantially remove the coating material. In some
embodiments, the method further comprises directing the energy beam
over the at least one surface to ablate the coating material. In
some embodiments, the method further comprises directing a gas flow
from a gas source over the at least one surface to dislodge the
coating material, the gas source disposed adjacent to the benchmark
calibration structure. In some embodiments, the method further
comprises directing a gas flow from a vacuum source over the at
least one surface to dislodge the coating material, the vacuum
source disposed adjacent to the benchmark calibration structure. In
some embodiments, the method further comprises directing a movable
member to move across the at least one surface to dislodge the
coating material, the movable member comprising a translatable
blade, a cylindrical wheel, or a combination thereof. In some
embodiments, detecting the returning radiation comprises using a
bore-sight view of the test calibration structure, which bore-sight
view comprises a shared portion of an energy beam optical path. In
some embodiments, detecting the returning radiation comprises a
non-direct view of the test calibration structure. In some
embodiments, detecting the returning radiation detects a
temperature of the requested footprint of the energy beam on the
test calibration structure, and/or a vicinity thereof. In some
embodiments, the vicinity extends to at most six fundamental length
scales of the requested footprint of the energy beam on the test
calibration structure. In some embodiments, the test calibration
structure comprises kinematic mounting. In some embodiments, the
one or more optical elements comprises a high thermal conductivity
optical element. In some embodiments, the one or more optical
elements comprises sapphire, crystal quartz, zinc selenide (ZnSe),
zinc sulfide (ZnS), magnesium fluoride (MgF2), calcium fluoride
(CaF2), fused silica, borosilicate, silicon fluoride, or
Pyrex.RTM.. In some embodiments, one or more of (a), (b), and (c)
are in real-time during the printing. In some embodiments, one or
more of (a), (b), and (c) is before the printing.
[0045] In another aspect, an apparatus for printing of at least one
three-dimensional object comprises: at least one controller that is
operatively coupled to one or more of: (i) an energy source
configured to generate an energy beam that transforms at least a
portion of a material bed to print the three-dimensional object,
which material bed has an exposed surface that has a roughness; and
(ii) a detector configured to detect a reflected radiation from the
exposed surface; which at least one controller is programmed to:
(a) direct the energy source to generate the energy beam to
irradiate at least a portion of the exposed surface and to form a
footprint on the exposed surface, which footprint emits the
reflected radiation from the exposed surface; (b) direct the
detector to detect the reflected radiation and generate an
associated signal; and (c) direct a signal analysis of the
associated signal to determine an exposed surface signal component,
which signal analysis comprises an optical variability of the
associated signal from the reflected radiation.
[0046] In some embodiments, the optical variability comprises a
spatial frequency variability. In some embodiments, the optical
variability comprises a variability span. In some embodiments, the
signal analysis comprises using an optical transfer function. In
some embodiments, the signal analysis comprises using a modulation
transfer function. In some embodiments, the at least one controller
is configured to direct translation of the energy beam along the
exposed surface, and direct a field of view of the detector to
synchronize with a translation of the energy beam along the exposed
surface. In some embodiments, the at least one controller is
configured to direct a translation of the energy beam along the
exposed surface. In some embodiments, the associated signal is
correlated with the translation. In some embodiments, the at least
one controller is programmed to direct the translation of the
energy beam at a rate that operable to retain the roughness of the
exposed surface and/or hinder transformation of the exposed surface
by the energy beam. In some embodiments, the at least one
controller is programmed to irradiate the energy beam at a power
density that operable to retain the roughness of the exposed
surface and/or hinder transformation of the exposed surface. In
some embodiments, the at least one controller is programmed to
direct the translation of the energy beam at a rate that is
operable to facilitate representative roughness sampling by the
reflected radiation. In some embodiments, the at least one
controller is programmed to direct the translation of the energy
beam at a rate that is operable to enable the detector to sample a
plurality of portions from the footprint, via the reflected
radiation. In some embodiments, a larger variability span in the
associated signal is correlated with the energy beam that is more
focused on the exposed surface, wherein larger variability span is
with respect to an optical variability of an associated signal of a
reflected radiation of the energy beam that is less focused on the
exposed surface. In some embodiments, a higher variability in the
associated signal is correlated with the energy beam that is more
focused on the exposed surface, wherein higher variability is with
respect to an optical variability of an associated signal of a
reflected radiation of the energy beam that is less focused on the
exposed surface. In some embodiments, a higher variability in the
associated signal is correlated with a smaller cross section of the
energy beam, wherein higher variability is with respect to an
optical variability of an associated signal of a reflected
radiation of the energy beam having a larger cross section. In some
embodiments, the signal analysis comprises a response to a wave
pattern of the energy beam emitted from the footprint, as a
function of the roughness of the exposed surface. In some
embodiments, the at least one controller is configured to direct
translation of the energy beam along the exposed surface, and
wherein the signal analysis comprises analyzing a wave pattern of
the energy beam emitted from the footprint during its translation.
In some embodiments, the energy beam has a first cross section
after irradiation through an optical arrangement, wherein the at
least one controller is configured to direct altering the first
cross section of the energy beam to a second cross section of the
energy beam after irradiation through the optical arrangement
(e.g., by altering the focus). In some embodiments, the at least
one controller is configured to alter an optical setting of the
optical arrangement. In some embodiments, altering the first cross
section comprises altering a focus of the energy beam on the
exposed surface. In some embodiments, the at least one controller
is further programmed to repeat (a) (b) and (c) for the second
cross section of the energy beam, and perform a comparison of the
respective signal analyses to produce a result. In some
embodiments, considering the result, the at least one controller is
programmed to (d) determine at least one characteristic of (i) a
fundamental length scale of the cross section, (ii) the roughness
of the exposed surface, and/or (iii) an optical arrangement setting
that is configured to direct the energy beam onto the exposed
surface. In some embodiments, the at least one controller is
operatively coupled with the optical arrangement. In some
embodiments, at least two of the direct the energy source in (a),
direct the detector in (b), direct the signal analysis of the
associated signal in (c), and determine the least one
characteristic in (d), are directed by different controllers. In
some embodiments, at least two of the direct the energy source in
(a), direct the detector in (b), direct the signal analysis of the
associated signal in (c), and determine the least one
characteristic in (d), are directed by the same controller. In some
embodiments, one or more of the direct the energy source in (a),
direct the detector in (b), direct the signal analysis of the
associated signal in (c), and determine the least one
characteristic in (d), is in real time during the printing. In some
embodiments, one or more of the direct the energy source in (a),
direct the detector in (b), direct the signal analysis of the
associated signal in (c), and determine the least one
characteristic in (d), is before the printing. In some embodiments,
the at least one controller is configured to determine the least
one characteristic by evaluating a deviation in an intensity of the
reflected radiation and/or signal variability of the reflected
radiation. In some embodiments, the at least one controller is
configured to direct detection of an astigmatism of the footprint
and/or of a cross section of the energy beam. In some embodiments,
the at least one controller is further programmed to direct the
energy beam to travel in a first direction with respect to the
exposed surface. In some embodiments, the at least one controller
is further programmed to direct the energy beam to travel in a
second direction with respect to the exposed surface. In some
embodiments, the second direction is perpendicular to the first
direction. In some embodiments, the at least one controller is
further programmed to direct a calibration of the at least one
characteristic by comparing a deviation of the optical variability
at a given energy beam cross section with a benchmark optical
variability value for the at least one characteristic at the given
energy beam cross section. In some embodiments, the benchmark
optical variability value is generated using a known roughness of
the exposed surface, and (i) a focal setting of the optical
arrangement and a varying height of the exposed surface or (ii) a
height of the exposed surface and a varying focal setting of the
optical arrangement. In some embodiments, the at least one
controller is configured to vary the height of the exposed surface
to alter a fundamental scale of the footprint on the exposed
surface. In some embodiments, the at least one controller is
configured to vary the focal setting of the optical arrangement to
alter a fundamental scale of the footprint on the exposed surface.
In some embodiments, the at least one controller is further
programmed to use the deviation to control the cross section of the
energy beam and/or an optical arrangement configuration. In some
embodiments, the apparatus further comprises an optical filter
disposed in an optical path comprising the detector, which optical
filter is configured to generate an optically filtered reflected
radiation. In some embodiments, the optically filtered reflected
radiation comprises a reduced specular reflection, which reduced is
relative to a specular reflection portion of the reflected
radiation. In some embodiments, the at least one controller is
further configured to direct a signal processing of the associated
signal and/or the exposed surface signal component. In some
embodiments, the signal processing of the associated signal and/or
the exposed surface signal component comprises computing a mean
value. In some embodiments, the signal processing of the associated
signal and/or the exposed surface signal component comprises
computing a standard deviation. In some embodiments, the signal
processing of the associated signal and/or the exposed surface
signal component comprises computing a normalized standard
deviation, which normalized standard deviation comprises a quotient
of a standard deviation and a mean value, which normalized
deviation is of the associated signal and/or the exposed surface
signal component. In some embodiments, the exposed surface is of a
material bed, which material bed comprises elemental metal, metal
alloy, salt, oxide, ceramic, or an allotrope of elemental carbon.
In some embodiments, the material bed comprises a particulate
material having a distribution. In some embodiments, the
distribution is a known distribution. In some embodiments, the at
least one controller comprises a graphical processing unit (GPU),
system-on-chip (SOC), application specific integrated circuit
(ASIC), application specific instruction-set processor (ASIPs),
programmable logic device (PLD), or field programmable gate array
(FPGA). In some embodiments, the exposed surface comprises a
kinematic support, or is operatively coupled to a kinematic
support.
[0047] In another aspect, a method for printing at least one
three-dimensional object comprises: (a) irradiating at least a
portion of an exposed surface of a material bed to form a footprint
on the exposed surface, which exposed surface has a roughness,
which footprint emits a reflected radiation from the exposed
surface; (b) detecting the reflected radiation and generating an
associated signal; and (c) analyzing the associated signal to
determine an exposed surface signal component, which signal
analysis comprises an optical variability of the associated signal
from the reflected radiation.
[0048] In some embodiments, the optical variability comprises a
spatial frequency variability. In some embodiments, the optical
variability comprises an extend of a variability span. In some
embodiments, analyzing the associated signal comprises using an
optical transfer function. In some embodiments, analyzing the
associated signal comprises using a modulation transfer function.
In some embodiments, the irradiating further comprises translating
an energy beam along the exposed surface, wherein the associated
signal is correlated with the translating. In some embodiments, the
method further comprises translating the energy beam at a rate,
which rate enables sampling a portion of the exposed surface (e.g.,
over a given time), via the reflected radiation. In some
embodiments, a larger variability span in the associated signal is
correlated with a more focused footprint of the energy beam on the
exposed surface, wherein larger variability span is with respect to
an optical variability of an associated signal of a reflected
radiation of a less focused footprint of the energy beam. In some
embodiments, a higher variability in the associated signal is
correlated with a more focused footprint of the energy beam on the
exposed surface, wherein higher variability is with respect to an
optical variability of an associated signal of a reflected
radiation of a less focused footprint of the energy beam. In some
embodiments, analyzing the signal comprises a response to a (e.g.,
periodic) wave pattern of an energy beam emitted from the
footprint, as a function of the roughness of the exposed surface.
In some embodiments, the method further comprises translating the
energy beam along the exposed surface, and wherein analyzing the
signal comprises analyzing the wave pattern of the energy beam
emitted from the footprint during its translation. In some
embodiments, analyzing the wave pattern comprises analyzing a
frequency variability in the wave pattern. In some embodiments,
analyzing the wave pattern comprises analyzing an amplitude
variability in the wave pattern. In some embodiments, the
irradiating comprises an energy beam having a first cross section,
wherein the method further comprises altering the first cross
section of the energy beam to a second cross section of the energy
beam (e.g., by altering the focus). In some embodiments, the
altering the first cross section of the energy beam comprises
altering a focus of the energy beam on the exposed surface. In some
embodiments, the method further comprises repeating (a), (b), and
(c) for the second cross section of the energy beam, and comparing
the respective signal analyses. In some embodiments, the method
further comprises determining at least one characteristic of (i) a
fundamental length scale of the footprint, (ii) the roughness of
the exposed surface, and/or (iii) an optical arrangement
configuration that is configured to direct the energy beam onto the
exposed surface, considering the comparing the respective signal
analyses. In some embodiments, one or more of irradiating at least
the portion of the exposed surface, detecting the reflected
radiation, analyzing the associated signal and determining the
least one characteristic, is (e.g., continuous) during the
printing. In some embodiments, one or more of irradiating at least
the portion of the exposed surface, detecting the reflected
radiation, analyzing the associated signal and determining the
least one characteristic, is before the printing. In some
embodiments, determining the least one characteristic comprises
evaluating a deviation in an intensity of the reflected radiation.
In some embodiments, the method further comprises evaluating a rate
of variability in the deviation in the intensity of the reflected
radiation. In some embodiments, the method further comprises
evaluating (e.g., an extend of) a span of variability of the
deviation in the intensity of the reflected radiation. In some
embodiments, the method further comprises determining any
astigmatism of the footprint. In some embodiments, the irradiating
comprises an energy beam traveling in a first direction with
respect to the exposed surface. In some embodiments, the method
further comprises the energy beam traveling in a second direction
with respect to the exposed surface. In some embodiments, the
second direction is perpendicular to the first direction. In some
embodiments, determining any astigmatism comprises comparing (i)
the optical variability of the associated signal from the reflected
radiation during travel of the energy beam in the first direction
with (ii) the optical variability of the associated signal from the
reflected radiation during travel of the energy beam in the second
direction. In some embodiments, the method further comprises
calibrating the at least one characteristic by comparing a
deviation of the optical variability at a given energy beam cross
section with a benchmark optical variability value for the at least
one characteristic at the given energy beam cross section. In some
embodiments, the method further comprises controlling the energy
beam cross section and/or the optical arrangement configuration,
considering the deviation. In some embodiments, the method further
comprises optically filtering the reflected radiation. In some
embodiments, the optically filtering reduces a specular reflection,
which reduces is relative to a specular reflection portion of the
reflected radiation. In some embodiments, the method further
comprises signal processing of the associated signal and/or the
exposed surface signal component. In some embodiments, the signal
processing of the associated signal and/or the exposed surface
signal component comprises computing a mean value. In some
embodiments, the signal processing of the associated signal and/or
the exposed surface signal component comprises computing a standard
deviation. In some embodiments, the signal processing of the
associated signal and/or the exposed surface signal component
comprises computing a normalized standard deviation, which
normalized standard deviation comprises a quotient of a standard
deviation and a mean value, which normalized deviation is of the
associated signal and/or the exposed surface signal component. In
some embodiments, the exposed surface comprises a material bed,
which material bed comprises elemental metal, metal alloy, salt,
oxide, ceramic, or an allotrope of elemental carbon. In some
embodiments, the material bed comprises a particulate material
having a distribution. In some embodiments, the distribution is a
known distribution. In some embodiments, the exposed surface
comprises a kinematic support, or is operatively coupled to a
kinematic support. In some embodiments, the irradiating comprises
an energy beam having a first cross section after passing through
an optical arrangement, wherein the method further comprises
altering the first cross section of the energy beam to a second
cross section of the energy beam after passing through the optical
arrangement, further comprising repeating (a), (b), and (c) for the
second cross section of the energy beam, and comparing the
respective signal analyses, and generating a benchmark optical
variability value from a known roughness of the exposed surface at
a (e.g., vertical) position of the exposed surface. In some
embodiments, altering the first cross section of the energy beam to
a second cross section of the energy beam comprises altering a
focal setting of the optical arrangement. In some embodiments, the
exposed surface has a first position, wherein the method further
comprises altering the first position of the exposed surface to a
second position of the exposed surface to alter a fundamental
length scale of the footprint on the exposed surface, wherein the
method further comprising repeating (a), (b), and (c) for the
second position of the exposed surface, and comparing the
respective signal analyses, and generating a benchmark optical
variability value from a known roughness of the exposed surface at
a focal setup of an optical arrangement. In some embodiments,
altering the first position comprises vertically altering the first
position. In some embodiments, the exposed surface is horizontal.
In some embodiments, the exposed surface is planar. In some
embodiments, the irradiating comprises an energy beam, and wherein
altering the first position comprises altering the first position
in a direction normal to a direction in which the energy beam
irradiates the exposed surface.
[0049] Another aspect of the present disclosure provides a system
for effectuating the methods disclosed herein.
[0050] Another aspect of the present disclosure provides an
apparatus for effectuating the methods disclosed herein.
[0051] Another aspect of the present disclosure provides an
apparatus comprising a controller that directs effectuating one or
more steps in the method disclosed herein, wherein the controller
is operatively coupled to the apparatuses, systems, and/or
mechanisms that it controls to effectuate the method.
[0052] Another aspect of the present disclosure provides a computer
system comprising one or more computer processors and a
non-transitory computer-readable medium coupled thereto. The
non-transitory computer-readable medium comprises
machine-executable code that, upon execution by the one or more
computer processors, implements any of the methods above or
elsewhere herein.
[0053] Another aspect of the present disclosure provides an
apparatus for printing one or more 3D objects comprises a
controller that is programmed to direct a mechanism used in a 3D
printing methodology to implement (e.g., effectuate) any of the
method disclosed herein, wherein the controller is operatively
coupled to the mechanism.
[0054] Another aspect of the present disclosure provides a computer
software product, comprising a non-transitory computer-readable
medium in which program instructions are stored, which
instructions, when read by a computer, cause the computer to direct
a mechanism used in the 3D printing process to implement (e.g.,
effectuate) any of the method disclosed herein, wherein the
non-transitory computer-readable medium is operatively coupled to
the mechanism.
[0055] Another aspect of the present disclosure provides a
non-transitory computer-readable medium comprising
machine-executable code that, upon execution by one or more
computer processors, implements any of the methods disclosed
herein.
[0056] Additional aspects and advantages of the present disclosure
will become readily apparent to those skilled in this art from the
following detailed description, wherein only illustrative
embodiments of the present disclosure are shown and described. As
will be realized, the present disclosure is capable of other and
different embodiments, and its several details are capable of
modifications in various obvious respects, all without departing
from the disclosure. Accordingly, the drawings and description are
to be regarded as illustrative in nature, and not as
restrictive.
INCORPORATION BY REFERENCE
[0057] All publications, patents, and patent applications mentioned
in this specification are herein incorporated by reference to the
same extent as if each individual publication, patent, or patent
application was specifically and individually indicated to be
incorporated by reference.
BRIEF DESCRIPTION OF DRAWINGS
[0058] The novel features of the invention are set forth with
particularity in the appended claims. A better understanding of the
features and advantages of the present invention will be obtained
by reference to the following detailed description that sets forth
illustrative embodiments, in which the principles of the invention
are utilized, and the accompanying drawings or figures (also "FIG."
and "FIGS." herein), of which:
[0059] FIG. 1 shows a schematic side view of a three-dimensional
(3D) printing system and its components;
[0060] FIGS. 2A-2B schematically illustrate vertical cross sections
of 3D printing systems and their components;
[0061] FIGS. 3A-3B schematically illustrate vertical cross sections
of 3D printing systems and their components;
[0062] FIG. 4 schematically illustrates a path;
[0063] FIG. 5 schematically illustrates various paths;
[0064] FIG. 6 schematically illustrates an optical system;
[0065] FIG. 7 schematically illustrates a computer control system
that is programmed or otherwise configured to facilitate the
formation of one or more 3D objects;
[0066] FIG. 8 schematically illustrates spatial intensity profiles
of irradiating energy;
[0067] FIG. 9 shows a schematic side view of a 3D printing system
and its components;
[0068] FIG. 10 shows various vertical cross-sectional views of
different 3D objects;
[0069] FIG. 11 shows a horizontal view of a 3D object;
[0070] FIG. 12 schematically illustrates various 3D printer
components;
[0071] FIG. 13 schematically illustrates a detection system and its
components;
[0072] FIG. 14 schematically illustrates a vertical cross section
of an optical fiber bundle;
[0073] FIG. 15 schematically illustrates an optical system;
[0074] FIG. 16 schematically illustrates components of an optical
system;
[0075] FIG. 17 shows a schematic side view of a 3D printing system
and its components;
[0076] FIGS. 18A-18C schematically illustrate various bitmaps;
[0077] FIGS. 19A-19C schematically illustrate various bitmaps;
[0078] FIGS. 20A-20C schematically illustrate various bitmaps;
[0079] FIGS. 21A-21C schematically illustrate various bitmaps;
[0080] FIGS. 22A-22B schematically illustrate components of a
calibration system;
[0081] FIGS. 23A-23C schematically illustrate components of a
calibration system;
[0082] FIG. 24A schematically illustrates components of a
calibration system, and FIG. 24B schematically illustrates a graph
used in the calibration;
[0083] FIGS. 25A-25C schematically illustrate components of a
calibration system;
[0084] FIG. 26A schematically illustrates components of a
calibration system, and FIG. 26B schematically illustrates a graph
used in the calibration;
[0085] FIGS. 27A-27B schematically illustrate energy beam cross
sections or footprints;
[0086] FIG. 28A schematically illustrates components of a
calibration system, and FIG. 28B schematically illustrates a graph
used in the calibration;
[0087] FIG. 29 schematically illustrates an example of systematic
variation within a 3D printer;
[0088] FIGS. 30A-30B schematically illustrate components of a
calibration system;
[0089] FIG. 31A schematically illustrates an image captured for
calibration, and FIG. 31B schematically illustrates a graph
corresponding to a calibration;
[0090] FIG. 32 schematically illustrates components of an optical
setup;
[0091] FIG. 33 schematically illustrates graphs used for
calibration;
[0092] FIG. 34A-34B schematically illustrate various 3D printer
components;
[0093] FIG. 35A-35B schematically illustrate various 3D printer
components;
[0094] FIG. 36 schematically illustrates a side view of various 3D
printer components;
[0095] FIG. 37 schematically illustrates a side view of various 3D
printer components;
[0096] FIG. 38 schematically illustrates beams shining through
lenses;
[0097] FIG. 39A schematically illustrates a graph used for
calibration; and
[0098] FIG. 39B schematically illustrates a setup used for
calibration.
[0099] The figures and components therein may not be drawn to
scale. Various components of the figures described herein may not
be drawn to scale.
DETAILED DESCRIPTION
[0100] While various embodiments of the invention have been shown,
and described herein, it will be obvious to those skilled in the
art that such embodiments are provided by way of example only.
Numerous variations, changes, and substitutions may occur to those
skilled in the art without departing from the invention. It should
be understood that various alternatives to the embodiments of the
invention described herein might be employed.
[0101] Terms such as "a," "an" and "the" are not intended to refer
to only a singular entity, but include the general class of which a
specific example may be used for illustration. The terminology
herein is used to describe specific embodiments of the invention,
but their usage does not delimit the invention. When ranges are
mentioned, the ranges are meant to be inclusive, unless otherwise
specified. For example, a range between value 1 and value 2 is
meant to be inclusive and include value 1 and value 2. The
inclusive range will span any value from about value 1 to about
value 2.
[0102] The term "adjacent" or "adjacent to," as used herein,
includes `next to`, `adjoining`, `in contact with,` and `in
proximity to.` In some instances, adjacent to may be `above` or
`below.`
[0103] The term "between" as used herein is meant to be inclusive
unless otherwise specified. For example, between X and Y is
understood herein to mean from X to Y.
[0104] The term "operatively coupled" or "operatively connected"
refers to a first mechanism that is coupled (or connected) to a
second mechanism to allow the intended operation of the second
and/or first mechanism. The term "configured to" refers to an
object or apparatus that is (e.g., structurally) configured to
bring about an intended result.
[0105] The phrase "a three-dimensional object" used herein may
refer to "one or more three-dimensional objects," as
applicable.
[0106] Three-dimensional printing (also "3D printing") generally
refers to a process for generating a 3D object. The apparatuses,
methods, controllers, and/or software described herein pertaining
to generating (e.g., forming, or printing) a 3D object, pertain
also to generating one or more 3D objects. For example, 3D printing
may refer to sequential addition of material layer or joining of
material layers (or parts of material layers) to form a 3D
structure, in a controlled manner. The controlled manner may
include automated control. In the 3D printing process, the
deposited material can be transformed (e.g., fused, sintered,
melted, bound, or otherwise connected) to subsequently harden and
form at least a part of the 3D object. Fusing (e.g., sintering or
melting) binding, or otherwise connecting the material is
collectively referred to herein as transforming the material (e.g.,
powder material). Fusing the material may include melting or
sintering the material. Binding can comprise chemical bonding.
Chemical bonding can comprise covalent bonding. Examples of 3D
printing include additive printing (e.g., layer by layer printing,
or additive manufacturing). 3D printing may include layered
manufacturing. 3D printing may include rapid prototyping. 3D
printing may include solid freeform fabrication. The 3D printing
may further comprise subtractive printing.
[0107] 3D printing methodologies can comprise extrusion, wire,
granular, laminated, light polymerization, or powder bed and inkjet
head 3D printing. Extrusion 3D printing can comprise robo-casting,
fused deposition modeling (FDM) or fused filament fabrication
(FFF). Wire 3D printing can comprise electron beam freeform
fabrication (EBF3). Granular 3D printing can comprise direct metal
laser sintering (DMLS), electron beam melting (EBM), selective
laser melting (SLM), selective heat sintering (SHS), or selective
laser sintering (SLS). Powder bed and inkjet head 3D printing can
comprise plaster-based 3D printing (PP). Laminated 3D printing can
comprise laminated object manufacturing (LOM). Light polymerized 3D
printing can comprise stereo-lithography (SLA), digital light
processing (DLP), or laminated object manufacturing (LOM). 3D
printing methodologies can comprise Direct Material Deposition
(DMD). The Direct Material Deposition may comprise, Laser Metal
Deposition (LMD, also known as, Laser deposition welding). 3D
printing methodologies can comprise powder feed, or wire
deposition.
[0108] 3D printing methodologies may differ from methods
traditionally used in semiconductor device fabrication (e.g., vapor
deposition, etching, annealing, masking, or molecular beam
epitaxy). In some instances, 3D printing may further comprise one
or more printing methodologies that are traditionally used in
semiconductor device fabrication. 3D printing methodologies can
differ from vapor deposition methods such as chemical vapor
deposition, physical vapor deposition, or electrochemical
deposition. In some instances, 3D printing may further include
vapor deposition methods.
[0109] The methods, apparatuses, and systems of the present
disclosure can be used to form 3D objects for various uses and
applications. Such uses and applications include, without
limitation, electronics, components of electronics (e.g., casings),
machines, parts of machines, tools, implants, prosthetics, fashion
items, clothing, shoes, or jewelry. The implants may be directed
(e.g., integrated) to a hard tissue, a soft tissue, or to a
combination of hard and soft tissues. The implants may form
adhesion with hard and/or soft tissue. The machines may include a
motor or motor part. The machines may include a vehicle. The
machines may comprise aerospace related machines. The machines may
comprise airborne machines. The vehicle may include an airplane,
drone, car, train, bicycle, boat, or shuttle (e.g., space shuttle).
The machine may include a satellite or a missile. The uses and
applications may include 3D objects relating to the industries
and/or products listed herein.
[0110] The present disclosure provides systems, apparatuses, and/or
methods for 3D printing of a desired 3D object from a
pre-transformed material (e.g., powder material). The object can be
pre-ordered, pre-designed, pre-modeled, or designed in real time
(i.e., during the process of 3D printing). The 3D printing method
can be an additive method in which a first layer is printed, and
thereafter a volume of a material is added to the first layer as a
separate sequential layer (or parts thereof). Each additional
sequential layer (or part thereof) can be added to the previous
layer by transforming (e.g., fusing (e.g., melting)) a fraction of
the pre-transformed (e.g., powder) material and subsequently
hardening the transformed material to form at least a portion of
the 3D object. The hardening can be actively induced (e.g., by
cooling) or can occur without intervention.
[0111] Pre-transformed material, as understood herein, is a
material before it has been first transformed (e.g., once
transformed) by an energy beam and/or flux during the 3D printing
process. The pre-transformed material may be a material that was,
or was not, transformed prior to its use in the 3D printing
process. The pre-transformed material may be a material that was
partially transformed prior to its use in the 3D printing process.
The pre-transformed material may be a starting material for the 3D
printing process. The pre-transformed material may be liquid,
solid, or semi-solid (e.g., gel). The pre-transformed material may
be a particulate material. The particulate material may be a powder
material. The powder material may comprise solid particles of
material. The particulate material may comprise vesicles (e.g.,
containing liquid or semi-solid material). The particulate material
may comprise solid or semi-solid material particles.
[0112] The fundamental length scale (e.g., the diameter, spherical
equivalent diameter, diameter of a bounding circle, or the largest
of height, width and length; abbreviated herein as "FLS") of the
printed 3D object can be at least about 50 micrometers (.mu.m), 80
.mu.m, 100 .mu.m, 120 .mu.m, 150 .mu.m, 170 .mu.m, 200 .mu.m, 230
.mu.m, 250 .mu.m, 270 .mu.m, 300 .mu.m, 400 .mu.m, 500 .mu.m, 600
.mu.m, 700 .mu.m, 800 .mu.m, 1 millimeter (mm), 1.5 mm, 2 mm, 5 mm,
1 centimeter (cm), 1.5 cm, 2 cm, 10 cm, 20 cm, 30 cm, 40 cm, 50 cm,
60 cm, 70 cm, 80 cm, 90 cm, 1 m, 2 m, 3 m, 4 m, 5 m, 10 m, 50 m, 80
m, or 100 m. The FLS of the printed 3D object can be at most about
1000 m, 500 m, 100 m, 80 m, 50 m, 10 m, 5 m, 4 m, 3 m, 2 m, 1 m, 90
cm, 80 cm, 60 cm, 50 cm, 40 cm, 30 cm, 20 cm, 10 cm, or 5 cm. In
some cases, the FLS of the printed 3D object may be in between any
of the afore-mentioned FLSs (e.g., from about 50 .mu.m to about
1000 m, from about 120 .mu.m to about 1000 m, from about 120 .mu.m
to about 10 m, from about 200 .mu.m to about 1 m, or from about 150
.mu.m to about 10 m).
[0113] In some instances, it is desired to control the manner in
which at least a portion of a layer of hardened material is formed.
The layer of hardened material may comprise a multiplicity of melt
pools. In some instances, it may be desired to control one or more
characteristics of the melt pools that form the layer of hardened
material. The characteristics may comprise the depth of a melt
pool, microstructure, or the repertoire of microstructures of the
melt pool. The microstructure of the melt pool may comprise the
crystalline structure, or crystalline structure repertoire that is
included in the melt pool.
[0114] The FLS (e.g., depth, or diameter) of the melt pool may be
at least about 0.5 .mu.m, 1 .mu.m, 5 .mu.m, 10 .mu.m, 20 .mu.m, 30
.mu.m, 40 .mu.m, or 50 .mu.m. The FLS of the melt pool may be at
most about 0.5 .mu.m, 1 .mu.m, 5 .mu.m, 10 .mu.m, 20 .mu.m, 30
.mu.m, 40 .mu.m, or 50 .mu.m. The FLS of the melt pool may be any
value between the aforementioned values (e.g., from about 0.5 .mu.m
to about 50 .mu.m, from about 0.5 .mu.m to about 10 .mu.m, from
about 10 .mu.m to about 30 .mu.m, or from about 30 .mu.m to about
50 .mu.m.
[0115] Transforming (e.g., tiling) may comprise heating at least a
portion of a target surface (e.g., exposed surface of a material
bed), and/or a previously formed area of hardened material using at
least one energy source. The energy source may generate an energy
beam. The energy source may be a radiative energy source. The
energy source may be a dispersive energy source (e.g., a fiber
laser). The energy source may generate a substantially uniform
(e.g., homogenous) energy stream. The energy source may comprise a
cross section (e.g., footprint) having a substantially homogenous
fluence. The energy generated for transforming a portion of
material (e.g., pre-transformed or transformed), by the energy
source will be referred herein as the "energy flux." The energy
flux can be provided as an energy beam (e.g., tiling energy beam).
The energy flux may heat a portion of a 3D object (e.g., an exposed
surface of the 3D object). The energy flux may heat a portion of
the target surface (e.g., an exposed surface of the material bed,
and/or a deeper portion of the material bed that is not exposed).
The target surface may include a pre-transformed material, a
partially transformed material and/or a transformed material. The
target surface may include a portion of the build platform (e.g.,
the base (e.g., FIG. 1, 102)). The target surface may comprise a
(surface) portion of a 3D object. The heating by the energy flux
may be substantially uniform.
[0116] The energy flux may irradiate (e.g., flash, flare, shine, or
stream) a target surface for a period of time (e.g., predetermined
period of time). The time in which the energy flux (e.g., beam)
irradiates may be referred to as a dwell time of the energy flux.
During this period of time (e.g., dwell time), the energy flux may
be substantially stationary. During that period of time, the energy
may substantially not translate (e.g., neither in a raster form nor
in a vector form). During this period of time (e.g., dwell time)
the energy density of the energy flux may be constant. In some
embodiments, during this period of time (e.g., dwell time) the
energy density of the energy flux may vary. The variation may be
predetermined. The variation may be controlled (e.g., by a
controller). The controller may determine the variation based on a
signal received by one or more sensors. The controller may
determine the variation based on an algorithm. The controlled
variation may be based on closed loop or open loop control. For
example, the variation may be determined based on temperature
and/or imaging measurements. The variation may be determined by
melt pool size evaluation. The variation may be determined based on
height measurements.
[0117] The energy flux may emit energy stream towards the target
surface in a step and repeat sequence. The energy flux may emit
energy stream towards the target surface in a step and tiling
heating or tile filling process. The energy flux may comprise a
radiative heat, electromagnetic radiation, charge particle
radiation (e.g., e-beam), or a plasma beam. The energy source may
comprise a heater (e.g., radiator or lamp), an electromagnetic
radiation generator (e.g., laser), a charge particle radiation
generator (e.g., electron gun), or a plasma generator. The energy
source may comprise a diode laser. The energy source may comprise
light emitting diode array (LED array).
[0118] The energy flux may irradiate a pre-transformed material, a
transformed material, or a hardened material (e.g., within the
material bed). The energy flux may irradiate a target surface. The
target surface may comprise a pre-transformed material, a
transformed material, or a hardened material. The (e.g., tiling)
energy source may point and irradiate an energy flux on the target
surface. The energy flux may heat the target surface. The energy
flux may transform the target surface (or a fraction thereof). The
energy flux may preheat the target surface (e.g., to be followed by
a scanning energy beam that optionally transforms at least a
portion of the preheated surface). The energy flux may post-heat
the target surface (e.g., following a transformation of the target
surface). The energy flux may post-heat the target surface in order
to reduce a cooling rate of the target surface. The heating may be
at a specific location (e.g., a tile). The tile may comprise a wide
exposure space (e.g., a wide footprint on the target surface). The
energy flux may have a long dwell time (e.g., exposure time) that
may be at least 1 millisecond, 1 minute, 1 hour, or 1 day. In
principle, the energy flux may have a dwell time that is infinity.
The energy flux may emit a low energy flux to control the cooling
rate of a position within a layer of transformed material. The low
cooling rate may control the solidification of the transformed
(e.g., molten) material. The low cooling rate may allow formation
of crystals (e.g., single crystals) at specified location within
the layer that is included in the 3D object.
[0119] The energy flux may transform (e.g., melt) a portion of a 3D
object (e.g., an exposed surface of the 3D object). The energy flux
may transform (e.g., fuse) a portion of the powder bed (e.g., an
exposed surface of the powder bed, a deeper portion of the powder
bed that is not exposed), and/or a portion of a powder stream
(e.g., directed toward a target surface). The transformation may be
substantially uniform.
[0120] The irradiated energy (e.g., energy beam) may comprise a
cross section having a substantially targeted projection (e.g.,
footprint).
[0121] FIG. 1 shows an example of a 3D printing system 100 and
apparatuses, a (e.g., first) energy source 122 (e.g., a tiling
energy source) that emits a (e.g., first) energy beam 119 (which
can provide an energy flux). In the example of FIG. 1 the energy
flux travels through an optical system 114 (e.g., comprising an
aperture, lens, mirror, or deflector) and an optical window 132, to
heat a target surface 131. The target surface may be a portion of a
hardened material (e.g., 106) that was formed by transforming at
least a portion of a target surface (e.g., 131) by a (e.g.,
scanning) energy beam. In the example of FIG. 1 a (e.g., second,
e.g., scanning) energy 101 is generated by a (e.g., second) energy
source 121. The generated (e.g., second) energy beam may travel
through an optical mechanism (e.g., 120) and/or an optical window
(e.g., 115). The first energy beam (which can provide the first
energy flux) and the second (e.g., scanning) energy beam may travel
through the same optical window and/or through the same optical
system. At times, the energy flux and the first (e.g., scanning)
energy beam may travel through their respective optical systems and
through the same optical window. FIG. 9 shows an example of a 3D
printing system 900 where an energy flux 919 (e.g., second energy
beam) is emitted from energy source 922, and a scanning energy beam
901 (e.g., first energy beam) is emitted from energy source 921.
Both energy beams can travel through their respective optical
mechanisms (e.g., 914, 920) and through the same optical window
(e.g., 932). In the example of FIG. 9, the energy flux 919 (e.g.,
second energy beam), after passing through the optical window 932,
forms emitted radiated energy 908. The emitted radiated energy
(e.g., 908) and first (e.g., scanning) energy beam (e.g., 901) may
be utilized to form a hardened material (e.g., 906) in a material
bed (e.g., 904). The first energy beam and the second energy beam
may have at least one characteristic that is the same. The energy
flux and the scanning energy beam may have at least one
characteristic that is the same. The first energy beam and the
second energy beam may have at least one characteristic that is
different. The energy flux and the scanning energy beam may have at
least one characteristic that is different. An optical window may
be a material (e.g., transparent material) that allows the
irradiating energy to travel through it without (e.g., substantial)
loss of radiation. The optical window can comprise a high thermal
conductivity material (e.g., a crystal quartz, zinc selenide
(ZnSe), magnesium fluoride (MgF.sub.2), or calcium fluoride
(CaF.sub.2), or sapphire optical window) as described herein.
Substantial may be relevant to the purpose of the radiation. In
some embodiments, the energy flux, and the scanning energy beam
both travel through the same optical system, albeit through
different components within the optical system and/or at different
instances. In some embodiments, the energy flux, and the scanning
energy beam both travel through the same optical system, albeit
through different configurations of the optical system and/or at
different instances. The emitted radiative energy (e.g., FIG. 1,
108) may travel through an aperture, deflector, and/or other parts
of an optical system (e.g., schematically represented as FIG. 1,
114). The aperture may restrict the amount of energy exerted by the
(e.g., tiling) energy source. The aperture restriction may redact
(e.g., cut off, block, obstruct, or discontinue) the energy beam to
form a desired shape of a tile.
[0122] In the example shown in FIG. 1, a part (e.g., hardened
material 106) represents a layer of transformed material in a
material bed 104. The material bed may be disposed above a
platform. The platform may comprise a substrate (e.g., 110) and/or
a base (e.g., 102). FIG. 1 shows an example of sealants 103 that
prevent the pre-transformed material from spilling from the
material bed (e.g., 104) to the bottom 111 of an enclosure 107. The
platform may translate (e.g., vertically, FIG. 1, 112) using a
translating mechanism (e.g., an actuator, e.g., an elevator 105).
The translating mechanism may travel in the direction to or away
from the bottom of the enclosure (e.g., 111) (e.g., vertically).
For example, the platform may decrease in height before a new layer
of pre-transformed material is dispensed by the material dispensing
mechanism (e.g., 116). The target surface (e.g., top surface of the
material bed) (e.g., 131) may be leveled using a leveling mechanism
(e.g., comprising parts 117 and/or 118). The mechanism may further
include a cooling member (e.g., heat sink 113). The interior volume
of the enclosure (e.g., 126) may comprise an inert gas or an oxygen
and/or humidity reduced atmosphere. The atmosphere may be any
atmosphere disclosed in patent application number PCT/US15/36802,
titled "APPARATUSES, SYSTEMS AND METHODS FOR THREE-DIMENSIONAL
PRINTING" that was filed on Jun. 19, 2015, which is incorporated
herein by reference in their entirety.
[0123] In some embodiments, the build module and the processing
chamber are separate. The separate build module and processing
chamber may comprise separate atmospheres. The separate build
module and processing chamber may (e.g., controllably) merge. For
example, the atmospheres of the build module and processing chamber
may merge. In the example of FIG. 1, the 3D printing system
comprises a processing chamber which comprises the irradiated
(e.g., irradiating) energy and the target surface (e.g., comprising
the atmosphere in the interior volume of the processing chamber,
e.g., 126). For example, the processing chamber may comprise a
first (e.g., scanning) energy beam (e.g., FIG. 1, 101) and/or a
second energy beam (e.g., energy flux) (e.g., FIG. 1, 108). The
enclosure may comprise one or more build modules (e.g., enclosed in
the dashed area 130). At times, at least one build module may be
situated in the enclosure comprising the processing chamber. At
times, at least one build module may engage with the processing
chamber (e.g., FIG. 1) (e.g., 107). At times, a plurality of build
modules may be coupled to the enclosure. The build module may
reversibly engage with (e.g., couple to) the processing chamber.
The engagement of the build module may be before or after the 3D
printing. The engagement of the build module with the processing
chamber may be controlled (e.g., by a controller, such as for
example by a microcontroller). The controller may be any controller
disclosed in: patent application serial number PCT/US17/18191,
titled "ACCURATE THREE-DIMENSIONAL PRINTING" that was filed on Feb.
16, 2017; patent application serial number U.S. Ser. No.
15/435,065, titled "ACCURATE THREE-DIMENSIONAL PRINTING" that was
filed on February 16; patent application serial number EP17156707,
titled "ACCURATE THREE-DIMENSIONAL PRINTING" that was filed on Feb.
17, 2017; each of which is incorporated herein by reference in its
entirety. The controller may direct the engagement and/or
dis-engagement of the build module. The control may be automatic
and/or manual. The engagement of the build module with the
processing chamber may be reversible. In some embodiments, the
engagement of the build module with the processing chamber may be
non-reversible (e.g., stable). The FLS (e.g., width, depth, and/or
height) of the processing chamber can be at least about 50
millimeters (mm), 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 200 mm, 250
mm, 280 mm, 400 mm, 500 mm, 800 mm, 900 mm, 1 meter (m), 2 m, or 5
m. The FLS of the processing chamber can be at most about 50
millimeters (mm), 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 200 mm, 250
mm, 400 mm, 500 mm, 800 mm, 900 mm, 1 meter (m), 2 m, or 5 m. The
FLS of the processing chamber can be between any of the
afore-mentioned values (e.g., 50 mm to about 5 m, from about 250 mm
to about 500 mm, or from about 500 mm to about 5 m).
[0124] In some embodiments, the atmospheres of the build module,
and enclosure (e.g., controllably) merge (e.g., during at least a
portion of the 3D printing process). The merging may comprise
engagement with a load lock mechanism. The merging may be through a
load lock environment (e.g., FIG. 2, 214). At times, during at
least a portion of the 3D printing process, the atmospheres of the
chamber and enclosure may be (e.g., remain) separate. FIG. 2A shows
an example of a processing chamber (e.g., FIG. 2A, 210) and a build
module (e.g., FIG. 2A, 220). The processing chamber comprises an
irradiating energy (e.g., FIG. 2A, 211). The build module comprises
a build platform comprising a substrate (e.g., FIG. 2A, 221), a
base (e.g., FIG. 2A, 222), and an elevator shaft (e.g., FIG. 2A,
223) that allows the platform to move vertically up and down. The
elevator shaft may comprise a single shaft (e.g., FIG. 2A, 223).
The elevator shaft may comprise a plurality of shafts. The build
module (e.g., FIG. 2A, 220) may comprise a shutter (e.g., FIG. 2A,
224). The processing chamber (e.g., FIG. 2A, 210) may comprise a
shutter (e.g., FIG. 2A, 212). The shutter may be openable (e.g., by
the build module controller, the processing chamber controller, or
the load lock controller). The shutter may be removable (e.g., by
the build module controller, the processing chamber controller, or
the load lock controller). The removal of the shutter may comprise
manual or automatic removal. The build module shutter may be opened
while being connected to the build module. The processing chamber
shutter may be opened while being connected to the processing
chamber (e.g., through connector). The shutter connector may
comprise a hinge, chain, or a rail. In an example, the shutter may
be opened in a manner similar to opening a door or a window. The
shutter may be opened by swiveling (e.g., similar to opening a door
or a window held on a hinge). The shutter may be opened by its
removal from the opening which it blocks. The removal may be guided
(e.g., by a rail, arm, pulley, crane, or conveyor). The guiding may
be using a robot. The guiding may be using at least one motor
and/or gear. The shutter may be opened while being disconnected
from the build module. For example, the shutter may be opened
similar to opening a lid. The shutter may be opened by shifting or
sliding (e.g., to a side). FIG. 3B shows an example where the
shutter (FIG. 2B, 274) of the build module (FIG. 2B, 270) is open
in a way that is disconnected from the build module. FIG. 2B shows
an example where the shutter (FIG. 2B, 254) of the processing
chamber (FIG. 2B, 250) is open in a way that is disconnected from
the processing chamber. The build module, processing chamber,
and/or enclosure may comprise one or more seals. The seal may be a
sliding seal or a top seal. For example, the build module and/or
processing chamber may comprise a sliding seal that meets with the
exterior of the build module upon engagement of the build module
with the processing chamber. For example, the processing chamber
may comprise a top seal that faces the build module and is pushed
upon engagement of the processing chamber with the build module.
For example, the build module may comprise a top seal that faces
the processing chamber and is pushed upon engagement of the
processing chamber with the build module. The seal may be a face
seal, or compression seal. The seal may comprise an O-ring. The
build module, processing chamber, and/or enclosure may be sealed,
sealable, or open. The atmosphere of the build module, processing
chamber, and/or enclosure may be regulated. The build module may be
sealed, sealable, or open. The processing chamber may be sealed,
sealable, or open. The enclosure may be sealed, sealable, or
open.
[0125] In some embodiments, the 3D printing system comprises a load
lock. The load lock may be disposed between the processing chamber
and the build module. The load lock may be formed by engaging the
build module with the processing chamber. The load lock may be
sealable. For example, the load lock may be sealed by engaging the
build module with the processing chamber (e.g., directly or
indirectly). FIG. 2A shows an example of a load lock 214 that is
formed when the build module 220 is engaged with the processing
chamber 210. An exchange of atmosphere may take place in the load
lock by evacuating gas from the load lock (e.g., through channel
215) and/or by inserting gas (e.g., through channel 215). FIG. 3A
shows an example of a load lock 360 that is formed when the build
module 370 is engaged with the processing chamber 350. An exchange
of atmosphere may take place in the load lock by evacuating gas
from the load lock (e.g., through channel 361) and/or by inserting
gas (e.g., through channel 361). In some embodiments, the load lock
may comprise one or more gas opening ports. At times, the load lock
may comprise one or more gas transport channels. At times, the load
lock may comprise one or more valves. A gas transport channel may
comprise a valve. The opening and/or closing of a first valve of
the 3D printing system may or may not be coordinated with the
opening and/or closing of a second valve of the 3D printing system.
The valve may be controlled automatically (e.g., by a controller)
and/or manually. The load lock may comprise a gas entry opening
port and a gas exit opening port. In some embodiments, a pressure
below ambient pressure (e.g., of 1 atmosphere) is formed in the
load lock. In some embodiments, a pressure exceeding ambient
pressure (e.g., of 1 atmosphere) is formed in the load lock. At
times, during the exchange of load lock atmosphere, a pressure
below and/or above ambient pressure if formed in the load lock. At
times, a pressure equal or substantially equal to ambient pressure
is maintained (e.g., automatically and/or manually) in the load
lock. The load lock, building module, processing chamber, and/or
enclosure may comprise a valve. The valve may comprise a pressure
relief, pressure release, pressure safety, safety relief,
pilot-operated relief, low pressure safety, vacuum pressure safety,
low and vacuum pressure safety, pressure vacuum release, snap
acting, or modulating valve. The valve may comply with the legal
industry standards presiding the jurisdiction. The volume of the
load lock may be smaller than the volume within the build module
and/or processing chamber. The total volume within the load lock
may be at most about 0.1%, 0.5%, 1%, 5%, 10%, 20%, 50%, or 80% of
the total volume encompassed by the build module and/or processing
chamber. The total volume within the load lock may be between any
of the aforementioned percentage values (e.g., from about 0.1% to
about 80%, from about 0.1% to about 5%, from about 5% to about 20%,
from about 20% to about 50%, or from about 50% to about 80%). The
percentage may be volume per volume percentage.
[0126] In some embodiments, the atmosphere of the build module
and/or the processing chamber is fluidly connected to the
atmosphere of the load lock. At times, conditioning the atmosphere
of the load lock will condition the atmosphere of the build module
and/or the processing chamber that is fluidly connected to the load
lock. The fluid connection may comprise gas flow. The fluid
connection may be through a gas permeable seal and/or through a
channel (e.g., a pipe). The channel may be a sealable channel
(e.g., using a valve).
[0127] In some embodiments, the shutter of the build module engages
with the shutter of the processing chamber. The engagement may be
spatially controlled. For example, when the shutter of the build
module is within a certain gap distance from the processing chamber
shutter, the build module shutter engages with the processing
chamber shutter. The gap distance may trigger an engagement
mechanism. The gap trigger may be sufficient to allow sensing of at
least one of the shutters. The engagement mechanism may comprise
magnetic, electrostatic, electric, hydraulic, pneumatic, or
physical force. The physical force may comprise manual force. FIG.
3A shows an example of a build module shutter 371 that is attracted
upwards toward the processing chamber shutter 351, and a processing
chamber shutter 351 that is attracted upwards toward the build
module shutter 371. FIG. 3B shows an example of a single unit
formed from the processing chamber shutter 351 and the build module
shutter 371, that is transferred away from the energy beam 312. In
the single unit, the processing chamber shutter 351 and the build
module shutter 371 are held together by 313 by the engagement
mechanism. Subsequent to the engagement, the single unit may
transfer (e.g., relocate, or move) away from the energy beam. For
example, the engagement may trigger the transferring (e.g.,
relocating) of the build module shutter and the processing chamber
shutter as a single unit.
[0128] At times, removal of the shutter (e.g., of the build module
and/or processing chamber) depends on reaching a certain (e.g.,
predetermined) level of at atmospheric characteristics comprising a
gas content (e.g., relative gas content), gas pressure, oxygen
level, humidity, argon level, or nitrogen level. For example, the
certain level may be an equilibrium between an atmospheric
characteristic in the build chamber and that atmospheric
characteristics in the processing chamber.
[0129] In one example of additive manufacturing, a layer of
pre-transformed material (e.g., powder material) is disposed
adjacent to the platform using the pre-transformed material
dispensing mechanism (e.g., FIG. 1, 116); the layer is leveled
using a leveling mechanism and a material removal mechanism (e.g.,
FIGS. 1, 117 and 118 respectively); an energy beam (e.g., FIG. 1,
101) and/or an energy flux (e.g., FIG. 1, 108) may be directed
towards the target surface to transform at least a portion of the
pre-transformed material to form a transformed material; the
platform is lowered; a new layer of pre-transformed material is
disposed into the material bed; that new layer is leveled and
subsequently irradiated. The process may be repeated sequentially
until the desired 3D object is formed from a successive generation
of layers of transformed material. In some examples, as the layers
of transformed material harden, they may deform upon hardening
(e.g., upon cooling). The methods, systems, apparatuses, and/or
software disclosed herein may control at least one characteristic
of the layer of hardened material (or a portion thereof). The
methods, systems, apparatuses, and/or software disclosed herein may
control the degree of deformation. The control may be an in-situ
control. The control may be control during formation of the at
least a portion of the 3D object. The control may comprise closed
loop control. The portion may be a surface, layer, multiplicity of
layers, portion of a layer, and/or portion of a multiplicity of
layers. The layer of hardened material within the 3D object may
comprise a multiplicity of melt pools. The layers' characteristics
may comprise planarity, curvature, or radius of curvature of the
layer (or a portion thereof). The characteristics may comprise the
thickness of the layer (or a portion thereof). The characteristics
may comprise the smoothness (e.g., planarity) of the layer (or a
portion thereof).
[0130] The methods, systems, apparatuses, and/or software described
herein may comprise providing a first layer of pre-transformed
material (e.g., powder) in an enclosure (e.g., FIG. 1, 126) to form
a material bed comprising a target surface (e.g., the exposed
surface of the material bed). The first layer may be provided on a
substrate or a base. The first layer may be provided on a
previously formed material bed. At least a portion of the first
layer of pre-transformed material may be transformed by using an
energy beam and/or flux (collectively referred to herein as
irradiating energy). For example, an irradiating energy may heat
the at least a portion of the first layer of pre-transformed
material to form a first transformed material. The first
transformed material may comprise a fused material. The methods,
systems, apparatuses, and/or software may further comprise
disposing a second layer of pre-transformed material adjacent to
(e.g., above) the first layer. At least a portion of the second
layer may be transformed (e.g., with the aid of the energy beam) to
form a second transformed material. The second transformed material
may at least in part connect to the first transformed material to
form a multi-layered object (e.g., a 3D object). Connect may
comprise fuse, weld, bond, and/or attach. The first and/or second
layer of transformed material may comprise a first and/or second
layer of hardened material respectively. The first and/or second
layer of transformed material may harden into a first and/or second
layer of hardened material respectively.
[0131] FIG. 6 shows an example of an optical mechanism in a 3D
printing system: an energy source 606 irradiates energy (e.g.,
emits an energy beam) that travels between mirror 605 and mirror
608, that direct it along beam path 607 through an optical window
604 to a position on the exposed surface 602 of a material bed. An
optical window can include a coating (e.g., an anti-reflective
coating) to pass a selected portion of an incident energy source to
form a modified directed energy beam (e.g., along path 603). The
energy that passes through the optical window (e.g., with an
anti-reflective coating) can be measured as one or more
characteristics, which may comprise wavelength, power, amplitude,
flux, footprint, intensity, fluence, energy, or charge. In some
cases, the (e.g., anti-reflective) coating can allow (e.g.,
substantially) all of a selected portion of an incident energy
source to pass therethrough. Substantially all can correspond to at
least about 80%, 85%, 90%, 95%, or 100% of the selected portion of
energy. Substantially all can correspond to between any of the
afore-mentioned values (e.g., from about 80% to about 100%, from
about 80% to about 90%, or from about 90% to about 100% of selected
portion of energy). The energy beam may also be directly projected
on the exposed surface, for example, an energy beam (e.g., 601) can
be generated by an energy source (e.g., 600) (e.g., that may
comprise an internal optical mechanism, such as within a laser) and
be directly projected onto the target surface.
[0132] The hardened material may comprise at least a portion of one
or more (e.g., a few) layers of hardened material disposed above a
pre-transformed material (e.g., powder) disposed in the material
bed. The one or more layers of hardened material may be susceptible
to deformation during formation, or not susceptible to deformation
during formation. The deformation may comprise bending, warping,
arching, curving, twisting, balling, cracking, or dislocating. In
some examples, the at least a portion of the one or more layers of
hardened material may comprise a ledge or a ceiling of a cavity.
The deformation may arise, for example, when the formed 3D object
(or a portion thereof) lacks auxiliary support structure(s). The
deformation may arise, for example, when the formed structure
(e.g., 3D object or a portion thereof) floats anchorless in the
material bed.
[0133] The energy flux may comprise (i) an extended exposure area,
(ii) extended exposure time, (iii) low power density (e.g., power
per unit area) or (iv) an intensity profile that can fill an area
with a flat (e.g., tophead) energy profile.
[0134] The extended exposure time may be at least about 1
millisecond and at most 100 milliseconds. In some embodiments, an
energy profile of the tiling energy source may exclude a Gaussian
beam or round top beam. In some embodiments, an energy profile of
the tiling energy source may include a Gaussian beam or round top
beam. In some embodiments, the 3D printer comprises a first and/or
second scanning energy beams. In some embodiments, an energy
profile of the first and/or second scanning energy may comprise a
Gaussian energy beam. In some embodiments, an energy profile of the
first and/or second scanning energy may exclude a Gaussian energy
beam. The first and/or second scanning energy may have any
cross-sectional shape comprising an ellipse (e.g., circle), or a
polygon (e.g., as disclosed herein). The scanning energy beam may
have a cross section with a diameter of at least about 50
micrometers (.mu.m), 100 .mu.m, 150 .mu.m, 200 .mu.m, or 250 .mu.m.
The scanning energy beam may have a cross section with a diameter
of at most about 60 micrometers (.mu.m), 100 .mu.m, 150 .mu.m, 200
.mu.m, or 250 .mu.m. The scanning energy beam may have a cross
section with a diameter of any value between the aforementioned
values (e.g., from about 50 .mu.m to about 250 .mu.m, from about 50
.mu.m to about 150 .mu.m, or from about 150 .mu.m to about 250
.mu.m). The power density (e.g., power per unit area) of the
scanning energy beam may at least about 10000 W/mm.sup.2, 20000
W/mm.sup.2, 30000 W/mm.sup.2, 50000 W/mm.sup.2, 60000 W/mm.sup.2,
70000 W/mm.sup.2, 80000 W/mm.sup.2, 90000 W/mm.sup.2, or 100000
W/mm.sup.2. The power density of the scanning energy beam may be at
most about 10000 W/mm.sup.2, 20000 W/mm.sup.2, 30000 W/mm.sup.2,
50000 W/mm.sup.2, 60000 W/mm.sup.2, 70000 W/mm.sup.2, 80000
W/mm.sup.2, 90000 W/mm.sup.2, or 100000 W/mm.sup.2. The power
density of the scanning energy beam may be any value between the
aforementioned values (e.g., from about 10000 W/mm.sup.2 to about
100000 W/mm.sup.2, from about 10000 W/mm.sup.2 to about 50000
W/mm.sup.2, or from about 50000 W/mm.sup.2 to about 100000
W/mm.sup.2). The scanning speed of the scanning energy beam may be
at least about 50 millimeters per second (mm/sec), 100 mm/sec, 500
mm/sec, 1000 mm/sec, 2000 mm/sec, 3000 mm/sec, 4000 mm/sec, or
50000 mm/sec. The scanning speed of the scanning energy beam may be
at most about 50 mm/sec, 100 mm/sec, 500 mm/sec, 1000 mm/sec, 2000
mm/sec, 3000 mm/sec, 4000 mm/sec, or 50000 mm/sec. The scanning
speed of the scanning energy beam may any value between the
aforementioned values (e.g., from about 50 mm/sec to about 50000
mm/sec, from about 50 mm/sec to about 3000 mm/sec, or from about
2000 mm/sec to about 50000 mm/sec). The second scanning energy beam
may be continuous or non-continuous (e.g., pulsing). The scanning
energy beam may compensate for heat loss at the edges of the target
surface after the heat tiling process.
[0135] In some embodiments, the tiling energy source may be the
same as the scanning energy source. The tiling energy source may be
different than the scanning energy source. FIG. 1 shows an example
where the tiling energy source 122 is different from the scanning
energy source 121. The energy flux generated by the tiling energy
source may travel through an identical, or a different optical
window than the scanning energy generated by the scanning energy
source. FIG. 1 shows an example where the energy flux 119 (e.g.,
from energy source 122) travels through one optical window 132, and
the (e.g, scanning) energy 101 travels through a second optical
window 115 that is different. The tiling energy source and/or
scanning energy source can be disposed within the enclosure,
outside of the enclosure (e.g., as in FIG. 1), or within at least
one wall of the enclosure. The optical mechanism through which the
energy flux and/or the scanning energy beam travel can be disposed
within the enclosure, outside of the enclosure, or within at least
one wall of the enclosure (e.g., as in FIGS. 1, 132 and 115). In
some embodiments, the optical mechanism is disposed within its own
(optical) enclosure. The optical enclosure may optionally be
coupled with the processing chamber.
[0136] The profile of the energy flux (e.g. beam) may represent the
spatial intensity profile of the energy flux (e.g., beam) at a
particular plane transverse to the beam propagation path. FIG. 8
shows examples of energy flux profiles (e.g., energy as a function
of distance from the center of the energy flux (e.g., beam)).
[0137] The energy flux profile (e.g., energy beam profile) may be
represented as the power or energy of the energy flux plotted as a
function of a distance within its cross section (e.g., that is
perpendicular to its propagation path). The energy flux profile of
the energy flux may be substantially uniform (e.g., homogenous).
The energy flux profile may correspond to the energy flux. The
energy beam profile may correspond to the first scanning energy
beam and/or the second scanning energy beam.
[0138] The system and/or apparatus may comprise an energy profile
alteration device that evens (e.g., is configured to smooth,
planarize or flatten) out any irregularities in the energy flux
profile. The system and/or apparatus may comprise an energy profile
alteration device that creates a more uniform energy flux profile.
The energy profile alteration device may comprise an energy flux
(e.g., beam) homogenizer. The homogenizer can comprise a mirror.
The mirror may be multifaceted. The mirror may comprise square
facets. The mirror may reflect the energy flux at various (e.g.,
different) angles to create a beam with a more uniform power across
at least a portion (e.g., the entire) beam profile (e.g., resulting
in a "top hat" profile), as compared to the original (e.g.,
incoming) energy flux. The energy profile alteration device may
output a substantially evenly distributed power/energy of the
energy flux (e.g., energy flux profile) instead of its original
energy flux profile shape (e.g., Gaussian shape). The energy
profile alteration device may comprise an energy flux profile
shaper (e.g., beam shaper). The energy profile alteration device
may create a certain shape to the energy flux profile. The energy
profile alteration device may spread the central concentrated
energy within the energy flux profile among the energy flux cross
section (e.g., FLS of the energy flux, or FLS of the tile (a.k.a.
"stamp")). The energy profile alteration device may output a grainy
energy flux profile. The energy profile alteration device may
comprise a dispersive, diffusive, or partially transparent glass.
The glass can be a frosted, milky, or murky glass. The energy
profile alteration device may generate a blurry energy flux. The
energy profile alteration device may generate a defocused energy
flux, after which the energy flux that entered the energy profile
alteration device will emerge as an energy flux having a more
homogenized energy flux profile.
[0139] The apparatus and/or systems disclosed herein may include an
optical diffuser. The optical diffuser may diffuse light
substantially homogenously. The optical diffuser may remove high
intensity energy (e.g., light) distribution and form a more even
distribution of light across the footprint of the energy beam
and/or flux. The optical diffuser may reduce the intensity of the
energy beam and/or flux (e.g., act as a screen). For example, the
optical diffuser may alter an energy beam with Gaussian profile, to
an energy beam having a top-hat profile. The optical diffuser may
comprise a diffuser wheel assembly.
[0140] The irradiating energy (e.g., energy beam) may have any of
the energy flux profiles in FIG. 8, wherein the "center" designates
the center of the energy beam footprint on the target surface. In
some embodiments, the "center" designates the center of the energy
beam cross-section. The energy beam (e.g., energy flux) profile may
be substantially uniform. The energy beam profile may comprise a
substantially uniform section. The energy beam profile may deviate
from uniformity. The energy beam profile may be non-uniform. The
energy beam profile may have a shape that facilitates substantially
uniform heating of at least the horizontal cross section of a tile
(e.g., substantially every point within the horizontal cross
section of the tile (e.g., including its rim)). The energy beam
profile may have a shape that facilitates substantially uniform
heating of the melt pools within the tile (e.g., substantially
every melt pool within the tile (e.g., including its rim)). The
energy beam profile may have a shape that facilitates substantially
uniform temperature of at least the horizontal cross section of the
tile (e.g., substantially every point within the horizontal cross
section of the tile (e.g., including its rim)). The energy flux
profile may have a shape that facilitates substantially uniform
temperature of the melt pools within the tile (e.g., substantially
every melt pool within the tile (e.g., including its rim)). The
energy beam profile may have a shape that facilitates formation of
a substantially uniform phase (e.g., solid or liquid) of the tile
(e.g., substantially every point within the tile (e.g., including
its rim)). The energy beam profile may have a shape that
facilitates substantially uniform phase of the melt pools within
(e.g., that form the) the tile (e.g., substantially every melt pool
within the tile (e.g., including its rim)). Substantially uniform
may be substantially similar, even, homogenous, invariable,
consistent, or equal). At times, the tile may comprise a melt
pool.
[0141] The energy beam (e.g., flux) profile of the energy beam
(e.g., flux) may comprise a square shaped beam. In some instances,
the energy beam profile may deviate from a square shaped beam. In
some examples, the energy beam profile may exclude a Gaussian
shaped beam (e.g., FIG. 8, energy beam profile 800 having Gaussian
profile 801). The shape of the beam may be the energy profile of
the beam with respect to a distance from the center. The center can
be a center of the energy footprint, cross section, and/or tile,
which it projects (e.g., through an aperture) onto the target
surface. The energy profile of the energy beam may comprise one or
more planar sections. FIG. 8, 822 shows an example of a planar
section of energy profile 821. FIG. 8, 830 shows an example of a
planar section 832 of energy profile 831. FIG. 8, 840 shows an
example of two planar sections 842 of energy profile 841. The
energy flux profile may comprise of a gradually increasing and/or
decreasing section. FIG. 8, 810 shows an example of an energy
profile 811 comprising a gradually increasing section 812, and a
gradually decreasing section 813. The energy flux profile may
comprise an abruptly increasing and/or decreasing sections. FIG. 8,
820 shows an example of an energy profile 821 comprising an
abruptly increasing section 823 and an abruptly decreasing section
824. The energy flux profile may comprise a section wherein the
energy flux profile deviates from planarity. FIG. 8, 840 shows an
example of an energy profile 841 comprising an energy flux profile
comprising a section 843 that deviates from planarity (e.g., by a
distance "h" of average flux profile 840). The energy flux profile
may comprise a section of fluctuating energy flux. The fluctuation
may deviate from an average planar surface of the energy flux
profile. FIG. 8,850 shows an example of an energy flux profile 851
comprising a fluctuating section 852. The fluctuating section 852
deviates from the average flat surface. The average flat surface
may be measured by the average power of that surface from a
baseline (e.g., FIG. 8, "H" of energy flux profile 850), by a
+/-distance of "h" of energy flux profile 850. The deviation (e.g.,
type and/or amount) from planarity of the energy flux profile may
relate to the temperature of the material bed and/or the target
surface. The deviation (e.g., a percentage of deviation) may be
calculated with respect to an average top surface of the energy
beam profile. The percentage deviation may be calculated according
to the mathematical formula 100*(H-h)/H), where the symbol "*"
designates the mathematical operation "multiplied by." In some
examples, when the material bed is at a temperature of below
500.degree. C., the deviation may be at most 1%, 5%, 10%, 15%, or
20%. In some examples, when the material bed is at a temperature of
below 500.degree. C., the deviation may be by any value between the
aforementioned values (e.g., from about 1% to about 20%, from about
10% to about 20%, or from about 5% to about 15%). When the material
bed is from about 500.degree. C. to below about 1000.degree. C.,
the deviation may be at most 10%, 15%, 20%, 25%, or 30%). When the
material bed is from about 500.degree. C. to below about
1000.degree. C., the deviation may be by any value between the
aforementioned values (e.g., from about 10% to about 30%, from
about 20% to about 30%, or from about 15% to about 25%). When the
material bed is above about 1000.degree. C., the deviation may be
at most 20%, 25%, 30%, 35%, or 40%). When the material bed is of
above about 1000.degree. C., the deviation may be by any value
between the aforementioned values (e.g., from about 20% to about
40%, from about 30% to about 40%, or from about 25% to about 35%).
Below 500.degree. C. comprises ambient temperature, or room
temperature (R.T.). Ambient refers to a condition to which people
are generally accustomed. For example, ambient pressure may be 1
atmosphere. Ambient temperature may be a typical temperature to
which humans are generally accustomed. For example, from about
15.degree. C. to about 30.degree. C., from 16.degree. C. to about
26.degree. C., from about 20.degree. C. to about 25.degree. C.
"Room temperature" may be measured in a confined or in a
non-confined space. For example, "room temperature" can be measured
in a room, an office, a factory, a vehicle, a container, or
outdoors. The vehicle may be a car, a truck, a bus, an airplane, a
space shuttle, a space ship, a ship, a boat, or any other vehicle.
Room temperature may represent the small range of temperatures at
which the atmosphere feels neither hot nor cold, approximately
24.degree. C. it may denote 20.degree. C., 25.degree. C., or any
value from about 20.degree. C. to about 25.degree. C.
[0142] The cross section of the tiling energy flux may comprise a
vector shaped scanning beam (VSB). The energy flux may comprise a
variable energy flux profile shape. The energy flux may comprise a
variable cross-sectional shape. The energy flux may comprise a
substantially non-variable energy flux profile shape. The energy
flux may comprise a substantially non-variable cross-sectional
shape. The energy flux (e.g., VSB) may translate across the target
surface (e.g., directly) to one or more locations specified by
vector coordinates. The energy flux (e.g., VSB) may irradiate once
over those one or more locations. The energy flux (e.g., VSB) may
substantially not irradiate (or irradiated to a considerably lower
extent) once between the locations.
[0143] In some examples, the scanning energy beam may have energy
flux profile characteristics of the energy flux (e.g., as
delineated herein).
[0144] The shape of the energy flux cross section may be the shape
of the energy flux footprint. The shape of the energy flux
footprint may (e.g., substantially) correspond to the sample of a
horizontal cross section of the tile. The shape of the energy flux
cross section (e.g., its circumference, also known as the edge of
its cross section, or beam edge) may substantially exclude a
curvature. The shape of an edge of the energy flux may
substantially comprise non-curved circumference. The shape of the
energy flux edge may comprise non-curved sides on its
circumference. The energy flux edge can comprise a flat top beam
(e.g., a top-hat beam). The energy flux may have a substantially
uniform energy density within its cross section. The beam may have
a substantially uniform fluence within its cross section.
Substantially uniform may be nearly uniform. The beam may be formed
by at least one (e.g., a multiplicity of) diffractive optical
element, lens, deflector, aperture, or any combination thereof. The
energy flux that reaches the target surface may originate from a
Gaussian beam. The target surface may be an exposed surface of the
material bed and/or an exposed surface of a 3D object (or a portion
thereof). The target surface may be an exposed surface of a layer
of hardened material. The energy flux may comprise a beam used in
laser drilling (e.g., of holes in printed circuit boards). The
energy flux may be similar to (e.g., of) the type of energy beam
used in high power laser systems (e.g., which use chains of optical
amplifiers to produce an intense beam). The energy flux may
comprise a shaped energy beam such as a vector shaped beam (VSB).
The energy flux may be similar to (e.g., of) the type used in the
process of generating an electronic chip (e.g., for making the mask
corresponding to the chip).
[0145] The energy source may emit energy flux that may slowly heat
a tile within the exposed surface of a 3D object (e.g., FIG. 1,
106). The tile may correspond to a cross section (e.g., footprint)
of the energy flux. The footprint may be on the target surface. The
radiative energy source may emit radiative energy that may
substantially evenly heat a tile within the target surface (e.g.,
of a 3D object, FIG. 1, 106). Heating may comprise
transforming.
[0146] At least a portion of the material bed can be heated by the
energy source (e.g., of the energy beam and/or tiling energy flux).
The portion of the material bed can be heated to a temperature that
is greater than or equal to a temperature wherein at least a
portion of the pre-transformed material is transformed. For
example, the portion of the material bed can be heated to a
temperature that is greater than or equal to a temperature wherein
at least a portion of the pre-transformed material is transformed
to a liquid state (referred to herein as the liquefying
temperature) at a given pressure (e.g., ambient pressure). The
liquefying temperature can be equal to a liquidus temperature where
the entire material is at a liquid state at a given pressure (e.g.,
ambient). The liquefying temperature of the pre-transformed
material can be the temperature at or above which at least part of
the pre-transformed material transitions from a solid to a liquid
phase at a given pressure (e.g., ambient).
[0147] In some embodiments, the energy beam paths may be heated by
a second (e.g., scanning) energy beam (e.g., an electron beam or a
laser). The second scanning energy beam may the same scanning
energy beam that is used to form the 3D object (e.g., first
scanning energy beam). The second scanning energy beam may a
different scanning energy beam from the one used to form the 3D
object (e.g., first scanning energy beam). The second scanning
energy beam may be generated by a second (e.g., scanning) energy
source. The second scanning energy source may be the same scanning
energy source that is used to generate the first scanning energy
beam, or may be a different energy source. The second energy source
may be the same scanning energy source that is used to generate the
energy flux, or be a different energy source.
[0148] In some embodiments, the scanning energy beam is a
substantially collimated beam. The scanning energy beam may not be
a substantially dispersed and/or diffused beam. The scanning energy
beam may follow a path. The path may form an internal path (e.g.,
vectorial path) within the portions. The scanning energy beam may
irradiate energy on the exposed target surface after the energy
flux irradiated one or more (e.g., all) of the tiles. The scanning
energy beam may heat at least a portion of the heated tile (e.g.,
along a path). The path of the scanning energy beam within the tile
is designated herein as the "internal path" within the tiles. The
internal path within the tiles may be of substantially the same
general shape as the shape of the path-of-tiles (e.g., both sine
waves). The internal path within the tiles may be of a different
general shape than the shape of the path-of-tiles (e.g., vector
lines vs. a sine wave). The path may follow a spiraling shape, or a
random shape (e.g., FIG. 5, 511). The path may be overlapping
(e.g., FIG. 5, 516) or non-overlapping. The path may comprise at
least one overlap. The path may be substantially devoid of overlap
(e.g., FIG. 5, 510).
[0149] The path of the scanning energy beam may comprise a finer
path. The finer path may be an oscillating path. FIG. 4 shows an
example of a path of the scanning energy beam 401. The path 401 is
composed of an oscillating sub-path 402. The oscillating sub path
can be a zigzag or sinusoidal path. The finer path may include or
substantially exclude a curvature.
[0150] The scanning energy beam may travel in a path that comprises
or substantially excludes a curvature. FIG. 5 shows various
examples of paths. The scanning energy beam may travel in each of
these types of paths. The path may substantially exclude a
curvature (e.g., 512-515). The path may include a curvature (e.g.,
510-511). The path may comprise hatching (e.g., 512-515). The
hatching may be directed in the same direction (e.g., 512 or 514).
Every adjacent hatching may be directed in an opposite direction
(e.g., 513 or 515). The hatching may have the same length (e.g.,
514 or 515). The hatching may have varied length (e.g., 512 or
513). The spacing between two adjacent path sections may be
substantially identical (e.g., 510) or non-identical (e.g., 511).
The path may comprise a repetitive feature (e.g., 510), or be
substantially non-repetitive (e.g., 511). The path may comprise
non-overlapping sections (e.g., 510), or overlapping sections
(e.g., 516). The tile may comprise a spiraling progression (e.g.,
516). The non-tiled sections of the target surface may be
irradiated by the scanning energy beam in any of the path types
described herein.
[0151] The heating can be done by the one or more energy sources.
At least two of the energy sources may heat the target surface
(e.g., and form tiles) simultaneously, sequentially, or a
combination thereof. At least two tiles can be heated sequentially.
At least two tiles can be heated substantially simultaneously. The
sequence of heating at least two of the tiles may overlap.
[0152] In some instances, the methods, systems and/or apparatuses
may comprise measuring the temperature and/or the shape of the
transformed (e.g., molten) fraction within the heated area of the
target surface (e.g., a tile). The temperature measurement may
comprise real time temperature measurement. The depth of the
transformed fraction may be estimated (e.g., based on the
temperature measurements). The temperature measurements and/or
estimation of the transformed fraction depth may be used to control
(e.g., regulate and/or direct) the energy irradiated at a
particular portion. Controlling the irradiating energy may comprise
its power, dwell time, or cross section on the exposed surface. The
control may comprise reducing (e.g., halting) the irradiating
energy on reaching a target depth. The dwell time (e.g., exposure
time) may be at least a few tenths of millisecond (e.g., from about
0.1), or at least a few milliseconds (e.g., from about 1 msec). The
exposure time (e.g., dwell time) may be as disclosed herein. The
control may comprise reducing (e.g., halting) the irradiating
energy while taking into account the rate at which the heated
portions cool down. The rate of heating and/or cooling the portions
may afford formation of desired microstructures (e.g., at
particular areas). The desired microstructures may be formed at a
particular area or in the entire layer of hardened material. The
temperature at the heated (e.g., heat tiled) area may be measured
(e.g., visually) (e.g., with a direct or indirect view of the
heated area). The measurement may comprise using a detector (e.g.,
CCD camera, video camera, fiber array coupled to a single pixel
detector, fiber array coupled to a plurality of pixel detectors,
and/or a spectrometer). The visual measurements may comprise using
image processing. The transformation of the heated tile may be
monitored (e.g., visually, and/or spectrally). The shape of the
transforming fraction of the heated area may be monitored (e.g.,
visually, and/or in real-time). The FLS of the transformed(ing)
fraction may be used to indicate the depth and/or volume of the
transformed material (e.g., melt pool). The monitoring (e.g., of
the heat and/or FLS of the transformed fraction within the heated
area) may be used to control one or more parameters of the energy
source, energy flux, energy source, and/or scanning energy beam.
The parameters may comprise (i) the power generated by the tiling
energy source (e.g., energy source of the energy flux) and/or
scanning energy source, (ii) the dwell time of energy flux, or
(iii) the speed of the scanning energy beam.
[0153] The control of the energy (e.g., beam and/or flux) may
comprise substantially ceasing (e.g., stopping) to irradiate the
target area when the temperature at the bottom skin reaches a
target temperature. The control of the energy (e.g., beam and/or
flux) may comprise substantially reducing the energy supplied to
(e.g., injected into) the target area when the temperature at the
bottom skin reached a target temperature. The control of the energy
(e.g., beam and/or flux) may comprise altering the energy profile
of the energy beam and/or flux respectively. The control may be
different (e.g., may vary) for layers that are closer to the bottom
skin layer as compared to layers that are more distant from the
bottom skin layer. The control may comprise turning the energy beam
and/or flux on and off. The control may comprise reducing the power
per unit area, cross section, focus, power, of energy beam and/or
flux. The control may comprise altering a property of the energy
beam and/or flux, which property may comprise the power, power per
unit area, cross section, energy profile, focus, scanning speed,
pulse frequency (when applicable), or dwell time of the energy beam
and/or flux respectively. During the "off" times (e.g.,
intermission), the power and/or power per unit area of the energy
beam and/or flux may be substantially reduced as compared to its
value at the "on" times (e.g., dwell times). During the
intermission, the energy beam and/or flux may relocate away from
the area which was tiled, to a different area in the target surface
that is substantially distant from area which was tiled. During the
dwell times, the energy beam and/or flux may relocate back to the
position adjacent to the area which was just tiled (e.g., as part
of the path-of-tiles).
[0154] The very first formed layer of hardened material in a 3D
object is referred to herein as the "bottom skin." In some
embodiments, the bottom skin layer is the very first layer in an
unsupported portion of a 3D object. The unsupported portion may not
be supported by auxiliary supports. The unsupported portion may be
connected to the center (e.g., core) of the 3D object and may not
be otherwise supported by, or anchored to, the platform. For
example, the unsupported portion may be a hanging structure (e.g.,
a ledge) or a cavity ceiling.
[0155] Cooling the tiles may comprise introducing a cooling member
(e.g., heat sink) to the heated area. FIG. 1 shows an example of an
optional cooling member (e.g., heat sink 113) that is disposed
above the exposed (e.g., top) surface 131 of the target surface
(e.g., material bed) 104. The cooling member may be translatable
vertically, horizontally, or at an angle (e.g., planar or
compound). The translation may be controlled manually and/or by a
controller. The cooling member may be operatively coupled to the
controller. The first energy source (e.g., for energy flux, e.g.,
FIG. 1, 122), the second (e.g., scanning) energy source, and/or the
cooling member may be translatable vertically, horizontally, or at
an angle (e.g., planar or compound). The translation may be
controlled manually and/or by a controller. The energy source for
energy flux, first scanning energy source, and/or second scanning
energy source may be operatively coupled to the controller. The
cooling member may control (e.g., prevent) accumulation of heat in
certain portions of the exposed 3D object (e.g., exposed layer of
hardened material). Heating a tile in a particular area of the
target surface may control (e.g., regulate) accumulation of heat in
certain portions of the exposed 3D object (e.g., exposed layer of
hardened material).
[0156] The control may be closed loop control, or an open loop
control (e.g., based on energy calculations comprising an
algorithm). The closed loop control may comprise feed-back or
feed-forward control. The algorithm may take into account one or
more temperature measurements (e.g., as disclosed herein),
metrological measurements, geometry of at least part of the 3D
object, heat depletion/conductance profile of at least part of the
3D object. The controller may modulate the irradiative energy
and/or the energy beam. The algorithm may take into account
pre-correction of an object (i.e., object pre-print correction,
OPC) to compensate for any distortion of the final 3D object. The
algorithm may comprise instructions to form a correctively deformed
object. The algorithm may comprise modification applied to the
model of a desired 3D object. Examples of modifications (e.g.,
corrective deformations) can be found in Patent Application Serial
No. PCT/US16/34857 filed on May 27, 2016, titled "THREE-DIMENSIONAL
PRINTING AND THREE-DIMENSIONAL OBJECTS FORMED USING THE SAME" or in
U.S. Provisional Patent Application Ser. No. 62/239,805, titled
"SYSTEMS, APPARATUSES AND METHODS FOR THREE-DIMENSIONAL PRINTING,
AS WELL AS THREE-DIMENSIONAL OBJECTS" that was filed on Oct. 9,
2015, both of which are entirely incorporated herein by reference.
The control may be any control disclosed in U.S. Provisional Patent
Application Ser. No. 62/401,534 filed on Sep. 29, 2016, titled
"ACCURATE THREE-DIMENSIONAL PRINTING", that is incorporated herein
by reference in its entirety.
[0157] The methods for generating one or more 3D objects described
herein may comprise: depositing a layer of pre-transformed material
(e.g., powder) in an enclosure; providing energy to a portion of
the layer of material (e.g., according to a path); transforming at
least a section of the portion of the layer of material to form a
transformed material by utilizing the energy; optionally allowing
the transformed material to harden into a hardened material; and
optionally repeating steps a) to d) to generate the one or more 3D
objects. The enclosure may comprise a platform (e.g., a substrate
and/or base). The enclosure may comprise a container. The 3D object
may be printed adjacent to (e.g., above) the platform. The
pre-transformed material may be deposited in the enclosure by a
material dispensing system to form a layer of pre-transformed
material within the enclosure. The deposited material may be
leveled by a leveling mechanism. The deposition of pre-transformed
material in the enclosure may form a material bed, or be deposited
on a platform. The leveling mechanism may comprise a leveling step
where the leveling mechanism does not contact the exposed surface
of the material (e.g., powder) bed. The material dispensing system
may comprise one or more dispensers. The material dispensing system
may comprise at least one material (e.g., bulk) reservoir. The
material may be deposited by a layer dispensing mechanism (e.g.,
recoater). The layer dispensing mechanism may level the dispensed
material without contacting the powder bed (e.g., the top surface
of the powder bed). The layer dispensing mechanism may include any
layer dispensing mechanism, material removal mechanism, and/or
powder dispensing mechanism that are disclosed in Patent
Application Serial No. PCT/US15/36802 that is incorporated herein
by reference in its entirety. The layer dispensing mechanism may
comprise a material dispensing mechanism, material leveling
mechanism, material removal mechanism, or any combination
thereof.
[0158] The system, apparatuses and/or method may comprise a layer
dispensing mechanism (e.g., recoater) that dispenses a layer of
pre-transformed (e.g., powder) material comprising an exposed
surface that is substantially planar. The layer dispensing
mechanism can be any layer dispensing mechanism disclosed in Patent
Application Serial No. PCT/US15/36802, which is incorporated herein
by reference in its entirety. FIG. 1 shows an example of a layer
dispensing mechanism comprising a material dispensing mechanism
116, a leveling mechanism 117, and a material removal mechanism 118
(The white arrows in 116 and 118 designate the direction in which
the pre-transformed material flows into/out of the material bed
(e.g., 104).
[0159] The 3D object may be subsequently cleaned and/or cooled
within the enclosure, and/or exit the enclosure through an exit.
The cleaning may comprise using gas pressure, vibrations, and/or
surface friction (e.g., brush). The cleaning may comprise a post
processing procedure as disclosed in Patent Application Serial No.
PCT/US15/36802, which is incorporated herein by reference in its
entirety.
[0160] The three-dimensional object can be devoid of surface
features that are indicative of the use of a post printing process.
The post printing process may comprise a trimming process (e.g., to
trim auxiliary supports). The trimming process may be an operation
conducted after the completion of the 3D printing process. The
trimming process may be a separate operation from the 3D printing
process. The trimming may comprise cutting (e.g., using a piercing
saw). The trimming can comprise polishing or blasting. The blasting
can comprise solid blasting, gas blasting, or liquid blasting. The
solid blasting can comprise sand blasting. The gas blasting can
comprise air blasting. The liquid blasting can comprise water
blasting. The blasting can comprise mechanical blasting.
[0161] The layered structure can be a substantially repetitive
layered structure. Each layer of the layered structure has an
average layer thickness greater than or equal to about 5
micrometers (.mu.m). Each layer of the layered structure has an
average layer thickness less than or equal to about 1000
micrometers (.mu.m). The layered structure can comprise individual
layers of the successive solidified melt pools. A given one of the
successive solidified melt pools can comprise a substantially
repetitive material variation selected from the group consisting of
variation in grain orientation, variation in material density,
variation in the degree of compound segregation to grain
boundaries, variation in the degree of element segregation to grain
boundaries, variation in material phase, variation in metallurgical
phase, variation in material porosity, variation in crystal phase,
and variation in crystal structure. A given one of the successive
solidified melt pools can comprise a crystal. The crystal can
comprise a single crystal. The layered structure can comprise one
or more features indicative of solidification of melt pools during
the three-dimensional printing process. The layered structure can
comprise a feature indicative of the use of the 3D printing
process. A fundamental length scale of the three-dimensional object
can be at least about 120 micrometers.
[0162] The layer of hardened material layer (or a portion thereof)
can have a thickness (e.g., layer height) of at least about 50
.mu.m, 100 .mu.m, 150 .mu.m, 200 .mu.m, 300 .mu.m, 400 .mu.m, 500
.mu.m, 600 .mu.m, 700 .mu.m, 800 .mu.m, 900 .mu.m, or 1000 .mu.m. A
hardened material layer (or a portion thereof) can have a thickness
of at most about 1000 .mu.m, 900 .mu.m, 800 .mu.m, 700 .mu.m, 60
.mu.m, 500 .mu.m, 450 .mu.m, 400 .mu.m, 350 .mu.m, 300 .mu.m, 250
.mu.m, 200 .mu.m, 150 .mu.m, 100 .mu.m, 75 .mu.m, or 50 .mu.m. A
hardened material layer (or a portion thereof) may have any value
in between the aforementioned layer thickness values (e.g., from
about 50 .mu.m to about 1000 .mu.m, from about 500 .mu.m to about
800 .mu.m, from about 300 .mu.m to about 600 .mu.m, from about 300
.mu.m to about 900 .mu.m, or from about 50 .mu.m to about 200
.mu.m).
[0163] In some instances, one, two, or more 3D objects may be
generated in a material bed (e.g., a single material bed; the same
material bed). The multiplicity of 3D object may be generated in
the material bed simultaneously or sequentially. At least two 3D
objects may be generated side by side. At least two 3D objects may
be generated one on top of the other. At least two 3D objects
generated in the material bed may have a gap between them (e.g.,
gap filled with pre-transformed material). At least two 3D objects
generated in the material bed may contact (e.g., not connect to)
each other. In some embodiments, the 3D objects may be
independently built one above the other. The generation of a
multiplicity of 3D objects in the material bed may allow continuous
creation of 3D objects.
[0164] The material (e.g., pre-transformed material, transformed
material, or hardened material) may comprise elemental metal, metal
alloy, ceramics, or an allotrope of elemental carbon. The allotrope
of elemental carbon may comprise amorphous carbon, graphite,
graphene, diamond, or fullerene. The fullerene may be selected from
the group consisting of a spherical, elliptical, linear, and
tubular fullerene. The fullerene may comprise a buckyball or a
carbon nanotube. The ceramic material may comprise cement. The
ceramic material may comprise alumina. The material may comprise
sand, glass, or stone. In some embodiments, the material may
comprise an organic material, for example, a polymer or a resin.
The organic material may comprise a hydrocarbon. The polymer may
comprise styrene. The organic material may comprise carbon and
hydrogen atoms. The organic material may comprise carbon and oxygen
atoms. The organic material may comprise carbon and nitrogen atoms.
The organic material may comprise carbon and sulfur atoms. In some
embodiments, the material may exclude an organic material. The
material may comprise a solid or a liquid. In some embodiments, the
material may comprise a silicon-based material, for example,
silicon based polymer or a resin. The material may comprise an
organosilicon-based material. The material may comprise silicon and
hydrogen atoms. The material may comprise silicon and carbon atoms.
In some embodiments, the material may exclude a silicon-based
material. The solid material may comprise powder material. The
powder material may be coated by a coating (e.g., organic coating
such as the organic material (e.g., plastic coating)). The material
may be devoid of organic material. The liquid material may be
compartmentalized into reactors, vesicles, or droplets. The
compartmentalized material may be compartmentalized in one or more
layers. The material may be a composite material comprising a
secondary material. The secondary material can be a reinforcing
material (e.g., a material that forms a fiber). The reinforcing
material may comprise a carbon fiber, Kevlar.RTM., Twaron.RTM.,
ultra-high-molecular-weight polyethylene, or glass fiber. The
material can comprise powder (e.g., granular material) or wires.
The material may comprise Carbon black, or glass (e.g., a fiber
thereof). The material may exclude (e.g., be devoid of) a polymer
and/or resin. The material may exclude (e.g., be devoid of) a
binder or a tacky material.
[0165] The material may comprise a powder material. The material
may comprise a solid material. The material may comprise one or
more particles or clusters. The term "powder," as used herein,
generally refers to a solid having fine particles. The powder may
also be referred to as "particulate material." Powders may be
granular materials. The powder particles may comprise micro
particles. The powder particles may comprise nanoparticles. In some
examples, a powder comprising particles having an average
fundamental length scale of at least about 5 nanometers (nm), 10
nm, 20 nm, 30 nm, 40 nm, 50 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500
nm, 1 .mu.m, 5 .mu.m, 10 .mu.m, 15 .mu.m, 20 .mu.m, 25 .mu.m, 30
.mu.m, 35 .mu.m, 40 .mu.m, 45 .mu.m, 50 .mu.m, 55 .mu.m, 60 .mu.m,
65 .mu.m, 70 .mu.m, 75 .mu.m, 80 .mu.m, or 100 .mu.m. The particles
comprising the powder may have an average fundamental length scale
of at most about 100 .mu.m, 80 .mu.m, 75 .mu.m, 70 .mu.m, 65 .mu.m,
60 .mu.m, 55 .mu.m, 50 .mu.m, 45 .mu.m, 40 .mu.m, 35 .mu.m, 30
.mu.m, 25 .mu.m, 20 .mu.m, 15 .mu.m, 10 .mu.m, 5 .mu.m, 1 .mu.m,
500 nm, 400 nm, 300 nm, 200 nm, 100 nm, 50 nm, 40 nm, 30 nm, 20 nm,
10 nm, or 5 nm. In some cases, the powder may have an average
fundamental length scale between any of the values of the average
particle fundamental length scale listed above (e.g., from about 5
nm to about 100 .mu.m, from about 1 .mu.m to about 100 .mu.m, from
about 15 .mu.m to about 45 .mu.m, from about 5 .mu.m to about 80
.mu.m, from about 20 .mu.m to about 80 .mu.m, or from about 500 nm
to about 50 .mu.m).
[0166] The powder can be composed of individual particles. The
individual particles can be spherical, oval, prismatic, cubic, or
irregularly shaped. The particles can have a fundamental length
scale. The powder can be composed of a homogenously shaped particle
mixture such that all of the particles have substantially the same
shape and fundamental length scale magnitude within at most 1%, 5%,
8%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 50%, 60%, or 70%,
distribution of fundamental length scale. In some cases, the powder
can be a heterogeneous mixture such that the particles have
variable shape and/or fundamental length scale magnitude.
[0167] At least parts of the layer can be transformed to a
transformed material that may subsequently form at least a fraction
(also used herein "a portion," or "a part") of a hardened (e.g.,
solidified) 3D object. At times a layer of transformed or hardened
material may comprise a cross section of a 3D object (e.g., a
horizontal cross section). At times a layer of transformed or
hardened material may comprise a deviation from a cross section of
a 3D object. The deviation may include vertical or horizontal
deviation. A pre-transformed material may be a powder material. A
pre-transformed material layer (or a portion thereof) can have a
thickness (e.g., layer height) of at least about 0.1 micrometer
(.mu.m), 0.5 .mu.m, 1.0 .mu.m, 10 .mu.m, 50 .mu.m, 100 .mu.m, 150
.mu.m, 200 .mu.m, 300 .mu.m, 400 .mu.m, 500 .mu.m, 600 .mu.m, 700
.mu.m, 800 .mu.m, 900 .mu.m, or 1000 .mu.m. A pre-transformed
material layer (or a portion thereof) can have a thickness of at
most about 1000 .mu.m, 900 .mu.m, 800 .mu.m, 700 .mu.m, 60 .mu.m,
500 .mu.m, 450 .mu.m, 400 .mu.m, 350 .mu.m, 300 .mu.m, 250 .mu.m,
200 .mu.m, 150 .mu.m, 100 .mu.m, 75 .mu.m, 50 .mu.m, 40 .mu.m, 30
.mu.m, 20 .mu.m, 10 .mu.m, 5 .mu.m, or 0.5 .mu.m. A pre-transformed
material layer (or a portion thereof) may have any value in between
the aforementioned layer thickness values (e.g., from about 0.1
.mu.m to about 1000 .mu.m, from about 1 .mu.m to about 800 .mu.m,
from about 20 .mu.m to about 600 .mu.m, from about 30 .mu.m to
about 300 .mu.m, or from about 10 .mu.m to about 1000 .mu.m).
[0168] The material composition of at least one layer within the
material bed may differ from the material composition within at
least one other layer in the material bed. The difference (e.g.,
variation) may comprise difference in crystal or grain structure.
The variation may comprise variation in grain orientation,
variation in material density, variation in the degree of compound
segregation to grain boundaries, variation in the degree of element
segregation to grain boundaries, variation in material phase,
variation in metallurgical phase, variation in material porosity,
variation in crystal phase, or variation in crystal structure. The
microstructure of the printed object may comprise planar structure,
cellular structure, columnar dendritic structure, or equiaxed
dendritic structure.
[0169] The pre-transformed materials of at least one layer in the
material bed may differ in the FLS of its particles (e.g., powder
particles) from the FLS of the pre-transformed material within at
least one other layer in the material bed. A layer may comprise two
or more material types at any combination. For example, two or more
elemental metals, two or more metal alloys, two or more ceramics,
two or more allotropes of elemental carbon. For example, an
elemental metal and a metal alloy, an elemental metal and a
ceramic, an elemental metal and an allotrope of elemental carbon, a
metal alloy and a ceramic, a metal alloy, and an allotrope of
elemental carbon, a ceramic and an allotrope of elemental carbon.
All the layers of pre-transformed material deposited during the 3D
printing process may be of the same material composition. In some
instances, a metal alloy is formed in situ during the process of
transforming at least a portion of the material bed. In some
instances, a metal alloy is not formed in situ during the process
of transforming at least a portion of the material bed. In some
instances, a metal alloy is formed prior to the process of
transforming at least a portion of the material bed. In a
multiplicity (e.g., mixture) of pre-transformed (e.g., powder)
materials, one pre-transformed material may be used as support
(e.g., supportive powder), as an insulator, as a cooling member
(e.g., heat sink), or as any combination thereof.
[0170] In some instances, adjacent components in the material bed
are separated from one another by one or more intervening layers.
In an example, a first layer is adjacent to a second layer when the
first layer is in direct contact with the second layer. In another
example, a first layer is adjacent to a second layer when the first
layer is separated from the second layer by at least one layer
(e.g., a third layer). The intervening layer may be of any layer
size disclosed herein.
[0171] The pre-transformed material (e.g., powder material) can be
chosen such that the material is the desired and/or otherwise
predetermined material for the 3D object. In some cases, a layer of
the 3D object comprises a single type of material. In some
examples, a layer of the 3D object may comprise a single elemental
metal type, or a single metal alloy type. In some examples, a layer
within the 3D object may comprise several types of material (e.g.,
an elemental metal and an alloy, an alloy and a ceramic, an alloy,
and an allotrope of elemental carbon). In certain embodiments, each
type of material comprises only a single member of that type. For
example: a single member of elemental metal (e.g., iron), a single
member of metal alloy (e.g., stainless steel), a single member of
ceramic material (e.g., silicon carbide or tungsten carbide), or a
single member (e.g., an allotrope) of elemental carbon (e.g.,
graphite). In some cases, a layer of the 3D object comprises more
than one type of material. In some cases, a layer of the 3D object
comprises more than one member of a material type.
[0172] The elemental metal can be an alkali metal, an alkaline
earth metal, a transition metal, a rare earth element metal, or
another metal. The alkali metal can be Lithium, Sodium, Potassium,
Rubidium, Cesium, or Francium. The alkali earth metal can be
Beryllium, Magnesium, Calcium, Strontium, Barium, or Radium. The
transition metal can be Scandium, Titanium, Vanadium, Chromium,
Manganese, Iron, Cobalt, Nickel, Copper, Zinc, Yttrium, Zirconium,
Platinum, Gold, Rutherfordium, Dubnium, Seaborgium, Bohrium,
Hassium, Meitnerium, Ununbium, Niobium, Iridium, Molybdenum,
Technetium, Ruthenium, Rhodium, Palladium, Silver, Cadmium,
Hafnium, Tantalum, Tungsten, Rhenium, or Osmium. The transition
metal can be mercury. The rare earth metal can be a lanthanide, or
an actinide. The lanthanide metal can be Lanthanum, Cerium,
Praseodymium, Neodymium, Promethium, Samarium, Europium,
Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium,
Ytterbium, or Lutetium. The actinide metal can be Actinium,
Thorium, Protactinium, Uranium, Neptunium, Plutonium, Americium,
Curium, Berkelium, Californium, Einsteinium, Fermium, Mendelevium,
Nobelium, or Lawrencium. The other metal can be Aluminum, Gallium,
Indium, Tin, Thallium, Lead, or Bismuth.
[0173] The metal alloy can be an iron based alloy, nickel based
alloy, cobalt based alloy, chrome based alloy, cobalt chrome based
alloy, titanium based alloy, magnesium based alloy, copper based
alloy, or any combination thereof. The alloy may comprise an
oxidation or corrosion resistant alloy. The alloy may comprise a
super alloy (e.g., Inconel). The super alloy may comprise Inconel
600, 617, 625, 690, 718, or X-750. The metal (e.g., alloy or
elemental) may comprise an alloy used for applications in
industries comprising aerospace (e.g., aerospace super alloys), jet
engine, missile, automotive, marine, locomotive, satellite,
defense, oil & gas, energy generation, semiconductor, fashion,
construction, agriculture, printing, or medical. The metal (e.g.,
alloy or elemental) may comprise an alloy used for products
comprising, devices, medical devices (human & veterinary),
machinery, cell phones, semiconductor equipment, generators,
engines, pistons, electronics (e.g., circuits), electronic
equipment, agriculture equipment, motor, gear, transmission,
communication equipment, computing equipment (e.g., laptop, cell
phone, tablet), air conditioning, generators, furniture, musical
equipment, art, jewelry, cooking equipment, or sport gear. The
metal (e.g., alloy or elemental) may comprise an alloy used for
products for human or veterinary applications comprising implants,
or prosthetics. The metal alloy may comprise an alloy used for
applications in the fields comprising human or veterinary surgery,
implants (e.g., dental), or prosthetics.
[0174] The alloy may include a superalloy. The alloy may include a
high-performance alloy. The alloy may include an alloy exhibiting
at least one of excellent mechanical strength, resistance to
thermal creep deformation, good surface stability, resistance to
corrosion, and resistance to oxidation. The alloy may include a
face-centered cubic austenitic crystal structure. The alloy may
comprise Hastelloy, Inconel, Waspaloy, Rene alloy (e.g., Rene-80,
Rene-77, Rene-220, or Rene-41), Haynes alloy (e.g., Haynes 282),
Incoloy, MP98T, TMS alloy, MTEK (e.g., MTEK grade MAR-M-247,
MAR-M-509, MAR-M-R41, or MAR-M-X-45), or CMSX (e.g., CMSX-3, or
CMSX-4). The alloy can be a single crystal alloy.
[0175] In some instances, the iron alloy comprises Elinvar,
Fernico, Ferroalloys, Invar, Iron hydride, Kovar, Spiegeleisen,
Staballoy (stainless steel), or Steel. In some instances, the metal
alloy is steel. The Ferroalloy may comprise Ferroboron,
Ferrocerium, Ferrochrome, Ferromagnesium, Ferromanganese,
Ferromolybdenum, Ferronickel, Ferrophosphorus, Ferrosilicon,
Ferrotitanium, Ferrouranium, or Ferrovanadium. The iron alloy may
include cast iron, or pig iron. The steel may include Bulat steel,
Chromoly, Crucible steel, Damascus steel, Hadfield steel, High
speed steel, HSLA steel, Maraging steel, Maraging steel (M300),
Reynolds 531, Silicon steel, Spring steel, Stainless steel, Tool
steel, Weathering steel, or Wootz steel. The high-speed steel may
include Mushet steel. The stainless steel may include AL-6XN, Alloy
20, celestrium, marine grade stainless, Martensitic stainless
steel, surgical stainless steel, or Zeron 100. The tool steel may
include Silver steel. The steel may comprise stainless steel,
Nickel steel, Nickel-chromium steel, Molybdenum steel, Chromium
steel, Chromium-vanadium steel, Tungsten steel,
Nickel-chromium-molybdenum steel, or Silicon-manganese steel. The
steel may be comprised of any Society of Automotive Engineers (SAE)
grade such as 440F, 410, 312, 430, 440A, 440B, 440C, 304, 305,
304L, 304L, 301, 304LN, 301LN, 2304, 316, 316L, 316LN, 317L, 2205,
409, 904L, 321, 254SMO, 316Ti, 321H, 17-4, 15-5, 420 or 304H. The
steel may comprise stainless steel of at least one crystalline
structure selected from the group consisting of austenitic,
superaustenitic, ferritic, martensitic, duplex, and
precipitation-hardening martensitic. Duplex stainless steel may be
lean duplex, standard duplex, super duplex, or hyper duplex. The
stainless steel may comprise surgical grade stainless steel (e.g.,
austenitic 316, martensitic 420, or martensitic 440). The
austenitic 316 stainless steel may include 316L, or 316LVM. The
steel may include 17-4 Precipitation Hardening steel (also known as
type 630, a chromium-copper precipitation hardening stainless
steel, 17-4PH steel).
[0176] The titanium-based alloys may include alpha alloys, near
alpha alloys, alpha and beta alloys, or beta alloys. The titanium
alloy may comprise grade 1, 2, 2H, 3, 4, 5, 6, 7, 7H, 8, 9, 10, 11,
12, 13, 14, 15, 16, 16H, 17, 18, 19, 20, 21, 2, 23, 24, 25, 26,
26H, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, or higher. In
some instances, the titanium base alloy includes Ti-6Al-4V or
Ti-6Al-7Nb.
[0177] The Nickel alloy may include Alnico, Alumel, Chromel,
Cupronickel, Ferronickel, German silver, Hastelloy, Inconel, Monel
metal, Nichrome, Nickel-carbon, Nicrosil, Nisil, Nitinol,
Hastelloy-X, Cobalt-Chromium or Magnetically "soft" alloys. The
magnetically "soft" alloys may comprise Mu-metal, Permalloy,
Supermalloy, or Brass. The brass may include Nickel hydride,
Stainless or Coin silver. The cobalt alloy may include Megallium,
Stellite (e.g. Talonite), Ultimet, or Vitallium. The chromium alloy
may include chromium hydroxide, or Nichrome.
[0178] The aluminum alloy may include AA-8000, Al--Li
(aluminum-lithium), Alnico, Duralumin, Hiduminium, Kryron
Magnalium, Nambe, Scandium-aluminum, or Y alloy. The magnesium
alloy may be Elektron, Magnox, or T-Mg--Al--Zn (Bergman phase)
alloy.
[0179] The copper alloy may comprise Arsenical copper, Beryllium
copper, Billon, Brass, Bronze, Constantan, Copper hydride,
Copper-tungsten, Corinthian bronze, Cunife, Cupronickel, Cymbal
alloys, Devarda's alloy, Electrum, Hepatizon, Heusler alloy,
Manganin, Molybdochalkos, Nickel silver, Nordic gold, Shakudo, or
Tumbaga. The Brass may include Calamine brass, Chinese silver,
Dutch metal, Gilding metal, Muntz metal, Pinchbeck, Prince's metal,
or Tombac. The Bronze may include Aluminum bronze, Arsenical
bronze, Bell metal, Florentine bronze, Guanin, Gunmetal, Glucydur,
Phosphor bronze, Ormolu, or Speculum metal. The copper alloy may be
a high-temperature copper alloy (e.g., GRCop-84).
[0180] The metal alloys can be Refractory Alloys. The refractory
metals and alloys may be used for heat coils, heat exchangers,
furnace components, or welding electrodes. The Refractory Alloys
may comprise a high melting points, low coefficient of expansion,
mechanically strong, low vapor pressure at elevated temperatures,
high thermal conductivity, or high electrical conductivity.
[0181] In some examples the material (e.g., powder material)
comprises a material wherein its constituents (e.g., atoms or
molecules) readily lose their outer shell electrons, resulting in a
free-flowing cloud of electrons within their otherwise solid
arrangement. In some examples the material is characterized in
having high electrical conductivity, low electrical resistivity,
high thermal conductivity, or high density (e.g., as measured at
ambient temperature (e.g., R.T., or 20.degree. C.)). The high
electrical conductivity can be at least about 1*10.sup.5 Siemens
per meter (S/m), 5*10.sup.5 S/m, 1*10.sup.6 S/m, 5*10.sup.6 S/m,
1*10.sup.7 S/m, 5*10.sup.7 S/m, or 1*10.sup.8 S/m. The symbol "*"
designates the mathematical operation "times," or "multiplied by."
The high electrical conductivity can be any value between the
aforementioned electrical conductivity values (e.g., from about
1*10.sup.5 S/m to about 1*10.sup.8 S/m). The low electrical
resistivity may be at most about 1*10.sup.-5 ohm times meter
(.OMEGA.*m), 5.10.sup.-6 .OMEGA.*m, 1.10.sup.-6 .OMEGA.*m,
5*10.sup.-7 .OMEGA.*m, 1*10.sup.-7 .OMEGA.*m, 5*10.sup.-8, or
1*10.sup.-8 .OMEGA.*m. The low electrical resistivity can be any
value between the aforementioned electrical resistivity values
(e.g., from about 1.times.10.sup.-5 .OMEGA.*m to about
1.times.10.sup.-8 .OMEGA.*m). The high thermal conductivity may be
at least about 20 Watts per meters times degrees Kelvin (W/mK), 50
W/mK, 100 W/mK, 150 W/mK, 200 W/mK, 205 W/mK, 300 W/mK, 350 W/mK,
400 W/mK, 450 W/mK, 500 W/mK, 550 W/mK, 600 W/mK, 700 W/mK, 800
W/mK, 900 W/mK, or 1000 W/mK. The high thermal conductivity can be
any value between the aforementioned thermal conductivity values
(e.g., from about 20 W/mK to about 1000 W/mK). The high density may
be at least about 1.5 grams per cubic centimeter (g/cm.sup.3), 2
g/cm.sup.3, 3 g/cm.sup.3, 4 g/cm.sup.3, 5 g/cm.sup.3, 6 g/cm.sup.3,
7 g/cm.sup.3, 8 g/cm.sup.3, 9 g/cm.sup.3, 10 g/cm.sup.3, 11
g/cm.sup.3, 12 g/cm.sup.3, 13 g/cm.sup.3, 14 g/cm.sup.3, 15
g/cm.sup.3, 16 g/cm.sup.3, 17 g/cm.sup.3, 18 g/cm.sup.3, 19
g/cm.sup.3, 20 g/cm.sup.3, or 25 g/cm.sup.3. The high density can
be any value between the aforementioned density values (e.g., from
about 1 g/cm.sup.3 to about 25 g/cm.sup.3).
[0182] A metallic material (e.g., elemental metal or metal alloy)
can comprise small amounts of non-metallic materials, such as, for
example, oxygen, sulfur, or nitrogen. In some cases, the metallic
material can comprise the non-metallic material in a trace amount.
A trace amount can be at most about 100000 parts per million (ppm),
10000 ppm, 1000 ppm, 500 ppm, 400 ppm, 200 ppm, 100 ppm, 50 ppm, 10
ppm, 5 ppm, or 1 ppm (on the basis of weight, w/w) of non-metallic
material. A trace amount can comprise at least about 10 ppt, 100
ppt, 1 ppb, 5 ppb, 10 ppb, 50 ppb, 100 ppb, 200 ppb, 400 ppb, 500
ppb, 1000 ppb, 1 ppm, 10 ppm, 100 ppm, 500 ppm, 1000 ppm, or 10000
ppm (on the basis of weight, w/w) of non-metallic material. A trace
amount can be any value between the afore-mentioned trace amounts
(e.g., from about 10 parts per trillion (ppt) to about 100000 ppm,
from about 1 ppb to about 100000 ppm, from about 1 ppm to about
10000 ppm, or from about 1 ppb to about 1000 ppm).
[0183] The one or more layers within the 3D object may be
substantially planar (e.g., flat). The planarity of the layer may
be substantially uniform. The height of the layer at a particular
position may be compared to an average plane. The average plane may
be defined by a least squares planar fit of the top-most part of
the surface of the layer of hardened material. The average plane
may be a plane calculated by averaging the material height at each
point on the top surface of the layer of hardened material. The
deviation from any point at the surface of the planar layer of
hardened material may be at most 20% 15%, 10%, 5%, 3%, 1%, or 0.5%
of the height (e.g., thickness) of the layer of hardened material.
The substantially planar one or more layers may have a large radius
of curvature. FIG. 10 shows an example of a vertical cross section
of a 3D object 1012 comprising planar layers (layers numbers 1-4)
and non-planar layers (e.g., layers numbers 5-6) that have a radius
of curvature. The curvature can be positive or negative with
respect to the platform and/or the exposed surface of the material
bed. For example, layered structure 1012 comprises layer number 6
that has a curvature that is negative, as the volume (e.g., area in
a vertical cross section of the volume) bound from the bottom of it
to the platform 1018 is a convex object 1019. Layer number 5 of
1012 has a curvature that is negative. Layer number 6 of 1012 has a
curvature that is more negative (e.g., has a curvature of greater
negative value) than layer number 5 of 1012. Layer number 4 of 1012
has a curvature that is (e.g., substantially) zero. Layer number 6
of 1014 has a curvature that is positive. Layer number 6 of 1012
has a curvature that is more negative than layer number 5 of 1012,
layer number 4 of 1012, and layer number 6 of 1014. Layer numbers
1-6 of 1013 are of substantially uniform (e.g., negative
curvature). FIGS. 10, 1016 and 1017 are super-positions of curved
layer on a circle 1015 having a radius of curvature "r." The one or
more layers may have a radius of curvature equal to the radius of
curvature of the layer surface. The radius of curvature may equal
infinity (e.g., when the layer is flat). The radius of curvature of
the layer surface (e.g., all the layers of the 3D object) may have
a value of at least about 0.1 centimeter (cm), 0.2 cm, 0.3 cm, 0.4
cm, 0.5 cm, 0.6 cm, 0.7 cm, 0.8 cm, 0.9 cm, 1 cm, 5 cm, 10 cm, 20
cm, 30 cm, 40 cm, 50 cm, 60 cm, 70 cm, 80 cm, 90 cm, 1 meter (m),
1.5 m, 2 m, 2.5 m, 3 m, 3.5 m, 4 m, 4.5 m, 5 m, 10 m, 15 m, 20 m,
25 m, 30 m, 50 m, or 100 m. The radius of curvature of the layer
surface (e.g., all the layers of the 3D object) may have a value of
at most about 0.1 centimeter (cm), 0.2 cm, 0.3 cm, 0.4 cm, 0.5 cm,
0.6 cm, 0.7 cm, 0.8 cm, 0.9 cm, 1 cm, 5 cm, 10 cm, 20 cm, 30 cm, 40
cm, 50 cm, 60 cm, 70 cm, 80 cm, 90 cm, 1 meter (m), 1.5 m, 2 m, 2.5
m, 3 m, 3.5 m, 4 m, 4.5 m, 5 m, 10 m, 15 m, 20 m, 25 m, 30 m, 50 m,
100 m, or infinity (i.e., flat, or planar layer). The radius of
curvature of the layer surface (e.g., all the layers of the 3D
object) may have any value between any of the afore-mentioned
values of the radius of curvature (e.g., from about 10 cm to about
90 m, from about 50 cm to about 10 m, from about 5 cm to about 1 m,
from about 50 cm to about 5 m, from about 5 cm to infinity, or from
about 40 cm to about 50 m). In some embodiments, a layer with an
infinite radius of curvature is a layer that is planar. In some
examples, the one or more layers may be included in a planar
section of the 3D object, or may be a planar 3D object (e.g., a
flat plane). In some instances, part of at least one layer within
the 3D object has the radius of curvature mentioned herein.
[0184] The 3D object may comprise a layering plane N of the layered
structure. The 3D object may comprise points X and Y, which reside
on the surface of the 3D object, wherein X is spaced apart from Y
by at least about 10.5 millimeters or more. FIG. 11 shows an
example of points X and Y on the surface of a 3D object. In some
embodiments, X is spaced apart from Y by the auxiliary feature
spacing distance. A sphere of radius XY that is centered at X lacks
one or more auxiliary supports or one or more auxiliary support
marks that are indicative of a presence or removal of the one or
more auxiliary support features. In some embodiments, Y is spaced
apart from X by at least about 10.5 millimeters or more. An acute
angle between the straight line XY and the direction normal to N
may be from about 45 degrees to about 90 degrees. The acute angle
between the straight line XY and the direction normal to the
layering plane may be of the value of the acute angle alpha. When
the angle between the straight line XY and the direction of normal
to N is greater than 90 degrees, one can consider the complementary
acute angle. The layer structure may comprise any material(s) used
for 3D printing described herein. Each layer of the 3D structure
can be made of a single material or of multiple materials.
Sometimes one part of the layer may comprise one material, and
another part may comprise a second material different than the
first material. A layer of the 3D object may be composed of a
composite material. The 3D object may be composed of a composite
material. The 3D object may comprise a functionally graded
material.
[0185] In some embodiments, the generated 3D object may be
generated with the accuracy of at least about 5 .mu.m, 10 .mu.m, 15
.mu.m, 20 .mu.m, 25 .mu.m, 30 .mu.m, 35 .mu.m, 40 .mu.m, 45 .mu.m,
50 .mu.m, 55 .mu.m, 60 .mu.m, 65 .mu.m, 70 .mu.m, 75 .mu.m, 80
.mu.m, 85 .mu.m, 90 .mu.m, 95 .mu.m, 100 .mu.m, 150 .mu.m, 200
.mu.m, 250 .mu.m, 300 .mu.m, 400 .mu.m, 500 .mu.m, 600 .mu.m, 700
.mu.m, 800 .mu.m, 900 .mu.m, 1000 .mu.m, 1100 .mu.m, or 1500 .mu.m
as compared to a model of the 3D object (e.g., the desired 3D
object). The generated 3D object may be generated with the accuracy
of at most about 5 .mu.m, 10 .mu.m, 15 .mu.m, 20 .mu.m, 25 .mu.m,
30 .mu.m, 35 .mu.m, 40 .mu.m, 45 .mu.m, 50 .mu.m, 55 .mu.m, 60
.mu.m, 65 .mu.m, 70 .mu.m, 75 .mu.m, 80 .mu.m, 85 .mu.m, 90 .mu.m,
95 .mu.m, 100 .mu.m, 150 .mu.m, 200 .mu.m, 250 .mu.m, 300 .mu.m,
400 .mu.m, 500 .mu.m, 600 .mu.m, 700 .mu.m, 800 .mu.m, 900 .mu.m,
1000 .mu.m, 1100 .mu.m, or 1500 .mu.m as compared to a model of the
3D object. As compared to a model of the 3D object, the generated
3D object may be generated with the accuracy of any accuracy value
between the aforementioned values (e.g., from about 5 .mu.m to
about 100 .mu.m, from about 15 .mu.m to about 35 .mu.m, from about
100 .mu.m to about 1500 .mu.m, from about 5 .mu.m to about 1500
.mu.m, or from about 400 .mu.m to about 600 .mu.m).
[0186] The hardened layer of transformed material may deform. The
deformation may cause a height deviation from a uniformly planar
layer of hardened material. The height uniformity (e.g., deviation
from average surface height) of the planar surface of the layer of
hardened material may be at least about 100 .mu.m, 90 .mu.m, 80
.mu.m, 70 .mu.m, 60 .mu.m, 50 .mu.m, 40 .mu.m, 30 .mu.m, 20 .mu.m,
10 .mu.m, or 5 .mu.m. The height uniformity of the planar surface
of the layer of hardened material may be at most about 100 .mu.m,
90 .mu.m, 80, 70 .mu.m, 60 .mu.m, 50 .mu.m, 40 .mu.m, 30 .mu.m, 20
.mu.m, 10 .mu.m, or 5 .mu.m. The height uniformity of the planar
surface of the layer of hardened material may be any value between
the afore-mentioned height deviation values (e.g., from about 100
.mu.m to about 5 .mu.m, from about 50 .mu.m to about 5 .mu.m, from
about 30 .mu.m to about 5 .mu.m, or from about 20 .mu.m to about 5
.mu.m). The height uniformity may comprise high precision
uniformity. The resolution of the 3D object may have any value of
the height uniformity value mentioned herein. The resolution of the
3D object may be at least about 100 dots per inch (dpi), 300 dpi,
600 dpi, 1200 dpi, 2400 dpi, 3600 dpi, or 4800 dpi. The resolution
of the 3D object may be at most about 100 dpi, 300 dpi, 600 dpi,
1200 dpi, 2400 dpi, 3600 dpi, or 4800 dip. The resolution of the 3D
object may be any value between the aforementioned values (e.g.,
from 100 dpi to 4800 dpi, from 300 dpi to 2400 dpi, or from 600 dpi
to 4800 dpi).
[0187] The height uniformity of a layer of hardened material may
persist across a portion of the layer surface that has a width or a
length of at least about 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, or 10 mm,
have a height deviation of at least about 10 mm, 9 mm, 8 mm, 7 mm,
6 mm, 5 mm, 4 mm, 3 mm, 2 mm, 1 mm, 500 .mu.m, 400 .mu.m, 300
.mu.m, 200 .mu.m, 100 .mu.m, 90 .mu.m, 80 .mu.m, 70 .mu.m, 60
.mu.m, 50 .mu.m, 40 .mu.m, 30 .mu.m, 20 .mu.m, or 10 .mu.m. The
height uniformity of a layer of hardened material may persist
across a portion of the target surface that has a width or a length
of most about 10 mm, 9 mm, 8 mm, 7 mm, 6 mm, 5 mm, 4 mm, 3 mm, 2
mm, 1 mm, 500 .mu.m, 400 .mu.m, 300 .mu.m, 200 .mu.m, 100 .mu.m, 90
.mu.m, 80, 70 .mu.m, 60 .mu.m, 50 .mu.m, 40 .mu.m, 30 .mu.m, 20
.mu.m, or 10 .mu.m. The height uniformity of a layer of hardened
material may persist across a portion of the target surface that
has a width or a length of or of any value between the
afore-mentioned width or length values (e.g., from about 10 mm to
about 10 .mu.m, from about 10 mm to about 100 .mu.m, or from about
5 mm to about 500 .mu.m).
[0188] Characteristics of the hardened material and/or any of its
parts (e.g., layer of hardened material) can be measured by any of
the following measurement methodologies. For example, the FLS
values (e.g., width), height uniformity, auxiliary support space,
and/or radius of curvature of the layer of the 3D object and any of
its components (e.g., layer of hardened material) may be measured
by any of the following measuring methodologies. The FLS of opening
ports may be measured by one or more of following measurement
methodologies. The measurement methodologies may comprise a
microscopy method (e.g., any microscopy method described herein).
The measurement methodologies may comprise a coordinate measuring
machine (CMM), measuring projector, vision measuring system, and/or
a gauge. The gauge can be a gauge distometer (e.g., caliper). The
gauge can be a go-no-go gauge. The measurement methodologies may
comprise a caliper (e.g., Vernier caliper), positive lens,
interferometer, or laser (e.g., tracker). The measurement
methodologies may comprise a contact or by a non-contact method.
The measurement methodologies may comprise one or more sensors
(e.g., optical sensors and/or metrological sensors). The
measurement methodologies may comprise a metrological measurement
device (e.g., using metrological sensor(s)). The measurements may
comprise a motor encoder (e.g., rotary, and/or linear). The
measurement methodologies may comprise using an electromagnetic
beam (e.g., visible or IR). The microscopy method may comprise
ultrasound or nuclear magnetic resonance. The microscopy method may
comprise optical microscopy. The microscopy method may comprise
electromagnetic, electron, or proximal probe microscopy. The
electron microscopy may comprise scanning, tunneling, X-ray photo-,
or Auger electron microscopy. The electromagnetic microscopy may
comprise confocal, stereoscope, or compound microscopy. The
microscopy method may comprise an inverted and/or non-inverted
microscope. The proximal probe microscopy may comprise atomic
force, or scanning tunneling microscopy, or any other microscopy
described herein. The microscopy measurements may comprise using an
image analysis system. The measurements may be conducted at ambient
temperatures (e.g., R.T.)
[0189] The microstructures (e.g., of melt pools) of the 3D object
may be measured by a microscopy method (e.g., any microscopy method
described herein). The microstructures may be measured by a contact
or by a non-contact method. The microstructures may be measured by
using an electromagnetic beam (e.g., visible or IR). The
microstructure measurements may comprise evaluating the dendritic
arm spacing and/or the secondary dendritic arm spacing (e.g., using
microscopy). The microscopy measurements may comprise using an
image analysis system. The measurements may be conducted at ambient
temperatures (e.g., R.T.).
[0190] Various distances relating to the chamber can be measured
using any of the following measurement techniques. Various
distances within the chamber can be measured using any of the
following measurement techniques. For example, the gap distance
(e.g., from the cooling member to the exposed surface of the
material bed) may be measured using any of the following
measurement techniques. The measurements techniques may comprise
interferometry and/or confocal chromatic measurements. The
measurements techniques may comprise at least one motor encoder
(rotary, linear). The measurement techniques may comprise one or
more sensors (e.g., optical sensors and/or metrological sensors).
The measurement techniques may comprise at least one inductive
sensor. The measurement techniques may include an electromagnetic
beam (e.g., visible or IR). The measurements may be conducted at
ambient temperature (e.g., R.T.).
[0191] The methods described herein can provide surface uniformity
across the exposed surface of the material bed (e.g., top of a
powder bed) such that portions of the exposed surface that
comprises the dispensed material, which are separated from one
another by a distance of from about 1 mm to about 10 mm, have a
height deviation from about 100 .mu.m to about 5 .mu.m. The methods
described herein may achieve a deviation from a planar uniformity
of the layer of pre-transformed material (e.g., powder) in at least
one plane (e.g., horizontal plane) of at most about 20%, 10%, 5%,
2%, 1% or 0.5%, as compared to the average plane (e.g., horizontal
plane) created at the exposed surface of the material bed (e.g.,
top of a powder bed). The height deviation can be measured by using
one or more sensors (e.g., optical sensors).
[0192] The 3D object can have various surface roughness profiles,
which may be suitable for various applications. The surface
roughness may be the deviations in the direction of the normal
vector of a real surface, from its ideal form. The surface
roughness may be measured as the arithmetic average of the
roughness profile (hereinafter "Ra"). The 3D object can have a Ra
value of at least about 200 .mu.m, 100 .mu.m, 75 .mu.m, 50 .mu.m,
45 .mu.m, 40 .mu.m, 35 .mu.m, 30 .mu.m, 25 .mu.m, 20 .mu.m, 15
.mu.m, 10 .mu.m, 7 .mu.m, 5 .mu.m, 3 .mu.m, 1 .mu.m, 500 nm, 400
nm, 300 nm, 200 nm, 100 nm, 50 nm, 40 nm, or 30 nm. The formed
object can have a Ra value of at most about 200 .mu.m, 100 .mu.m,
75 .mu.m, 50 .mu.m, 45 .mu.m, 40 .mu.m, 35 .mu.m, 30 .mu.m, 25
.mu.m, 20 .mu.m, 15 .mu.m, 10 .mu.m, 7 .mu.m, 5 .mu.m, 3 .mu.m, 1
.mu.m, 500 nm, 400 nm, 300 nm, 200 nm, 100 nm, 50 nm, 40 nm, or 30
nm. The 3D object can have a Ra value between any of the
aforementioned Ra values (e.g., from about 30 nm to about 50 .mu.m,
from about 5 .mu.m to about 40 .mu.m, from about 3 .mu.m to about
30 .mu.m, from about 10 nm to about 50 .mu.m, or from about 15 nm
to about 80 .mu.m). The Ra values may be measured by a contact or
by a non-contact method. The Ra values may be measured by a
roughness tester and/or by a microscopy method (e.g., any
microscopy method described herein). The measurements may be
conducted at ambient temperatures (e.g., R.T.). The roughness may
be measured by a contact or by a non-contact method. The roughness
measurement may comprise one or more sensors (e.g., optical
sensors). The roughness measurement may comprise a metrological
measurement device (e.g., using metrological sensor(s)). The
roughness may be measured using an electromagnetic beam (e.g.,
visible or IR).
[0193] The 3D object may be composed of successive layers (e.g.,
successive cross sections) of solid material that originated from a
transformed material (e.g., fused, sintered, melted, bound, or
otherwise connected powder material), and subsequently hardened.
The transformed powder material may be connected to a hardened
(e.g., solidified) material. The hardened material may reside
within the same layer, or in another layer (e.g., a previous
layer). In some examples, the hardened material comprises
disconnected parts of the three-dimensional object, that are
subsequently connected by the newly transformed material (e.g., by
fusing, sintering, melting, binding or otherwise connecting a
powder material).
[0194] A cross section (e.g., vertical cross section) of the
generated (e.g., formed) 3D object may reveal a microstructure or a
grain structure indicative of a layered deposition. Without wishing
to be bound to theory, the microstructure or grain structure may
arise due to the solidification of transformed powder material that
is typical to and/or indicative of the 3D printing method. For
example, a cross section may reveal a microstructure resembling
ripples or waves that are indicative of solidified melt pools that
may be formed during the 3D printing process. The repetitive
layered structure of the solidified melt pools may reveal the
orientation at which the part was printed. The cross section may
reveal a substantially repetitive microstructure or grain
structure. The microstructure or grain structure may comprise
substantially repetitive variations in material composition, grain
orientation, material density, degree of compound segregation or of
element segregation to grain boundaries, material phase,
metallurgical phase, crystal phase, crystal structure, material
porosity, or any combination thereof. The microstructure or grain
structure may comprise substantially repetitive solidification of
layered melt pools. The substantially repetitive microstructure may
have an average layer height of at least about 0.5 .mu.m, 1 .mu.m,
5 .mu.m, 10 .mu.m, 20 .mu.m, 30 .mu.m, 40 .mu.m, 50 .mu.m, 60
.mu.m, 70 .mu.m, 80 .mu.m, 90 .mu.m, 100 .mu.m, 150 .mu.m, 200
.mu.m, 250 .mu.m, 300 .mu.m, 350 .mu.m, 400 .mu.m, 450 .mu.m, or
500 .mu.m. The substantially repetitive microstructure may have an
average layer height of at most about 500 .mu.m, 450 .mu.m, 400
.mu.m, 350 .mu.m, 300 .mu.m, 250 .mu.m, 200 .mu.m, 150 .mu.m, 100
.mu.m, 90 .mu.m, 80 .mu.m, 70 .mu.m, 60 .mu.m, 50 .mu.m, 40 .mu.m,
30 .mu.m, 20 .mu.m, or 10 .mu.m. The substantially repetitive
microstructure may have an average layer height of any value
between the aforementioned values of layer heights (e.g., from
about 0.5 .mu.m to about 500 .mu.m, from about 15 .mu.m to about 50
.mu.m, from about 5 .mu.m to about 150 .mu.m, from about 20 .mu.m
to about 100 .mu.m, or from about 10 .mu.m to about 80 .mu.m). In
some cases, the layer height can refer to a distance between layers
(e.g., FIG. 10, distance between layers e.g., 1 and 2).
[0195] The pre-transformed material within the material bed (e.g.,
powder) can be configured to provide support to the 3D object. For
example, the supportive powder may be of the same type of powder
from which the 3D object is generated, of a different type, or any
combination thereof. In some instances, a low flowability powder
can be capable of supporting a 3D object better than a high
flowability powder. A low flowability powder can be achieved inter
alia with a powder composed of relatively small particles, with
particles of non-uniform size or with particles that attract each
other. The powder may be of low, medium, or high flowability. The
powder material may have compressibility of at least about 1%, 2%,
3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10% in response to an applied force
of 15 kilo Pascals (kPa). The powder may have a compressibility of
at most about 9%, 8%, 7%, 6%, 5%, 4.5%, 4.0%, 3.5%, 3.0%, 2.5%,
2.0%, 1.5%, 1.0%, or 0.5% in response to an applied force of 15
kilo Pascals (kPa). The powder may have basic flow energy of at
least about 100 milli-Joule (mJ), 200 mJ, 300 mJ, 400 mJ, 450 mJ,
500 mJ, 550 mJ, 600 mJ, 650 mJ, 700 mJ, 750 mJ, 800 mJ, or 900 mJ.
The powder may have basic flow energy of at most about 200 mJ, 300
mJ, 400 mJ, 450 mJ, 500 mJ, 550 mJ, 600 mJ, 650 mJ, 700 mJ, 750 mJ,
800 mJ, 900 mJ, or 1000 mJ. The powder may have basic flow energy
in between the above listed values of basic flow energy (e.g., from
about 100 mJ to about 1000 mJ, from about 100 mJ to about 600 mJ,
or from about 500mJ to about 1000 mJ). The powder may have a
specific energy of at least about 1.0 milli-Joule per gram (mJ/g),
1.5 mJ/g, 2.0 mJ/g, 2.5 mJ/g, 3.0 mJ/g, 3.5 mJ/g, 4.0 mJ/g, 4.5
mJ/g, or 5.0 mJ/g. The powder may have a specific energy of at most
5.0 mJ/g, 4.5 mJ/g, 4.0 mJ/g, 3.5 mJ/g, 3.0 mJ/g, 2.5 mJ/g, 2.0
mJ/g, 1.5 mJ/g, or 1.0 mJ/g. The powder may have a specific energy
in between any of the above values of specific energy (e.g., from
about 1.0 mJ/g to about 5.0 mJ/g, from about 3.0 mJ/g to about 5
mJ/g, or from about 1.0 mJ/g to about 3.5 mJ/g).
[0196] In some embodiments, the 3D object includes one or more
auxiliary features. The auxiliary feature(s) can be supported by
the material (e.g., powder) bed. The term "auxiliary features," as
used herein, generally refers to features that are part of a
printed 3D object, but are not part of the desired, intended,
designed, ordered, modeled, or final 3D object. Auxiliary features
(e.g., auxiliary supports) may provide structural support during
and/or subsequent to the formation of the 3D object. Auxiliary
features may enable the removal or energy from the 3D object that
is being formed. Examples of auxiliary features comprise heat fins,
wires, anchors, handles, supports, pillars, columns, frame,
footing, scaffold, flange, projection, protrusion, mold (a.k.a.
mould), or other stabilization features. In some instances, the
auxiliary support is a scaffold that encloses the 3D object or part
thereof. The scaffold may comprise lightly sintered or lightly
fused powder material. The 3D object can have auxiliary features
that can be supported by the material bed (e.g., powder bed) and
not touch the base, substrate, container accommodating the material
bed, or the bottom of the enclosure. The 3D part (3D object) in a
complete or partially formed state can be completely supported by
the material bed (e.g., without touching the substrate, base,
container accommodating the powder bed, or enclosure). The 3D
object in a complete or partially formed state can be completely
supported by the powder bed (e.g., without touching anything except
the powder bed). The 3D object in a complete or partially formed
state can be suspended in the powder bed without resting on any
additional support structures. In some cases, the 3D object in a
complete or partially formed (e.g., nascent) state can freely float
(e.g., anchorless) in the material bed.
[0197] In some examples, the 3D object may not be anchored (e.g.,
connected) to the platform and/or walls that define the material
bed (e.g., during formation). The 3D object may not touch (e.g.,
contact) to the platform and/or walls that define the material bed
(e.g., during formation). The 3D object be suspended (e.g., float)
in the material bed. The scaffold may comprise a continuously
sintered (e.g., lightly sintered) structure that is at most 1
millimeter (mm), 2 mm, 5 mm or 10 mm. The scaffold may comprise a
continuously sintered structure that is at least 1 millimeter (mm),
2 mm, 5 mm or 10 mm. The scaffold may comprise a continuously
sintered structure having dimensions between any of the
aforementioned dimensions (e.g., from about 1 mm to about 10 mm, or
from about 1 mm to about 5 mm). In some examples, the 3D object may
be printed without a supporting scaffold. The supporting scaffold
may engulf the 3D object. The supporting scaffold may float in the
material bed.
[0198] The printed 3D object may be printed without the use of
auxiliary features, may be printed using a reduced number of
auxiliary features, or printed using spaced apart auxiliary
features. In some embodiments, the printed 3D object may be devoid
of one or more auxiliary support features or auxiliary support
feature marks that are indicative of a presence or removal of the
auxiliary support features. The 3D object may be devoid of one or
more auxiliary support features and of one or more marks of an
auxiliary feature (including a base structure) that was removed
(e.g., subsequent to, or contemporaneous with, the generation of
the 3D object). The printed 3D object may comprise a single
auxiliary support mark. The single auxiliary feature (e.g.,
auxiliary support or auxiliary structure) may be a platform (e.g.,
a building platform such as a base or substrate), or a mold. The
auxiliary support may be adhered to the platform or mold. The 3D
object may comprise marks belonging to one or more auxiliary
structures. The 3D object may comprise two or more marks belonging
to auxiliary features. The 3D object may be devoid of marks
pertaining to an auxiliary support. The 3D object may be devoid of
an auxiliary support. The mark may comprise variation in grain
orientation, variation in layering orientation, layering thickness,
material density, the degree of compound segregation to grain
boundaries, material porosity, the degree of element segregation to
grain boundaries, material phase, metallurgical phase, crystal
phase, or crystal structure; wherein the variation may not have
been created by the geometry of the 3D object alone, and may thus
be indicative of a prior existing auxiliary support that was
removed. The variation may be forced upon the generated 3D object
by the geometry of the support. In some instances, the 3D structure
of the printed object may be forced by the auxiliary support (e.g.,
by a mold). For example, a mark may be a point of discontinuity
that is not explained by the geometry of the 3D object, which does
not include any auxiliary supports. A mark may be a surface feature
that cannot be explained by the geometry of a 3D object, which does
not include any auxiliary supports (e.g., a mold). The two or more
auxiliary features or auxiliary support feature marks may be spaced
apart by a spacing distance of at least 1.5 millimeters (mm), 2 mm,
2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7
mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm, 10.5 mm, 11 mm, 11.5
mm, 12 mm, 12.5 mm, 13 mm, 13.5 mm, 14 mm, 14.5 mm, 15 mm, 15.5 mm,
16 mm, 20 mm, 20.5 mm, 21 mm, 25 mm, 30 mm, 30.5 mm, 31 mm, 35 mm,
40 mm, 40.5 mm, 41 mm, 45 mm, 50 mm, 80 mm, 100 mm, 200 mm 300 mm,
or 500 mm. The two or more auxiliary support features or auxiliary
support feature marks may be spaced apart by a spacing distance of
at most 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5
mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm,
10.5 mm, 11 mm, 11.5 mm, 12 mm, 12.5 mm, 13 mm, 13.5 mm, 14 mm,
14.5 mm, 15 mm, 15.5 mm, 16 mm, 20 mm, 20.5 mm, 21 mm, 25 mm, 30
mm, 30.5 mm, 31 mm, 35 mm, 40 mm, 40.5 mm, 41 mm, 45 mm, 50 mm, 80
mm, 100 mm, 200 mm 300 mm, or 500 mm. The two or more auxiliary
support features or auxiliary support feature marks may be spaced
apart by a spacing distance of any value between the aforementioned
auxiliary support space values (e.g., from 1.5 mm to 500 mm, from 2
mm to 100 mm, from 15 mm to 50 mm, or from 45 mm to 200 mm).
Collectively referred to herein as the "auxiliary feature spacing
distance."
[0199] In some embodiments, the 3D object comprises a layered
structure indicative of 3D printing process that is devoid of one
or more auxiliary support features or one or more auxiliary support
feature marks that are indicative of a presence or removal of the
one or more auxiliary support features. The 3D object may comprise
a layered structure indicative of 3D printing process, which
includes one, two, or more auxiliary support marks. The supports or
support marks can be on the surface of the 3D object. The auxiliary
supports, or support marks can be on an external, on an internal
surface (e.g., a cavity within the 3D object), or both. The layered
structure can have a layering plane. In one example, two auxiliary
support features or auxiliary support feature marks present in the
3D object may be spaced apart by the auxiliary feature spacing
distance. The acute (e.g., sharp) angle alpha between the straight
line connecting the two auxiliary supports or auxiliary support
marks and the direction of normal to the layering plane may be at
least about 45 degrees (.degree.), 50.degree., 55.degree.,
60.degree., 65.degree., 70.degree., 75.degree., 80.degree., or
85.degree.. The acute angle alpha between the straight line
connecting the two auxiliary supports or auxiliary support marks
and the direction of normal to the layering plane may be at most
about 90.degree., 85.degree., 80.degree., 75.degree., 70.degree.,
65.degree., 60.degree., 55.degree., 50.degree., or 45.degree..
[0200] The acute angle alpha between the straight line connecting
the two auxiliary supports or auxiliary support marks and the
direction of normal to the layering plane may be any angle range
between the aforementioned angles (e.g., from about 45 degrees
(.degree.), to about 90.degree., from about 60.degree. to about
90.degree., from about 75.degree. to about 90.degree., from about
80.degree. to about 90.degree., from about 85.degree. to about
90.degree.). The acute angle alpha between the straight line
connecting the two auxiliary supports or auxiliary support marks
and the direction normal to the layering plane may from about
87.degree. to about 90.degree.. An example of a layering plane can
be seen in FIG. 10 showing a vertical cross section of a 3D object
1011 that comprises layers 1 to 6, each of which are substantially
planar. In the schematic example in FIG. 10, the layering plane of
the layers can be the layer. For example, layer 1 could correspond
to both the layer and the layering plane of layer 1. When the layer
is not planar (e.g., FIG. 10, layer 5 of 3D object 1012), the
layering plane would be the average plane of the layer. The two
auxiliary supports, or auxiliary support feature marks can be on
the same surface. The same surface can be an external surface or an
internal surface (e.g., a surface of a cavity within the 3D
object). When the angle between the shortest straight line
connecting the two auxiliary supports or auxiliary support marks
and the direction of normal to the layering plane is greater than
90 degrees, one can consider the complementary acute angle. In some
embodiments, any two auxiliary supports, or auxiliary support marks
are spaced apart by at least about 10.5 millimeters or more. In
some embodiments, any two auxiliary supports, or auxiliary support
marks are spaced apart by at least about 40.5 millimeters or more.
In some embodiments, any two auxiliary supports, or auxiliary
support marks are spaced apart by the auxiliary feature spacing
distance.
[0201] In some embodiments, the 3D object can be formed without one
or more auxiliary features and/or without contacting a platform
(e.g., a base, a substrate, or a bottom of an enclosure). The one
or more auxiliary features (which may include a base support) can
be used to hold or restrain the 3D object during formation. In some
cases, auxiliary features can be used to anchor or hold a 3D object
or a portion of a 3D object in a material bed. The one or more
auxiliary features can be specific to a part and can increase the
time needed to form the 3D object. The one or more auxiliary
features can be removed prior to use or distribution of the 3D
object. The longest dimension of a cross-section of an auxiliary
feature can be at most about 50 nm, 100 nm, 200 nm, 300 nm, 400 nm,
500 nm, 600 nm, 700 nm, 800 nm, 900 nm, or 1000 nm, 1 .mu.m, 3
.mu.m, 10 .mu.m, 20 .mu.m, 30 .mu.m, 100 .mu.m, 200 .mu.m, 300
.mu.m, 400 .mu.m, 500 .mu.m, 700 .mu.m, 1 mm, 3 mm, 5 mm, 10 mm, 20
mm, 30 mm, 50 mm, 100 mm, or 300 mm. The longest dimension of a
cross-section of an auxiliary feature can be at least about 50 nm,
100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900
nm, or 1000 nm, 1 .mu.m, 3 .mu.m, 10 .mu.m, 20 .mu.m, 30 .mu.m, 100
.mu.m, 200 .mu.m, 300 .mu.m, 400 .mu.m, 500 .mu.m, 700 .mu.m, 1 mm,
3 mm, 5 mm, 10 mm, 20 mm, 30 mm, 50 mm, 100 mm, or 300 mm. The
longest dimension of a cross-section of an auxiliary feature can be
any value between the above-mentioned values (e.g., from about 50
nm to about 300 mm, from about 5 .mu.m to about 10 mm, from about
50 nm to about 10 mm, or from about 5 mm to about 300 mm).
Eliminating the need for auxiliary features can decrease the time
and cost associated with generating the three-dimensional part. In
some examples, the 3D object may be formed with auxiliary features.
In some examples, the 3D object may be formed with contact to the
container accommodating the material bed (e.g., side(s) and/or
bottom of the container).
[0202] In some examples, the diminished number of auxiliary
supports or lack of one or more auxiliary support, will provide a
3D printing process that requires a smaller amount of material,
produces a smaller amount of material waste, and/or requires
smaller energy as compared to commercially available 3D printing
processes. The smaller amount can be smaller by at least about 1.1,
1.3, 1.5, 2, 3, 4, 5, 6, 7, 8, 9, or 10. The smaller amount may be
smaller by any value between the aforesaid values (e.g., from about
1.1 to about 10, or from about 1.5 to about 5).
[0203] FIG. 1 depicts an example of a system that can be used to
generate a 3D object using a 3D printing process disclosed herein.
The system can include an enclosure (e.g., a chamber 107). At least
a fraction of the components in the system can be enclosed in the
chamber. At least a fraction of the chamber can be filled with a
gas to create a gaseous environment (e.g., an atmosphere). The gas
can be an inert gas (e.g., Argon, Neon, Helium, Nitrogen). The
chamber can be filled with another gas or mixture of gases. The gas
can be a non-reactive gas (e.g., an inert gas). The gaseous
environment can comprise argon, nitrogen, helium, neon, krypton,
xenon, hydrogen, carbon monoxide, or carbon dioxide. The pressure
in the chamber can be at least 10.sup.-7 Torr, 10.sup.-6 Torr,
10.sup.-5 Torr, 10.sup.-4 Torr, 10.sup.-3 Torr, 10.sup.-2 Torr,
10.sup.-1 Torr, 1 Torr, 10 Torr, 100 Torr, 1 bar, 2 bar, 3 bar, 4
bar, 5 bar, 10 bar, 20 bar, 30 bar, 40 bar, 50 bar, 100 bar, 200
bar, 300 bar, 400 bar, 500 bar, 1000 bar, or more. The pressure in
the chamber can be at least 100 Torr, 200 Torr, 300 Torr, 400 Torr,
500 Torr, 600 Torr, 700 Torr, 720 Torr, 740 Torr, 750 Torr, 760
Torr, 900 Torr, 1000 Torr, 1100 Torr, or 1200 Torr. The pressure in
the chamber can be at most 10.sup.-7 Torr, 10.sup.-6 Torr,
10.sup.-5 Torr, or 10.sup.-4 Torr, 10.sup.-3 Torr, 10.sup.-2 Torr,
10.sup.-1 Torr, 1 Torr, 10 Torr, 100 Torr, 200 Torr, 300 Torr, 400
Torr, 500 Torr, 600 Torr, 700 Torr, 720 Torr, 740 Torr, 750 Torr,
760 Torr, 900 Torr, 1000 Torr, 1100 Torr, or 1200 Torr. The
pressure in the chamber can be at a range between any of the
aforementioned pressure values (e.g., from about 10.sup.-7 Torr to
about 1200 Torr, from about 10.sup.-7 Torr to about 1 Torr, from
about 1 Torr to about 1200 Torr, or from about 10.sup.-2 Torr to
about 10 Torr). The pressure can be measured by a pressure gauge.
The pressure can be measured at ambient temperature (e.g., R.T.).
In some cases, the pressure in the chamber can be standard
atmospheric pressure. In some cases, the pressure in the chamber
can be ambient pressure (e.g., neutral pressure). In some examples,
the chamber can be under vacuum pressure. In some examples, the
chamber can be under a positive pressure (e.g., above ambient
pressure). The pressure may be maintained and/or adjusted by a
pump. For example, the pressure in the area enclosing the
processing chamber may be at a positive pressure with respect to
the ambient pressure. At times, the gas flow pressure within the
processing chamber and the pressure directly adjacent to the pump,
may be different. The raised pressure may be at least about 0.5
psi, 1 psi, 2 psi, 3 psi, 4 psi, 5 psi, 6 psi, 7 psi, 8 psi, 9 psi,
or 10 psi above the ambient pressure. The raised pressure may be
any value between the afore-mentioned values, for example, from
about 0.5 psi to about 10 psi, or from about 0.5 psi to about 5
psi. The raised pressure may be the pressure directly adjacent to
the pump (e.g., behind the pump).
[0204] The concentration of oxygen and/or humidity in the enclosure
(e.g., chamber) can be minimized (e.g., below a predetermined
threshold value). For example, the gas composition of the chamber
can contain a level of oxygen and/or humidity that is at most about
100 parts per billion (ppb), 10 ppb, 1 ppb, 0.1 ppb, 0.01 ppb,
0.001 ppb, 100 parts per million (ppm), 10 ppm, 1 ppm, 0.1 ppm,
0.01 ppm, or 0.001 ppm. The gas composition of the chamber can
contain an oxygen and/or humidity level between any of the
aforementioned values (e.g., from about 100 ppb to about 0.001 ppm,
from about 1 ppb to about 0.01 ppm, or from about 1 ppm to about
0.1 ppm). The gas composition may be measures by one or more
sensors (e.g., an oxygen and/or humidity sensor.). In some cases,
the chamber can be opened at the completion of a formation of a 3D
object. When the chamber is opened, ambient air containing oxygen
and/or humidity can enter the chamber. Exposure of one or more
components inside of the chamber to air can be reduced by, for
example, flowing an inert gas while the chamber is open (e.g., to
prevent entry of ambient air), or by flowing a heavy gas (e.g.,
argon) that rests on the surface of the powder bed. In some cases,
components that absorb oxygen and/or humidity on to their
surface(s) can be sealed while the chamber is open.
[0205] The chamber can be configured such that gas inside of the
chamber has a relatively low leak rate from the chamber to an
environment outside of the chamber. In some cases, the leak rate
can be at most about 100 milliTorr/minute (mTorr/min), 50
mTorr/min, 25 mTorr/min, 15 mTorr/min, 10 mTorr/min, 5 mTorr/min, 1
mTorr/min, 0.5 mTorr/min, 0.1 mTorr/min, 0.05 mTorr/min, 0.01
mTorr/min, 0.005 mTorr/min, 0.001 mTorr/min, 0.0005 mTorr/min, or
0.0001 mTorr/min. The leak rate may be between any of the
aforementioned leak rates (e.g., from about 0.0001 mTorr/min to
about, 100 mTorr/min, from about 1 mTorr/min to about, 100
mTorr/min, or from about 1 mTorr/min to about, 100 mTorr/min). The
leak rate may be measured by one or more pressure gauges and/or
sensors (e.g., at ambient temperature). The enclosure can be sealed
such that the leak rate of gas from inside the chamber to an
environment outside of the chamber is low (e.g., below a certain
level). The seals can comprise O-rings, rubber seals, metal seals,
load-locks, or bellows on a piston. In some cases, the chamber can
have a controller configured to detect leaks above a specified leak
rate (e.g., by using at least one sensor). The sensor may be
coupled to a controller. In some instances, the controller is able
to identify and/or control (e.g., direct and/or regulate). For
example, the controller may be able to identify a leak by detecting
a decrease in pressure in side of the chamber over a given time
interval.
[0206] One or more of the system components can be contained in the
enclosure (e.g., chamber). The enclosure can include a reaction
space that is suitable for introducing precursor to form a 3D
object, such as powder material. The enclosure can contain the
platform. In some cases, the enclosure can be a vacuum chamber, a
positive pressure chamber, or an ambient pressure chamber. The
enclosure can comprise a gaseous environment with a controlled
pressure, temperature, and/or gas composition. The gas composition
in the environment contained by the enclosure can comprise a
substantially oxygen free environment. For example, the gas
composition can contain at most at most about 100,000 parts per
million (ppm), 10,000 ppm, 1000 ppm, 500 ppm, 400 ppm, 200 ppm, 100
ppm, 50 ppm, 10 ppm, 5 ppm, 1 ppm, 100,000 parts per billion (ppb),
10,000 ppb, 1000 ppb, 500 ppb, 400 ppb, 200 ppb, 100 ppb, 50 ppb,
10 ppb, 5 ppb, 1 ppb, 100,000 parts per trillion (ppt), 10,000 ppt,
1000 ppt, 500 ppt, 400 ppt, 200 ppt, 100 ppt, 50 ppt, 10 ppt, 5
ppt, or 1 ppt oxygen. The gas composition in the environment
contained within the enclosure can comprise a substantially
moisture (e.g., water) free environment. The gaseous environment
can comprise at most about 100,000 ppm, 10,000 ppm, 1000 ppm, 500
ppm, 400 ppm, 200 ppm, 100 ppm, 50 ppm, 10 ppm, 5 ppm, 1 ppm,
100,000 ppb, 10,000 ppb, 1000 ppb, 500 ppb, 400 ppb, 200 ppb, 100
ppb, 50 ppb, 10 ppb, 5 ppb, 1 ppb, 100,000 ppt, 10,000 ppt, 1000
ppt, 500 ppt, 400 ppt, 200 ppt, 100 ppt, 50 ppt, 10 ppt, 5 ppt, or
1 ppt water. The gaseous environment can comprise a gas selected
from the group consisting of argon, nitrogen, helium, neon,
krypton, xenon, hydrogen, carbon monoxide, carbon dioxide, and
oxygen. The gaseous environment can comprise air. The chamber
pressure can be at least about 10.sup.-7 Torr, 10.sup.-6 Torr,
10.sup.-5 Torr, 10.sup.-4 Torr, 10.sup.-3 Torr, 10.sup.-2 Torr,
10.sup.-1 Torr, 1 Torr, 10 Torr, 100 Torr, 1 bar, 760 Torr, 1000
Torr, 1100 Torr, 2 bar, 3 bar, 4 bar, 5 bar, or 10 bar. The chamber
pressure can be of any value between the afore-mentioned chamber
pressure values (e.g., from about 10.sup.-7 Torr to about 10 bar,
from about 10.sup.-7 Torr to about 1 bar, or from about 1 bar to
about 10 bar). In some cases, the enclosure pressure can be
standard atmospheric pressure. The gas can be an ultrahigh purity
gas. For example, the ultrahigh purity gas can be at least about
99%, 99.9%, 99.99%, or 99.999% pure. The gas may comprise less than
about 2 ppm oxygen, less than about 3 ppm moisture, less than about
1 ppm hydrocarbons, or less than about 6 ppm nitrogen.
[0207] The enclosure can be maintained under vacuum or under an
inert, dry, non-reactive and/or oxygen reduced (or otherwise
controlled) atmosphere (e.g., a nitrogen (N2), helium (He), or
argon (Ar) atmosphere). In some examples, the enclosure is under
vacuum. In some examples, the enclosure is under pressure of at
most about 1 Torr, 10.sup.-3 Torr, 10.sup.-6 Torr, or 10.sup.-8
Torr. The atmosphere can be provided by providing an inert, dry,
non-reactive, and/or oxygen reduced gas (e.g., Ar) and/or flowing
the gas through the chamber.
[0208] In some examples, a pressure system is in fluid
communication with the enclosure. The pressure system can be
configured to regulate the pressure in the enclosure. In some
examples, the pressure system includes one or more vacuum pumps
selected from mechanical pumps, rotary vain pumps, turbomolecular
pumps, ion pumps, cryopumps, and diffusion pumps. The one or more
vacuum pumps may comprise Rotary vane pump, diaphragm pump, liquid
ring pump, piston pump, scroll pump, screw pump, Wankel pump,
external vane pump, roots blower, multistage Roots pump, Toepler
pump, or Lobe pump. The one or more vacuum pumps may comprise
momentum transfer pump, regenerative pump, entrapment pump, Venturi
vacuum pump, or team ejector. The pressure system can include
valves; such as throttle valves. The pressure system can include a
pressure sensor for measuring the pressure of the chamber and
relaying the pressure to the controller, which can regulate the
pressure with the aid of one or more vacuum pumps of the pressure
system. The pressure sensor can be coupled to a control system. The
pressure can be electronically or manually controlled.
[0209] The system and/or apparatus components described herein can
be adapted and configured to generate a 3D object. The 3D object
can be generated through a 3D printing process. A first layer of
material can be provided adjacent to a platform. A base can be a
previously formed layer of the 3D object or any other surface upon
which a layer or bed of material is spread, held, placed, or
supported. In the case of formation of the first layer of the 3D
object the first material layer can be formed in the material bed
without a base, without one or more auxiliary support features
(e.g., rods), or without other supporting structure other than the
material (e.g., within the material bed). Subsequent layers can be
formed such that at least one portion of the subsequent layer
melts, sinters, fuses, binds and/or otherwise connects to the at
least a portion of a previously formed layer. In some instances,
the at least a portion of the previously formed layer that is
transformed and subsequently hardens into a hardened material, acts
as a base for formation of the 3D object. In some cases, the first
layer comprises at least a portion of the base. The material type
of the material layer can be any material described herein. The
material layer can comprise particles of homogeneous or
heterogeneous size and/or shape.
[0210] The system and/or apparatus described herein may comprise at
least one energy source (e.g., the energy source generating the
scanning energy beam, and/or the tiling energy flux). The first
energy source may project a first irradiating energy (e.g., a first
energy beam). The first energy beam may travel (e.g., scan) along a
path. The path may be predetermined (e.g., by the controller). The
apparatuses may comprise at least a second energy source. The
second energy source may comprise the tiling energy source and/or
the second scanning energy source. The second energy source may
generate a second irradiating energy (e.g., second energy beam).
The first and/or the second energy may transform at least a portion
of the pre-transformed material in the material bed to a
transformed material. In some embodiments, the first and/or second
energy beam/flux may heat but not transform at least a portion of
the pre-transformed material in the material bed. In some cases,
the system can comprise 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 30, 100,
300, 1000 or more energy fluxes (e.g., beams) and/or sources. The
system can comprise an array of energy sources (e.g., laser diode
array). Alternatively, or additionally the target surface, material
bed, 3D object (or part thereof), or any combination thereof may be
heated by a heating mechanism. The heating mechanism may comprise
dispersed energy beams. In some cases, the at least one energy
source is a single (e.g., first) energy source.
[0211] An energy source can be a source configured to deliver
energy to an area (e.g., a confined area). An energy source can
deliver energy to the confined area through radiative heat
transfer. The energy source can project energy (e.g., heat energy,
and/or energy beam). The energy (e.g., beam) can interact with at
least a portion of the pre-transformed material (e.g., in the
material bed). The energy can heat the material in the material bed
before, during and/or after the material is being transformed. The
energy can heat at least a fraction of a 3D object at any point
during formation of the 3D object. Alternatively, or additionally,
the material bed may be heated by a heating mechanism projecting
energy (e.g., radiative heat and/or energy beam). The energy may
include an energy beam and/or dispersed energy (e.g., radiator or
lamp). The energy may include radiative heat. The radiative heat
may be projected by a dispersive and/or diffusive energy source
(e.g., a heating mechanism) comprising a lamp, a strip heater
(e.g., mica strip heater, or any combination thereof), a heating
rod (e.g., quartz rod), or a radiator (e.g., a panel radiator). The
heating mechanism may comprise an inductance heater. The heating
mechanism may comprise a resistor (e.g., variable resistor). The
resistor may comprise a varistor or rheostat. A multiplicity of
resistors may be configured in series, parallel, or any combination
thereof. In some cases, the system can have a single (e.g., first)
energy source (e.g., that may generate the energy flux and/or
scanning energy source). An energy source can be a source
configured to deliver energy to an area (e.g., a confined area). An
energy source can deliver energy to the confined area through
radiative heat transfer (e.g., as described herein).
[0212] The energy beam may include a radiation comprising an
electromagnetic, or charged particle beam. The energy beam may
include radiation comprising electromagnetic, electron, positron,
proton, plasma, or ionic radiation. The electromagnetic beam may
comprise microwave, infrared, ultraviolet, or visible radiation.
The energy beam may include an electromagnetic energy beam,
electron beam, particle beam, or ion beam. An ion beam may include
a cation or an anion. A particle beam may include radicals. The
electromagnetic beam may comprise a laser beam. The energy beam may
comprise plasma. The energy source may include a laser source. The
energy source may include an electron gun. The energy source may
include an energy source capable of delivering energy to a point or
to an area. In some embodiments, the energy source can be a laser
source. The laser source may comprise a CO.sub.2, Nd:YAG, Neodymium
(e.g., neodymium-glass), an Ytterbium, or an excimer laser. The
laser may be a fiber laser. The energy source may include an energy
source capable of delivering energy to a point or to an area. The
energy source (e.g., first scanning energy source) can provide an
energy beam having an energy density of at least about 50
joules/cm.sup.2 (J/cm.sup.2), 100 J/cm.sup.2, 200 J/cm.sup.2, 300
J/cm.sup.2, 400 J/cm.sup.2, 500 J/cm.sup.2, 600 J/cm.sup.2, 700
J/cm.sup.2, 800 J/cm.sup.2, 1000 J/cm.sup.2, 1500 J/cm.sup.2, 2000
J/cm.sup.2, 2500 J/cm.sup.2, 3000 J/cm.sup.2, 3500 J/cm.sup.2, 4000
J/cm.sup.2, 4500 J/cm.sup.2, or 5000 J/cm.sup.2. The energy source
(e.g., first scanning energy source) can provide an energy beam
having an energy density of at most about 50 J/cm.sup.2, 100
J/cm.sup.2, 200 J/cm.sup.2, 300 J/cm.sup.2, 400 J/cm.sup.2, 500
J/cm.sup.2, 600 J/cm.sup.2, 700 J/cm.sup.2, 800 J/cm.sup.2, 1000
J/cm.sup.2, 500 J/cm.sup.2, 1000 J/cm.sup.2, 1500 J/cm.sup.2, 2000
J/cm.sup.2, 2500 J/cm.sup.2, 3000 J/cm.sup.2, 3500 J/cm.sup.2, 4000
J/cm.sup.2, 4500 J/cm.sup.2, or 5000 J/cm.sup.2. The energy source
(e.g., scanning energy source) can provide an energy beam having an
energy density of a value between the afore-mentioned values (e.g.,
from about 50 J/cm.sup.2 to about 5000 J/cm.sup.2, from about 200
J/cm.sup.2 to about 1500 J/cm.sup.2, from about 1500 J/cm.sup.2 to
about 2500 J/cm.sup.2, from about 100 J/cm.sup.2 to about 3000
J/cm.sup.2, or from about 2500 J/cm.sup.2 to about 5000
J/cm.sup.2). In an example a laser (e.g., scanning energy source)
can provide electromagnetic (e.g., light) energy at a peak
wavelength of at least about 100 nanometer (nm), 400 nm, 500 nm,
750 nm, 1000 nm, 1010 nm, 1020 nm, 1030 nm, 1040 nm, 1050 nm, 1060
nm, 1070 nm, 1080 nm, 1090 nm, 1100 nm, 1200 nm, 1500 nm, 1600 nm,
1700 nm, 1800 nm, 1900 nm, or 2000 nm. In an example a laser can
provide light energy at a peak wavelength of at most about 2000 nm,
1900 nm, 1800 nm, 1700 nm, 1600 nm, 1500 nm, 1200 nm, 1100 nm, 1090
nm, 1080 nm, 1070 nm, 1060 nm, 1050 nm, 1040 nm, 1030 nm, 1020 nm,
1010 nm, 1000 nm, 750 nm, 500 nm, 400 nm, or 100 nm. The laser can
provide light energy at a peak wavelength between any of the
afore-mentioned peak wavelength values (e.g., from about 100 nm to
about 2000 nm, from about 500 nm to about 1500 nm, or from about
1000 nm to about 1100 nm). The energy beam (e.g., laser) may have a
power of at least about 0.5 Watt (W), 1 W, 2 W, 3 W, 4 W, 5 W, 10
W, 20 W, 30 W, 40 W, 50 W, 60 W, 70 W, 80 W, 90 W, 100 W, 120 W,
150 W, 200 W, 250 W, 300 W, 350 W, 400 W, 500 W, 750 W, 800 W, 900
W, 1000 W, 1500 W, 2000 W, 3000 W, or 4000 W. The energy beam may
have a power of at most about 0.5 W, 1 W, 2 W, 3 W, 4 W, 5 W, 10 W,
20 W, 30 W, 40 W, 50 W, 60 W, 70 W, 80 W, 90 W, 100 W, 120 W, 150
W, 200 W, 250 W, 300 W, 350 W, 400 W, 500 W, 750 W, 800 W, 900 W,
1000 W, 1500, 2000 W, 3000 W, or 4000 W. The energy beam may have a
power between any of the afore-mentioned laser power values (e.g.,
from about 0.5 W to about 100 W, from about 1 W to about 10 W, from
about 100 W to about 1000 W, or from about 1000 W to about 4000 W).
The first energy source (e.g., producing the first scanning energy
beam) may have at least one of the characteristics of the second
energy source (e.g., producing the second scanning energy beam).
The energy flux may have the same characteristics disclosed herein
for the energy beam. The energy flux may be generated from the same
energy source or from different energy sources. The energy flux may
be of a lesser power as compared to the scanning energy beam.
Lesser power may be by about 0.25, 0.5, 0.75, or 1 (one) order of
magnitude. The scanning energy beam may operate independently with
the energy flux. The scanning energy beam and the energy flux may
be generated by the same energy source that operates in two modules
(e.g., different modules) respectively. The characteristics of the
irradiating energy may comprise wavelength, power, amplitude,
trajectory, footprint, intensity, energy, fluence, Andrew Number,
hatch spacing, scan speed, or charge. The charge can be electrical
and/or magnetic charge. Andrew number is proportional to the power
of the irradiating energy over the multiplication product of its
velocity (e.g., scan speed) by the its hatch spacing. The Andrew
number is at times referred to as the area filling power of the
irradiating energy.
[0213] An energy beam from the energy source(s) can be incident on,
or be directed perpendicular to, the target surface. An energy beam
from the energy source(s) can be directed at an acute angle within
a value of from parallel to perpendicular relative to the target
surface. The energy beam can be directed onto a specified area of
at least a portion of the source surface and/or target surface for
a specified time period. The material in target surface (e.g.,
powder material such as in a top surface of a powder bed) can
absorb the energy from the energy beam and, and as a result, a
localized region of the solid material can increase in temperature.
The energy beam can be moveable such that it can translate relative
to the source surface and/or target surface. The energy source may
be movable such that it can translate relative to the target
surface. The energy beam(s) can be moved via a scanner (e.g., as
disclosed herein). At least two (e.g., all) of the energy sources
can be movable with the same scanner. A least two (e.g., all) of
the energy beams can be movable with the same scanner. At least two
of the energy source(s) and/or beam(s) can be movable (e.g.,
translated) independently of each other. In some cases, at least
two of the energy source(s) and/or beam(s) can be translated at
different rates (e.g., velocities). In some cases, at least two of
the energy source(s) and/or beam(s) can be comprise at least one
different characteristic. The characteristics may comprise
wavelength, power, amplitude, trajectory, footprint, intensity,
energy, or charge. The charge can be electrical and/or magnetic
charge.
[0214] The energy source can be an array, or a matrix, of energy
sources (e.g., laser diodes). Each of the energy sources in the
array, or matrix, can be independently controlled (e.g., by a
control mechanism) such that the energy beams can be turned off and
on independently. At least a part of the energy sources in the
array or matrix can be collectively controlled such that the at
least two (e.g., all) of the energy sources can be turned off and
on simultaneously. The energy per unit area or intensity of at
least two energy sources in the matrix or array can be modulated
independently (e.g., by a control mechanism or system). At times,
the energy per unit area or intensity of at least two (e.g., all)
of the energy sources in the matrix or array can be modulated
collectively (e.g., by a control mechanism). The energy source can
scan along the source surface and/or target surface by mechanical
movement of the energy source(s), one or more adjustable reflective
mirrors, or one or more polygon light scanners. The energy
source(s) can project energy using a DLP modulator, a
one-dimensional scanner, a two-dimensional scanner, or any
combination thereof. The energy source(s) can be stationary. The
target and/or source surface can translate vertically,
horizontally, or in an angle (e.g., planar or compound).
Translation of the target and/or surface can be manual, automatic,
or a combination thereof. Translation can be controlled by at least
one controller which at least one controller can operate to
maintain a selected focus (or de-focus) of an energy source at or
near the target and/or surface. Translation control can be local or
remote (e.g., controlled over a network connection). The selected
focus can be a variable focus.
[0215] The energy source can be modulated. The energy flux (e.g.,
beam) emitted by the energy source can be modulated. The modulator
can include amplitude modulator, phase modulator, or polarization
modulator. The modulation may alter the intensity of the energy
beam. The modulation may alter the current supplied to the energy
source (e.g., direct modulation). The modulation may affect the
energy beam (e.g., external modulation such as external light
modulator). The modulation may include direct modulation (e.g., by
a modulator). The modulation may include an external modulator. The
modulator can include an acousto-optic modulator or an
electro-optic modulator. The modulator can comprise an absorptive
modulator or a refractive modulator. The modulation may alter the
absorption coefficient the material that is used to modulate the
energy beam. The modulator may alter the refractive index of the
material that is used to modulate the energy beam.
[0216] An energy beam from the first and/or second energy source
can be incident on, or be directed to, a target surface (e.g., the
exposed surface of the material bed). The energy beam can be
directed to the pre-transformed or transformed material for a
specified time period. That pre-transformed or transformed material
can absorb the energy from the energy source (e.g., energy beam,
diffused energy, and/or dispersed energy), and as a result, a
localized region of that pre-transformed or transformed material
can increase in temperature. The energy source and/or beam can be
moveable such that it can translate relative to the surface (e.g.,
the target surface). In some instances, the energy source may be
movable such that it can translate across (e.g., laterally) the top
surface of the material bed. The energy beam(s) and/or source(s)
can be moved via a scanner. The scanner may comprise a galvanometer
scanner, a polygon, a mechanical-stage (e.g., X-Y-stage), a
piezoelectric device, gimble, or any combination of thereof. The
galvanometer may comprise a mirror. The scanner may comprise a
modulator. The scanner may comprise a polygonal mirror. The scanner
can be the same scanner for two or more energy sources and/or
beams. At least two (e.g., each) energy source and/or beam may have
a separate scanner. The energy sources can be translated
independently of each other. In some cases, at least two energy
sources and/or beams can be translated at different rates, and/or
along different paths. For example, the movement of the first
energy source may be faster (e.g., at a greater rate) as compared
to the movement of the second energy source. The systems and/or
apparatuses disclosed herein may comprise one or more shutters
(e.g., safety shutters). The energy beam(s), energy source(s),
and/or the platform can be moved by the scanner. The galvanometer
scanner may comprise a two-axis galvanometer scanner. The scanner
may comprise a modulator (e.g., as described herein). The energy
source(s) can project energy using a DLP modulator, a
one-dimensional scanner, a two-dimensional scanner, or any
combination thereof. The energy source(s) can be stationary or
translatable. The energy source(s) can translate vertically,
horizontally, or in an angle (e.g., planar or compound angle). The
energy source(s) can be modulated. The scanner can be included in
an optical system that is configured to direct energy from the
energy source to a predetermined position on the target surface
(e.g., exposed surface of the material bed). The controller can be
programmed to control a trajectory of the energy source(s) with the
aid of the optical system. The controller can regulate a supply of
energy from the energy source to the material (e.g., at the target
surface) to form a transformed material. The optical system may be
enclosed in an optical enclosure. An optical enclosure may be any
optical enclosure disclosed in patent application number
PCT/US17/64474, titled "OPTICS, DETECTORS, AND THREE-DIMENSIONAL
PRINTING" that was filed Dec. 4, 2017, which is incorporated herein
by reference in its entirety.
[0217] The energy beam(s) emitted by the energy source(s) can be
modulated. The modulator can include an amplitude modulator, phase
modulator, or polarization modulator. The modulation may alter the
intensity of the energy beam. The modulation may alter the current
supplied to the energy source (e.g., direct modulation). The
modulation may affect the energy beam (e.g., external modulation
such as external light modulator). The modulation may include
direct modulation (e.g., by a modulator). The modulation may
include an external modulator. The modulator can include an
acousto-optic modulator or an electro-optic modulator. The
modulator can comprise an absorptive modulator or a refractive
modulator. The modulation may alter the absorption coefficient the
material that is used to modulate the energy beam. The modulator
may alter the refractive index of the material that is used to
modulate the energy beam.
[0218] Energy (e.g., heat) can be transferred from the material bed
to a cooling member (e.g., heat sink FIG. 1, 113). The cooling
member can facilitate transfer of energy away from a least a
portion of a pre-transformed material layer. In some cases, the
cooling member can be a thermally conductive plate. The cooling
member can be passive. The cooling member can comprise a cleaning
mechanism (e.g., cleaning device), which removes powder and/or
process debris from a surface of the cooling member to sustain
efficient cooling. Debris can comprise dirt, dust, powder (e.g.,
that result from heating, melting, evaporation and/or other process
transitions), or hardened material that did not form a part of the
3D object. In some cases, the cleaning mechanism can comprise a
stationary rotating rod, roll, brush, rake, spatula, or blade that
rotates when the cooling member (e.g., heat sink) moves in a
direction adjacent to the platform (e.g., laterally). The cleaning
mechanism may comprise a vertical cross section (e.g., side cross
section) of a circle, triangle, square, pentagon, hexagon, octagon,
or any other polygon. The vertical cross section may be of an
amorphous shape. In some cases, the cleaning mechanism rotates when
the cooling member moves in a direction that is not lateral. In
some cases, the cleaning mechanism rotates without movement of the
cooling member. In some cases, the cooling member comprises at
least one surface that is coated with a layer that prevents powder
and/or debris from coupling (e.g., attaching) to the at least one
surface (e.g., an anti-stick layer).
[0219] In another aspect, the 3D printer comprises a detection
system. In some embodiments, the detection system detects one or
more characteristics and/or features of the irradiating energy. In
some embodiments, the detection system detects one or more
characteristics and/or features caused by the irradiating energy
(e.g., on the target surface). In some embodiments, the detection
system detects one or more characteristics and/or features of an
electromagnetic radiation. In some embodiments, the detection
system detects one or more characteristics and/or features of a
black body radiation. FIG. 13 shows an example of a (e.g., optical)
detection system (e.g., FIG. 13, 1300) as part of a 3D printer. The
detection system may be operatively coupled to at least one
component of the processing chamber. The at least one component of
the processing chamber may comprise the irradiating energy, the
controller, the target surface, or the platform. The detection
system may be operatively coupled to the build module. The
detection system may be a part of the optical system. The detection
system may be separate from (e.g., different than) the optical
system. The detection system may be operatively coupled to an
energy source (e.g., FIG. 13, 1302). The energy source may be any
energy source disclosed herein (e.g., tiling energy source and/or
scanning energy source). The energy source may irradiate a with
transforming energy (e.g., beam or flux). The irradiated
transforming energy may heat (e.g., at transform) a material at the
target surface, and subsequently emit an electromagnetic radiation
of a different wavelength (e.g., a thermal radiation, e.g., a black
body radiation) and/or be reflected back (e.g., away from the
material). The different wavelength may be a larger wavelength as
compared to the wavelength of the irradiating energy by the energy
source. For example, a laser may emit laser energy towards the
target surface at a position, which irradiation will cause the
irradiated position to heat (e.g., at transform). The laser
irradiation may be reflected back from the target surface (e.g.,
exposed surface of a material bed). The heating of the position at
the target surface may cause emittance of heat radiation. The heat
radiation may have a larger wavelength as compared to the laser
irradiation wavelength. At times, the irradiating energy may
illuminate the enclosure environment. At times, the target surface
may be illuminated by the irradiating energy (e.g., direct or
reflected) or the produced black body radiation. At times, the
enclosure environment may include a separate illumination source
(e.g., a light-emitting diode (LED)). The back reflected
irradiating energy and/or the electromagnetic radiation of a
different wavelength are referred to herein as "the returned energy
beams." The returned energy beams may be detected via one or more
detectors. The detection may be performed in real-time (e.g.,
during at least a portion of the 3D printing). For example, the
real-time detection may be during the transformation of the
pre-transformed material. The irradiating energy may be focused on
a position at the target surface. The returned energy beams may be
focused on their respective detectors. In some embodiments, the
irradiating energy is focused on a position at the target surface
as at least a portion of the returned energy beams are focused on
at least one of their respective detectors. The returned energy
beam can provide energy at a peak wavelength of at least about 100
nanometer (nm), 400 nm, 500 nm, 750 nm, 1000 nm, 1010 nm, 1020 nm,
1030 nm, 1040 nm, 1050 nm, 1060 nm, 1070 nm, 1080 nm, 1090 nm, 1100
nm, 1200 nm, 1500 nm, 1600 nm, 1700 nm, 1800 nm, 1900 nm, 2000 nm,
2100 nm, 2200 nm, 2300 nm, 2400 nm, 2500 nm, 2600 nm, 2700 nm, 2800
nm, 2900 nm 3000 nm, or 3500 nm. The returned energy beam can
provide energy at a peak wavelength of at most about 3500 nm, 3000
nm, 2900 nm, 2800 nm, 2700 nm, 2600 nm, 2500 nm, 2400 nm, 2300 nm,
2200 nm, 2100 nm, 2000 nm, 1900 nm, 1800 nm, 1700 nm, 1600 nm, 1500
nm, 1200 nm, 1100 nm, 1090 nm, 1080 nm, 1070 nm, 1060 nm, 1050 nm,
1040 nm, 1030 nm, 1020 nm, 1010 nm, 1000 nm, 750 nm, 500 nm, 400
nm, or 100 nm. The returned energy beam can provide energy at a
peak wavelength between any of the afore-mentioned peak wavelength
values (e.g., from about 100 nm to about 3500 nm, from about 1000
nm to about 1500 nm, from about 1700 nm to about 2600 nm, or from
about 1000 nm to about 1100 nm). In some embodiments, the detection
system may comprise aberration--correcting optics (e.g., spherical
aberration correcting optics, chromatic aberration correcting
optics, achromatic optics, apochromatic optics, superachromatic
optics, f-theta achromatic optics, or any combinations thereof). In
some embodiments, the aberration-correcting optics is devoid of an
f-theta lens. In some embodiments, the aberration corrective optics
is devoid of f-theta achromatic optics. The detector of the
returned energy beam may detect the energy at the above mentioned
peak wavelengths. The peak wavelength may be a wavelength at full
width at half maximal of the energy profile of the returned energy
beam.
[0220] In some cases, one or more optical elements of a detection
system (e.g., comprising a lens, mirror, or beam splitter) is
comprised of an optical material having high thermal conductivity
(e.g., having any value of high thermal conductivity disclosed
herein). The optical element may be any optical element disclosed
in patent application serial number PCT/US17/64474, or in patent
application serial number PCT/US17/60035, titled "GAS FLOW IN
THREE-DIMENSIONAL PRINTING" that was filed on Nov. 3, 2017, each of
which is incorporated herein by reference in its entirety. The
optical material may have a thermal conductivity of at least about
1.5 W/m.degree. C. (Watts per meter per degree Celsius), 2
W/m.degree. C., 2.5 W/m.degree. C., 3 W/m.degree. C., 3.5
W/m.degree. C., 4 W/m.degree. C., 4.5 W/m.degree. C., 5 W/m.degree.
C., 5.5 W/m.degree. C., 6 W/m.degree. C., 7 W/m.degree. C., 8
W/m.degree. C. 9 W/m.degree. C., 10 W/m.degree. C., or 15
W/m.degree. C., at 300 K (Kelvin). The optical material may have a
thermal conductivity ranging between any of the afore-mentioned
values (e.g., from about 1.5 W/m.degree. C. to about 20 W/m.degree.
C., from about 1.5 W/m.degree. C. to about 5 W/m.degree. C., or
from about 5 W/m.degree. C. to about 20 W/m.degree. C.), at 300K.
In some embodiments, the optical element (e.g., that includes the
high thermally conductivity material) comprises sapphire, crystal
quartz, zinc selenide (ZnSe), magnesium fluoride (MgF.sub.2), or
calcium fluoride (CaF.sub.2). In some embodiments, the optical
element comprises fused silica (e.g., UV fused silica), or fused
quartz. The optical element may comprise sodium carbonate
(Na.sub.2CO.sub.3), lime (CaO), magnesium oxide (MgO), aluminum
oxide (Al.sub.2O.sub.3), boron trioxide (B.sub.2O.sub.3), soda
(Na.sub.2O.sub.3), barium oxide (BaO), lead oxide (PbO), potassium
oxide (K.sub.2O), zinc oxide (ZnO), or germanium oxide
(GeO.sub.2).
[0221] In some embodiments, the optical element comprises a
material having a higher thermal conductivity than that of fused
silica (e.g., higher than about 1.38 W/m.degree. C.), for example,
Zerodur.RTM.. In some embodiments, the optical material comprises
sapphire. In some embodiments, the optical element comprises a
material having a lower thermal conductivity than that of fused
silica and/or fused quartz (e.g., lower than about 1.38 W/m.degree.
C.), for example, borosilicate (e.g., BK 7), silicon fluoride
(e.g., SF 2), or Pyrex.RTM.. In some embodiments, the optical
material may have a thermal conductivity of at most about 20
W/m.degree. C., 10 W/m.degree. C., 9 W/m.degree. C., 8 W/m.degree.
C., 7 W/m.degree. C., 6 W/m.degree. C., 5.5 W/m.degree. C., 5
W/m.degree. C., 4.5 W/m.degree. C., 4 W/m.degree. C., 3.5
W/m.degree. C., 3 W/m.degree. C., 2.5 W/m.degree. C., or 2
W/m.degree. C., at 300K. An optical element having a high
reflectivity may have a reflectivity of at least about 88% (e.g.,
percentage of incident radiative energy), 90%, 92%, 94%, 96%, 98%,
99%, 99.5%, or 99.9%, at a specified wavelength or wavelength
range, for an incident radiative energy. The optical material
having a high reflectivity may have a reflectivity ranging between
any of the afore-mentioned values (e.g., from about 90% to about
99.9%, from about 90% to about 95%, or from about 95% to about
99.9%). An optical element having a high reflectivity can be
comprised of any optical element material disclosed herein. In some
embodiments, the optical element having a high reflectivity
comprises a metallic coating. The metallic coating may comprise
aluminum, UV enhanced aluminum, protected aluminum, silver,
protected silver, gold, or protected gold. In some embodiments, the
optical element (e.g., having a high reflectivity) comprises a
dielectric coating or an (e.g., ion-beam) sputtered coating. In
some embodiments, the optical element comprises a material with a
linear coefficient of thermal expansion of at most about 10 ppm, 8
ppm, 6 ppm, 5 ppm, 3 ppm, 2 ppm, 1 ppm, or 0.5 ppm per degree
Celsius. The optical element may comprise a material with a linear
coefficient of thermal expansion between any of the afore-mentioned
values (e.g., from about 10 ppm to about 0.5 ppm, from about 5 ppm
to about 0.5 ppm, or from about 2 ppm to about 0.5 ppm per degree
Celsius). In some embodiments, the optical element comprises a
material with an optical absorption coefficient of at most about 10
ppm, 50 ppm, 100 ppm, 250 ppm, 500 ppm, 750 ppm, or 900 ppm per
centimeter, at the wavelength of the laser. The optical element may
comprise a material with an optical absorption coefficient of any
value between the afore-mentioned values (e.g., from about 10 ppm
to about 900 ppm, from about 10 ppm to about 500 ppm, from about
250 ppm to about 750 ppm, or from about 750 ppm to about 900 ppm
per centimeter, at the wavelength of the laser). The material can
be an optically transparent material.
[0222] In some embodiments, the irradiating energy is collimated
(e.g., by a collimator). The energy source may be operatively
coupled to a collimator (e.g., FIG. 13, 1305). The collimator may
collimate (e.g., narrow, parallelize, and/or align along a specific
direction) the irradiating energy (e.g., the energy beam or the
energy flux). The collimator may be an optical collimator (e.g.,
may comprise a curved lens or mirror and a light source). The
collimator may include a fiducial marker (e.g., an image) to focus
on. The fiducial marker may assist in collimating the energy beam
to a specific focus. The collimator may include one or more filters
(e.g., wavelength filters, gamma ray filters, neutron filters,
X-ray filters, and/or electromagnetic radiation filters). The
collimator may comprise parallel hole collimator, pinhole
collimator, diverging collimator, converging collimator, fanbeam
collimator, or slanthole collimator.
[0223] The collimated irradiating energy may be directed in an
optical path (e.g., FIG. 13, 1371, or 1375) to a position (e.g.,
1381, or 1384) on the target surface (e.g., 1316). The optical path
may diverge or converge the irradiating energy. The divergence or
convergence of the irradiating energy may comprise a lens. The lens
may be a converging lens or a diverging lens. At least one lens may
be movable (e.g., laterally) relative to the target surface.
[0224] In some embodiments, the optical path from the energy
source, passing the target surface, to the detector(s) comprises a
variable focus mechanism (e.g., aberration-correcting optics, e.g.,
achromatic optics). The optical path (or the variable focus
mechanism) may comprise one or more optical elements (e.g., FIG.
13, 1370, 1365, 1345, 1350). The optical path may be controlled
manually and/or by a controller. The control may be real-time
control during at least a portion of the 3D printing. The
controller may control the positions of the optical elements to
adjust the optical path. The controller may control the positions
of the optical elements to adjust the focus of the beam on the
target surface and/or on the detector(s). The one or more optical
elements may be translatable. The one or more optical elements may
be stationary. The optical element may be a negative optical
element (e.g., a concave lens or a diverging lens). The optical
element may be a positive optical element (e.g., a convex lens or a
converging lens). The optical element may be a beam splitter (e.g.,
1370). The optical elements in the optical path may be arranged
achromatically (e.g., to allow simultaneous focus on at least one
detector and on a position on the target surface). The achromatic
optics may keep the optical detectors and an imaging device (e.g.,
a fiber optics coupled to a single detector) in focus. Optionally,
a portion of the collimated energy beam may be deflected (e.g.,
1354, through filter 1391) or reflected (e.g., 1342, reflected
returning energy source radiation from a target surface). The
deflected and/or reflected energy beam may be optionally filtered
by a filter (e.g., FIG. 13, beam 1344 filtered by filter 1394). The
deflected and/or reflected energy beam may be directed to a
detector (e.g., FIGS. 13, 1328 and/or 1329 for deflected and
reflected, respectively). The detector may be an optical detector.
The detector may comprise a spectrometer. The detector can be an
imaging detector. The detector may be an intensity reflection
detector. The detector may allow analyzing (e.g., visual, and/or
reflective analysis) of an irradiated position at the target
surface (e.g., a melt pool).
[0225] In some examples, at least one optical element translates
before, after, and/or during at least a portion of the 3D printing
(e.g., in real time). In some examples, at least one optical
element is stationary. In some examples, at least one optical
element is controlled before, after, and/or during at least a
portion of the 3D printing (e.g., in real time). The first optical
element (e.g., FIG. 13, 1365) may be translatable (e.g., laterally,
according to arrow 1366). The first optical element may be coupled
to a movable element (e.g., a swivel mount, a gimbal, a motor, an
electronic controller, a moving belt, or a scanner) that translates
the first optical element. The first optical element may be coupled
to an actuator (e.g., lateral actuator). The translation of the
movable element may be before, after during and/or during at least
a portion of the 3D printing. For example, the movable element may
translate in real-time. The speed of translation of the first
optical element may be correlated (e.g., coupled, and/or
synchronized) with the translated transforming energy beam. The
correlation may be in real-time. The second optical element (e.g.,
FIG. 13, 1345) and/or third optical element (e.g., FIG. 13, 1350)
may be stationary. The second and/or third optical elements may be
positioned to adjust the focus of at least one of (i) the
irradiating energy, (ii) the back reflected irradiating energy, and
(iii) the electromagnetic radiation of a different wavelength. For
example, the second and/or third optical elements may be positioned
to adjust the focus of the irradiating energy, and at least one of
(i) the back reflected irradiating energy, and (ii) the
electromagnetic radiation of a different wavelength. The focus may
be adjusted before, during and/or after at least a portion of the
3D printing (e.g., in real-time). The focus may be adjusted before
transforming, during transforming and/or after transforming a
portion of the target surface (e.g., a layer of material bed).
[0226] One or more electromagnetic radiation beams (e.g., FIG. 13,
1358, 1360) having a different wavelength from the transforming
energy beam (e.g., 1370) may be directed from the target surface to
one or more optical elements (e.g., lens, mirror, beam splitter,
beam filter) of the detection system. The optical element may be a
wide field lens. The wide field lens may be placed in the path of
the transforming energy beam (e.g., between the scanner and the
target surface). The wide field lens may be placed in the optical
path (e.g., between the optical elements and the detector). The
wide field lens may have a focal length shorter than a normal lens.
The shorter focal length allows the energy beam to cover a wider
area of the target surface. The electromagnetic radiation beams
having a different wavelength from the transforming energy beam may
be a large wavelength energy beam (e.g., as they are of a larger
wavelength than the transforming energy beam). The transforming
energy beam may be the irradiating energy (e.g., energy flux and/or
scanning energy beam). One or more of the optical element (e.g.,
mirror, FIG. 13, 1331, 1335) may be translatable (e.g., rotating).
Translatable may be vertically, horizontal, and/or at an angle. The
mirror may facilitate aligning the returned energy beams on the
detector(s) (e.g., each respectively). In some examples, the image
directed on the detector correlates to the transforming energy beam
spot on the target surface. At times, the returned energy beams
(e.g., large wavelength energy beams) originating from the target
surface (e.g., 1380) are split into two wavelength ranges. The
wavelength range split may utilize a filter (e.g., 1393) and/or
beam splitter (e.g., 1332). Each of one or more returned energy
beams may have a different energy beam characteristics (e.g.,
wavelength). Each of one or more detectors may be susceptible to
(e.g., sensitive to detecting) different beam characteristics
(e.g., wavelength range). The filter element may allow an energy
beam with a particular characteristic (e.g., a polarity, wavelength
range, intensity, profile). The filter may filter the returned
energy beam based on at least one of its characteristic. For
example, a first detector energy beam (e.g., FIG. 13, 1340) may be
susceptible to a shorter wavelength as compared to a second
detector energy beam (e.g., FIG. 13, 1380). At least two returned
energy beams (or range groups thereof) may be separated by the same
filter. At least two returned energy beams (or range groups
thereof) may be separated by their respective and different filter
(e.g., a first filter that filters shorter wavelength energy beam
and a second filter that filters a longer wavelength energy beam).
Each filter can isolate one or more wavelengths. Each filter may
isolate a narrower range of wavelengths as compared to the returned
energy beams. The filters can be optical, electronic, and/or
magnetic filter. The filter may comprise a high pass filter,
bandpass filter, a notch filter, a multi-bandpass filter or a low
pass filter. The filter may comprise an absorption filter or a
reflection filter. The filter elements may be fixed. At times, the
filter elements may be translatable (e.g., before, after, and/or
during at least a portion of the 3D printing). One or more filter
elements may be coupled to a translatable element (e.g., a robotic
arm, motor, gimbal, controller, a swivel mount, a moving belt, or a
scanner). Optionally, a converging optical element (e.g., 1330,
1333) may be placed along the returned energy beam path. The
converging optical element may focus one or more (e.g., all)
detector energy beams on the detectors. In some embodiments, an
optical fiber is connected to a detector. In some embodiments, at
least one optical fiber is connected to a detector. For example, a
plurality of optical fibers may be connected to a (e.g., one)
detector. The (e.g., converging) optical element may focus one or
more (e.g., all) detector energy beams on (e.g., onto) an optical
fiber. A filter element may be selected such that the filter
element may balance the spot size on the detector and/or optical
fiber (e.g., that is coupled thereto). A narrow filter element may
provide a narrow wavelength range (e.g., having a lower signal
intensity relative to a wide filter). A wide filter element may
provide a wide wavelength range (e.g., having a higher signal
intensity relative to a narrow filter).
[0227] In some embodiments, the energy beam is operatively coupled
to an optical system comprising one or more detectors. The
returning energy beams may be directed by an optical system (e.g.,
component(s) thereof) to one or more detectors (e.g., FIG. 13,
1320, 1325, 1327). Each detector may detect a different wavelength
range of the returning energy beams. Each detector may have a
different gain pattern. The gain pattern of the detector may be
susceptible (e.g., respond) to a wavelength (e.g., range) of the
energy beam that is directed to it. The gain pattern of the
detector may be susceptible to an intensity of the energy beam that
is directed to it. In some cases, at least one of the detectors can
be a charge-coupled device (CCD) camera. At least one of the
detectors can be a pyrometer and/or a bolometer. At least one of
the detectors comprise an In GaAs and/or Gallium sensor. At times,
the detector may be coupled to at least one optical fiber (e.g., a
fiber coupled to a detector). At times, the detector may comprise a
multiplicity of detectors. Each of the multiplicity of detectors
may be coupled to a different optical fiber respectively. At times,
an optical fiber may be coupled to a single detector. At times, at
least two detectors may be coupled to an optical fiber. At times,
at least two optical fibers may be coupled to a detector. The
different optical fibers may form an optical fiber bundle. The
optical fiber detector may comprise a magnifier and/or a
de-magnifier coupled to a fiber. The optical fiber bundle may be a
coherent bundle of fiber. The optical fiber may split to two or
more detectors. The optical fiber detector may be positioned prior
to the detector and after the optical element (e.g., filter,
mirror, or beam splitter, whichever disposed before the optical
fiber). At times, the detector may be a single (e.g., pixel)
detector. The detector may be devoid of (e.g., not include, or
exclude) spatial information.
[0228] One or more optical elements (e.g., lenses, FIG. 13, 1390,
1385, 1395) may be placed preceding the one or more detectors, and
along the path of the returning energy beam. Optionally, there may
be one or more filter elements (e.g., 1397, 1398, 1399, 1396)
placed before each of the optical element. The optical element may
maintain the focus of the detector energy beam (e.g., 1382, 1383)
on each detector (e.g., simultaneously with maintaining the focus
of the transforming energy beam on the target surface). The optical
element may remain in a fixed position while maintaining the focus
of the detector energy beam. The optical element may be movable
(e.g., translatable) for maintaining the focus of the detector
energy beam. The optical element can move (e.g., according to
arrows next to 1385, 1390, 1395) before, during, and/or after
processing of the target material. The optical element may alter a
focus of the returning energy beam on each detector. At times, the
optical element may maintain and/or alter an image size of one or
more detected images (e.g., perform chromatic aberration and/or
correction). At times, the optical element may synchronize one or
more images from the imaging sensor.
[0229] At least one optical element may direct the irradiating
energy to a scanner (e.g., X-Y scanner, galvanometer scanner). FIG.
13 shows an example in which three lenses (1365, 1345, and 1350)
direct the irradiating energy 1372 to the scanner 1310. The scanner
may be any scanner disclosed herein. The irradiating energy may be
directed to one or more scanners. The scanner may direct the
irradiating energy on to a position at the target surface. The
energy beam may travel through one or more filters, apertures, or
optical windows on its way to the target surface (e.g., as depicted
in FIGS. 1 and 9).
[0230] In some embodiments, a multiplicity of scanners directs a
multiplicity of energy beams respectively to the target surface
(e.g., to different positions of the target surface). The
multiplicity of energy beams may be of different characteristics
(e.g., large vs. small cross section) and/or functions (e.g.,
hatching vs. tiling) in the 3D printing process. The scanners may
be controlled manually and/or by at least one controller. For
example, at least two scanners may be directed by the same
controller. For example, at least two scanners may be directed each
by their own different controller. The multiplicity of controllers
may be operatively coupled to each other. The multiplicity of
energy beams may irradiate the surface simultaneously or
sequentially. The multiplicity of energy beams may be directed
towards the same position at the target surface, or to different
positions at the target surface. The multiplicity of energy beams
may comprise the energy flux, or scanning energy beam. The one or
more scanners may be positioned at an angle (e.g., tilted) with
respect to the material bed. The one or more sensors may be
disposed adjacent to the material bed. The one or more sensors may
be disposed in an indirect view of the target surface. The one or
more sensors may be configured to have a field of view of at least
a portion of an exposed surface of the material bed. A portion of
the enclosure, that is occupied by the energy beam (e.g., the
energy flux or the scanning energy beam) can define a processing
cone. FIG. 16 shows an example of two scanners (e.g., 1620, 1610)
that are tilted at an angle 1630 with respect to the target surface
1615. The scanner may be positioned such that the processing cones
of the scanners (e.g., FIG. 16, 1675, 1670) may have a large
overlap region (e.g., 1650) of potential irradiation of the target
surface. Positioned may include angular position (e.g., 1630). In
some embodiments one or more scanners may be positioned at a normal
to the target surface. The target surface may be the exposed
surface of a material bed. Large may include covering a maximum
number of positions on the target surface. Large may include
covering all the positions on the target surface. Each position on
the target surface may receive exposure from each of the scanners.
At times, the target surface may be translated to achieve a desired
exposure from each of the scanners. The scanners may comprise high
conductivity and/or high reflectivity mirrors (e.g., sapphire
mirrors, beryllium mirrors, e.g., as disclosed herein).
[0231] A controller may be operatively coupled to at least one
component of the detection system. The controller may control the
amount of translation of the variable focus system. The controller
may adjust the position of the optical elements to vary the
cross-section of the transforming beam. The controller may adjust
the position of the optical elements to vary a footprint of the
transforming beam and/or its focus on the target surface. The
controller may direct the one or more filters of the optical system
to activate or de-activate. Activating or de-activating a filter
may allow a specific type of energy beam (e.g., beam of a certain
wavelength region) to radiate. The controller may adjust at least
one characteristic of the irradiating energy (e.g., as disclosed
herein). For example, the controller may adjust the power density
and/or fluence of the energy beam. Adjustments by the controller
may be static (e.g., not in real-time). Adjustments by the
controller may be dynamic (e.g., in real-time). Static adjustments
may be done before or after 3D printing. Dynamic adjustments may be
done during at least a portion of the 3D printing (e.g., during
transformation of the pre-transformed material). At times, static
adjustments may be done before and/or after an optical detection.
At times, dynamic adjustments may be done during optical
detection.
[0232] FIG. 14 shows an example of an optical fiber bundle (e.g.,
1400). The optical fiber bundle may include one or more single
(e.g., pixel) detectors. Each pixel detector may be optionally
coupled to an optical fiber. The optical fiber bundle may comprise
a central fiber (e.g., 1410). One or more independent single
detectors (e.g., at least 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10
detectors) coupled to one or more independent optical fibers (e.g.,
at least 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 optical fibers)
respectively may be disposed adjacent to the central fiber. For
example, the one or more independent optical fibers may engulf
(e.g., surround) the central fiber. The number of independent
optical fibers that engulf the central fiber may vary (e.g., the
central fiber may be engulfed by at least 1, 2, 3, 4, 5, 6, 7, 8, 9
or 10 optical fibers). The engulfed optical fibers may be engulfed
by one or more independent optical fibers (e.g., the first one or
more independent fibers adjacent to the central fiber may be
engulfed by at least 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 optical
fibers). Engulf may be in at least one cross-sectional circular
arrangement (e.g., FIG. 14). In some embodiments, the optical fiber
bundle comprises (i) another optical fiber that has a cross section
that is (e.g., substantially) the same as the cross section of the
central optical fiber, or (ii) another optical fiber that has a
cross section that is different (e.g., smaller, or larger) from the
cross section of the central optical fiber. In some embodiments,
the one or more independent optical fibers have a cross section
that is (e.g., substantially) the same (e.g., 1420) as the cross
section of the central optical fiber (e.g., 1410). In some
embodiments, the one or more independent optical fibers have a
cross section that is different than the cross section of the
central optical fiber. For example, the one or more independent
optical fibers may have a cross section that is larger (e.g., 1430,
1440) than the cross section of the central optical fiber (e.g.,
1410). The larger cross section of the optical fiber may facilitate
detection of a returning energy beam striking a larger cross
section of the optical fiber, and thus allowing for detection of a
lower intensity energy beam. The adjacent one or more single
detectors may allow detection of energy beam that strikes an area
larger than the area detected by the central fiber. For example,
the outermost single detector (e.g., 1440) may detect (e.g.,
collect irradiation from) an area that is larger than the area
detected by the central fiber. Larger may comprise at least about
2, 3, 5, 10, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80,
85, 90, 95 or 100 times larger area than the area detected by the
central fiber. Larger may comprise at most about 2, 3, 5, 10, 20,
25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 or 100
times larger area than the area detected by the central fiber. The
outermost single detector may detect an area larger than the area
detected by the central fiber, wherein larger can be between any of
the afore-mentioned values (e.g., 2 times to 100 times, from about
2 times to about 30 times, from about 35 times to about 70 times,
or from about 75 times to about 100 times). The central fiber may
detect a pixel at its highest resolution. As the detection area
increases amongst the surrounding single detectors, the surrounding
fiber may detect one or more lower resolution pixels. The at least
one optical fiber in the bundle may be aligned with the portion of
the energy beam that has the strongest signal intensity (e.g.,
radiation energy). The one optical fiber can be aligned (e.g., in
real time) to be the central optical fiber. As the detection area
of the fiber detectors increase, the signal intensity may drop. The
increasing area of the detector may allow improvement of the signal
(e.g., as the signal to noise ratio decreases). The fiber bundle
may allow maximizing the collection rate of (e.g., optical)
information (e.g., by selecting a sample of optical fiber
detectors, by varying the sampling frequency of the detectors). The
optical fiber bundle may be a lower cost alternative to thermal
imaging detectors (e.g., In GaAs or Ge). The optical fiber bundle
(e.g., having varied cross sectional optical fibers), may allow
quicker focusing and/or signal detection.
[0233] The detector may be any detector disclosed in patent
application number PCT/US15/65297, titled "FEEDBACK CONTROL SYSTEMS
FOR THREE-DIMENSIONAL PRINTING" that was filed on Dec. 11, 2015,
which is incorporated herein by reference in its entirety. The
detectors can comprise the sensors. The detectors (e.g., sensors)
can be configured to measure one or more properties of the 3D
object and/or the pre-transformed material (e.g., powder). The
detectors can collect one or more signals from the 3D object and/or
the target surface (e.g., by using the returning energy beams). In
some cases, the detectors can collect signals from one or more
optical sensors (e.g., as disclosed herein). The detectors can
collect signals from one or more vision sensors (e.g. camera),
thermal sensors, acoustic sensors, vibration sensors, spectroscopic
sensor, radar sensors, and/or motion sensors. The optical sensor
may include an analogue device (e.g., CCD). The optical sensor may
include a p-doped metal-oxide-semiconductor (MOS) capacitor,
charge-coupled device (CCD), active-pixel sensor (APS),
micro/nano-electro-mechanical-system (MEMS/NEMS) based sensor, or
any combination thereof. The APS may be a complementary MOS (CMOS)
sensor. The MEMS/NEMS sensor may include a MEMS/NEMS inertial
sensor. The MEMS/NEMS sensor may be based on silicon, polymer,
metal, ceramics, or any combination thereof. The detector (e.g.,
optical detector) may be coupled to an optical fiber.
[0234] The detector may include a temperature sensor. The
temperature sensor (e.g., thermal sensor) may sense a IR radiation
(e.g., photons). The thermal sensor may sense a temperature of at
least one melt pool. The metrology sensor may comprise a sensor
that measures the FLS (e.g., depth) of at least one melt pool. The
transforming energy beam and the detector energy beam (e.g.,
thermal sensor beam and/or metrology sensor energy beam) may be
focused on substantially the same position. The transforming energy
beam and the detector energy beam (e.g., thermal sensor beam and/or
metrology sensor energy beam) may be confocal.
[0235] The detector may include an imaging sensor. The imaging
sensor can image a surface of the target surface comprising
untransformed (e.g., pre-transformed) material and at least a
portion of the 3D object. The imaging sensor may be coupled to an
optical fiber. The imaging sensor can image (e.g. using the
returning energy beam) a portion of the target surface comprising
transforming material (e.g., one or more melt pools and/or its
vicinity). The optical filter or CCD can allow transmission of
background lighting at a predetermined wavelength or within a range
of wavelengths.
[0236] The detector may include a reflectivity sensor. The
reflectivity sensor may include an imaging component. The
reflectivity sensor can image the material surface at variable
heights and/or angles relative to the (target) surface. In some
cases, reflectivity measurements can be processed to distinguish
between the exposed surface of the material bed and a surface of
the 3D object. For example, the untransformed (e.g.,
pre-transformed) material in the target surface can be a diffuse
reflector and the 3D object (or a melt pool, a melt pool keyhole)
can be a specular reflector. Images from the detectors can be
processed to determine topography, roughness, and/or reflectivity
of the surface comprising the untransformed (e.g., pre-transformed)
material and the 3D object. The detector may be used to perform
thermal analysis of a melt pool and/or its vicinity (e.g.,
detecting keyhole, balling and/or spatter formation). The surface
can be sensed (e.g., measured) with dark-field and/or bright field
illumination and a map and/or image of the illumination can be
generated from signals detected during the dark-field and/or bright
field illumination. The maps from the dark-field and/or bright
field illumination can be compared to characterize the target
surface (e.g., of the material bed and/or of the 3D object). For
example, surface roughness can be determined from a comparison of
dark-field and/or bright field detection measurements. In some
cases, analyzing the signals can include polarization analysis of
reflected or scattered light signals.
[0237] In some embodiments, measurements are made by a detector
system (e.g., comprising an optical system) having an indirect view
(e.g., devoid of a direct view) of one or more of (i) a target
surface, (ii) a processing beam (e.g., a transforming energy beam
or a scanning energy beam), (iii) a processing area (e.g., a
position where an irradiating energy beam is incident on a surface,
e.g., a footprint of the energy beam on the target surface), (iv) a
calibration structure, and/or (v) a portion of a forming 3D object.
In some embodiments, the indirect measurements can measure
reflection of energy (e.g., in the form of light) from a target
surface and/or at least one species (e.g., particles, gas, and/or
plasma) within the enclosure, while the detector is situated
outside of the enclosure. The detector system can comprise one or
more detectors. The detector system can comprise one or more
optical elements (e.g., mirror, beam splitter, wave guide or
filter). The wave guide can comprise an optical fiber. Measurements
can be taken before, during and/or after processing (e.g.,
transforming) one or more (e.g., pre-transformed) materials. In
some embodiments one or more measurements can be taken before
processing of a material (e.g., of a background level of radiation
in an enclosure). The one or more measurements can be used as a
baseline measurement (set) against which subsequent measurements
are compared (e.g., measurements of radiation levels in an
enclosure during processing). The detector can comprise one or more
sensors (e.g., one or more photodiode((s)), photoconductive
detector, and/or cameras (e.g., CCD, IR), e.g., as described
herein. The detector(s) can detect an intensity of illumination
(e.g., electromagnetic radiation)) that is reflected and/or
scattered (e.g., off the target surface). An indirect measurement
as described herein can be a measurement of illumination that that
is not (e.g., directly) emanating from a transformation region
(e.g., a melt pool)) during a transformation process. For example,
an indirect measurement can be a measurement of illumination
emanating from a vicinity of a transformation region during a
transformation process. The vicinity can extend to up to about 1,
2, 3, 4, 5, 6, or 7 melt pool FLS (e.g., diameters) beyond the
transformation (e.g., melt pool formation) region. The detector
systems can comprise one or more filters (e.g., a polarity filter,
a high pass filter, a low pass filter, a notch filter, a bandpass
filter, and/or a multibandpass filter). As non-limiting examples,
the detector(s) can comprise (i) a UV bandpass filter, (ii) an IR
bandpass filter, and/or (iii) a near-IR bandpass filter. The filter
can be operable to reject electromagnetic wavelengths that
correspond to illumination wavelengths that emanate from a
transformation region (such as a melt pool) of a target material or
from a vicinity thereof (e.g., an immediate vicinity thereof).
Processing of measurements (e.g., generated by a gray field
detector) can distinguish any (e.g., at least one) of the material
characteristics as described herein, for example. The material
characteristics may comprise a topography, roughness, or
reflectivity of one or more materials (e.g., of pre-transformed
material, transformed material, and/or target surface). The
measurements can be processed to provide input data (e.g., to a
control system, e.g., feedback data) regarding a processing state.
For example, that a target surface is undergoing a (e.g., average,
intense and/or abrupt) transformation, a (e.g., average or intense)
temperature change, or any combination thereof. An intense and/or
abrupt transformation may correspond to a material (e.g., surface)
that is at a temperature at which vaporization of the material
occurs. An average transformation may correspond to a material
(e.g., surface) that is below a temperature at which vaporization
of the material occurs. For example, that a chamber environment is
undergoing a (e.g., average, intense and/or abrupt) temperature
change. The change in the chamber environment can be averaged on
the volume of the chamber. The change in the chamber environment
can be at a volume in the chamber. For example, that a target
surface is undergoing a welding transformation, (e.g., intense
and/or abrupt) splatter, (e.g., average, intense and/or abrupt)
temperature change, and/or that a target surface is undergoing
keyhole formation. At least one element of the detector system may
be controlled manually and/or automatically (e.g., using a
controller). The control may be before, after, and/or during the
operation of the energy beam. Controlling can be before, during, or
after processing of the one or more materials. At times,
measurements from a first detector (e.g., the system of FIG. 13,
1320) can be correlated with measurements of a second detector
(e.g., FIG. 13, 1325) to determine at least one characteristic of,
for example, the (i) a target material surface, (ii) a processing
beam (e.g., a transforming energy beam or a scanning energy beam),
(iii) a processing area (e.g., a position where an irradiating
energy beam is incident on a surface), (iv) a calibration
structure, and/or (v) a portion of a forming 3D object.
[0238] In some cases, one or more of the detectors can be movable.
For example, the one or more detectors can be movable along a plane
that is parallel to the target surface (e.g., to the exposed
surface of the material bed. The one or more detectors can be
movable horizontally, vertically, and/or in an angle (e.g., planar
or compound). The one or more detectors can be movable along a
plane that is parallel to a surface of the target surface. The one
or more detectors can be movable along an axis this is orthogonal
to the target surface and/or a surface of the material bed. The one
or more detectors can be translated, rotated, and/or tilted at an
angle (e.g., planar or compound) before, after, and/or during at
least a portion of the 3D printing.
[0239] The one or more detectors can be disposed within the
enclosure, outside the enclosure, within the structure of the
enclosure (e.g., within a wall of the enclosure), or any
combination thereof. The one or more detectors can be oriented in a
location such that the detector can receive one or more signals in
the field of view of the detector. A viewing angle and/or field of
view of at least one of the one or more detectors can be
maneuverable via a scanner. In some cases, the viewing angle and/or
field of view can be maneuverable relative to an energy beam that
is employed to additively generate the 3D object. In some cases,
the variable focus mechanism may synchronize the movement of the
transforming energy beam to be within the range of the detectors
that may be detecting the detecting energy beam. In some cases,
movement (e.g., scanning) of the energy beam and maneuvering of the
viewing angle and/or field of view of one or more detectors can be
synchronized.
[0240] A controller may receive signals from the detector. The
controller may be a part of a high-speed computing environment. The
computing environment may be any computing environment described
herein. The computing environment may be any computer and/or
processor described herein. The controller may control (e.g.,
alter, adjust) the parameters of the components of the 3D printer
(e.g., before, after, and/or during at least a portion of the 3D
printing). The control (e.g., open loop control) may comprise a
calculation. The control may comprise using an algorithm. The
control may comprise feedback loop control. In some examples, the
control may comprise at least two of (i) open loop (e.g., empirical
calculations), and (ii) closed loop (e.g., feed forward and/or
feedback loop) control. In some examples, the feedback loop(s)
control comprises one or more comparisons with an input parameter
and/or threshold value. The setpoint may comprise calculated (e.g.,
predicted) setpoint value. The setpoint may comprise adjustment
according to the closed loop and/or feedback control. The
controller may use metrological and/or temperature measurements of
at least one position of the target surface (e.g., melt pool). The
controller may use porosity and/or roughness measurements (e.g., of
the layer of hardened material). The controller may direct
adjustment of one or more systems and/or apparatuses in the 3D
printing system. For example, the controller may direct adjustment
of the force exerted by the material removal mechanism (e.g., force
of vacuum suction). For example, the controller may direct
adjustment of a spot size and/or focus of a detected energy beam by
adjusting the optical elements.
[0241] In some embodiments, an astigmatism system (e.g., FIG. 15,
1500) is coupled to the 3D printer. The astigmatism system may be
disposed adjacent (e.g., in, or outside of) the processing chamber
in which the irradiated beam generates the 3D object (e.g., FIG. 1,
126). The astigmatism system may be operatively coupled to an
energy source, and/or to a controller. At least one element of the
astigmatism system may be controlled before, after, and/or during
at least a portion of the 3D printing (e.g., in real time). At
least one element of the astigmatism system may be controlled
manually and/or automatically (e.g., using a controller). The
energy source may irradiate energy (e.g., FIG. 15, 1505 depicting
an energy beam). The astigmatism system may be used to form an
elongated cross-sectional beam (e.g., narrow, and/or long, FIG. 15,
1540) that irradiates the target surface (e.g., 1535). The energy
beam may be elongated along the X-Y plane (e.g., FIG. 15). At
times, the footprint of the energy beam may be elongated by an
energy beam perforation (e.g., an elongated slit) that the energy
beam may be allowed to pass through. At times, the movement of the
energy beam may be controlled to perform a scan or a retro scan to
form an elongated energy beam footprint.
[0242] In some embodiments, the astigmatism system includes two or
more optical elements (e.g., lenses, FIG. 15,1510, 1530). The
optical elements may diverge or converge an irradiating energy
(e.g., beam) that travels therethrough. The optical elements may
have a constant focus. The optical elements may have a variable
focus. At times, the optical element may converge the rays of the
energy beam. At times, the optical element may diverge the rays of
the energy beam. For example, the first optical element may be a
diverging lens. The astigmatism system may comprise one or more
medias (e.g., 1515, 1525). The medium may have a high refractive
index (e.g., a high refractive index relative to the wavelength of
the incoming energy beam). At least one medium may be stationary,
translating, or rotating (e.g., rotating along an axis, FIG. 15,
1520, 1550). Translating and/or rotating may be performed before,
after, or during at least a portion of the 3D printing. The first
medium may translate and/or rotate along a different axis than the
second medium. The translating axes of the mediums may be different
than (e.g., perpendicular to) the traveling axis of the irradiating
energy. For example, the first medium (e.g., 1515) may translate
and/or rotate along the Z axis (e.g., 1520), the second medium
(e.g., 1525) may translate and/or rotate along the Y axis (e.g.,
1550), and the irradiating energy (e.g., 1505) may travel along the
X axis. The distance between the media may be such that they do not
collide with each other when translating (and/or rotating) (e.g.,
when both media are rotating simultaneously). The irradiating
energy may be directed to the second medium after it emerges from
the first medium. The first optical element (e.g., 1510) may direct
the energy beam to a medium (e.g., an optical window, e.g., 1515).
The medium may (e.g., substantially) allow the energy beam to pass
through (e.g., may not absorb a substantial portion of the passing
energy beam). Substantially may be relative to the intended purpose
of the energy beam (e.g., to transform the pre-transformed
material).
[0243] In some embodiments, the optical astigmatism of the
irradiating energy refers to an elliptical cross section of the
irradiating energy that differs from a circle. Without wishing to
be bound to theory, the different paths (e.g., lengths thereof) of
the various irradiating energy rays (e.g., 1551-1553), interacting
with various thicknesses of the media (having an effective
refractive index), may lead to an elongated cross section of the
irradiating energy, and subsequently to an elongated footprint of
the irradiating energy on the target surface. The relative position
of the first media (e.g., optical window) and the second media may
lead to an optical astigmatism. The degree and/or direction of the
astigmatism may vary (e.g., before, after, and/or during at least a
portion of the 3D printing) in relation to the relative positioning
of the two media. The degree and/or direction of the astigmatism
may due to the relative positioning of the two media. The angular
position of the media may be controlled (e.g., manually, and/or
automatically). For example, the angular position of the media may
be controlled by one or more controllers. Controlling may include
altering the angular position of the media relative to each other.
Controlling may include altering the angular position not relative
to each other (e.g., relative to the target surface and/or to the
energy source). Controlling the degree of astigmatism may lead to
controlling the length and/or width of the irradiating energy on
the target surface. The irradiating energy may be directed to a
second optical element (e.g., FIG. 15, 1530) from the (e.g., first
or second) medium. The second optical element may be a converging
lens. The converging lens may focus the irradiating energy after
its emergence from the (e.g., first or second) medium. The
converging lens may translatable (e.g., to vary the focus). The
focusing power of the lens (e.g., converging lens) may be variable
(e.g., electronically, magnetically, or thermally). The second
optical element may be placed after the (e.g., first or second)
medium. The energy beam may be directed (e.g., converged) on to a
reflective element (e.g., mirror, FIG. 15, 1545) and/or a scanner.
The energy beam may be directed (e.g., converged) on to a beam
directing element. The beam directing (e.g., reflective) element
may be translatable. The beam directing element may direct the
energy beam to the target surface (e.g., material bed, FIG. 15,
1535). The directed energy beam may be an elongated energy beam.
The mirror may be highly reflective mirror (e.g., Beryllium
mirror).
[0244] In some embodiments, a calibration system is operatively
coupled to (e.g., included in) the 3D printer. The calibration
system may comprise a calibration structure (e.g., FIG. 17, 1713),
sensor, detector, or a control system. The sensor may be any sensor
described herein. The detector may be any detector described
herein. The calibration system may calibrate one or more components
of the energy source and/or the optical system (e.g., the
irradiating energy). The calibration system may calibrate one or
more characteristics of the irradiating energy. For example, the
calibration system may calibrate (i) the position at which the
irradiating energy contacts a surface (e.g., the target surface),
(ii) the energy beam footprint size, (iii) the shape of the
footprint of the energy beam at the (e.g., target) surface, (iv)
the energy density of the of the energy beam projected to the
(e.g., target) surface, (v) the velocity of the irradiating energy
relative to the (e.g., target) surface, (vi) the energy profile of
the energy beam across its footprint at the (e.g., target) surface,
and/or (vii) the XY offset of the energy beam with respect to the
(e.g., target) surface. The characteristics of the irradiating
energy may be calibrated along a field of view of the optical
system (e.g., and/or detector). The field of view (e.g., FIG. 12,
1240) may be described as the maximum area of target surface that
is covered (e.g., intersected, or accessed) by the optical system
(e.g., by the irradiating energy). The field of view may be
indirect (e.g., devoid of a direct view). The field of view may be
constrained, constricted or otherwise limited, for example, to
increase a resolution of an image, to reduce contrast, to exclude a
portion of the field of view. The field of view may be
substantially concentric with a location of the irradiating energy
on a surface (e.g., a calibration structure, and/or the target
surface) (e.g., FIG. 13, 1358, 1381). The field of view may include
one or more dimensions (e.g., horizontal plane, XY plane). The
field of view may include an angle of coverage.
[0245] In some embodiments, the enclosure comprises at least a
portion of the calibration system. For example, the enclosure may
comprise a calibration structure. The calibration structure may be
disposed in a manner that allows interaction of the irradiating
energy (e.g., energy beam) with the calibration structure. The
calibration structure may be a part of the build module (e.g., FIG.
17, 1711). The calibration structure may be located within the
processing chamber (e.g., having the internal volume 1726). The
calibration structure may be disposed within the enclosure (e.g.,
FIG. 17, 1707). For example, the calibration structure may be
disposed at the bottom of the build module (e.g., floor of the
build module, e.g., 1716), at or adjacent to the platform (e.g.,
the base 1715). For example, the calibration structure may be
disposed at the bottom of the processing chamber (e.g., 1714).
Bottom may be in the direction of the gravitational center. Bottom
may be in the direction away from the optical mechanism (e.g.,
1732. e.g., comprising a scanner). The calibration structure may be
located outside of the build module (e.g., in the processing
chamber). The calibration structure may be located outside of the
processing chamber (e.g., in the build module).
[0246] The calibration structure may be translatable (e.g.,
laterally 1717) or non-translatable (e.g., static). The calibration
structure may be disposed on, or be a part of, a support (e.g.,
1712). The support that may be referred herein as a "stage." The
stage may be movable. The movable stage may translate horizontally
and/or vertically. The movable support may be laterally
translatable. The movable stage may be translatable before, after,
or during at least a portion of the 3D printing. The translation of
the movable stage may be controlled (e.g., manually and/or by a
controller). The movable stage may translate and/or be controlled
before, after, and/or during at least a portion of the 3D printing.
The stage may move towards a stopper. The stage may engage (e.g.,
reversibly) with the stopper. The engagement may ensure that the
stage is disposed (e.g., substantially) at the same position on
each engagement. The stage and/or stopper may comprise a mechanism
that ensures positional accurate engagement of the stage with the
stopper. The positional accuracy may be in the vertical and/or
horizontal direction. The mechanism for ensuring positional
accuracy may comprise a kinematic mechanism. For example, the stage
and/or stopper may comprise one or more kinematic support, or
arrangement. The stopper and the stage may couple (e.g., to ensure
accurate positional engagement). The coupling may comprise
kinematic coupling. For example, the stage and/or stopper may
comprise one or more complementary fixtures that are designed to
(e.g., precisely) constrain each other on mutual engagement. The
engagement of the complementary fixtures may trigger a signal. The
signal may be an electronic, pneumatic, sound (e.g., acoustic),
light (e.g., electromagnetic), or magnetic signal. The signal may
be detectable. The signal may be (e.g., represent) an assertion of
the engagement of the stage with the stopper.
[0247] The fixtures may comprise a protrusion and a complementary
indentation. The engagement can comprise at least one protrusion
that fits into at least one complementary indentation respectively.
For example, the stage may comprise a first fixture and the stopper
may comprise a second fixture that is complementary to the first
fixture, which fit into each other on engagement of the stage with
the stopper. The fitting into each other on engagement may prevent
one or more degrees of freedom. For example, a horizontal and/or
vertical degree of freedom of the stage. The fixture may comprise a
cross section having a geometrical shape (e.g., any geometrical
shape described herein, e.g., a polygon). The fixture may have a 3D
shape. The 3D shape may comprise a cuboid (e.g., cube), or a
tetrahedron. The 3D shape may comprise a polyhedron (e.g., primary
parallelohedron), at least a portion of an ellipse (e.g., circle),
a cone, or a cylinder. The polyhedron may be a prism (e.g.,
hexagonal prism), or octahedron (e.g., truncated octahedron). The
fixture may comprise a Platonic solid. The fixture may comprise
octahedra, truncated octahedron, or a cube. The fixture may
comprise convex polyhedra (e.g., with regular faces). The fixture
may comprise a triangular prism, hexagonal prism, cube, truncated
octahedron, or gyrobifastigium. The fixture may comprise a
pentagonal pyramid. The fixture may be an indentation of the 3D
shape (e.g., a V-groove is an indentation of a cone). The portion
of the ellipse may be a hemisphere. For example, the engagement
(e.g., coupling) of the stopper with the stage may comprise
engagement of one or more (e.g., three) radial v-grooves with one
or more complementary hemispheres. One or more may comprise at
least 1, 2, 3, 4, or 5. The engagement of the complementary
fixtures may comprise at least one (e.g., two, or three) contact
point. The contact point may constrain the degree of freedom of the
stage. In some examples, the complementary fixtures may engage with
each other, and not precisely fit into each other. In some
examples, the complementary fixtures may engage with each other,
and restrain at least one degree of freedom of at least one of the
stage and the stopper. For example, the first fixture may be a
V-groove and its complementary fixture may be a hemisphere. For
example, the first fixture may be a tetrahedral dent, and its
complementary fixture may be a hemisphere. For example, the first
fixture may be a rectangular depression, and its complementary
fixture may be a hemisphere. The kinematic coupling may comprise
Kelvin or Maxwell coupling.
[0248] FIG. 30A shows a side view example of a 3D printer
comprising an energy beam 3003 that is directed towards a platform
3009 that is supported by a plurality of vertically movable shafts
3010. The enclosure of the 3D printer 3001 comprises a stage 3008
on which a calibration structure 3002 is mounted. The stage 3008 is
laterally movable (e.g., in the direction of 3017). When the 3D
printing is in process, the stage 3008 is retracted from an area
above the platform 3009 (e.g., towards an area to the side of the
platform, e.g., 3012). The movement of the platform may be
effectuated by one or more (e.g., two or three) shafts (e.g.,
3007). The shafts may be constructed from a strong material that
supports the stage without sagging, when the stage engages with the
stopper 3006. The stage 3008 may comprise a fixture (e.g.,
indentation 3011) that at least restrains a degree of movement of
the stage 3008 by engaging with a fixture of the stopper (e.g.,
3004). The fixture on the stopper may comprise an optional
pneumatic, electronic, magnetic, auditory, or optical mechanism
(e.g., 3005). FIG. 30B shows a horizontal (e.g., plan) view of a
stage 3050 having three (indentation) fixtures (e.g., 3081-3083)
that complement three (protruding) fixtures (e.g., 3071-3073)
respectively on engagement of the stage 3050 with the stopper 3051.
The stage may be laterally movable (e.g., 3057) and mounted by one
or more shafts (e.g., 3052 and 3053). The stopper 3051 may be
stationary. One or more fixtures on the stopper (e.g., 3051) may
comprise optional pneumatic, electronic, magnetic, auditory, or
optical mechanism (e.g., 3061-3063). At least two of the plurality
of the afore-mentioned mechanisms may be of the same type (e.g.,
all pneumatic). At least two of the plurality of the
afore-mentioned mechanisms may be of different types (e.g., one
electronic and one optical). The shafts may translate vertically
and/or horizontally. The shafts and/or stage may translate before,
after, and/or during the 3D printing (e.g., when the irradiated is
not used to form the 3D object). The shafts and/or stage may be
controlled before, after, and/or during the 3D printing (e.g., when
the irradiated is not used to form the 3D object). The control may
be manual and/or automatic (e.g., using a controller).
[0249] The calibration structure (e.g., FIG. 17, 1713) may be
located at and/or adjacent to the load lock system (e.g., as part
of a portion of the load lock system, e.g., FIG. 2A, 212, 224). The
calibration structure may be placed adjacent to the platform. The
calibration structure may be placed adjacent to the target surface
(e.g., adjacent to the exposed surface of the material bed (e.g.,
1704). The calibration structure may (e.g., 1713) be disposed
parallel to the target surface (e.g., 1725). The calibration
structure may be disposed on a shutter associated with the load
lock mechanism (e.g., FIGS. 3, 371, and/or 351). The calibration
structure may be disposed on a top surface of the shutter. Top may
be in the direction opposite to the gravitational center. Top may
be in the direction towards the optical mechanism (e.g., FIG. 2A,
230). Top may be in a direction that allows interaction of the
irradiating energy (e.g., 211) with the calibration structure. For
example, the calibration structure may be disposed on (or be a part
of) the shutter of the processing chamber (e.g., 212). For example,
the calibration structure may be disposed on (or be a part of) the
shutter of the build module (e.g., 224).
[0250] The calibration structure may facilitate calibration of
features such as average lateral (e.g., FIG. 17, 1717, XY) offset
of the irradiating energy (e.g., energy beam), average velocity
scale factor and/or average scale factor of the energy beam.
[0251] The calibration system may facilitate calibration of (i)
locality of the footprint of the irradiating energy in the XY plane
(e.g., FIG. 17), the fluence of energy of the irradiating energy
(e.g., its power density per unit time and/or its Andrew number).
The fluence of the irradiating energy may relate to its footprint
on the exposed surface, to its power density, to its velocity, to
the optical (e.g., variable) focus elements (e.g., position and
sensitivity). The calibration system may comprise a calibration
structure. The calibration structure may be stationary (e.g.,
passive) or modular (e.g., movable). The calibration structure may
be a passive structure of a known shape. For example, it may be a
map or an array (e.g., FIG. 18A-C, 19A-C, 20A-C, or 21A-C). The
calibration structure may be formed by methods comprising machining
(e.g., embossing) or lithography. The calibration structure may
comprise a grid.
[0252] The calibration system may use an electromagnetic radiation.
The electromagnetic radiation may be the same or different from the
irradiating energy used to form the 3D object. The electromagnetic
radiation used for the calibration may be a laser (e.g., a pilot
laser, or a 3D printing laser). The electromagnetic radiation used
for the calibration may comprise structured light (e.g., a pattern
of light, e.g., comprising light or dark fringes). The calibration
may take place during, after, or before printing a 3D object. For
example, between at least two build cycles of the 3D printer.
[0253] The calibration system may comprise a detector, sensor,
and/or image processor. For example, the calibration system may
comprise a camera, a non-imaging sensor (e.g., performing a point
measurement, e.g., a silicon detector, or a spectrometer). The
calibration system may detect information pertaining to the power
density of the energy beam, for example, by using the
reflectivity/absorption of the energy beam from the calibration
structure (e.g., from the calibration mark) and comparing to a
reference reflectivity/absorption value, respectively.
[0254] In some embodiments, the resolution of the calibration is
not limited by the resolution of the detector. In some embodiments,
the resolution of the calibration is determined by the steps of the
irradiating energy (e.g., pulse frequency, or translation
step).
[0255] Calibration may be performed before, during, and/or after at
least a portion of the 3D printing. For example, calibration may be
performed after at least one (e.g., after every) 3D printing cycle.
The calibration may be performed before, during, and/or after
performing a load lock engagement of the build module with the
processing chamber (e.g., on merging the processing chamber with
the build module, on sealing the processing chamber with the load
lock shutter, and/or on sealing the build module with the load lock
shutter).
[0256] The calibration structure may comprise a mark (referred to
herein as "calibration-mark"). The calibration-mark may be an area
comprising an impression, embossing, depression, protrusion, line,
point, abrasion, erosion, scar, polish, brilliance, glaze, sparkle,
light, glossy surface, matte surface, dispersive surface, diffusive
surface, or stain. The calibration structure may comprise a
calibration-mark type having a detectable border. The calibration
structure may comprise two or more calibration-marks. For example,
the calibration structure may include a calibration-mark type,
wherein the border between every two calibration marks (e.g., of
the same type) is detectable. The calibration structure may include
two different calibration-marks. The calibration structure may
include two different mark types. The two different mark types may
constitute a bitmap. The two different mark types may differ in at
least one detectable property (e.g., reflective vs. diffusive
(e.g., and dispersive) surfaces, black vs. white stain, depression
vs. protrusion). The two calibration-mark types in the calibration
structure (e.g., each of the two-bit types in the bitmap) may
differ at least in their surface roughness, surface reflectivity,
surface color, material density, material composition. The
difference between the two calibration marks may be a difference in
their surface. The calibration-marks may comprise surface marks.
FIG. 18A shows an example of a bitmap in which the black tiles
(e.g., 1806) represent a first mark type having a detectable
property of a first value (or a first range of values), and the
white tiles (e.g., 1805) represent a second mark type of the
detectable property having a second value (or a second range of
values), wherein the first value (range) differs from the second
value (range) in a detectable manner. For example, the first value
range may differ from the second value range in a threshold value
(e.g., the first value range is above the threshold value, and the
second value range is below the threshold value). The value range
may at times constitute (e.g., substantially) a single value. The
bitmap may comprise any bitmap image. For example, the bitmap may
comprise an irregular bitmap image. The bitmap may comprise a
repeating or non-repeating sequence. The bitmap may comprise a
series. The series may be composed of the first mark type and the
second mark type. The bitmap may comprise one or more pitches. For
example, a pitch may be represented as a bit (e.g., mark type) on
the bitmap, the pitch may have a detectable property such as an
incline, a height, a gradient, a dip, a slope, an angle. The bitmap
may have a coverage area that spans an area (e.g., substantially)
equivalent to at least a portion of the target surface (e.g., the
energy beam processing cone area that intersects the target
surface). FIG. 12 shows an example of a processing cone (e.g.,
1230). A maximal portion of the enclosure, that is occupied by the
irradiating energy (e.g., during the 3D printing) can define a
processing cone (e.g., FIG. 12, 1230). An intersection of the
processing cone with a surface (e.g., of the calibration structure
and/or material bed) can be defined as the field of view of the
irradiating energy. The bitmap may span an area (e.g.,
substantially) equivalent to the target surface (e.g., exposed
surface of the material bed, and/or platform). The calibration-mark
may be regularly shaped (e.g., a line, rectangle (e.g., FIG. 18A,
1805), ellipse (e.g., FIG. 21A, 2101), or any other geometrical or
non-geometric shape). The rectangle may comprise a square (e.g.,
FIG. 18, 1825). The ellipse may comprise a circle (e.g., FIG. 21B,
2121). The calibration-mark may be irregularly shaped. The
calibration-mark may comprise a line. The line may comprise a
curvature. The line may be straight. At least two of the lines in
the calibration structure may be (e.g., substantially) equal in
width, length, angle relative to an edge of the calibration
structure, line-shape, or any combination thereof. At least two of
the lines in the calibration structure may differ in width, length,
angle relative to an edge of the calibration structure, line-shape,
or any combination thereof. At least one line in the calibration
structure may be straight. At least one line in the calibration
structure may comprise a curvature. At least two lines in the
calibration structure may intersect, and/or overlap. The
intersecting lines may form a grid. The manhattan distance may be
between two intersecting line points in the grid, based on a
strictly horizontal and/or vertical path (e.g., the distance
between two points measured along axes at right angles). At times,
at least two manhattan distances in the grid is (e.g.,
substantially) equal. At times, at least two manhattan distances in
the grid differ from each other. The calibration structure may
comprise at least two manhattan lines. The calibration-mark lines
may be arranged to provide a manhattan distance. Every two of at
least three calibration marks may be placed equidistant to each
other. The calibration-mark may have a regular surface (e.g.,
smooth surface). The calibration-mark may have an irregular surface
(e.g., comprising a protrusion or indentation). The
calibration-mark may have one or more colors (e.g., two tone
colors). The calibration-mark may have at least one varied physical
property that is measurable (e.g., varied reflectivity, variable
roughness, specular reflection, diffuse reflection, diffused
absorption). The varied physical property may comprise a range of
the physical property. The calibration-mark may be of a small size
(e.g., size of the smallest footprint and/or cross-section of the
energy beam and/or energy flux). The calibration-mark may be
passive. The calibration-mark may be an active calibration-mark
(e.g., electrically, electronically, magnetically, chemically,
and/or thermally active). The active calibration-mark may be
activated (e.g., using a trigger and/or an agent) manually and/or
by a controller before, after, and/or during at least a portion of
the 3D printing. The trigger and/or agent may be electronic,
magnetic, thermic, and/or chemical. The trigger and/or agent may
activate using a processor (e.g., comprising a software).
[0257] The calibration-marks may be arranged in a pattern (e.g., a
checkerboard pattern, and/or a manhattan grid pattern). FIGS.
18A-18C, 19A-19C, 20A-20C, and 21A-21C show various top view
examples of at least portion of various calibration structures,
each of which comprises two calibration-mark types (represented as
black and white areas) that are arranged in different patterns. For
example, a parallel straight-line pattern (e.g., FIG. 18A), a
checkerboard pattern (FIG. 18B), and a non-parallel straight-line
pattern (e.g., FIG. 18C). The checkerboard pattern may be an
example of (e.g., substantially) uniform calibration marks (e.g.,
FIG. 18A, 1805 and 1806). The pattern may include at least one
calibration mark type having of uniform FLS (e.g., length 1813
and/or width 1812). The pattern may include at least one
calibration mark type having of non-uniform FLS. FIG. 19A shows an
example of at least a portion of a calibration structure including
a first calibration mark type (e.g., 1905), and second calibration
mark type (e.g., 1906), wherein the calibration marks belonging to
the first (black) type are of a (e.g., substantially) equal width
and length, and wherein the calibration marks of the second (white)
type is of a (e.g., substantially) equal length and varied width
(e.g., 1907).
[0258] In some embodiments, the (lateral) area of the calibration
mark is at least equal to the cross section and/or footprint of the
irradiating energy on the exposed surface. For example, the area of
the calibration mark may be greater by at least 1.5*, 2*, 5*, 10*,
15* or 20* the cross-sectional area and/or footprint of the
irradiating energy on the exposed surface. The area of the
calibration mark may be of any value between the afore-mentioned
values (e.g., from about 1.5* to about 20* the cross-sectional area
and/or footprint of the irradiating energy on the exposed surface).
The symbol "*" designates the mathematical operation "times". In
some embodiments, the FLS (e.g., width and/or depth) of the
calibration mark is at least equal to the cross section and/or
footprint of the irradiating energy on the exposed surface. For
example, the FLS of the calibration mark may be greater by at least
1.5*, 2*, 5*, 10*, 15* or 20* the FLS of the cross-section and/or
footprint of the irradiating energy on the exposed surface. The FLS
of the calibration mark may be of any value between the
afore-mentioned values (e.g., from about 1.5* to about 20* the FLS
of the cross section and/or footprint of the irradiating energy on
the exposed surface). The pitch may have a minimum size. The pitch
may have a maximum size. The pitch may have a FLS. For example, the
pitch may be of a size (e.g., have a specific width, length or
height) that can accommodate one or more errors (e.g., residual
errors, bitmap pattern errors). For example, the pitch may be wide
enough to accommodate errors that are smaller than or equal to half
the size of the pitch. Accommodate may include detect. Accommodate
may include adjust. The pattern may comprise irregular shaped lines
and/or areas (e.g., FIG. 21C). The lines may intersect one or more
lines. The lines (e.g., FIG. 18C, 1820) may be disposed at various
angles (e.g., 1.degree., 2.degree., 3.degree., 4.degree.,
5.degree., 10.degree., 15.degree., 20.degree., 30.degree.,
40.degree., 50.degree., 60.degree., 70.degree., 80.degree.,
90.degree., 100.degree., 120.degree., 140.degree., 160.degree.,
180.degree.) with respect to a side of the calibration structure
(e.g., 1821).
[0259] The calibration mark may be space-filling polygons. The
calibration structure may be filled with space-filling polygons.
The calibration mark may comprise a polygon. The polygon may
comprise at least 3, 4, 5, 6, 7, 8, 9, or 10 faces. The calibration
mark may comprise any number of faces between the aforementioned
number of faces (e.g., from 3 to 10). The polygon may comprise at
least 3, 4, 5, 6, 7, 8, 9, or 10 vertices. The calibration mark may
comprise any number of vertices between the aforementioned number
of faces (e.g., from 3 to 10). The calibration mark may comprise a
concave or, convex polygon. The polygon may be a closed polygon.
The polygon may be equilateral, equiangular, regular convex,
cyclic, tangential, edge-transitive, rectilinear, or any
combination thereof. For example, the calibration mark may comprise
a square, rectangle, triangle, pentagon, hexagon, heptagon,
octagon, nonagon, octagon, circle, or icosahedron.
[0260] The calibration structure may comprise a tessellation. The
calibration structure may be (e.g., substantially) planar. The
tessellation may one or more calibration marks. The calibration
marks may comprise geometric shapes. The calibration marks in the
calibration structure may be arranged with without overlaps and
without gaps. At least two of the calibration marks in the
calibration structure may border each other. The tessellation may
comprise a periodic repetition of the one or more calibration marks
(e.g., calibration mark types). The tessellation may comprise
edge-to-edge arrangement of the calibration marks (e.g., where
adjacent calibration marks share one full side, or where the
calibration marks do not share a partial side or more than one side
with any other tile). For example, the sides of the calibration
marks and the edges of the calibration marks (e.g., polygons) may
be the same. The arrangement of the calibration marks in the
tessellation may be normal, monohedral, regular (e.g., highly
symmetric tessellation), semi-regular, or edge. The regular
tessellation may comprise hequilateral triangular, regular
hexagonal, or square calibration marks. The semi-regular
tessellation may comprise more than one type of regular polygon in
an isogonal arrangement. The tessellation may comprise
non-edge-to-edge arrangement of Euclidean planes. For example,
Pythagorean arrangement, tessellations that use two (parameterised)
sizes of square, each square touching four squares of the other
size. The tessellation may comprise an edge tessellation (e.g., in
which each calibration mark can be reflected over an edge to take
up the position of a neighboring calibration mark). For example, an
array of equilateral or isosceles triangular calibration marks.
[0261] In some examples, at least a portion of the calibration
structure is imprinted on a material. For example, at least a
portion of the calibration structure may be imprinted on a surface
(e.g., of the shutter, platform, moving structure, or enclosure
floor). The enclosure floor may comprise the processing chamber
floor or the build module floor. The material may comprise chrome
or glass. The material may comprise any material disclosed herein
(e.g., polymer, resin, elemental metal, metal alloy, ceramic, or an
allotrope of elemental carbon). In some embodiments, only the first
mark type is imprinted on the material, whereas the second mark
type constitutes the non-imprinted material. In some embodiments,
both the first mark type and the second mark type are imprinted on
the material. Imprinting may comprise physical etching, chemical
etching, blasting (e.g., sand blasting), carving, ablating,
machining, abasing, or embossing. One or more topographical
features (e.g., indentations, protrusions, roughness, smoothness,
granular, or planar) may be imprinted on the material. Imprinting
may comprise chemical imprinting. The chemical imprinting may
comprise altering a material property and/or composition. The
chemical alteration may comprise addition or subtraction of at
least one element. The chemical alteration may comprise altering a
chemical bond, material morphology, grain structure, and/or crystal
structure. Imprinting may comprise thermal imprinting. The chemical
and/or physical alteration may comprise altering the surface
reflectivity. The calibration structure may comprise at least one
detectable property. The detectable property may be a physically
detectable property (e.g., protrusions, indentations, roughness, or
smoothness). The detectable property may be an optically detectable
property (e.g., reflectivity, absorption, or image analysis). The
detectable property may be a thermally detectable property (e.g.,
heat conductivity, or heat intensity). The detectable property may
be a magnetically detectable property (e.g., magnetic field
intensity, or magnetic field direction). The detectable property
may be an electrical and/or electronically detectable property
(e.g., bits, voltage, current, resistance, or inductance). At
times, the calibration structure may comprise more than one
detectable properties.
[0262] The bitmap may comprise one or more bitmap subsets (e.g., a
series of bitmaps, a geometric pattern, an array, a repeatable
pattern). A bitmap subset may comprise a single dimension (e.g., a
series of lines in one direction. e.g., FIG. 19A). A bitmap subset
may comprise two dimensions (e.g., a series of lines in two
directions. e.g., FIGS. 19B and 19C). At least a calibration mark
of the calibration structure may be calibrated (e.g., by
calibrating based on its at least one detectable property).
[0263] In some embodiments, the calibration structure is used to
calibrate one or more properties of the optical system and/or the
detection system. Calibrating may include benchmarking, certifying,
and/or evaluating the detectable property. Additionally, or
alternatively, calibrating may include ensuring operation of the
optical system in conjunction with one or more components of the 3D
printer. FIGS. 22A-22B show examples of calibrating an optical
property (e.g., the locality of the energy beam footprint) of the
optical system. FIG. 22A shows an example of a calibration
structure of a checkerboard bitmap (e.g., 2215). The energy source
may direct the irradiating energy (e.g., scanning energy beam, or
energy flux) such that the irradiating energy interests with the
calibration structure within a calibration mark (e.g., 2110). A
portion of the calibration structure which the irradiating energy
intersects, may be detected by a detector (e.g., an image
detector). The detector may be any detector described herein. The
detected portion (e.g., FIG. 22A, 2211) of the bitmap may include
one or more portions of one or more calibration marks of the bitmap
(e.g., including a portion of the black pitch 2201 and/or a portion
of the white pitch 2202). FIG. 22B shows an example 2255 of a
magnification of the calibration structure portion 2211, in which
2251 is a portion of a white calibration mark and 2252 is a portion
of a black calibration mark, and 2230 is a footprint of the
irradiating energy on another white calibration mark. The detected
portion of the calibration structure may include a (e.g.,
pre-determined and/or known) central position. The central position
(also herein "center position") may be any accurately detectable
position of the calibration structure. For example, the central
position may be indicated by an intersection of at least two
calibration marks or portions thereof (e.g., FIG. 20A, 2001). For
example, the central position may be an intersection of four
calibration marks (e.g., FIG. 20B, 2021, FIG. 20C, 2031, or FIG.
22B, 2220). For example, the central position may be an
intersection of eight calibration marks (e.g., FIG. 21B, 2122). The
detected calibration structure portion (e.g., 2255, or 2211) may
capture the position of the irradiating energy (e.g., 2230, or
2210). At times, the detected position may not coincide with the
center position. A deviation (e.g., 2235, 2240) of the detected
position of the energy beam (e.g., 2230) with respect to the center
position (e.g., 2220) may be calculated. The deviation may be
calculated in at least one dimension (e.g., horizontal direction
(X), or vertical direction (Y)). The calculation may be done
manually and/or automatically (e.g., by a controller), before,
after and/or during at least a portion of the 3D printing. The
calculation may be done in real-time (e.g., during build of at
least a portion of the 3D object). The calculation may be done when
performing calibration (e.g., before, and/or, after build of the 3D
object). Based on the calculated deviation, the position at which
the irradiating energy intersects the calibration structure and/or
target surface may be adjusted (e.g., before, after and/or during
the 3D printing; manually, and/or automatically). Adjusting may
include coinciding (e.g., calibrating) (i) the footprint position
of the irradiating energy on the calibration structure, with (ii)
the center position (e.g., 2220). Adjusting may include altering
the projection position and/or angle of the irradiating energy on
the calibration structure and/or target surface. Adjusting may be
done during, before, or after build of the 3D object. Adjusting may
be performed manually or by a controller. At times, calculating and
adjusting may be performed by the same controller. At times,
calculating and adjusting may be performed by different
controllers. At least one controller may be a control system. The
controller may include a processing unit (e.g., CPU, GPU, and/or
FPGA). Controller may be programmable. The controller may operate
upon request. The controller may be any controller described
herein.
[0264] In some embodiments, finding the center position comprises
translating the irradiating energy (e.g., vectorially) through a
plurality (e.g., at least four) transition lines of calibration
marks, which calibration marks contact a point (e.g., FIG. 18,
1814). Translating may comprise translating around or at the
central position. The translation may comprise a circular
translation along an ellipse (e.g., circle), wherein the center
position is disposed in the ellipse (including its circumference).
The translation can be along a circumference of a rectangle (e.g.,
cube), wherein the center position resides in the rectangle (e.g.,
1814) (including its circumference). Such circling translation may
allow finding the center position, and/or the XY calibration offset
(e.g., by comparing to a benchmark).
[0265] In some examples, the irradiating energy scans the
calibration structure and transitions from one calibration mark
type to another. The transition is through a transition line or
point. FIG. 23C illustrates an example of a vertical cross section
of a bitmap calibration structure that comprises a transition line
(e.g., 2325) between a first calibration mark type (e.g., 2345) and
a second calibration mark type (e.g., 2340). The transition line
may be a line that transitions a property (e.g., reflectivity,
intensity) of a calibration mark from a first side of the line
(e.g., 2345) to a second side of the line (e.g., 2340). The bitmap
may comprise one or more transition lines. The irradiating energy
may scan across a portion of the bitmap (e.g., from the first side
of the transition line to the second side) along a path. The path
may be directional (e.g., vectorial). FIG. 23C shows an example of
the direction of the irradiating energy path (e.g., 2315). The
energy beam may irradiate (e.g., and heat) one or more positions
(e.g., 2310) as it scans across the portion of the bitmap (e.g.,
across the transition line 2325). A detector may capture a
detectable property (e.g., intensity of a reflected signal) at one
or more spots along the scan path (e.g., 2315) of the irradiating
energy. At times, the detector may detect an alteration in the
detectable property (e.g., an alteration of the reflectivity,
absorption, material composition, etc.) For example, the detector
may detect a change in the reflected signal along a portion of the
field of view of the detector. The change may be abrupt. The change
may be gradual. The change may indicate a transition around the
threshold value of the detectable property (e.g., from beneath the
threshold value to above the threshold value, or from above the
threshold value to beneath the threshold value). The transition
around the threshold value may differentiate transit of the
irradiating energy from one calibration mark type to the second
calibration mark type. FIGS. 25A-25C show vertical cross sections
of at least a portions of various calibration structures, in which
the variation along the Z direction represents a variation in the
detectable property, and the variation along the X and/or Y axis
represents relative distances. FIG. 25A, shows an example of an
abrupt variation in a detectable property value between one
calibration mark type (e.g., 2511) having a (e.g., substantially)
constant first detectable property value, and the second
calibration mark type (e.g., 2512) having a (e.g., substantially)
constant second detectable property value, as indicated by a
straight transition line comprising the right angle 2513, which
transition is relative to a threshold value 2514. In FIG. 25A, at
least one of the width and length of the two calibration mark types
is (e.g., substantially) identical. FIG. 25B, shows an example of
gradual variation in a detectable property value between one
calibration mark type (e.g., 2521) having a first detectable
property value maximum peak, and the second calibration mark type
(e.g., 2522) having a second detectable property value minimum
peak, as indicated by the gradual transition line 2523, which
transition is relative to a threshold value 2524. In FIG. 25B, at
least one of the width and length of the two calibration mark types
is (e.g., substantially) identical. FIG. 25C, shows an example of
an abrupt variation in a detectable property value between one
calibration mark type (e.g., 2531) having a variable first
detectable property value (e.g., a rough surface), and the second
calibration mark type (e.g., 2532) having a (e.g., substantially)
constant second detectable property value (e.g., a planar and/or
smooth surface), as indicated by a straight transition line
comprising the right angle 2533, which transition is relative to a
threshold value 2534. In FIG. 25C, at least one of the width and
length of the two calibration mark types varies between the
calibration marks.
[0266] In some embodiments, the detector detects the detectable
property (e.g., the reflected optical signal) along at least a
portion of (e.g., the entire) field of view of the detector. The
detector may detect the location of the transition line, transition
point, and/or central position. The detector may detect a change in
the intensity of at least one signal (e.g., an optical signal that
is reflected from the calibration structure). The intensity of the
detected signal may be lower on a first side of the transition line
than an intensity of the detected signal on a second side of the
transition line (e.g., that opposes the first side). The detected
position of the transition line may be compared to the central
position on the control structure. The central position may (e.g.,
optically) be pre-determined, known, relatively determined,
absolutely determined. The determination may comprise pattern
recognition (e.g., picture recognition). The determination may
comprise signal recognition. The signal may be optical, acoustic,
thermal, electrical, magnetic, or any combination thereof. A
deviation between the detected position of the transition line (or
point) as compared to the expected position of the transition line
may be calculated. The calculation may be done manually or
automatically (e.g., by a controller). The calculation may be done
in real-time (e.g., during build of the 3D object). The calculation
may be done when performing calibration (e.g., before, and/or,
after build of the 3D object). The position of the energy beam may
be adjusted based on the calculated deviation. Adjusting may
comprise coinciding (e.g., calibrating) the transition position of
the irradiating energy with the expected position of the transition
line. For example, adjusting may comprise adjusting the expected
position of the transition line. Adjusting may comprise altering
the position and/or angle of the irradiating energy. Adjusting may
comprise altering the position at which the irradiating energy
intersects with the calibration structure and/or target surface.
Adjusting may be performed during, before, or after build of the 3D
object. At times, calculating and adjusting may be performed by the
same controller. At times, calculating and adjusting may be
performed by different controllers. The controller may comprise a
control system. The controller may be programmable. The controller
may operate upon request. The controller may be any controller
described herein. Control may comprise regulate, manipulate,
restrict, direct, monitor, adjust, attenuate, maintain, or
manage.
[0267] FIGS. 22A-22B illustrates examples of calibrating an optical
property (e.g., the energy beam distribution and/or a spot size
(e.g., footprint) of the irradiating energy). The irradiating
energy may follow on a path (e.g., a predetermined path) along the
calibration structure. The irradiating energy may be continuous or
pulsing. The irradiating energy may be projected on one or more
positions of the calibration structure. At times, each irradiated
position may be equidistant from another irradiated position (e.g.,
a pulsing energy beam). During its progression along the path, the
irradiating energy may project at a position on at least two (e.g.,
adjacent) calibration marks of the calibration structure. The path
of the irradiating energy may be directed in a direction that is
perpendicular relative to the alignment direction of a series of
calibration marks (when such alignment is present. e.g., FIG. 20A,
2007). The path of the irradiating energy may be directed in a
direction that is perpendicular relative to the alignment direction
of a series of transition lines between the two calibration mark
types when such alignment is present (e.g., FIG. 20B, 2025 and/or
2026). The irradiating energy may cause a detectable signal (e.g.,
reflected beam) from the irradiated position. The magnitude (e.g.,
intensity) of the detected signal (e.g., reflectivity) of at least
two irradiated positions of the calibration structure may be
different (e.g., FIG. 21C, 2135 and 2136). FIG. 24A shows a
vertical cross section of at least a portion of a calibration
structure, in which the variation along the Z direction represents
a variation in the detectable property, and the variation along the
X and/or Y axis represents relative distances between the
calibration marks. In the example shown in FIG. 24A, there is a
gradual variation in a detectable property value between one
calibration mark type (e.g., 2421) having a first detectable
property value maximum peak, and the second calibration mark type
(e.g., 2422) having a second detectable property value minimum
peak, as indicated by the gradual transition line 2423, which
transition is relative to a threshold value 2420. In FIG. 24B, at
least one of the width and length of the two calibration mark types
is (e.g., substantially) identical. In the example shown in FIG.
24A, various positions of the irradiating energy on a surface of
the calibration structure are indicated as circles numbered 1 to 5,
wherein each circle designates an irradiation position of the
irradiating energy on the calibration structure. The detected
signal may be measured from at least two calibration mark types
(e.g., that contact each other). One or more detected signals may
be measured from one or more positions in a calibration mark (e.g.,
FIG. 24A, positions #1 and #2 irradiated in calibration mark 2440,
or positions #4 and #5 irradiated in calibration mark 2445). The
detected signal may be averaged amongst a plurality of irradiated
positions within a calibration mark. The measurement may be done by
a detector. The detector may be stationary or mobile. For example,
the mobile detector may be a scanning detector. The scanning
detector may be any detector disclosed in patent application number
PCT/US15/65297, titled "FEEDBACK CONTROL SYSTEMS FOR
THREE-DIMENSIONAL PRINTING" that was filed on Dec. 11, 2015, which
is incorporated herein by reference in its entirety. The detected
signal (e.g. FIG. 24B, 2490) may be graphically represented against
the relative position of the irradiating energy (e.g., projected
spot, FIG. 24B, 2485). The graphical representation may generate a
detected signal curve (e.g., 2410). The detected signal curve may
reveal the transition point between a first calibration mark type
and a second calibration mark type (e.g., adjacent to irradiated
position #3 in the example in FIG. 24A, which corresponds to
plotted position #3 of FIG. 24B). For example, a derivative of the
detected signal curve (e.g., 2415) may facilitate finding the
transition position between a first mark type and a second mark
type. One or more characterizations of the modified detected signal
(e.g., the derivative of the detected signal curve) can be made.
For example, a full width at half maximum (FWHM) measurement (e.g.,
FIG. 24B, 2465) can be indicative of a transition point between a
first calibration mark and a second calibration mark.
[0268] Calibrating the optical property may comprise measuring
(e.g., at least one) detected signal at varying irradiating energy
beam values. For example, measuring a detected signal as a
magnification, focus, and/or spot size of the irradiating energy
beam (e.g., controllably and/or dynamically) varies. The spot size
may be the size of the footprint of the energy beam on a target
surface. One or more graphical representations of the varying
irradiating energy beam value measurements may be generated. One or
more graphical representations of the detected signal as a function
of the varying irradiating energy beam value may comprise a curve
representing (e.g., a maximum value of) a derivative of the
detected signal. In some embodiments, a characteristic of the
(e.g., derivative) curve (e.g., a maximum value thereof) may
facilitate determination of one or more conditions of the varying
irradiating energy beam (e.g., a magnification, focus, and/or spot
size thereof).
[0269] In some embodiments, the calibration structure facilitates a
measure of the power density (e.g., power per unit area)
distribution. The power density distribution can be the irradiating
energy across its projection (e.g., footprint) on the calibration
structure. The measure of the power density distribution can be an
integral of the power density distribution along a direction (e.g.,
X, and/or Y). The measure of the power density distribution can be
derived from the detected signal curve. The measure of the power
density distribution may comprise observing a change in the
detectable property as the energy beam projection travels through a
contact between one calibration mark and a second calibration mark
(e.g., of a different type). The measure of the power density
distribution may be obtained by at least one of (i) measuring the
projection of the irradiating energy on the calibration structure,
(ii) identifying at least one characteristic metric for the power
density distribution, (iii) integrating the power density
distribution across the contact point of a first calibration mark
to a second calibration mark, or (iv) any combination or
permutation thereof. Without wishing to be bound to theory, as the
power density distribution does not depend on the power of the
irradiating energy, a measure of the power density distribution may
be obtained regardless of the actual detectable properties of the
calibration marks. The power density distribution may be measured
in one or more directions (e.g., horizontal, and/or vertical
direction, e.g., FIG. 22A, X and Y). The measure of the power
density distribution may be measured at different times and/or
positions relative to the calibration structure. The measure of the
power density distribution may use a (e.g., at least one) detected
signal from a plurality of focusing positions of the irradiating
energy with respect to the calibration structure. A focus shift may
be calibrated using the measured power density distribution at
different focus positions. One or more positions of the focus
mechanism (e.g., FIG. 13, and/or FIG. 15) may be calibrated using
the power density distribution measure. In some embodiments, the
optical system comprises a variable focus mechanism. The motion of
the variable focus mechanism may be calibrated using the power
density distribution measure. The calibration of the focus
mechanism may achieve a desired spot size for various locations in
the field of view of the irradiating energy (e.g., intersection of
the processing cone with the target surface and/or calibration
structure surface). The power density distribution measure may be
calibrated (e.g., substantially) identically, or differently, along
the field of view of the irradiating energy. In some embodiments,
different positions in the field of view may require different
focus offsets and/or or footprint size.
[0270] FIG. 12 shows an example of an enclosure comprising an
atmosphere 1226, in which an irradiating energy (e.g. energy beam)
1201 travels. The energy beam 1201 is generated by an energy source
1221, travels through an optical mechanism (e.g., a scanner) 1220,
and an optical window 1215, towards a material bed 1204 disposed on
a platform (e.g., base 1223). As the irradiative energy irradiates
and travels along the material bed 1204, it may form at least a
portion of a 3D object (e.g., 1206). The maximal portion of the
enclosure, that may be occupied by the irradiating energy (e.g.,
during the 3D printing) is depicted as the processing cone 1230,
having a field of view that is the exposed surface of the material
bed (e.g., 1240).
[0271] In some embodiments, a calibration map is generated using
the power density distribution measurements. The calibration map
may comprise different positional offsets of the irradiating energy
(e.g., beam). The calibration map may comprise different power
density offsets of the irradiating energy. The calibration map may
comprise different focus offsets of the optical system. For
example, the calibration map may be used to find a selected focus
(e.g., and/or spot size). For example, the calibration map may be
used to find a required focus shift for a desired location in the
field of view. The power density distribution measurement may be
used to determine an effective footprint size, and/or shape. For
example, the power density distribution measurement may be used to
determine the circularity of the power density distribution, an
astigmatism of the footprint, an optical deformation of the
footprint, non-uniformity of the footprint and/or the energy
profile across the footprint of the energy beam on the calibration
structure.
[0272] In some embodiments, the circularity (e.g., astigmatism) of
the energy beam footprint is measured and/or adjusted using the
calibration system (e.g., in conjunction with the astigmatism
system, e.g., FIG. 15). The calibration structure may facilitate
measurement of the power density distribution in at least one
lateral direction (e.g., X and/or Y direction). FIG. 27A, shows an
example of a top view of a footprint of an energy beam 2700 that is
circular, an X direction 2740, a Y direction 2720, and angular
directions 2710, and 2730. FIG. 27B, shows an example of a top view
of a footprint of an energy beam 2790 that is elliptical, an X
direction 2780, a Y direction 2760, and angular directions 2750,
and 2770. The astigmatism calibration of the footprint may be
performed using any of the calibration structures described herein.
For example, the calibration structure may comprise one or more
positions at which at least two marks of different types, meet at a
line (e.g., FIG. 18A, 1807; FIG. 18C, 1822; FIG. 19A, 1906; or FIG.
20A, 2005). For example, the calibration structure may comprise one
or more positions at which at least four marks, comprising two mark
types, meet at a point (e.g., FIG. 18B, 1826; 19B, 1926; 19C, 1936,
20B, 2021; 20C, 2031; 21B, 2126; or 21C, 2137). For example, the
calibration structure may comprise one or more elliptical
calibration marks (e.g., FIG. 21A, 2101, or FIG. 21B, 2121). At
times, the calibration marks may be elongated (e.g., elliptical, or
oval). The elongated calibration marks may allow measurement of the
power density distribution in any lateral XY direction (e.g., FIG.
27B). The calibration structure may allow measurement of the power
density distribution in any XY direction.
[0273] The measured power density distribution across the footprint
of the energy beam on the calibration structure (e.g., surface) may
be compared to a respective actual power density distribution
(e.g., pre-determined, known footprint size and/or shape at the
position, and/or a power density distribution determined from the
calibration map). A deviation of the power density distribution as
compared to the actual power density distribution may be
calculated. The calculation may be done manually and/or
automatically (e.g., by a controller). The calculation may be done
in real-time (e.g., during build of the 3D object, e.g., during the
3D printing when the irradiating energy is not used to transform
the pre-transformed material). The calculation may be done when
performing calibration (e.g., before, and/or, after build of the 3D
object). Based on the calculated deviation, the position, power
density (e.g., distribution thereof), footprint size, focus, and/or
astigmatism of the footprint of the irradiating energy may be
adjusted. Adjusting may include adjusting homogenously or
heterogeneously at least across the X and Y axis (e.g., narrow or
broaden the spot size by adjusting one or more optical elements).
Adjusting may include adjusting the footprint astigmatically (e.g.,
by adjusting the degree of astigmatism, adjusting the position of
one or more elements of the astigmatic system, e.g., FIG. 15).
Adjusting may include adjusting the position of at least one
optical medium (e.g., FIG. 15, 1525 by rotating around axis 1550,
and/or 1515 by rotating around axis 1520). Adjusting may be done
during, before, and/or after build of the 3D object. Adjusting may
be performed manually and/or automatically (e.g., by a controller).
At times, calculating and adjusting may be performed by the same
controller. At times, calculating and adjusting may be performed by
different controllers (e.g., that are operatively coupled). The
controller may comprise a control system. The controller may
comprise a processing unit. The controller may be programmable. The
controller may operate upon request (e.g., by a user). The
controller may be any controller described herein.
[0274] FIGS. 23A-23B illustrate examples of calibrating a property
(e.g., the velocity of the footprint of the irradiating energy on
the calibration structure). The irradiating energy may be projected
on one or more positions across the calibration structure. Each
position may be equidistant from another spot. The irradiating
energy may be projected onto a calibration mark (e.g., including on
an edge and/or corner of that calibration mark). The irradiating
energy may be projected on at least two calibration marks that
contact each other. The at least two calibration marks that contact
each other may be of different types (e.g., a black mark and a
white marks). Contacting each other may comprise bordering each
other. Contacting each other may comprise a point of contact (e.g.,
the corners thereof contact each other). A sensor may be used to
measure the velocity of the irradiating energy footprint (e.g.,
moving energy beam) across the at least one calibration mark (e.g.,
two different calibration mark types). A sensor may be used to
measure the velocity of the irradiating energy footprint as it
travels across at least one calibration mark edge and/or corner.
The edge and/or corner may be identified by a transition from a
first mark type to a second mark type. The sensor may comprise any
sensor disclosed herein. For example, the sensor may be an imaging
sensor. For example, the sensor may be a non-imaging sensor. The
sensor may comprise a spectrometer. The sensor may comprise an
optical sensor (e.g., as described herein). The sensor (e.g.,
imaging sensor) may sense the movement of the irradiating energy
footprint across an edge and/or corner of at least one calibration
mark (e.g., across two types of calibration marks that contact each
other). Sensing of that movement may be used to measure the
velocity, position, path, and/or direction across the calibration
structure. The sensor (e.g., non-imaging sensor) may measure the
reflected signal (e.g., reflectivity) emitted from the calibration
structure position that the energy beam is directed to. The
reflected (e.g., optical) signal may be used to measure the
velocity, position, path, and/or direction across the calibration
structure of the irradiating energy as it translates across at
least a portion of the calibration structure. The sensor may be a
single output device (e.g., a silicon (Si) detector). The sensor
may be any sensor described herein. The velocity may be measured
one or more times. At least two of a multiplicity of measurements
may be in different directions with respect to each other. For
example, FIG. 23A illustrates measuring velocity in a forward
direction (e.g., left to right direction, 2330). FIG. 23B
illustrates measuring velocity in the reverse direction (e.g.,
right to left direction, 2335). Measuring the velocity more than
once may facilitate reduction (e.g., eliminate) in locality
uncertainty.
[0275] In some embodiments, during the calibration process, a
measured velocity, position, path, and/or direction across the
calibration structure of the irradiating energy is compared to an
expected velocity, position, path, and/or direction across the
calibration structure respectively (e.g., pre-determined, or known
velocity, position, path, and/or direction across the calibration
structure, respectively). A deviation of the measured velocity,
position, path, and/or direction across the calibration structure
as compared to the expected velocity, position, path, and/or
direction across the calibration structure, respectively, may be
calculated from that comparison. The expected velocity, position,
path, and/or direction across the calibration structure may serve
as a benchmark (e.g., for comparison). The calculation may be done
manually and/or automatically (e.g., using a controller). The
calculation may be done in real-time (e.g., during build of the 3D
object). The calculation may be done when performing calibration
(e.g., before, and/or, after build of the 3D object). Based on the
calculated deviation, the velocity of the energy beam may be
adjusted. Adjusting may include adjusting a position of the
galvanometer scanner. Adjusting may include adjusting a position of
a mirror within the galvanometer scanner. Adjusting may be done
during, before, or after build of the 3D object. Adjusting may be
performed by a controller (e.g., automatic, computer, or manual).
At times, calculating and adjusting may be performed by the same
controller. At times, calculating and adjusting may be performed by
different controllers. The controller may be any controller
described herein.
[0276] At times, a calibration structure may be covered (e.g., at
least partially) by a material (e.g., pre-transformed material
and/or contaminant(s), such as soot). In some embodiments, the
calibration process comprises cleaning a (e.g., to-be irradiated)
calibration surface prior to directing the irradiating beam at the
calibration structure. The calibration structure can be any
calibration structure as disclosed herein. A cleaning process may
comprise directing the irradiating beam onto the covered surface
(e.g., ablating). Cleaning may comprise material removal by means
of a moving apparatus (e.g., a translating blade, a squeegee, a
grinder, a polisher, and/or a rolling wheel), by directing a flow
of gas (e.g., gas jet), directing a flow of particulate matter
(e.g., sputtering), by a chemical process (e.g., etching), and/or
by suction (e.g., vacuum). The cleaning of the calibration
structure may comprise a portion of the benchmarking and/or
subsequent calibration measurement processes (e.g., may comprise an
initial step thereof). The cleaning of the calibration structure
may be performed before, during, and/or after a 3D printing
process. The cleaning of the calibration structure may be performed
in real time (e.g., during operation of the irradiating beam). The
cleaning process may be performed by a controller (e.g., automatic,
computer, or manual). At times, the cleaning process may be
controlled by at least one controller and/or manually. At times,
the cleaning process may be performed by different controllers. The
controller may be any controller described herein.
[0277] In some embodiments, at least one characteristic of the
irradiating energy (e.g., the power density distribution of the
irradiating energy) is calibrated. The characteristics of the
irradiating energy may comprise trajectory (e.g., path), footprint
(e.g., its astigmatism, size, focus), power per unit area, fluence,
Andrew Number, hatch spacing, scan speed, scan direction, or
charge. The calibration system may be used to calibrate one or more
optical elements (e.g., lenses) of the optical system. The
calibration system may facilitate focus calibration, and focus
sensitivity (e.g., resolution) study of the optical system. The
calibration system may facilitate calibrating the one or more
scanners of the 3D printer. For example, the angle (e.g., FIG. 16,
1630) of the scanner (e.g., 1610), e.g., with respect to the target
surface. The characteristics of the irradiating energy may be any
irradiating energy characteristics described herein. The power
density of the irradiating energy may change over time and/or
depending on a position in the field of view. The irradiating
energy may be projected on one or more positions across the
calibration structure. The plurality of positions may be
equidistant from another spot. The irradiating energy may be
projected on at least one calibration mark. The irradiating energy
may be projected on at least one edge and/or corner position of a
calibration mark. The irradiating energy may be projected on a
position on two or more calibration marks across the calibration
structure. The irradiating energy may be projected on a position on
two or more calibration marks that contact each other (e.g., border
each other) across the calibration structure. At least two of the
contacting calibration marks may be of a different type (e.g., such
that their contact position is identifiable). The projected
position on the at least one calibration mark may exert a
detectable signal (e.g., reflective radiation, e.g., reflective
beam). The detectable signal may be sensed by the sensor. The
detected signal may be measured for one or more positions of the
calibration structure to which the irradiating energy is directed
to. A detector may be used to detect the detectable signal. The
detector may comprise an optical detector. The detector may be
coupled to one or more optical fibers (e.g., fiber bundle, e.g.,
FIG. 14). The detector and/or optical fiber may be any detector
and/or fiber optic described herein respectively. The measured
characteristics of the irradiating energy (e.g., power density) may
be compared to the expected respective characteristics of the
irradiating energy (e.g., pre-determined, and/or known). The
expected respective characteristics of the irradiating energy may
be a benchmark (e.g., for comparison). A deviation of the measured
characteristics of the irradiating energy as compared to the
expected characteristics of the irradiating energy may be
calculated. The calculation may be done manually and/or by a
controller. The calculation may be done in real-time (e.g., during
build of the 3D object). The calculation may be done when
performing calibration (e.g., before, and/or, after build of the 3D
object). Based on the calculated deviation, the characteristics of
the irradiating energy may be adjusted. Adjusting may include
adjusting one or more optical elements of the optical system and/or
optical mechanism (e.g., lens, mirror, and/or optical medium, at
least one element of the scanner and/or astigmatism system).
Adjusting may be done during, before, or after build of the 3D
object. Adjusting may be performed manually and/or by a controller.
At times, calculating and adjusting may be performed by the same
controller. At times, calculating and adjusting may be performed by
different controllers. The controller may be any controller
described herein.
[0278] FIG. 29 illustrates an example of systematic variation
within a 3D printer. A portion (e.g., 2950) of the target surface
(e.g., 2915) or a position therein (e.g., 2955), may be viewed at a
different angle (or range of angles) from one or more components of
the 3D printer (e.g., with respect to the target surface). For
example, a portion in the field of view (e.g., FIG. 29, 2950) may
be viewed at a first angle (e.g., FIG. 29, 2975) from the optical
system (e.g., FIG. 29, 2920), and from a second angle (e.g., FIG.
29, 2970) from a detection system (e.g., FIG. 29, 2910). The first
angle may be different from the second angle. The difference in the
first angle and/or second angle may induce a systematic (e.g.,
instrumentation) variation when measuring within the field of view.
The systematic variation may be pre-calculated and/or calibrated.
The pre-calculated systematic variation may be considered when
performing measurement of one or more optical properties (e.g., XY
offset of the energy beam relative to the target surface, or
velocity of the energy beam).
[0279] In some embodiments, a detection system that is
operationally coupled to a 3D printing system (e.g., included as
part of a 3D printer) comprises an apparatus configured to project
structured electromagnetic radiation (e.g., structured light)
within the 3D printing system (e.g., within its enclosure, e.g.,
within its processing chamber of). In some embodiments, an optical
system may comprise a (e.g., structured) light projection apparatus
(e.g., FIG. 29, 2920). The light projection apparatus may be
configured to project (e.g., structured) light over a field of view
of a surface, for example, a (e.g., portion and/or entirety of a)
target surface (e.g., FIG. 29, 2915). The (e.g., structured light)
detection system may comprise at least one detector (e.g., FIG. 29,
2910) configured to receive illumination (e.g., reflected,
scattered, and/or a combination thereof) from the projected
radiation, and to generate one or more signals therefrom (e.g.,
corresponding to an image). Examples of detection systems can be
found in patent application serial number PCT/US2015/065297, that
is incorporated herein by reference in its entirety. The structured
light apparatus may comprise a projector, a laser, or a combination
thereof. The structured light apparatus can project any suitable
pattern onto a surface for detection by the detector. The
structured light may form a projection on a target surface. The
structured light may be devoid of a pattern. The structured light
may comprise a map or an image. The structured light may comprise a
known and/or predetermined projection. Examples of patterns are
alternating light and dark shapes (e.g., stripes and/or fringes), a
(e.g., pixelated) grid, a (e.g., solid line) grid, and/or a (e.g.,
plurality of) spiral(s). The pattern may (e.g., controllably)
evolve (e.g., change) over time. The change may comprise a change
in an orientation and/or scale of at least part of the pattern. The
pattern may be static, or moving (e.g., dynamic), for example,
during at least part of projection time on the target surface. The
pattern may be projected (on the target surface) during at least
part of the 3D printing. For example, the pattern may be projected
during processing of the energy beam. For example, the pattern may
be projected during formation of a planar surface adjacent to the
platform. Adjacent may be above.
[0280] The target surface (e.g., comprising the pre-transformed
material, transformed material, build platform, or enclosure floor)
may comprise at least one detectable property. The detectable
property may be a physically detectable property (e.g.,
protrusions, indentations, roughness, smoothness, regularity, or
planarity). The detectable property may be an optically detectable
property (e.g., via reflectivity, absorption, and/or image
analysis). Images from the structured light detector system may be
processed to determine a topography, and/or reflectivity of at
least a fraction of the target surface. The at least the fraction
of the target surface may comprise a pre-transformed material or a
transformed material (e.g., as part of the 3D object). The
transformed material may be, or become, a hard material. For
example, one or more topographical features (e.g., indentations,
protrusions, roughness, smoothness, granular, or planar) may be
detected on the at least the fraction of the target surface.
[0281] In some embodiments, a structured light detection system is
used to monitor and/or calibrate one or more processes (e.g., in a
3D printing system). For example, a structured light detection
system may be used to characterize a topography of a target surface
and/or and adjacent build platform surface before, during and/or
after a 3D printing process (e.g., formation of one or more layers
of hardened material layer, and/or a building cycle). The 3D
printing process may comprise printing one or more layers of
hardened material. A building cycle, as understood herein,
comprises printing all hardened material layers of a print job
(which may comprise printing one or more 3D objects above a
platform). Characterizing may include measuring protrusions,
indentations, (e.g., average) roughness, planarity, reflectivity,
or smoothness of a surface (and/or a portion of pre-transformed
and/or transformed material thereon). At times, a target surface
comprises at least two materials (e.g., pre-transformed and
transformed material) having (e.g., substantially) different
optical qualities. Different optical qualities can include
specularity, reflectivity, absorptivity, and/or scattering.
Substantially different optical qualities of materials within a
field of view of a detector can create a contrast ratio condition
for the detector that is (e.g., readily) detectable.
[0282] A contrast ratio condition may occur when a field of view of
the detector (e.g., a subset of pixels of the detector) comprises
regions having both relatively low and high (e.g., at least one
region of each) of an optical quality. For example, a region of the
field of view corresponding to a plurality of pixels may comprise
both relatively low and high reflectivity. A resolution of the
detector (e.g., pixel resolution) may determine a size of the
region over which a contrast ratio condition may occur. A contrast
ratio image may include one or more regions (e.g., corresponding to
high and/or low reflective portions of a field of view) that are
outside a threshold range of the image pixel values of the detector
(e.g., clipped pixel data). This may lead to data loss within the
image (e.g., pixels in the image that are set to a maximum
brightness and/or darkness value) with regard to the field of
view.
[0283] In some embodiments, a structured light detection system
comprises a characterization of a contrast (e.g., a contrast
characterization) of an image (e.g., captured from a portion of a
field of view of the detector). A contrast characterization can
measure the contrast of an image by any suitable measure, such as a
Weber contrast, a Michelson contrast, or a root mean square (RMS)
contrast. A contrast characterization may be based on a histogram
of the image pixel data reflecting the physically detectable
property (e.g., intensities of the pixels in the image). An image
contrast may be characterized by a (e.g., at least one) threshold
contrast value. A threshold contrast ratio value may an upper
contrast ratio value (e.g., a threshold number of pixels at or near
maximal brightness), a lower contrast ratio value (e.g., a
threshold number of pixels at or near minimal brightness), or a
combination thereof. The threshold contrast ratio value may
correspond to a contrast level at which one or more regions of an
image comprise data loss (e.g., clipped pixels, or redacted
pixels). The threshold contrast ratio value may correspond to the
one or more regions of the image having a threshold size (e.g.,
area of data loss with respect to a total area of the image). The
threshold contrast ratio value may correspond to a locality of the
one or more regions of the image, for example, position(s) of
pixels having data loss with respect to one another, and/or a
feature of interest in the image). The pixels qualified for data
loss, may be configured to adopt an (e.g., average or mean) value
of nearby pixels. The nearby pixels may be directly nearby and/or
bordering pixels.
[0284] In some embodiments, the pre-transformed material and/or
transformed material are diffusive (e.g., and dispersive). In some
embodiments, the pre-transformed material and/or transformed
material are specular. The pre-transformed material (e.g., in an
exposed surface of a material bed) may be at least 50%, 60%, 70%,
80%, or 90% diffusive, relative to its total reflection. The
pre-transformed material (e.g., in an exposed surface of a material
bed) may be diffusive in any percentage between the afore-mentioned
percentages, relative to its total reflection (e.g., from 50% to
90%). In some embodiments, the transformed material (e.g., an
exposed surface thereof) is at least about 50%, 60%, 70%, 80%, 90%,
or 95% specular, relative to its total reflection. The transformed
material (e.g., an exposed surface thereof) may be specular in any
percentage between the afore-mentioned percentages, relative to its
total reflection (e.g., from 50% to 95%). The detected spatial
(e.g., horizontal and/or vertical) deviation detected by the
detector may be of at least 10 .mu.m, 30 .mu.m, 50 .mu.m, 70 .mu.m,
100 .mu.m, or 150 .mu.m. The detected spatial (e.g., horizontal
and/or vertical) deviation detected by the detector may be of any
value between the afore-mentioned values (e.g., from about 10 .mu.m
to about 150 .mu.m, from about 10 .mu.m to about 50 .mu.m, or from
about 50 .mu.m to about 150 .mu.m). The detected spatial deviation
may correlate to the resolution of the detector, optical
element(s), and/or detectable image.
[0285] In some embodiments, a filter is coupled to the detector
that detects the structured light. The filter may be configured to
alter an intensity and/or focus of at least a portion of the
structured light received at the detector. The filter may be
configured to average an intensity of at least a portion of the
structured light received at the detector. The filter may be
configured to lower the resolution of the detectable light image
captured by the detector (e.g., to be closer to a resolution of the
detector). The filter may comprise a frequency cut-off filter. The
filter may comprise a low pass filter. The detector may be an
optical detector (e.g., a camera).
[0286] In some embodiments, a structured light detection system
comprises one or more polarizing filters (e.g., FIG. 29; 2960,
2965). In some embodiments, the polarizer is an optical filter that
allows light waves of a polarization pass, and block light waves of
other polarizations. The polarization filters may comprise linear
or circular polarizing filters. The polarizers may comprise
birefringent polarizers. The polarizers may comprise thin film, or
wire-grid polarizers. The linear polarizer may comprise ab
absorptive, beam splitting, or cartesian polarizer. The polarizer
may comprise homogenous circular polarizer. The polarizing
filter(s) may be coupled with the structured light source, the
detector, or a combination thereof. The structured light source may
be polarized. The structure light source may become polarized by
operatively coupling it to a first polarizer (e.g., irradiating it
through the first polarizer). When irradiating (e.g., shining) the
structured light on a target surface, some of the light may reflect
diffusively (e.g., and dispersively), e.g., from a rough surface.
When irradiating the structured light on a target surface, some of
the light may reflect specularly, e.g., from a low roughness (e.g.,
smooth) surface. A polarizer (e.g., second polarizer) may be
configured to filter out the specularly reflected light from the
target surface (e.g., and thereby reduce the amount of specular
reflected light from reaching the field of view of a detector). The
polarizing filter(s) may be configured to reduce a contrast ratio
value within a detector field of view (e.g., by changing a
polarization axis of light, via the filter). Reducing a contrast
ratio value may include reducing a (e.g., detected) brightness of a
region (e.g., highly reflective region), increasing a (e.g.,
detected) brightness of a region (e.g., a low reflective region),
or a combination thereof. The reduction may be confined to above
and/or below a threshold value. For example, the reduction may be
confined to a threshold region, or to outside of a threshold
region. The operation of the polarizing filter(s) may be controlled
(e.g., before, after, and/or during the 3D printing). At times, the
system may comprise one polarizing filter (e.g., when the generated
structured light is polarized). The polarizer may be configured to
at least partially cancel out (e.g., counter or neutralize) the
polarization of the structured light. The polarization of the
polarizer may be (e.g., about) normal to the polarization of the
structured light. Varying the angle of polarization of the
polarizers (e.g., polarization angle that is passed by the
polarizer, e.g., not filtered out by the polarizer) relative to the
polarization of the structured light may in turn vary the amount of
specular reflection that reaches the detector. The polarization
angle relative to the polarization of the structured light may be
from about 70.degree., from about 80.degree., or from about
85.degree.; to about 90.degree. with respect to each other. At
times, the system may comprise at least two polarizing filters
(e.g., when the generated structured light is non-polarized). The
second polarizer may be configured to at least partially cancel out
(e.g., counter or neutralize) the first polarizer. The amount of
neutralization may vary the amount of specular reflection that
reaches the detector. The polarization angle of the first polarizer
may be (e.g., about) normal to the polarization angle of the second
polarizer. Varying the angle of polarization of the two polarizers
may vary the amount of specular radiation that reaches the
detector. The polarization of the two polarizers may be from about
70.degree., from about 80.degree., or from about 85.degree., to
about 90.degree. with respect to each other. The polarizing
filter(s) may be controlled separately, or in coordination with one
another. Control may be manual and/or automatic control. Control
may be based on a threshold level of the image (e.g., a threshold
contrast ratio level). At times, movement of (e.g., at least one)
polarizing filter is controlled, e.g., when a detected threshold
contrast ratio value (e.g., a high or low contrast ratio condition)
of an image is present.
[0287] In some embodiments, the contrast ratio of an image is
altered. A process (e.g., contrast optimization process) of
alternating a contrast ratio of the image (e.g., of a field of view
in a 3D printing system) may be performed before, during, and/or
after a portion of a 3D printing process. Alteration of the image
may comprise image processing. The contrast optimization process
may comprise analyzing image data corresponding to (e.g., each of)
a sequence of images captured of the field of view. The contrast
optimization process may comprise determination of whether or not a
threshold contrast ratio value is present in the image. The
contrast optimization process may alter a position of one or more
polarizing filters between image captures of the image capture
sequence. The alteration in position may be pre-determined (e.g., a
pre-determined rotation of the filter) and/or based on a (e.g.,
prior) image contrast value. The contrast optimization process may
comprise analysis of a distribution of pixel data of the image
(e.g., a distribution of pixel data in a luminance, intensity,
and/or brightness histogram). The contrast optimization process may
comprise analysis of altered (e.g., removed and/or averaged) pixels
of an image. A selected (e.g., substantially optimal) position of
the polarizer(s) may be determined based on the image contrast
ratio value (e.g., having a value within an acceptable range
thereof) (e.g., via a histogram of image pixels). The threshold
value and/or range may be altered as part of the image processing.
The alteration of the threshold value and/or range may comprise
considering an average physical property of the pixels in the
image, e.g., in a majority of the image or in an identifiable
portion of the image. The identifiable portion may comprise a
pre-transformed material, or a transformed material.
[0288] FIG. 31A depicts an example of a composition of images of a
target surface comprising pre-transformed material 3107 and
transformed material 3105, in a field of view of a detection
system. The composition of images may correspond to different
polarizing filter(s) position(s) and/or thresholds of the light
projection apparatus, the detector, or a combination thereof. The
composition of images in the example of FIG. 31A comprises an image
portion captured at a polarizing filter condition pf1, and an image
portion captured at a polarizing filter condition pf2. In the
example of FIG. 31A, a region 3125 corresponds to a field of view
comprising the pre-transformed material, a region 3155 corresponds
to a field of view comprising the transformed material, and a
region 3135 corresponds to a field of view comprising a portion of
the pre-transformed material and a portion of the transformed
material (e.g., an edge transition region). An image of a region of
a field of view comprising pre-transformed material adjacent to
transformed material (e.g., a melt pool) may comprise a contrast
ratio. FIG. 31B depicts a relationship between a contrast ratio
value 3160 and an image region 3165 (e.g., comprising one or more
regions such as those corresponding to FIG. 31A, regions 3135,
3145, and 3155). The contrast ratio value 3160 comprises a
threshold contrast ratio value 3164. In the example of FIG. 31B,
the graphed column 3180 (e.g., corresponding to FIG. 31A, 3155) has
a contrast ratio value below the threshold contrast ratio value,
and the graphed column 3185 (e.g., corresponding to FIG. 31A, 3135)
has a contrast ratio value above the threshold contrast ratio
value. Regions of an image having contrast value(s) outside of a
threshold level (e.g., above the threshold levels) may be
challenging for detection of detectable properties (e.g.,
protrusions, indentations, roughness, or smoothness) of materials
and/or surfaces in the field of view of the image. At times, an
image determined to have a contrast ratio value beyond a threshold
value (e.g., above a threshold) causes (e.g., a controller)
performance of a contrast optimization process. The contrast
optimization process may comprise capturing a sequence of images,
with each image having a different (e.g., known) exposure settings,
such as exposure time, and/or aperture size. The contrast
optimization process may comprise capturing a sequence of images,
with each image having a different (e.g., polarizing filter
position) condition. In the example of FIG. 31A, the image portion
pf2 corresponds to an altered position of one or more polarizing
filter(s), which alteration causes a change in the overall contrast
ratio of the image portion. FIG. 31A depicts a region 3145
corresponding to a field of view comprising a portion of the
pre-transformed surface and a portion of the transformed surface
(e.g., an edge transition region). FIG. 31B depicts a contrast
ratio value of portion 3185 (as a graphed column) corresponding to
region 3145 that is outside of the upper threshold value 3164, and
a corresponding adjusted graphed column 3195 that is within an
acceptable contrast ratio value range (e.g., is below the threshold
contrast ratio value). Regions of an image having contrast ratio
value(s) within of a threshold level may be beneficial for
detection of detectable properties (e.g., protrusions,
indentations, roughness, or smoothness) of materials and/or
surfaces in the field of view of the image.
[0289] In some embodiments, one or more measurements based on
image(s) taken by the structured light detection system may exhibit
one or more measurement anomalies. A measurement anomaly may be a
measurement data that does not correspond with the imaged surface.
For example, a profile measurement of a (e.g., substantially
planar, having at most about 10 .mu.m Ra) surface having a
measurement anomaly may include anomalous measurement values
indicating a (e.g., non-existent) protrusion and/or a (e.g.,
non-existent) indentation on the surface. A measurement anomaly may
be generated when an artifact (e.g., an edge artifact) is present
in the image pixel data on which the measurement is made. An edge
artifact may be present at (e.g., a portion of) an image having a
(e.g., sharp, or abrupt) transition in a detectable signal. The
detectable signal may comprise the detectable optical quality,
e.g., as described herein. The detectable optical quality may
correspond to a boundary between a pre-transformed material and
transformed material (e.g., portions 3147 within region 3145 of
FIG. 31A). An artifact may be present before, during and/or
following a (e.g., controlled) contrast adjustment.
[0290] In some embodiments, an approach for generating a
measurement (e.g., a feature height, protrusions, indentations,
roughness, or smoothness) from a surface image comprising (e.g., at
least one) image artifact includes modifying the image pixel data.
Modifying image pixel data may comprise masking image pixel data.
Masking pixel data may comprise excluding pixel data corresponding
to pixels above and/or below threshold level(s), e.g., and
performing the measurement(s) with the remaining pixel data. In
some embodiments, masking pixel data comprises altering a value for
the (e.g., edge) pixel(s). For example, an altered value may be
generated from surrounding (e.g., average) pixel values. In some
embodiments, masking pixel data may comprise generating a map of
pixels to be excluded. The map may be generated from a different
image (portion) of the field of view. For example, an image
comprising a gradient map of the field of view can be captured. In
some embodiments, the excluded pixels are selected using an edge
filter (e.g., any suitable edge filter scheme). An image filter may
operate along one image axis (e.g., one dimension), and/or along
two image axes (e.g., two-dimensional). In some embodiments, an
image filter may be applied along one image axis to detect features
(e.g., edges) along that axis (e.g., an edge running generally
perpendicular to the applied axis). Examples of edge and/or image
gradient filters include a Canny edge detector, a Prewitt operator,
a Sobel operator, a Scharr filter, and a Log Gabor filter). Pixels
corresponding to regions of the map that satisfy a given condition
(e.g., having a threshold change in color, e.g., change in
intensity, brightness, shade, hue, or saturation of the color) may
form a portion of a masking pixel image. The masking pixel image
may be used to exclude selected portions of an image taken with the
structured light detection system. For example, the excluded
selected portions may correspond with one or more edges of a
structure in the target surface and/or anomalies in the target
surface. The edge may comprise a physical boundary (e.g., a change
in material type and/or property) and/or a change in optical
characteristic (e.g., reflectivity and/or specularity).
[0291] In some embodiments, a structured light detection system is
used as an interlock aid in a 3D printing process. For example, the
structured light detection system may be used to image a target
surface and/or a build platform before, during, and/or after a
print operation (e.g., within a printing cycle, or of a printing
cycle). The structured light detection system may be used in the
determination of a clearance between one or more components of the
3D printing system, for example, by measuring a height and/or
topography of the an exposed layer of a material bed, a transformed
material, a build platform and/or a test structure. The structured
light detection system may be operable to detect other (e.g.,
unexpected) articles or components that are present in the field of
view (e.g., on the target surface). The structured light detection
system may be operationally coupled with one or more controllers of
the 3D printing system. The structured light may provide one or
more signals that causes the controller to alter a 3D printing
process (e.g., pause and/or stop a printing operation, alter a
function of a component of the 3D printing, generate a message
and/or alert, and/or change a process parameter of the 3D printing
process). For example, the structured light detection system may
detect a protruding object from the exposed surface of the material
bed that may damage the leveler (and optionally: facilitate
directing halting of the planarization operation; lower the build
platform to prevent damage of the leveler (e.g., upon projected
contact with the protruding object); facilitate direction a change
in at least one characteristic of the energy beam to adjust the
printing procedure in light of the protruding object; or any
combination thereof). For example, the structured light detection
system may detect a deviation from requested planarity of the
exposed surface prior to processing of the energy beam, and/or
after a recoating operation (and optionally: facilitate directing a
second planarization operation to correct the defective
deviation).
[0292] In some embodiments, the projected pattern may be adjusted
(e.g., in real time) to facilitate detecting an altered resolution
of a target surface and/or altered topographic range of features of
the target surface. A measurement range for the structured light
detection system may depend on the projected pattern. For example,
a projected pattern having (e.g., relatively) finely spaced
elements (e.g., features such as fringes) may have a reduced
measurement range (e.g., maximum-to-minimum height range detected,
for example, 0.5-2 mm), with increased resolution (e.g., height
resolution of 25-150 microns). Conversely, a structured light
detection system having (e.g., relatively) widely spaced elements
may have an increased measurement range (e.g., maximum-to-minimum
height range detected, for example, 0.5-15 cm), with decreased
resolution (e.g., height resolution 500-1000 microns). Determining
a position of a target surface may include a combination of
measurements taken at both low resolution (e.g., high range)
settings and high resolution (e.g., low range) values. For example,
locating a position of a top surface of a platform in the 3D
printing system may comprise an initial (e.g., several) images
captured by the structured light detection system in a high range
setting, as the platform may be located relatively far (e.g.,
several millimeters or more) from a nominal position. Once the
build plate is located (e.g., relative to its nominal position) it
can be controlled to move (e.g., via an actuator, e.g., an
elevator) toward a target position (e.g., height). The structured
light detection system may be used in an iterative manner, e.g.,
with a controlled movement to position the platform at a nominal
(e.g., controlled) position. As the platform approaches the nominal
position, the structured light detection system may be operable to
use different (e.g., ever-finer) spacing (e.g., higher resolution)
projected light patterns to fine-tune the position of the platform.
At times, portions of a platform comprise specularity and/or
reflectivity outside of a (e.g., contrast ratio) threshold of the
structured light detection system. In such cases, a surface (e.g.,
of the platform, and/or of a test structure) may be conditioned to
be more diffusive (e.g., via sandblasting, etching, scribing, or
any other method, e.g., as described herein) to produce a (e.g.,
relatively) improved surface quality.
[0293] In some embodiments, the calibration structure (e.g., test
structure) does not include a bitmap. In some embodiments, the
target surface serves as the calibration structure. In some
embodiments, the calibration structure is formed (e.g.,
dynamically) at the target surface (e.g., by transforming
pre-transformed material). A dynamically formed calibration
structure can comprise one or more calibration marks, for example,
a transition line (e.g., as in FIG. 23, 2325) between a first
calibration mark type (e.g., comprising a pre-transformed material)
and a second calibration mark type (e.g., comprising a transformed
material). The transition line may be a line that transitions a
property (e.g., reflectivity, intensity) of a calibration mark from
a first side of the line to a second side of the line. At times,
the calibration of properties of the optical system and/or the
detector (e.g., power density distribution, spot size, irradiating
energy footprint shape, and/or power of the energy beam) may be
performed without a bitmap (e.g., and use the target surface as the
calibration structure). In some embodiments, the exposed surface of
the material bed (e.g., powder bed) may be used for calibration.
The target surface may be the exposed surface of the material bed.
The material bed may comprise particulate material of one or more
sizes. The energy irradiated onto the surface of the material bed
may be diffused and/or dispersed. Some of the diffused and/or
dispersed energy may be detected by a detector (e.g., that is
located at a known position). The known position may comprise a
fixed position. The known position may alter in time. In some
embodiments the larger the footprint of the irradiating energy, the
smaller the changes that are detected as the energy beam scans the
target surface. In some embodiments the smaller the footprint of
the irradiating energy, the larger the changes that are detected as
the energy beam scans the target surface. Without wishing to be
bound to theory, the smaller the diameter of the irradiated beam
projection (e.g., footprint), the higher a rate of variability in
its detected intensity (e.g., amplitude of change) from the target
surface may be (e.g., keeping the velocity of the scanning
irradiating energy constant). The amplitude of the standard
deviation of the change of intensity may be calculated. For
example, for "I" being the detector signal, the normalized standard
deviation (e.g., normalized change in detected intensity) may be
calculated (e.g., by Std(I)/mean(I)). The normalized standard
deviation may be calibrated for a certain particular material that
constitutes the material bed (e.g., target surface thereof). The
detection may allow derivation of the footprint size and/or shape
(e.g., astigmatism), the focus of the footprint, and/or the measure
of the power density distribution of the irradiating energy. For
example, detection in different (e.g., X and Y) directions may be
utilized to find an astigmatism of the footprint. For example, the
measure of the power density distribution may be the integral of
the power density distribution (e.g., along one or more specific
directions). In some examples, using the target surface for
locality calibration may not be effective.
[0294] In some embodiments, as a beam becomes more focused, higher
variability is detected in the reflected radiation from an exposed
surface which it irradiates during propagation (e.g., higher
resolution image may be detected). In some embodiments, the
variability range of the reflected radiation from the surface may
be used to facilitate calibration of the spot size of the energy
beam (e.g., whether it is in focus or out of focus, and how much
out of focus it is). An exposed surface of the material bed may be
used as a target surface. For example, the exposed surface of the
material bed may be characterized with an energy beam having
several known focal positions (e.g., spot sizes), which energy beam
travels laterally along the exposed surface of the material bed
(e.g., powder bed). The reflected radiation may be collected with a
sensor (e.g., detector), e.g., a camera or a thermal detector. Once
the surface has been characterized with known focal position, the
beam may be characterized (e.g., in real time) with a known surface
(e.g., known powder bed). The target surface may comprise a random
pattern. The randomness may be characteristic of that surface or
surface type.
[0295] FIG. 28A shows an example of an irradiating energy (e.g.,
beam) 2803 that irradiates a target surface 2806 of a material bed
(e.g., comprising a particulate material), which irradiating energy
is generated by an energy source 2801; and a detector 2802 that
detects the reflected irradiating energy 2805 having a footprint
2807 on the exposed surface (e.g., target surface) 2806. FIG. 28B
shows an example of a change in the normalized standard deviation
(e.g., Std(I)/mean(I), 2851) that is plotted as a function (e.g.,
2850) of an area or FLS of the footprint (e.g., length, or width,
2852). The length or width of the footprint may be obtained by
scanning the irradiating energy at different directions (e.g., X or
Y) along the target surface. By calibrating a change in the
normalized standard deviation of the irradiating energy amplitude
change as a function of the FLS or area of the footprint (e.g., the
graph in FIG. 28B) for a target surface comprising a certain
particulate material, one may derive at least the area and/or FLS
of the footprint.
[0296] As an example, in order to calibrate a focus shift of the
irradiating energy, the irradiating energy may be directed on one
or more positions on the target surface. The target surface may
exert a reflected signal. The reflected signal may include diffused
signals (e.g., due to the particulate material). For example, the
reflected signal may comprise a white noise signal. The reflected
signal may comprise a spectral content. A focus shift of the
irradiating energy footprint on the target surface at a given
position may be measured based on an alteration in the spectral
content of the reflected signal. Measuring the focus shift at
different positions on the target surface (e.g., FIG. 26A, 2620)
may be repeated for one or more focal offsets (e.g., FIG. 26A,
2635, 2630, 2625, 2615, and 2605).
[0297] The reflected signal may comprise a frequency content. For
example, the particulate material may contribute a
particulate-specific frequency pattern to the reflected signal
(e.g., high frequency). An amplitude of that particulate-specific
frequency pattern may be utilized to determine the footprint FLS
(when measured at different directions) and/or area. The reflected
signal may be detected and analyzed. The analysis may comprise an
optical transfer function (e.g., determining how different spatial
frequencies are affected as they are reflected from the target
surface). The optical transfer function (OTF) may or may not
comprise considering phase effects. For example, the OTF may not
consider phase effects. For example, the OTF may be a modulation
transfer function (MTF). The OTF (e.g., MTF) for the reflected
signal (e.g., FIG. 26B, 2690) at the different focal offsets (e.g.,
FIG. 26B, 2685) may be generated (e.g., FIG. 26B, 2610). The OTF
may be a combination of the OTF of the one or more optical elements
that generate the irradiating energy along with the OTF of the
target surface (e.g., the particulate material in the exposed
surface of the material bed). A selected focus shift (e.g., FIG.
26B, position #3 of 2685) may be determined from the one or more
measured focus shifts at different focal offsets. The selected
focus shift may be the region (e.g., spot) that has the highest
intensity in the reflected signal. Similar to the focus shift, the
process can be used to measure other characteristics of the
irradiating energy (e.g., power density distribution, footprint
position, footprint shape, scan direction, and/or scan velocity of
the irradiating energy). A source of uncontrolled focus shift can
be thermal lensing, that is addressed herein.
[0298] A calibration structure can comprise a heat sink. A
calibration structure may comprise any material disclosed herein. A
calibration structure can comprise two or more elemental metals,
two or more metal alloys, two or more ceramics, and/or two or more
allotropes of elemental carbon. For example, an elemental metal and
a metal alloy, an elemental metal and a ceramic, an elemental metal
and an allotrope of elemental carbon, a metal alloy and a ceramic,
a metal alloy, and an allotrope of elemental carbon, a ceramic and
an allotrope of elemental carbon. The calibration structure may
comprise one or more salts or oxides. A calibration structure can
be formed as a regular or irregular shaped solid. The calibration
structure may have a 3D shape. The 3D shape may comprise a cuboid
(e.g., cube), or a tetrahedron. The 3D shape may comprise a
polyhedron (e.g., primary parallelohedron), at least a portion of
an ellipse (e.g., circle), a cone, or a cylinder. The polyhedron
may be a prism (e.g., hexagonal prism), or octahedron (e.g.,
truncated octahedron). The calibration structure may comprise a
Platonic solid. The calibration structure may comprise octahedra,
truncated octahedron, or a cube. The calibration structure may
comprise convex polyhedra (e.g., with regular faces). The
calibration structure may comprise a triangular prism, hexagonal
prism, cube, truncated octahedron, or gyrobifastigium. The
calibration structure may comprise a pentagonal pyramid. One or
more (e.g., at least one) surfaces of the calibration structure may
be substantially planar (e.g., smooth). A substantially planar
surface of a calibration structure can be disposed (e.g., adjacent
to the target surface) in a field of view of a detector. A
substantially planar surface of a calibration structure can be
disposed away from a field of view of a detector (e.g., having an
indirect view of the detector). At times, a process of monitoring
the optical element(s) condition can comprise directing the
irradiating energy beam at one or more calibration marks of a
calibration structure, prior to (e.g., in a benchmark condition)
and following the heating irradiation and/or transforming the
pre-transformed material into a transformed material as part of the
3D printing. The path of the irradiating energy may be directed in
a direction that is perpendicular relative to the alignment
direction of a series of transition lines between (e.g., two)
calibration mark types when such alignment is present (e.g., FIGS.
32, 3220 and 3230). A detector (e.g., gray field detector) may
produce a detected signal (e.g., optical signal) that may be
measured from at least two calibration mark types (e.g., that
contact each other), as described herein. The detected signal may
be averaged amongst a plurality of irradiated positions within a
calibration mark. The detected signal may be used to generate one
or more graphical representations (e.g., as in FIG. 33). The
graphical representations can depict one or more changes in the
irradiating energy beam over time (e.g., as in curves 3320, 3330,
3340 of FIG. 33), which one or more changes can be correlated to an
onset of and/or change in a thermal lensing condition of an optical
element (e.g., of a 3D printing system).
[0299] In another example for calibrating locality of the
irradiating energy footprint, the irradiating energy may be
directed to a position in the enclosure (e.g., build module and/or
the processing chamber). The enclosure may have a fixed size. The
edge and/or corner of the enclosure may be pre-determined and/or
know. For example, the edge and/or corner may be fixed. The one or
more positions may serve as a calibration mark. A detector may
detect the footprint of the irradiating energy on the edge and/or
corner. A sensor may sense the footprint of the irradiating energy
on the edge and/or corner. The detector may indicate a deviation of
the footprint position relative to the corner and/or edge of the
enclosure. The deviation may be calculated. The calculation may be
done by a controller. The controller may be any controller
described herein. Based on the calculated deviation, at least one
characteristic of the irradiating energy may be adjusted.
Adjustment may include aligning (e.g., bringing into coincidence)
the location of the irradiating energy footprint with the fixed
location of the enclosure, (e.g., edge and/or corner).
[0300] At times, a sensor array (e.g., a camera, an imaging
calibration sensor) may be pre-calibrated as a calibration
structure (e.g., bitmap). The sensor array may be a detecting unit
(e.g., camera). The sensor array may act in a similar manner to a
calibration mark of the calibration structure. The sensor array may
be a pixel. The sensor array may border each other. For example, to
pre-calibrate a camera as a bitmap (e.g., virtual bitmap), the
camera may be used to measure one or more locations of a
calibration mark (e.g., a transition between the pixels may act as
the detectable transition between the calibration marks). In some
embodiments, finding the center position comprises translating the
irradiating energy (e.g., vectorially) through a plurality (e.g.,
at least four) of transition lines between the pixels, which pixels
contact a point (e.g., in a similar manner to FIG. 18, 1814). The
pixels may be (e.g., substantially) identical. The transition
between pixels may be detectable. The detection unit (e.g., camera)
may record the detected reflected signals (e.g., the picture of the
reflected signal may be recorded by the camera). In some
embodiments, the irradiating energy translates with respect to the
target surface, causing the reflected signal to travel between
pixels. The transition between pixels may be detectable, which
detection may allow calibration of the position and/or at least one
characteristic of the irradiating energy (e.g., a measure of the
power per unit area distribution), as disclosed herein for the
calibration surface. The sensor array (e.g., pixel array) may
function as the calibration structure. The sensor array (e.g.,
camera) may be calibrated in terms of image scaling, position,
position offset (e.g., shift), or any combination thereof. In some
embodiments, the irradiating energy does not translate, and the
pixels that detect the reflected signals are collectively analyzed,
facilitating the positioning and/or at least one characteristic of
the irradiating energy, as disclosed herein for the calibration
surface. For example, the focal point of the beam may be determined
by analyzing the pixels which detect the reflected signal. In an
example, the measured location may be compared to the expected
location of the calibration mark. The measured location may deviate
from the expected location. The camera may comprise an imaging
sensor, a row of the imaging sensor, a line of the imaging sensor,
a pixel of the imaging sensor, or a set of pixels of the imaging
sensor.
[0301] To calibrate the properties of the irradiating energy, the
irradiating energy may be directed to move (e.g., scan) in a
direction that crosses at least one connection point of two pixels
(e.g., border). For example, the irradiating energy may be directed
to travel in a direction parallel to two or more (e.g., a row or
line of) sensors. The travel of the irradiating energy along the
target surface may be continuous or in steps (e.g., pulses). The
travel (e.g., scan) of the irradiating energy may be performed at a
higher resolution than the resolution of the sensor (e.g., using
smaller travel steps than the pixel size). The translation of the
irradiating energy may be performed at a lower resolution than the
resolution of the detecting unit sensor(s). The translation of the
irradiating energy may be at a resolution (e.g., substantially)
equal to the resolution of the imaging sensor. A detector and/or
sensor may detect and/or sense the reflected signal of the
irradiating energy (e.g., from a target surface). The deviation may
be calculated based on comparing the detected and/or sensed signal
with an expected signal (e.g., pre-determined, or known). The
comparison may be as to a position of the irradiating energy
footprint on the surface (e.g., target surface), and/or to any
other characteristics of the irradiating energy. The position
and/or at least one irradiating energy characteristics may be
adjusted based on the calculated deviation. For example, the
distribution of the power density measure across the footprint of
the irradiating energy (e.g., on the calibration structure surface)
may be calibrated in a similar method. For example, to calibrate
the velocity and/or the locality of the energy beam, the size of
the target surface may be measured (e.g., by measuring from one
edge to the second edge of the material bed) by the sensor(s)
and/or detector(s). The measured size of the target surface may be
compared to the expected size (e.g., predetermined, known) of the
target surface. The deviation of the measured size to the expected
size may be calculated. The position of the energy beam may be
adjusted, based on the calculated deviation.
[0302] One or more sensors (at least one sensor) can detect the
topology of the exposed surface of the material bed and/or the
exposed surface of the 3D object or any part thereof. The sensor
can detect the amount of material deposited in the material bed.
The sensor can be a proximity sensor. For example, the sensor can
detect the amount of powder material deposited on the exposes
surface of a powder bed. The sensor can detect the physical state
of material deposited on the target surface (e.g., liquid, or solid
(e.g., powder or bulk)). The sensor can detect the crystallinity of
material deposited on the target surface. The sensor can detect the
amount of material transferred by the material dispensing
mechanism. The sensor can detect the amount of material relocated
by a leveling mechanism. The sensor can detect the temperature of
the material. For example, the sensor may detect the temperature of
the material in a material (e.g., powder) dispensing mechanism,
and/or in the material bed. The sensor may detect the temperature
of the material during and/or after its transformation. The sensor
may detect the temperature and/or pressure of the atmosphere within
an enclosure (e.g., chamber). The sensor may detect the temperature
of the material (e.g., powder) bed at one or more locations.
[0303] The at least one sensor can be operatively coupled to a
control system (e.g., computer control system). The sensor may
comprise light sensor, acoustic sensor, vibration sensor, chemical
sensor, electrical sensor, magnetic sensor, fluidity sensor,
movement sensor, speed sensor, position sensor, pressure sensor,
force sensor, density sensor, distance sensor, or proximity sensor.
The sensor may include temperature sensor, weight sensor, material
(e.g., powder) level sensor, metrology sensor, gas sensor, or
humidity sensor. The metrology sensor may comprise a measurement
sensor (e.g., height, length, width, angle, and/or volume). The
metrology sensor may comprise a magnetic, acceleration,
orientation, or optical sensor. The sensor may transmit and/or
receive sound (e.g., echo), magnetic, electronic, or
electromagnetic signal. The electromagnetic signal may comprise a
visible, infrared, ultraviolet, ultrasound, radio wave, or
microwave signal. The metrology sensor may measure the tile. The
metrology sensor may measure the gap. The metrology sensor may
measure at least a portion of the layer of material. The layer of
material may be a pre-transformed material (e.g., powder),
transformed material, or hardened material. The metrology sensor
may measure at least a portion of the 3D object. The gas sensor may
sense any of the gas delineated herein. The distance sensor can be
a type of metrology sensor. The distance sensor may comprise an
optical sensor, or capacitance sensor. The temperature sensor can
comprise Bolometer, Bimetallic strip, calorimeter, Exhaust gas
temperature gauge, Flame detection, Gardon gauge, Golay cell, Heat
flux sensor, Infrared thermometer, Microbolometer, Microwave
radiometer, Net radiometer, Quartz thermometer, Resistance
temperature detector, Resistance thermometer, Silicon band gap
temperature sensor, Special sensor microwave/imager, Temperature
gauge, Thermistor, Thermocouple, Thermometer (e.g., resistance
thermometer), or Pyrometer. The temperature sensor may comprise an
optical sensor. The temperature sensor may comprise image
processing. The temperature sensor may comprise a camera (e.g., IR
camera, CCD camera). The pressure sensor may comprise Barograph,
Barometer, Boost gauge, Bourdon gauge, Hot filament ionization
gauge, Ionization gauge, McLeod gauge, Oscillating U-tube,
Permanent Downhole Gauge, Piezometer, Pirani gauge, Pressure
sensor, Pressure gauge, Tactile sensor, or Time pressure gauge. The
position sensor may comprise Auxanometer, Capacitive displacement
sensor, Capacitive sensing, Free fall sensor, Gravimeter,
Gyroscopic sensor, Impact sensor, Inclinometer, Integrated circuit
piezoelectric sensor, Laser rangefinder, Laser surface velocimeter,
LIDAR, Linear encoder, Linear variable differential transformer
(LVDT), Liquid capacitive inclinometers, Odometer, Photoelectric
sensor, Piezoelectric accelerometer, Rate sensor, Rotary encoder,
Rotary variable differential transformer, Selsyn, Shock detector,
Shock data logger, Tilt sensor, Tachometer, Ultrasonic thickness
gauge, Variable reluctance sensor, or Velocity receiver. The
optical sensor may comprise a Charge-coupled device, Colorimeter,
Contact image sensor, Electro-optical sensor, Infra-red sensor,
Kinetic inductance detector, light emitting diode (e.g., light
sensor), Light-addressable potentiometric sensor, Nichols
radiometer, Fiber optic sensors, Optical position sensor, Photo
detector, Photodiode, Photomultiplier tubes, Phototransistor,
Photoelectric sensor, Photoionization detector, Photomultiplier,
Photo resistor, Photo switch, Phototube, Scintillometer,
Shack-Hartmann, Single-photon avalanche diode, Superconducting
nanowire single-photon detector, Transition edge sensor, Visible
light photon counter, or Wave front sensor.
[0304] The weight of the material bed can be monitored by one or
more weight sensors in, or adjacent to, the material. For example,
a weight sensor in the material bed can be at the bottom of the
material bed. The weight sensor can be between the bottom of the
enclosure (e.g., FIG. 1, 111) and the substrate (e.g., FIG. 1, 109)
on which the base (e.g., FIG. 1, 102) or the material bed (e.g.,
FIG. 1, 104) may be disposed. The weight sensor can be between the
bottom of the enclosure and the base on which the material bed may
be disposed. The weight sensor can be between the bottom of the
enclosure and the material bed. A weight sensor can comprise a
pressure sensor. The weight sensor may comprise a spring scale, a
hydraulic scale, a pneumatic scale, or a balance. At least a
portion of the pressure sensor can be exposed on a bottom surface
of the material bed. In some cases, the weight sensor can comprise
a button load cell. The button load cell can sense pressure from
powder adjacent to the load cell. In another example, one or more
sensors (e.g., optical sensors or optical level sensors) can be
provided adjacent to the material bed such as above, below, or to
the side of the material bed. In some examples, the one or more
sensors can sense the powder level. The material (e.g., powder)
level sensor can be in communication with a material dispensing
mechanism (e.g., powder dispenser). Alternatively, or additionally
a sensor can be configured to monitor the weight of the material
bed by monitoring a weight of a structure that contains the
material bed. One or more position sensors (e.g., height sensors)
can measure the height of the material bed relative to the
substrate. The position sensors can be optical sensors. The
position sensors can determine a distance between one or more
energy beams (e.g., a laser or an electron beam.) and a surface of
the material (e.g., powder). The one or more sensors may be
connected to a control system (e.g., to a processor, to a
computer).
[0305] The systems and/or apparatuses disclosed herein may comprise
one or more motors. The motors may comprise servomotors. The
servomotors may comprise actuated linear lead screw drive motors.
The motors may comprise belt drive motors. The motors may comprise
rotary encoders. The apparatuses and/or systems may comprise
switches. The switches may comprise homing or limit switches. The
motors may comprise actuators. The motors may comprise linear
actuators. The motors may comprise belt driven actuators. The
motors may comprise lead screw driven actuators. The actuators may
comprise linear actuators. The systems and/or apparatuses disclosed
herein may comprise one or more pistons.
[0306] The exit opening of the material dispenser can comprise a
mesh or a plane with holes (collectively referred to herein as
"mesh"). The mesh comprises a hole (or an array of holes). The hole
(or holes) can allow the material to exit the material dispenser.
The hole (e.g., opening can have a FLS of at least about 0.001 mm,
0.01 mm, 0.03 mm, 0.05 mm, 0.07 mm, 0.09 mm, 0.1 mm, 1 mm, 2 mm, 3
mm, 4 mm, 5 mm, or 10 mm. The hole can have a FLS of at most about
0.001 mm, 0.01 mm, 0.03 mm, 0.05 mm, 0.07 mm, 0.09 mm, 0.1 mm, 1
mm, 2 mm, 3 mm, 4 mm, 5 mm, or 10 mm. The hole can have a FLS
between any of the aforementioned values (e.g., from about 0.001 mm
to about 10 mm, or from 0.1 mm to about 5 mm). In some embodiments,
the hole can have a FLS of at least about 30 .mu.m, 40 .mu.m, 50
.mu.m, 60 .mu.m, 70 .mu.m, 80 .mu.m, 90 .mu.m, 100 .mu.m, 110
.mu.m, 120 .mu.m, 130 .mu.m, 140 .mu.m, 150 .mu.m, 160 .mu.m, 170
.mu.m, 180 .mu.m, 190 .mu.m, 200 .mu.m, 250 .mu.m, 300 .mu.m, 350
.mu.m, 400 .mu.m, 450 .mu.m, 500 .mu.m, 550 .mu.m, 600 .mu.m, 650
.mu.m, 700 .mu.m, 750 .mu.m, 800 .mu.m, 850 .mu.m, 900 .mu.m 950,
.mu.m, or 1000 .mu.m. The hole in the mesh can have a FLS of at
most about 40 .mu.m, 50 .mu.m, 60 .mu.m, 70 .mu.m, 80 .mu.m, 90
.mu.m, 100 .mu.m, 110 .mu.m, 120 .mu.m, 130 .mu.m, 140 .mu.m, 150
.mu.m, 160 .mu.m, 170 .mu.m, 180 .mu.m, 190 .mu.m, 200 .mu.m, 250
.mu.m, 300 .mu.m, 350 .mu.m, 400 .mu.m, 450 .mu.m, 500 .mu.m, 550
.mu.m, 600 .mu.m, 650 .mu.m, 700 .mu.m, 750 .mu.m, 800 .mu.m, 850
.mu.m, 900 .mu.m 950, .mu.m, or 1000 .mu.m. The hole in the mesh
can have a FLS of any value between the afore-mentioned fundamental
length scales (e.g., from about 30 .mu.m to about 1000 .mu.m, from
about 10 .mu.m to about 600 .mu.m, from about 500 .mu.m to about
1000 .mu.m, or from about 50 .mu.m to about 300 .mu.m). The FLS of
the holes may be adjustable or fixed. In some embodiments, the
opening comprises two or more meshes. At least one of the two or
more meshes may be movable. The movement of the two or more meshes
may be controlled manually or automatically (e.g., by a
controller). The relative position of the two or more meshes with
respect to each other may determine the rate at which the material
passes through the hole (or holes). The FLS of the holes may be
electrically controlled. The fundamental length scale of the holes
may be thermally controlled. The mesh may be heated or cooled. The
may vibrate (e.g., controllably vibrate). The temperature and/or
vibration of the mesh may be controlled manually or by the
controller. The holes of the mesh can shrink or expand as a
function of the temperature and/or electrical charge of the mesh.
The mesh can be conductive. The mesh may comprise a mesh of
standard mesh number 50, 70, 90, 100, 120, 140, 170, 200, 230, 270,
325, 550, or 625. The mesh may comprise a mesh of standard mesh
number between any of the aforementioned mesh numbers (e.g., from
50 to 625, from 50 to 230, from 230 to 625, or from 100 to 325).
The standard mesh number may be US or Tyler standards. The two
meshes may have at least one position where no material can pass
through the exit opening. The two meshes may have a least one
position where a maximum amount of material can pass through the
exit opening. The two meshes can be identical or different. The
size of the holes in the two meshes can be identical or different.
The shape of the holes in the two meshes can be identical or
different. The shape of the holes can be any hole shape described
herein.
[0307] The methods described herein may comprise vibrating at least
part of the material, or at least part of the material dispensing
mechanism. The at least part of the material dispensing mechanism
may comprise vibrating at least part of the exit opening of the
material dispensing mechanism. The method may comprise vibrating
the material in the material bed to level the top surface of the
material bed. The method may comprise vibrating the enclosure, the
substrate, the base, the container that accommodates the material
bed, or any combination thereof, to level the material (e.g., at
the top surface of the material bed). The vibrations may be
ultrasonic vibrations. The leveling may be able to level the top
surface of the material with a deviation from the average plane
created by the top surface. The deviation from the average plane
may be of any deviation from average plane value disclosed herein.
The material dispensing method may utilize any of the material
dispensing mechanism described herein. The material dispensing
method may utilize gravitational force, and/or one that uses gas
flow (e.g., airflow).
[0308] In some examples, the pressure system includes one or more
pumps. The one or more pumps may comprise a positive displacement
pump. The positive displacement pump may comprise rotary-type
positive displacement pump, reciprocating-type positive
displacement pump, or linear-type positive displacement pump. The
positive displacement pump may comprise rotary lobe pump,
progressive cavity pump, rotary gear pump, piston pump, diaphragm
pump, screw pump, gear pump, hydraulic pump, rotary vane pump,
regenerative (peripheral) pump, peristaltic pump, rope pump, or
flexible impeller. Rotary positive displacement pump may comprise
gear pump, screw pump, or rotary vane pump. The reciprocating pump
comprises plunger pump, diaphragm pump, piston pumps displacement
pumps, or radial piston pump. The pump may comprise a valveless
pump, steam pump, gravity pump, eductor-jet pump, mixed-flow pump,
bellow pump, axial-flow pumps, radial-flow pump, velocity pump,
hydraulic ram pump, impulse pump, rope pump, compressed-air-powered
double-diaphragm pump, triplex-style plunger pump, plunger pump,
peristaltic pump, roots-type pumps, progressing cavity pump, screw
pump, or gear pump.
[0309] The systems, apparatuses, and/or methods described herein
can comprise a material recycling mechanism. The recycling
mechanism can collect unused pre-transformed material and return
the unused pre-transformed material to a reservoir of a material
dispensing mechanism (e.g., the material dispensing reservoir), or
to the bulk reservoir that feeds the material dispensing mechanism.
Unused pre-transformed material may be material that was not used
to form at least a portion of the 3D object. At least a fraction of
the pre-transformed material removed from the material bed by the
leveling mechanism and/or material removal mechanism can be
recovered by the recycling system. At least a fraction of the
material within the material bed that did not transform to
subsequently form the 3D object can be recovered by the recycling
system. A vacuum nozzle (e.g., which can be located at an edge of
the material bed) can collect unused pre-transformed material.
Unused pre-transformed material can be removed from the material
bed without vacuum. Unused pre-transformed (e.g., powder) material
can be removed from the material bed manually. Unused
pre-transformed material can be removed from the material bed by
positive pressure (e.g., by blowing away the unused material).
Unused pre-transformed material can be removed from the material
bed by actively pushing it from the material bed (e.g.,
mechanically or using a positive pressurized gas). A gas flow can
direct unused pre-transformed material to the vacuum nozzle. A
material collecting mechanism (e.g., a shovel) can direct unused
material to exit the material bed (and optionally enter the
recycling mechanism). The recycling mechanism can comprise one or
more filters to control a size range of the particles returned to
the reservoir. In some cases, a Venturi scavenging nozzle can
collect unused material. The nozzle can have a high aspect ratio
(e.g., at least about 2:1, 5:1, 10:1, 20:1, 30:1, 40:1, or 100:1)
such that the nozzle does not become clogged with material
particle(s). In some embodiments, the material may be collected by
a drainage mechanism through one or more drainage ports that drain
material from the material bed into one or more drainage
reservoirs. The material in the one or more drainage reservoirs may
be re used (e.g., after filtration and/or further treatment).
[0310] In some cases, unused material can surround the 3D object in
the material bed. The unused material can be substantially removed
from the 3D object. Substantial removal may refer to material
covering at most about 20%, 15%, 10%, 8%, 6%, 4%, 2%, 1%, 0.5%, or
0.1% of the surface of the 3D object after removal. Substantial
removal may refer to removal of all the material that was disposed
in the material bed and remained as material at the end of the 3D
printing process (e.g., the remainder), except for at most about
10%, 3%, 1%, 0.3%, or 0.1% of the weight of the remainder.
Substantial removal may refer to removal of all the remainder
except for at most abbot 50%, 10%, 3%, 1%, 0.3%, or 0.1% of the
weight of the printed 3D object. The unused material can be removed
to permit retrieval of the 3D object without digging through the
material bed. For example, the unused material can be suctioned out
of the material bed by one or more vacuum ports (e.g., nozzles)
built adjacent to the material bed, by brushing off the remainder
of unused material, by lifting the 3D object from the unused
material, by allowing the unused material to flow away from the 3D
object (e.g., by opening an exit opening port on the side(s) or on
the bottom of the material bed from which the unused material can
exit). After the unused material is evacuated, the 3D object can be
removed, and the unused material can be re-circulated to a material
reservoir for use in future builds.
[0311] In some embodiments, the platform may comprise a mesh. The
base and/or substrate may comprise a mesh. The 3D object can be
generated on a mesh. The mesh holes can be blocked. The mesh holes
can be openable (e.g., by a controller and/or manually). A solid
platform (e.g., base or substrate) can be disposed underneath the
mesh such that the material stays confined in the material bed and
the mesh holes are blocked. The blocking of the mesh holes may not
allow a substantial amount of material to flow through. The mesh
can be moved (e.g., vertically or at an angle) relative to the
solid platform by pulling on one or more posts connected to either
the mesh or the solid platform (e.g., at the one or more edges of
the mesh or of the base) such that the mesh becomes unblocked. The
one or more posts can be removable from the one or more edges by a
threaded connection. The mesh substrate can be lifted out of the
material bed with the 3D object to retrieve the 3D object such that
the mesh becomes unblocked. Alternatively, or additionally, the
platform can be tilted, horizontally moved such that the mesh
becomes unblocked. The platform can include the base, substrate, or
bottom of the enclosure. When the mesh is unblocked, at least part
of the pre-transformed material flows from the material bed through
the mesh while the 3D object remains on the mesh. In some
instances, two meshes may be situated such that in one position
their holes are blocked, and in the other position, opened. The 3D
object can be built on a construct comprising a first and a second
mesh, such that at a first position the holes of the first mesh are
completely obstructed by the solid parts of the second mesh such
that no material can flow through the two meshes at the first
position, as both mesh holes become blocked. The first mesh, the
second mesh, or both can be controllably moved (e.g., horizontally
or in an angle) to a second position. In the second position, the
holes of the first mesh and the holes of the second mesh are at
least partially aligned such that the material disposed in the
material bed is able to flow through to a position below the two
meshes, leaving the exposed 3D object.
[0312] In some cases, cooling gas can be directed to the hardened
material (e.g., 3D object) for cooling the hardened material during
and/or following its retrieval. The mesh can be of a size such that
the unused material will sift through the mesh as the 3D object
becomes exposed from the material bed. In some cases, the mesh can
be coupled (e.g., attached) to a pulley or other mechanical device
such that the mesh can be moved (e.g., lifted) out of the material
bed with the 3D part.
[0313] In some embodiments, one or more optical elements in the
optical path may be susceptible to thermal lensing. The optical
elements may comprise an optical window, lens, beam-splitter, or
mirror. The power density of the energy beam may be measured after
passing through the one or more optical elements, and at the target
surface (e.g., exposed surface of the material bed). The power
density of the energy beam may be measured at the surface of the
one or more optical element. The power density of the energy beam
at the surface of the one or more optical element and/or target
surface may be at least about 10 W/cm.sup.2, 50 W/cm.sup.2, 100
W/cm.sup.2, 500 W/cm.sup.2, 1000 W/cm.sup.2, 1500 W/cm.sup.2, or
2000 W/cm.sup.2. The power density value of the energy beam at the
surface of the one or more optical element and/or target surface
may be between any value between the afore-mentioned power density
values (e.g., from about 10 W/cm.sup.2 to about 2000 W/cm.sup.2,
from about 10 W/cm.sup.2 to about 1000 W/cm.sup.2, or from about
1000 W/cm.sup.2 to about 2000 W/cm.sup.2).
[0314] A source of uncontrolled focus shift can be thermal lensing.
The thermal lensing can result in a positive or negative shift in
an optical property of an optical element experience thermal
lensing. For example, the thermal lensing can result in an increase
or decrease in the optical power of the one or more optical element
(e.g., in case of a lens). As understood herein, thermal lensing is
an effect wherein one or more optical properties of an optical
element (e.g., a lens, window, mirror, and/or beam splitter) is
altered in response to heating. The change in the optical property
may be (e.g., manifested as) a change in the (e.g., nominal) focal
length of the optical element. FIG. 38 shows an example of a first
optical element 3801 that does not experience thermal lensing,
having a first beam traveling therethrough with a focal point 3804
at a target surface 3807; a second optical element 3802 that
experiences thermal lensing (e.g., resulting in an increased
optical power with respect to 3801) and a second beam traveling
therethrough having a focal point 3805 above the target surface
3807; a third optical element 3803 that experiences more thermal
lensing (e.g., a further increase in optical power with respect to
3802) and a third beam traveling therethrough having a focal point
3815 above the target surface 3807; and a fourth optical element
3809 that experiences thermal lensing (e.g., resulting in a
decreased optical power with respect to 3801) and a fourth beam
traveling therethrough having a focal point 3806 below the target
surface 3807. The thermal lensing may result in a negative or
positive effect (e.g., retracting or expanding the distance of the
focal point from the optical element). In some embodiments, the
optical setup is configured such that the focal point of the
optical element devoid of thermal lensing is at the target surface.
The heating can be induced by incident energy radiation (e.g., an
energy beam) that interacts with the optical element. The change
may be an intrinsic change in at least one material property of the
optical element. The at least one material property may comprise an
internal or a surface material property of the optical element. For
example, an index of refraction of the optical element can change
in response to heating. For example, the volume and/or shape of the
optical element may change. For example, a surface property of the
optical element may change (e.g., reflectivity). The change can be
either an increase or a decrease in the at least one property. The
change can include an aberration. The change may comprise a loss in
the amount of radiation transmitted through the optical element.
The change may comprise an alteration of (i) a position of a focal
point of the energy beam, (ii) focus of the energy beam on the
exposed surface, or (iii) spot size of the energy beam on the
exposed surface. Once the incident energy is removed from
contacting the optical element, the optical element may return to a
non-thermal lensing condition. At times, once the incident energy
is removed the optical element does not return to a non-thermal
lensing condition. For example, one or more contaminants (e.g.,
soot, dirt, atmospheric particles, silicon-based compounds, organic
compounds, and/or hydrocarbons) can be present (e.g., introduced)
on a surface of the optical element (e.g., during lensing). A
contaminant can cause a temporary, semi-permanent, or permanent
thermal lensing effect in the optical element. Semi-permanent can
refer to a contamination condition that persistently exhibits
thermal lensing in an optical element, which thermal lensing
subsides when the contamination is removed. Permanent can refer to
a contamination condition that persistently exhibits thermal
lensing in an optical element, which thermal lensing does not
(e.g., completely) subside due to an inability to (e.g.,
completely) remove the contamination.
[0315] A timescale of thermal lensing cycling (e.g., time between
introduction of incident energy and initiation of thermal lensing)
can be dependent on one or more characteristics of the energy beam
(e.g., a power and/or a power density) and/or one or more
characteristics of a material of the optical element (e.g., thermal
conductivity, temperature coefficient of the refractive index,
absorption coefficient, and/or thermal expansion). A timescale for
onset of thermal lensing in the optical element can be
approximately from about 0.005 seconds (sec) to about 30 sec, from
about 0.01 sec to about 0.5 sec, from about 0.1 sec to about 10
sec, or from about 10 sec to about 30 sec. For example, a Metallic
mirror may exhibit complete (e.g., settled) thermal lensing after
about 0.2 sec. A timescale for an ending of a thermal lensing
condition in the optical element (e.g., once incident energy is no
longer present) can be at least about 10 sec, 20 sec, 30 sec, 40
sec, 50 sec or 60 sec; at least about 2 minutes (min), 3 min, 4
min, 5 min, 10 min, 30 min, or 60 min; or at least about 2 hours
(h), 3 h, 4 h, 5 h, 10 h, or 24 h. A timescale for an initiation
and ending of a thermal lensing condition in the optical element
may be material dependent.
[0316] Without wishing to be bound by theory, to an extent, the
optical elements exhibit some amount of thermal lensing (e.g.,
depending on the material makeup). For example, impurities within
the optical element can absorb energy from the incident radiative
energy. For example, optical elements can be coated with one or
more coatings (e.g., anti-reflective), which coatings can absorb a
portion of incident radiative energy. For example, particulates
present in an atmosphere in which the optical element is present
can adsorb and/or adhere to a surface of the optical element,
forming a coating. A coating can absorb radiation from an
irradiative energy source and thereby heat a surface of the optical
element. A change in temperature at the surface and/or within the
bulk volume of an optical element can change the at least one
material property of the optical element (e.g., refractive index
thereof). A change in the at least one material property can induce
a change in a focus of the optical element, e.g., acting as a
(e.g., thermal) lens. A change in the focus comprises an alteration
of (i) a position of a focal point of the energy beam, (ii) focus
of the energy beam on the exposed surface, or (iii) spot size of
the energy beam on the exposed surface. The magnitude of the change
in focus can change in a manner that is correlated to the
temperature change in the optical element. Thermal lensing may
occur during at least a portion of 3D printing. For example,
thermal lensing can occur after a total energy density (measured in
kilowatt-hours per square centimeter (kWh)/cm.sup.2)) incident upon
(e.g., through) an optical measurement is at least about
2.8*10.sup.-6 kWh/cm.sup.2, 1*10.sup.-5 kWh/cm.sup.2, 5*10.sup.-5
kWh/cm.sup.2, 1*10.sup.-4 kWh/cm.sup.2, 10*10.sup.-4 kWh/cm.sup.2,
100*10.sup.-4 kWh/cm.sup.2, or 417*10.sup.-4 kWh/cm.sup.2. Thermal
lensing can occur after a total energy density is about 5*10.sup.-2
kWh/cm.sup.2, 1*10.sup.-1 kWh/cm.sup.2, 5*10.sup.-1 kWh/cm.sup.2, 1
kWh/cm.sup.2, or 1.25 kWh/cm.sup.2. The thermal lensing can occur
after a total energy density is at most about 1.25 kWh/cm.sup.2,
5*10.sup.-1 kWh/cm.sup.2, 1*10.sup.-1 kWh/cm.sup.2, 5*10.sup.-2
kWh/cm.sup.2, 417*10.sup.-4 kWh/cm.sup.2, 100*10.sup.-4
kWh/cm.sup.2, 10*10.sup.-4 kWh/cm.sup.2, 1*10.sup.-4 kWh/cm.sup.2,
5*10.sup.-5 kWh/cm.sup.2, 1*10.sup.-5 kWh/cm.sup.2, or
2.8*10.sup.-6 kWh/cm.sup.2. Thermal lensing can occur after a total
energy density incident on an optical element between any of the
afore-mentioned values. For example, the total energy density
incident on the optical element can be from about 2.8*10.sup.-6
kWh/cm.sup.2 to about 1.25 kWh/cm.sup.2, from about 2.8*10.sup.-6
kWh/cm.sup.2 to about 5*10.sup.-2 kWh/cm.sup.2, or from about 5*
10.sup.-2 kWh/cm.sup.2 to about 1.25 kWh/cm.sup.2. For example,
thermal lensing can occur after radiative energy through the
optical element is at least about 1*10.sup.-3 kilowatt hour (kWh),
2*10.sup.-3 kWh, 1*10.sup.-2 kWh, 2*10.sup.-2 kWh, 1*10.sup.-1 kWh,
5*10.sup.-1 kWh, 1 kWh, 2 kWh, 5 kWh, 10 kWh, 20 kWh, 30 kWh, 40
kWh, 50 kWh, 60 kWh, 70 kWh, 80 kWh or 90 kWh. The symbol "*"
designates the mathematical operation of "multiplied by" or
"times." The thermal lensing can occur after radiative energy
through the optical element of at most about 90 kWh, 80 kWh, 70
kWh, 60 kWh, 50 kWh, 40 kWh, 30 kWh, 20 kWh, 10 kWh, 5 kWh, 2 kWh,
1 kWh, 5*10.sup.-1 kWh, 1*10.sup.-1 kWh, 2*10.sup.-2 kWh,
1*10.sup.-2 kWh, 2*10.sup.-3 kWh, or 1*10.sup.-3 kWh. Thermal
lensing can occur with an amount of radiative energy through the
optical element between any of the afore-mentioned values. For
example, the amount of radiative energy causing thermal lensing can
be from about 1*10.sup.-1 kWh to about 90 kWh, from about
1*10.sup.-1 kWh to about 50 kWh, or from about 50 kWh to about 90
kWh. Thermal lensing may occur after a volume of material
transformed (e.g., from a pre-transformed material) is at least
about 200 cm.sup.3, 225 cm.sup.3, 250 cm.sup.3, 275 cm.sup.3, 300
cm.sup.3, 350 cm.sup.3, 400 cm.sup.3, 450 cm.sup.3, 500 cm.sup.3,
600 cm.sup.3, 700 cm.sup.3, 800 cm, 900 cm.sup.3, 1000 cm.sup.3, or
1100 cm.sup.3. Thermal lensing may occur after a volume of material
transformed is at most about 1100 cm.sup.3, 1000 cm.sup.3, 900
cm.sup.3, 800 cm.sup.3, 700 cm.sup.3, 600 cm.sup.3, 500 cm.sup.3,
450 cm.sup.3, 400 cm.sup.3, 350 cm.sup.3, 300 cm.sup.3, 275
cm.sup.3, 250 cm.sup.3, 225 cm.sup.3, or 200 cm.sup.3. Thermal
lensing may occur between any of the afore-mentioned values, for
example, a volume of material transformed may be from about 200
cm.sup.3 to about 1100 cm.sup.3, from about 200 cm.sup.3 to about
700 cm.sup.3, or from about 700 cm.sup.3 to about 1100
cm.sup.3.
[0317] The one or more optical elements (e.g., lens and/or mirror)
may comprise a coating. The coating may comprise anti-reflective or
high reflectivity coating. The coating may dissipate heat into the
interior of the optical element. The coating may dissipate
projected heat towards an exterior of the element (e.g., sideways
with respect to the radiation direction). The coating may not
dissipate heat into the interior of the optical element.
[0318] The one or more optical elements may be resistant to damage
(e.g., withstand operating conditions) up to a power density
threshold without substantial thermal lensing. Substantial thermal
lensing may be detectable and/or detrimentally affects the 3D
printing. For example, the thermal lensing detrimentally affects
the building of the 3D object. For example, the thermal lensing
detrimentally affects the dimensions and/or surface roughness of
the 3D object. For example, the thermal lensing detrimentally
affects the material properties of the 3D object (e.g. increases
defects such as cracks and/or pores). For example, the thermal
lensing detrimentally affects the printing of the 3D object such
that it cannot be used in for its intended purpose. The one or more
optical elements may be rated to operate at one or more conditions
(of the 3D printing) at or below a power density threshold. The
power density threshold for the one or more optical elements can be
at least about 0.5 kilowatt-hours per square centimeter
(kWh)/cm.sup.2), 1 kWh/cm.sup.2, 2 kWh/cm.sup.2, 5 kWh/cm.sup.2, 10
kWh/cm.sup.2, or 15 kWh/cm.sup.2. The power density threshold can
be at most about 15 kWh/cm.sup.2, 10 kWh/cm.sup.2, 5 kWh/cm.sup.2,
2 kWh/cm.sup.2, 1 kWh/cm.sup.2, or 0.5 kWh/cm.sup.2. The power
density threshold can be between any of the afore-mentioned values.
For example, the power density threshold may be from about 0.5
kWh/cm.sup.2 to about 15 kWh/cm.sup.2, from about 0.5 kWh/cm.sup.2
to about 5 kWh/cm.sup.2, or from about 5 kWh/cm.sup.2 to about 15
kWh/cm.sup.2. A power density threshold may be reduced for an
optical element operating out of a nominal condition (e.g.,
affected by one or more contaminants). The power density threshold
may be reduced, e.g., when the one or more optical elements are
coated by a contaminant, and can be from about 0.1
kWh/cm.sup.2.
[0319] FIG. 32 shows an example of an optical element (e.g., lens
3240) having a focus 3250 (e.g., devoid of thermal lensing). In the
example of FIG. 32 the focal point of the lens is incident upon a
(e.g., target) surface 3210, the surface comprising a dark portion
3220 (e.g., a first calibration-mark) and a light portion 3230
(e.g., a second calibration-mark). In the example of FIG. 32, the
dark portion and light portion signify a detectable difference in a
material property at the target. In the example of FIG. 32 the
optical element possesses a different focus when thermal lensing is
present (e.g., 3260), which causes a beam passing through the
optical element to be out of focus at the surface 3210. The surface
can include one or more calibration surfaces and/or structures, as
described herein. A detector (e.g., an optical detector) can
generate a signal based upon incident (e.g., irradiating) energy
reflected and/or scattered off of the surface. A detected signal
intensity (e.g., FIG. 33, 3370) may be graphically represented
against the relative position (e.g., FIG. 33, 3375) of the
irradiating energy on the target (e.g., FIG. 32, 3210). The
graphical representation may comprise a detected signal curve as a
function of position. The detected signal curve may reveal the
transition point between a first calibration-mark type (e.g., dark
portion, FIG. 32, 3220) and a second calibration-mark type (e.g.,
light portion, FIG. 32, 3230). The transition point may be an
inflection point on the detected signal curve, and/or a point
(e.g., midpoint) between adjacent inflection points on the detected
signal curve. The detected signal curve can have a different (e.g.,
characteristic) shape for a lens that is (e.g., substantially)
properly focused on the target than for a lens that exhibits
thermal lensing. In the example of FIG. 33, curve 3310 corresponds
with a substantially properly focusing (e.g., in-focus, e.g.,
recorded at time t1) lens, while curve 3315 corresponds with a lens
exhibiting (e.g., some degree of) thermal lensing (e.g., recorded
at time t2).
[0320] Thermal lensing can occur during and/or after at least a
portion of a 3D printing process. The thermal lensing may occur
(timewise) in close to the proximity of the 3D printing. For
example, thermal lensing may occur (e.g., initiate) after at least
about 0.05 second (sec), 0.1 sec, 0.3 sec, 0.5 sec, 0.7 sec, or 1.0
sec. of irradiation of the transforming energy beam through the one
or more optical element (e.g., as part of the 3D printing). Thermal
lensing may not be (e.g., no longer) present at the outset of a 3D
printing process, and/or after a sufficient time has lapsed (e.g.,
10-600 seconds) following reduction (e.g., in power) or removal of
incident energy on the optical element. Thermal lensing can cause
one or more characteristics of the 3D printing process to vary. For
example, (i) the position at which the (e.g., irradiating) energy
beam contacts a target (e.g., the target surface), (ii) the energy
beam footprint on the target surface, (iii) the energy density of
the of the energy beam projected to the surface, (iv) the energy
profile of the energy beam across its footprint at the surface, (v)
the XY offset of the energy beam with respect to the surface,
and/or (vi) the focus of the energy beam at the surface, may vary
due to thermal lensing of the at least one optical element. A
change in the energy beam footprint on the target may comprise
change in the footprint area, FLS, or shape.
[0321] In some embodiments, a detector (e.g., such as described
herein) generates one or more signals, which can be graphically
represented to characterize and/or monitor (e.g., a thermal lensing
condition) one or more characteristics of the energy beam. At
times, during a 3D printing process an elapse of time leads to an
increase in the energy beam footprint (e.g., due to thermal
lensing), e.g., comprising footprint area, FLS, or shape. At times,
during a 3D printing process an elapse of time leads to a decrease
in the energy beam footprint (e.g., due to thermal lensing), e.g.,
comprising footprint area, FLS, or shape. Taking a plurality of
measurements at different points in time (e.g., at least two), with
one or more detectors, can serve to monitor and/or characterize one
or more optical elements (e.g., a thermal lensing condition) via
the one or more characteristics of the energy beam. For example, a
first measurement of the energy beam corresponding with the optical
element at a given condition (e.g., before a 3D printing process,
before beginning a layer build) can serve as a benchmark (e.g.,
calibration) measurement, against which subsequent (e.g., at least
one subsequent) measurements of the energy beam that correspond
with the optical element at a subsequent condition (e.g., during
and/or after a 3D printing process) can be compared. FIG. 33, 3320
shows an example of a graphical representation of an energy beam
footprint size 3380 as a function of time 3385. At time "t1"
(corresponding to, for example, no thermal lensing) the energy beam
footprint has a first (e.g., nominal) characteristic. At time "t2"
corresponding to a time following "t1," for example, following a
portion of a 3D printing process during which thermal lensing
occurs, the energy beam footprint has a second (e.g., increased)
characteristic. The footprint characteristic can comprise FLS, or
area.
[0322] FIGS. 33, 3330 and 3340 shows examples of a graphical
representations of Peak Intensity Ratio (PIR) 3390 of an energy
beam as a function of time 3395 for two energy beams (e.g., two
different energy beam, or of the same energy beam irradiating at
different conditions). A PIR comprises a ratio of a measurement of
an energy beam intensity (e.g., peak intensity) at an initial time
(e.g., before commencement of a 3D printing process), to a
measurement of the energy beam intensity at a later time (e.g.,
during or after a 3D printing process, during or after a layer
build). The peak intensity can be detected (e.g., by a gray field
detector) by directing the energy beam at one or more calibration
marks (e.g., as described herein, for example, the surface 3210).
In the example of FIG. 33, two curves are present, a curve 3330
corresponding to a relatively low power (e.g., 150 W) energy beam,
and a curve 3340 corresponding to a relatively high power (e.g.,
700 W) energy beam. At an initial time (e.g., t=0), the PIR has a
value of 1. After some time has elapsed the PIR can be below 1, for
example, once thermal lensing is generated in one or more optical
elements and causes a reduction in the peak intensity of the energy
beam. In the example of FIG. 33, after time "t1" the PIR of curve
3340 has decreased to a greater extent than the curve 3330. After
time "t2" the PIR of curve 3340 has continued to decrease, which
decrease is greater than the decrease depicted for curve 3330. The
PIR curve of an optical element can change over time, for example,
as contamination accumulates. That is, the PIR curve for an optical
element can decrease at a first rate for less contaminated optics
(e.g., having less debris adhered to the optical element(s)), and
at a second rate for the optical element at a more contaminated
condition. The term "PIR reduction" can refer to a comparison of
(e.g., at least two) PIR curves for the same optical element, one
curve generated at an earlier (e.g., relatively low contamination)
state and a second curve generated at a later (e.g., relatively
more contaminated) state. A difference between these (e.g., at
least two) PIR curves is the "PIR reduction."
[0323] The energy beam footprint (e.g., 3380), the PIR (e.g.,
3390), or a combination thereof can be correlated to the presence
of (e.g., a degree of) thermal lensing. An optical element that is
has (e.g., substantially) stable thermal lensing conditions over
the 3D printing period, can have a well-maintained (e.g., nominal)
focus, which can direct an energy beam to have a relatively small
cross-sectional footprint at the surface. An optical element that
is (e.g., substantially) devoid of thermal lensing can have a
well-maintained (e.g., nominal) focus, which can direct an energy
beam to have a relatively small cross-sectional footprint at the
surface. An energy beam having a (relatively small) well defined
cross-sectional footprint directed at a calibration-mark (e.g.,
3210) can produce a relatively sharp transition in a signal
generated at a detector (e.g., 3310), as the energy beam moves
across an edge of the calibration-mark (e.g., from 3220 to 3230).
Conversely, an optical element that exhibits a thermal lensing
condition can have a less well-maintained and/or well-defined focus
(e.g., a fuzzy and/or fluctuating focus). Such an optical element
can alter an energy beam to become relatively unstable and/or
out-of-focus (e.g., defocused), which defocused and/or unstable
focused energy beam can produce a relatively gradual transition in
a signal generated at a detector (e.g., 3315), as the energy beam
moves across an edge of the calibration-mark. In the example of
FIG. 33, the curve 3310 can correspond to the time "t1," where
little or no thermal lensing is present. The curve 3315 can
correspond to the time "t2," where (e.g., at least some) thermal
lensing is present in one or more optical elements.
[0324] The surface (e.g., FIG. 32, 3210) can be used in the
calibration of one or more characteristics of the energy beam. The
calibration can comprise (i) the position at which the (e.g.,
irradiating) energy beam contacts a target (e.g., the target
surface), (ii) the energy beam footprint on the target surface,
(iii) the energy density of the of the energy beam projected to the
surface, (iv) the energy profile of the energy beam across its
footprint at the surface, (v) the XY offset of the energy beam with
respect to the surface, (vi) the Z offset of the energy beam focus
with respect to the target surface, and/or (vii) the focus of the
energy beam at the surface, may vary due to thermal lensing of the
at least one optical element. The calibration of the footprint may
comprise calibration of the footprint area, FLS, or shape.
[0325] In some embodiments, a discrepancy in the optical setting of
the optical arrangement is compensated in the 3D printing system. A
discrepancy in the optical setting can be a deviation from a
requested optical setting (e.g., due to thermal lensing). The
requested optical setting can be a requested focal distance and/or
cross section of an energy beam emerging out of the optical
arrangement. The compensation may comprise: (i) adjusting one or
more components of the optical arrangement (e.g., adjusting the
resulting focal distance thereof), (ii) adjusting the power of the
energy source, (iii) adjusting at least one characteristic of the
energy beam (e.g., cross section, and/or power density), or (iv)
adjusting a relative gap distance between the target surface and
the optical arrangement. The gap distance may be from the last
component of the optical arrangement before the target surface.
Adjusting a relative gap distance may comprise adjusting a height
of the target surface. For example, adjusting the height of the
platform. For example, adjusting the height of an exposed surface
of the material bed. For example, adjusting the height of the
optical arrangement. The gap may comprise a vertical distance. The
gap may be an atmospheric gap. The compensation may be controlled
(e.g., manually or automatically, e.g., using a controller). The
control may be before, or in real time during the 3D printing. The
control may be during the 3D printing when the transforming energy
beam is idle (e.g., not processing).
[0326] The presence of contaminants (e.g., as described herein) on
one or more surfaces of an optical element may increase a
likelihood of a thermal lensing condition for the optical element.
Approaches for reducing and/or preventing a thermal lensing
condition of the optical element may address the source(s) of
contaminants in an environment near the optical element, and/or
removal of contaminants that are already present (e.g., on the
optical element). Factors that can mitigate (or conversely,
aggravate) a thermal lensing condition of one or more optical
elements (e.g., of a 3D printing system) comprise (i) material
composition(s) of the optical element(s), (ii) environmental
condition(s) in an optical path of the optical element(s), (iii)
the degree of thermal variance, and/or (iv) environmental
condition(s) in a vicinity of (e.g., at or near the surface of) the
optical element(s). The degree of thermal variance may be
correlated to the power density of the energy beam and/or time of
irradiation through the optical element. Optical materials that can
be characterized as having a (e.g., relatively) high thermal
conductivity, a (e.g., relatively) low optical absorption
coefficient, and/or a (e.g., relatively) low temperature
coefficient of the refractive index (dn/dT), may exhibit a reduced
thermal lensing effect (e.g., over the time required for 3D
printing). A reduced thermal lensing effect can refer to a reduced
change in optical behavior (e.g., compared with another optical
element), and/or an increased throughput of energy prior to onset
of a (e.g., measurable) thermal lensing condition.
[0327] An optical element having high thermal conductivity can be
any high thermal conductivity value disclosed herein. An optical
element having a low optical absorption coefficient can be at most
about 10 ppm, 50 ppm, 100 ppm, 250 ppm, 500 ppm or 600 ppm per
centimeter at the wavelength of the irradiating energy beam. A low
temperature coefficient of refractive index can refer to an optical
element that has a refractive index deviation (e.g., at the
wavelength of the irradiating energy beam) of at most 2%, 5%, 8%,
10%, 12% or 15%, in a temperature range at least about 10.degree.
C. to at most about 140.degree. C. A low temperature coefficient of
refractive index can be a relative change in refractive index, for
example at a temperature change from 20.degree. C. to 100.degree.
C. at the irradiating wavelength (e.g., 1060 nm, or 1080 nm), from
about 1.2*10.sup.-6/Kelvin (K) to about 2.2*10.sup.-6/K, from about
1.5*10.sup.-6/K to about 3*10.sup.-6/K, or from about 3*10.sup.-6/K
to about 4.5*10.sup.-6/K, around ambient pressure (e.g., in a range
from about 398 Torr to about 1182 Torr). In some embodiments, the
one or more optical elements comprise a low temperature coefficient
of refractive index, around ambient pressure (e.g., in a range from
about 398 Torr to about 1182 Torr) and at a wavelength of the
energy beam. The low temperature coefficient of refractive index
may be of at most about 1.2*10.sup.-6/Kelvin, 1.5*10.sup.-6/Kelvin,
1.8*10.sup.-6/Kelvin, 2*10.sup.-6/Kelvin, 3*10.sup.-6/Kelvin,
4*10.sup.-6/Kelvin, 5*10.sup.-6/Kelvin, 6*10.sup.-6/Kelvin,
7*10.sup.-6/Kelvin, 8*10.sup.-6/Kelvin, 9*10.sup.-6/Kelvin,
10*10.sup.-6/Kelvin, 13*10.sup.-6/Kelvin, 15*10.sup.-6/Kelvin, or
20*10.sup.-6/Kelvin. The low temperature coefficient of refractive
index may be of any value between the afore-mentioned values (e.g.,
from about 1.2*10.sup.-6/Kelvin to about 20*10.sup.-6/Kelvin, from
about 1.2*10.sup.-6/Kelvin to about 5*10.sup.-6/Kelvin, or from
about 5*10.sup.-6/Kelvin to about 20*10.sup.-6/Kelvin). The
refractive index may be measured at a standard measurement
condition (e.g., at ambient temperature, and/or R.T.). The low
temperature coefficient of refractive index may be measured at
ambient pressure (e.g., of one (1) atmosphere). Materials that may
exhibit a reduced thermal lensing effect include calcium fluoride
(CaF.sub.2), magnesium fluoride (MgF2), crystal quartz, sapphire,
zinc selenide (ZnSe), zinc sulfide (ZnS), potassium fluoride (KF),
barium fluoride (BaF.sub.2), gallium arsenide (GaAs), germanium,
lithium fluoride (LiF), magnesium fluoride (MgF2), potassium
bromide (KBr), potassium chloride (KCl), and/or crystalline
silicon. The optical element having the reduced thermal lensing
effect can be an optical window, a mirror, a lens, and/or a beam
splitter. The optical element (having the reduced thermal effect)
can comprise any of the materials exhibiting the reduced thermal
lensing effect.
[0328] At times, it may be useful to define a Thermal Lensing
Figure of Merit (TLFoM) measure, which is equal to dn/dT, the rate
of change of refractive index with temperature (measured in units
of 1/Kelvin) divided by the thermal conductivity of this material,
often denoted k (measured in units of Watt/(Meter*Kelvin))
(TLFoM=(dn/dT)/k). TLFoM has units of meter/Watt. The thermal
conductivity referred herein is at room temperature. The dn/dT can
be at standard temperature and pressure, and at the operating
wavelength of the energy beam. The at least one optical element may
have a TLFoM value of at most about 0.025*10.sup.-6 meter/Watt
(m/W), 0.5*10.sup.-6 m/W, 1*10.sup.-6 m/W, 2*10.sup.-6 m/W,
3*10.sup.-6 m/W, 4*10.sup.-6 m/W, 5*10.sup.-6 m/W, 6*10.sup.-6 m/W,
or 7*10.sup.-6 m/W. The at least one optical element may have a
TLFoM value between any of the afore-mentioned values (e.g., from
about 0.25*10.sup.-6 m/W to about 7*10.sup.-6 m/W, from about
0.25*10.sup.-6 m/W to about 4*10.sup.-6 m/W, or from about
0.25*10.sup.-6 m/W to about 2*10.sup.-6 m/W).
[0329] In some embodiments, the one or more optical elements are
configured to experience insignificant thermal lensing during
transformation of a pre-transformed material to a transformed
material. The transformation may be of at least about 100 cubic
centimeters (cm.sup.3), 500 cm.sup.3, 1000 cm.sup.3, 1500 cm.sup.3,
2000 cm.sup.3, 5000 cm.sup.3, or 10000 cm.sup.3 of pre-transformed
material to a transformed material. The transformation may be of
any volume between the afore-mentioned volumes (e.g., from about
100 cm.sup.3 to about 10000 cm.sup.3, from about 500 cm.sup.3, to
about 1500 cm.sup.3, from about 1000 cm.sup.3 to about 10000
cm.sup.3) of pre-transformed material to a transformed material.
The insignificant thermal lensing may be during at least a 10
second (sec), 20 sec, 30 sec, 60 sec, 90 sec, or 120 sec
irradiation of the energy beam through the optical element(s). The
insignificant thermal lensing may be during any period between the
afore-mentioned periods (e.g., from about 10 sec to about 120 sec,
from about 10 sec to about 60 sec, or from ab out 60 sec to about
120 sec) irradiation of the energy beam through the optical
element(s). The power density of the energy beam (at a nominal
power of the energy source) may diminish by at most about 20%, 10%,
5%, 3%, 1% or 0.5% percent relative to the power density at a
beginning of the irradiation period (e.g., of 30 seconds). The
power density of the energy beam (at a nominal power of the energy
source) may diminish by any percentage value between the afore
mentioned percentage values (e.g., from about 0.5% to about 20%,
from about 0.5% to about 10%, or from about 10% to about 20%)
relative to the power density at a beginning of the irradiation
period (e.g., of 30 seconds). The energy density may be measured at
the target surface. In some embodiments, the (e.g., peak) power
density changes by at most about 30%, 20%, 10%, 5% or 1% (e.g.,
during the irradiation). The (e.g., peak) power density may change
by any percentage value between the afore-mentioned percentage
values (e.g., by from about 1% to about 30%, from about 1% to about
10%, or from about 10% to about 30%), e.g., during the irradiation.
In some embodiments, the FLS of the spot size changes by at most
about 20%, 15%, 10%, 5%, 3%, or 1%. The FLS of the spot size may
change by any percentage value between the afore-mentioned
percentage values (e.g., from about 1% to about 20%, from about 1%
to about 10%, or from about 10% to about 20%). In some embodiments,
the focal point of optical element(s) may shift by at most about 15
mm, 10 mm, 7 mm, 5 mm, 3 mm, 1 mm, 0.7 mm, 0.5 mm, 0.2 mm, or 0.1
mm. The shift may be in the direction along the propagation
direction of the energy beam (e.g., in a direction normal to the
target surface). The focal point of the optical element(s) may
shift by any value between the afore-mentioned values (e.g., from
about 0.1 mm to about 15 mm, from about 0.1 to about 5 mm, or from
about 5 mm to about 15 mm). A wave-front distortion of the energy
beam may be at most about 0.05, 0.1, 0.2, 0.25, 0.5, 0.75, or 1
wavelength of the energy beam. A wave-front distortion of the
energy beam may be of any wavelength fraction between the
afore-mentioned energy beam wavelength fractions (e.g., from about
0.05 to about 1, from about 0.05 to about 0.5, or from about 0.5 to
about 1).
[0330] An approach to mitigating a thermal lensing condition (e.g.,
reducing a magnitude and/or onset thereof) may comprise heating a
portion of the optical element. Heating one or more portions of the
optical element may maintain the heated optical element at an
optically stable lensing condition. Heating one or more portions of
the optical element may reduce optical fluctuations of the heated
optical element during lensing. Heating one or more portions of the
optical element may decrease a temperature gradient within a bulk
of or at the surface of an optical element. In some embodiments, a
(e.g., secondary) heating (e.g., irradiation) source is operatively
coupled to (e.g., contacts or directed at) the optical element,
such that heat and/or irradiation from the secondary heating source
heats one or more portions of the optical element that are adjacent
to a (e.g., central) portion through which the irradiating energy
beam (e.g., transforming energy beam) travels. In some embodiments,
a heating element is operably coupled with the optical element, the
heating element configured to heat the optical element (via direct
or indirect contact) to raise an overall temperature thereof. The
heating element may be passive or active. The active heating
element can comprise a fluid-filled body (e.g., a coil) disposed
adjacent to the optical element. A heating element can comprise
heated (e.g., filtered) gas directed at the optical element. The
heating element may heat by conduction and/or convection. The
(e.g., passive) heating element can comprise a (e.g., resistive)
heating plate or coil disposed adjacent to the optical element. The
overall temperature of the optical element may be raised to at
least about 45.degree. C., 60.degree. C., 75.degree. C., 90.degree.
C., 110.degree. C., or 125.degree. C. In some embodiments the
optical element is raised to at most about 125.degree. C.,
110.degree. C., 90.degree. C., 75.degree. C., 60.degree. C., or
45.degree. C. The optical element may be raised to a temperature
between (inclusive) any of the afore-mentioned values, for example,
between 45.degree. C.-125.degree. C., between about 45.degree.
C.-90.degree. C., or between about 90.degree. C.-125.degree. C.
[0331] Contaminants in the vicinity (e.g., on a surface) of the
optical element can lead to an onset of and/or increase in a
thermal lensing condition for the optical element. As described
herein, contaminants (e.g., debris comprising reactive gas,
oxidizing agent, atmospheric dust, silicon-based compounds, organic
compounds (e.g., hydrocarbons), pre-transformed material, or soot,)
can form a coating on one or more surfaces of the optical element.
A coating can absorb radiation from an irradiative energy source
and thereby heat a surface and/or bulk material of the optical
element, leading to (e.g., onset of) a thermal lensing
condition.
[0332] In some embodiments, an optical path environment that is
maintained to be (e.g., substantially) free from contaminants
(e.g., clean optical path) reduces the incidence of a thermal
lensing condition in one or more optical elements. One manner of
maintaining a clean optical path (e.g., cleaner than in a
processing chamber) can be to isolate the optical elements (and any
ancillary structures, such as support structures) along the optical
path from an exterior (e.g., external) atmosphere. An exterior
atmosphere can be an ambient atmosphere. An exterior atmosphere can
be an atmosphere in a processing chamber of a 3D printing system
(e.g., when the optical elements are comprised in an enclosure).
Isolation can comprise disposing the optical element(s) in an
optical chamber. Isolation can take the form of (e.g., enclosure)
channel(s) that surround and enclose the elements along the optical
path, e.g., in the optical chamber. The channels can be covered
channels (e.g., tubes). Isolation can take the form of a sealed
optical chamber. The sealed optical chamber can isolate the optical
element in terms of gas and/or radiation. Isolation can comprise
maintaining a positive pressure in the isolation component(s)
(e.g., the enclosure channel(s), the optical chamber). For example,
the pressure in the area enclosing the isolation component(s) may
be at a positive pressure with respect to the ambient pressure. At
times, a gas flow pressure within the isolation component(s) and
the pressure directly adjacent to the isolation component(s), may
be different. The raised pressure may be at least about 0.5
pounds/inch (psi), 1 psi, 2 psi, 3 psi, 4 psi, 5 psi, 6 psi, 7 psi,
8 psi, 9 psi, or 10 psi above the ambient pressure. The raised
pressure may be any value between the afore-mentioned values, for
example, from about 0.5 psi to about 10 psi, or from about 0.5 psi
to about 5 psi. The raised pressure may be the pressure directly
adjacent to the isolation component(s). The raised pressure may be
the average pressure in the isolation component(s). Isolation can
comprise maintaining an atmosphere that is filtered (e.g., using
one or more filtration devices coupled to intake and/or exit
outlets). The gas intake and/or exit outlets may be coupled to the
optical chamber and/or to the channel(s). Gas flow exiting a gas
outlet of the optical chamber can include solid and/or gaseous
contaminants such as debris. In some embodiments, a filtration
system filters out at least some of the solid (e.g., debris) and/or
gaseous contaminants, thereby providing a clean gas (e.g., cleaner
than gas flow outside of the optical path environment). The
filtration system can include one or more filters. The filters may
comprise oil filters, particulate filters (e.g., HEPA filters),
humidity filters or chemical filters (e.g., column). Monitoring
filter performance can include one or more sensors (e.g., an
optical sensor, and/or a chemical sensor,) configured to detect a
corresponding sensate (e.g., particulates, humidity, carbohydrates
and/or silicates) present in the optical path environment. The
optical sensor may comprise optical density sensor, spectroscopy
sensor, IR sensor, Visible light sensor, or UV light sensor). The
chemical sensor may sense metal, oxygen, humidity, carbohydrates,
or silicates. The chemical sensor may sense oil. Isolation can
comprise maintaining an atmosphere of a (e.g., substantially inert
and/or clean) gas composition (e.g., comprising clean air, argon
gas, or nitrogen gas).
[0333] In some embodiments, enclosure channel(s) that surround and
enclose the elements along the optical path comprise at least one
of opening (e.g., holes, slits, vents, perforations). The opening
may allow gas from within the enclosure channel(s) to exit
therethrough (e.g., via positive pressure maintained within the
enclosure channel(s) with respect to outside the enclosure
channel(s)). The holes may be disposed at locations along the
enclosure channel(s) that are removed from (e.g., not adjacent to)
an optical element. Thus, (I) the gaseous atmosphere in a vicinity
of the optical element(s) may be maintained at a condition of lower
turbulence with respect to the atmosphere in the vicinity of the
opening and/or (II) any contaminants that are present within the
enclosure channel(s) may be less likely to contact and/or adhere to
the optical element(s).
[0334] In some embodiments, enclosure channel(s) comprise (e.g., at
least two) segments joined by a (e.g., at least partially)
mis-fitting seal, which mis-fitting seal comprises at least one
seal surface having a controlled leak path. The (controlled leak
path) mis-fitting seal may be referred to herein as "leaky" (e.g.,
a leaky seal). The leaky seal may allow gas from within the
enclosure channels to exit therethrough (e.g., via positive
pressure maintained within the enclosure channels with respect to
outside the enclosure channels). The mis-fitting seal(s) may be
disposed at locations along the enclosure channels that are remove
from (e.g., not adjacent to) the optical element(s). In this manner
the gaseous atmosphere in a vicinity of the optical element(s) may
be maintained at a condition of lower turbulence with respect to
the atmosphere in the vicinity of the leaky seal(s). Any
contaminants that are present within the enclosure channels may be
less likely to contact and adhere to the optical element(s) when a
path of travel to an exit of the enclosure tubes (e.g., a leaky
seal) is not adjacent to an optical element. Clean gas may be
provided to the enclosure (e.g., to a sealed optical enclosure,
and/or to enclosure channels comprising the opening and/or the
leaky seals). Clean gas may be provided by means of an inlet and/or
outlet port, one or more filters, a pump, inert gas(es), or a
combination thereof "Clean gas" may refer to a gas that is cleaner
(e.g., has a lower concentration of contaminants) than an exterior
of the enclosure tube.
[0335] FIG. 34A depicts an example of a portion of a 3D printing
system comprising an optical system 3410 configured to direct
irradiating energy from an energy source 3406 to travel between
mirrors 3405 and 3408 along a beam path 3407, the beam path
continuing down 3417 through an optical window 3404. FIG. 34B
depicts an example of an energy beam following a beam path 3418 in
an optical system, through an optical window 3414, to a position on
a target surface 3402 (e.g., exposed surface of a material bed).
The optical window may comprise a coating and/or a filter, forming
a modified irradiating energy beam (e.g., FIG. 34B, along path
3413). In the example of FIG. 34A, an enclosure channel 3409
surrounds and/or encloses the optical elements (e.g., 3404, 3405,
and 3408), including the entry point of the irradiating energy beam
from the energy source. In the example of FIG. 34A, the enclosure
tube 3409 comprises a section 3411 having a plurality of openings
3421, and a mis-fitting seal 3412 comprising a leaky region 3422.
In the example FIG. 34A, magnified regions corresponding to 3411
and 3412 depict arrows representing a flow of gas within the
enclosure tube (e.g., exit flow out of the openings and leaky seal,
respectively).
[0336] In some embodiments, an optical enclosure (e.g., fully)
encompasses an optical system of a 3D printing system. FIG. 35A
depicts an example of (e.g., a portion of) a 3D printing system
comprising an optical system configured to direct irradiating
energy from an energy source 3506 to travel between mirrors 3505
and 3508 along a beam path 3507 (e.g., enclosed by tube 3509), the
beam path continuing down 3517 through an optical window 3504. FIG.
35B depicts an example of an energy beam following a beam path 3518
in an optical system, through an optical window 3514, to a position
on an exposed surface 3502 (e.g., of a material bed). The optical
window may comprise a coating and/or a filter, forming a modified
irradiating energy beam (e.g., FIG. 35B, along path 3503). In the
example of FIG. 35A an optical enclosure 3510 surrounds and/or
encloses the optical elements (e.g., 3504, 3405, 3508 and 3409),
including the entry point of the irradiating energy beam from the
energy source. The optical enclosure can completely enclose and/or
surround the (e.g., totality of) optical elements of the optical
system, forming a (e.g., substantially) isolated environment within
the optical enclosure. The optical enclosure can be maintained at a
positive pressure, such that atmospheric gases at a surrounding
area of the optical enclosure (e.g., within a processing chamber
and/or within an ambient environment) do not enter the environment
of the optical enclosure. The optical enclosure can include an
(e.g., at least one) inlet port and an (e.g., at least one) outlet
port configured for gas exchange. The optical enclosure can
comprise any filtration system, e.g., as described herein. One or
more filters of the filtration system can be disposed adjacent to
the inlet port, the outlet port, or a combination thereof. The
optical enclosure can comprise one or more sensors, e.g.,
configured to detect particulates and/or other material (e.g.,
contaminants). The sensors can be any sensors described herein. One
or more contaminant sensors can be disposed at the inlet port, the
outlet port, in proximity (e.g., adjacent) to one or more optical
elements, or a combination thereof. The gas flow, filtration
system, or any components thereof (e.g., pumps, sensors, filters,
and controllers) can be any of those described in patent
application serial number PCT/US17/60035 that is incorporated
herein by reference in its entirety.
[0337] A source of contaminants may be the processing chamber of
the 3D printing system. While optical elements in an optical system
may be isolated (e.g., via a sealed enclosure, and/or enclosure
tubes) and maintained in a substantially clean environment, one or
more optical elements (e.g., an optical window) may remain at least
partially exposed to an external environment (e.g., with respect to
the optical system environment, for example, a processing chamber).
An optical window may serve as an interface between an optical
system and a processing chamber in a 3D printing system. A
processing chamber of a 3D printing system may comprise
contaminants (e.g., debris), which contaminants can travel and
adhere to an optical element (e.g., an optical window), increasing
a likelihood of a thermal lensing condition for the optical
element. In some embodiments a (e.g., clean) gas can be directed
toward an optical element, to provide gas purging (i) of optical
element area and/or (ii) to protect the optical element area from
debris. Systems for gas flow and/or gas purging can be any systems
as disclosed in patent application number PCT/US17/60035 that is
incorporated herein by reference in its entirety. Gas purging of an
optical element (e.g., optical window) can dislodge particles
(e.g., contaminants) that are present at a surface of the optical
element, and/or form a (e.g., moving gas) barrier to contaminants
that would otherwise be coming into contact with the optical
element. In some embodiments, a pressurized clean gas is filtered
through a filter (e.g., one or more HEPA filters), e.g., prior to
reaching the optical element (e.g., optical window). In some
embodiments, the one or more filters are configured to filter out
particles having nanometer-scale (e.g., from about 10 nanometers
(nm) to about 2000 nm) diameters.
[0338] In some embodiments, a 3D printing system includes, or is
operationally coupled to, one or more gas recycling systems. FIG.
36 shows a schematic side view of an example 3D printing system
3600 that is coupled to a gas recycling system 3603 in accordance
with some embodiments. 3D printing system 3600 includes processing
chamber 3602, which includes gas inlet 3604 and gas outlet 3605.
The gas recycling system (e.g., 3603) of a 3D printing system can
be configured to recirculate the flow of gas from the gas outlet
(e.g., 3605) back into the processing chamber (e.g., 3602) via the
gas inlet (e.g., 3604). Gas flow (e.g., 3606) exiting the gas
outlet can include solid and/or gaseous contaminants. In some
embodiments, a filtration system (e.g., 3608) filters out at least
some of the solid and/or gaseous contaminants, thereby providing a
clean gas (e.g., 3609) (e.g., cleaner than gas flow 3606). The
filtration system can include one or more filters. The filters may
comprise HEPA filters or chemical filters. The clean gas (e.g.,
3609) exiting the filtration system can be under relatively low
pressure, and therefore can be directed through a pump (e.g., 3610)
to regulate (e.g., increase) its relative pressure prior to entry
to the processing chamber and/or optical chamber. Clean gas (e.g.,
3611) with a regulated pressure that exits the pump can be directed
through one or more sensors (e.g., 3612). The one or more sensors
may comprise a flow meter, which can measure the flow (e.g.,
pressure) of the pressurized clean gas. The one or more sensors may
comprise temperature, humidity, oil, or oxygen sensors. In some
cases, the clean gas can have an ambient pressure or higher. The
higher pressure may provide a positive pressure within the
processing chamber (see example values of positive pressure
described herein). A first portion of the clean gas can be directed
through an inlet (e.g., 3604) of a gas inlet portion of the
enclosure, while a second portion of the clean gas can be directed
to first and/or second window holders (e.g., 3614 and 3616) that
provide gas purging of optical window areas, as described herein.
That is, the gas recycling system can provide clean gas to provide
a primary gas flow for the 3D printing system, as well as a
secondary gas flow (e.g., window purging). In some embodiments, the
pressurized clean gas is further filtered through a filter (e.g.,
3617 (e.g., one or more HEPA filters)) prior to reaching one or
both of the window holders. In some embodiments, the one or more
filters (e.g., as part of filters 3617 and/or filtration system
3608) are configured to filter out particles having nanometer-scale
(e.g., about 10 to 500 nm) diameters. In some embodiments, the gas
recycling system alternatively or additionally provides clean gas
to a recessed portion (e.g., 3618) of the enclosure.
[0339] In some embodiments, a 3D printing system comprises a
controller configured to generate an alert, message, and/or to
initiate a purging and/or cleaning cycle in response to detecting a
thermal lensing condition. A thermal lensing condition can be
determined (e.g., to be present) based on one or more
characteristics of the irradiating energy beam. The alert, message,
initiated cleaning cycle and/or purging cycle may be based on a
threshold level of thermal lensing. A threshold level of thermal
lensing may correspond with a (e.g., change in) spot size of the
beam at the target surface. The change may be referenced against a
nominal (e.g., benchmark, controlled) value. For example, a
threshold change in a spot size of the irradiating energy beam at
the target surface may be a change of 50 microns, 100 microns, or
150 microns. The optical element may be maintained at a requested
temperature by purging gas. For example, a cooling gas or heating
gas. For example, a gas at a high temperature, or a gas at a low
temperature.
[0340] In some embodiments, a 3D printing system comprises an
apparatus (e.g., coupled with an optical element) to perform a
cleaning cycle. The apparatus may be configured for dislodging
and/or preventing contaminants from being adhered to a surface of
the optical element. The apparatus for dislodging can comprise an
ultrasonic transducer, an ionized gas flow, or a combination
thereof. An ultrasonic transducer may induce a vibration in the
optical element such that a contaminant particle has a reduced
likelihood of binding to a surface of the optical element. For
example, a vibration of the optical element may reduce a time
(e.g., duration) in which the contaminant particle comes into
contact with a surface of the optical element. For example, a
vibration of the optical element may increase a binding energy
required for the contaminant particle to bind to a surface of the
optical element. An ionized gas flow can ionize the debris and/or
surface of the optical element to prevent adhesion of the debris to
the surface of the optical element (e.g., by mutual repulsion that
is induced by the ionized gas). An ultrasonic transducer can be
controlled to operate at one or more frequencies, and/or one or
more magnitudes (e.g., amplitudes) of vibration. An electrical bias
circuit can be controlled to generate one or more electric field
magnitudes (e.g., a voltage at a surface at an optical element), at
one or more electric field polarities. Control can be manual and/or
automatic control. The control can be in response to a detected
contaminant condition (e.g., based on one or more contaminant
sensor measurements, as described herein). A detected contaminant
condition may comprise contaminants detected at a surface of the
optical element, in the optical chamber, and/or in the channel(s)
(e.g., via an optical density measurement). A detected contaminant
condition may comprise contaminants detected (e.g., at a threshold
level) within an environment in a vicinity of the optical element
(e.g., in a processing chamber, and/or an optical enclosure).
[0341] FIG. 37 shows an example of an (e.g., processing chamber)
enclosure comprising an atmosphere 3726, in which an irradiating
energy (e.g. energy beam) 3701 travels. The energy beam 3701 is
generated by an energy source 3721, travels through an optical
mechanism (e.g., a scanner) 3720, and an optical window 3715,
towards a material bed 3704 disposed on a platform (e.g., base
3723). As the irradiative energy irradiates and travels along the
material bed 3704, it may form at least a portion of a 3D object
(e.g., 3706). In the example of FIG. 37, an ultrasonic transducer
3755 is coupled with (e.g., via vibrational element 3760) the
optical window 3715. In some embodiments, an optical window may be
induced to vibrate via activation of the ultrasonic transducer
(e.g., mediated by a vibrational element). In the example of FIG.
37, an ionized gas flow ionizes (i) an exposed surface of an
optical element of the scanner 3720 to generates an electric charge
(schematically show as) 3785 and (ii) an exposed surface of a
debris particle 3775 with a similar electrical charge type, which
repel each other (being of the same type). At times, a vibrating
optical element (e.g., optical window) and/or an optical element
having an electric charge (due to ionization) may repel contaminant
particles.
[0342] At times, it is beneficial to characterize at least one
component of an optical setup. For example, it may be beneficial to
characterize the thermal response of the at least one component of
the optical setup (e.g., thermal lensing characteristics). The
thermal response of the at least one component of the optical setup
may affect the focal point of the energy beam traveling through the
at least one component of the optical setup. In some embodiments,
the characterization of the at least one component of the optical
setup may be used as a benchmark to ascertain a status of the
optical setup at a given time (e.g., in terms of thermal lensing).
Ascertaining the status of the at least one component of the
optical setup may be in real time during the printing, e.g., during
operation of the transforming energy beam.
[0343] In some embodiments, a detector is configured to measure the
footprint of an energy beam traveling through the at least one
component of the optical setup, which footprint is on a target
surface. The detector may measure the footprint directly (e.g.,
using an imaging technique, e.g., a high-resolution (e.g., CCD)
camera), or indirectly. Indirect measurement of the footprint may
comprise (i) measuring the thermal signal of the energy beam on the
target surface, (ii) measuring the power density of the energy beam
at the target surface, or (iii) measuring the beam profile at the
target surface. The detector may have direct or indirect view of
the footprint. The detector may use the optics of the transforming
energy beam (e.g., a bore-sight detector). The detector may use a
different optical path (e.g., non-direct imaging), for example, by
using a imager such as a camera.
[0344] In some embodiments, a characterization of the at least one
component of the optical setup in non-thermal lensing regime
comprises irradiating a steady pulse (e.g., a tile) on a position
on a target surface (e.g., on a target structure) at several known
focal positions (e.g., various beam spot sizes) and measuring the
signal (e.g., intensity thereof). Such a measurement may result in
a relationship between beam intensity and spot size that is
characteristic for the at least one component of the optical setup,
which may be represented in a graph form (e.g., FIG. 39A). The
steady pulse may comprise a stationary or a substantially
stationary irradiation at a position for a period. Substantially
stationary may comprise a back and forth movement of the energy
beam (e.g., a pendulum movement) about a position, which movement
span is smaller than the FLS of the energy beam footprint. The
period can be at least about 50 microseconds (.mu.sec), 100
.mu.sec, 500 .mu.sec, lmilliseconds, 50 msec, or 90 msec. The
period can be at most about 100 .mu.sec, 500 .mu.sec, 1
milliseconds (msec), 10 msec, 25 msec, 50 msec, or 100 msec. The
period can be between any of the aforementioned period time spans
(e.g., from about 50 .mu.sec to about 100 msec, from about 50
.mu.sec to about 25 msec, or from 10 msec to about 90 msec). The
power density of the energy beam may be chosen to not invoke (e.g.,
substantial) thermal lensing in the at least one component of the
optical setup. The power density of the energy beam may be any
power density described herein. The target structure may comprise
any geometric shape (e.g., as described herein).
[0345] In some embodiments, thermal response of the at least one
component of the optical setup may be characterized. The
characterization of the at least one component of the optical setup
may comprise choosing a known focal point (corresponding to a known
spot size), and inducing a thermal response in the at least one
component of the optical setup in a controlled manner. The
characterization may further comprise measuring the spot size of
the energy beam on the target surface as a function of time (e.g.,
as the thermal effect progresses in the at least one component of
the optical setup). Inducing the thermal response may comprise
irradiating a first area (e.g., serpentine starting from position
3925) for a first period that is sufficient to induce a thermal
response. Measuring the spot size may comprise moving the energy
beam to a second area (e.g., 3927) distant from the first area, and
detecting the footprint of the energy beam on the second area. In
some embodiments, the distant between the second area and the first
area should be sufficiently large that the second area is not
(detectibly) thermally affected by heating of the first area during
irradiation by the energy beam. In some embodiments, irradiating to
induce a thermal response in the optical element(s) is on a first
calibration structure, and measuring the spot size is on a second
calibration structure that is different from the first calibration
structure. The power of the energy source may be held constant
during the measurement. The first measurement may be when the at
least one component of the optical setup is cold (e.g., devoid of
thermal lensing). The second measurement onwards may be when the at
least one component of the optical setup experiences thermal
lensing. FIG. 39B shows an example of an experimental setup
comprising an energy source 3921 irradiating an energy beam 3923 on
a target structure 3926 at position 3925 following a serpentine
path, and a measurement position 3927, from which radiation 3924 is
emanating and captured by a detector 3922. FIG. 39B shows also an
example of an optional target structure 3929 having a measurement
position 3928, and an irradiation position around it (e.g., 3931).
The target structure may be in a material bed (e.g., 3930). In some
embodiments, the thermal lensing status of the at least one
component of the optical setup may be measured and identified in
real time, once it characterized optically (in terms of spot size
and power density) and thermal response. In response to the
identification, measures may be taken in response to a deviation
from the requested spot size and power density. The identification
may be used by quality assurance. A maintenance procedure may be
initiated (e.g., cooling the at least one component of the optical
setup). At least one characteristic of the energy beam may be
altered (e.g., increase energy source power, alter focus, alter
translation speed). The alteration may be a dynamic alteration
(e.g., dynamic compensation for the thermal lensing). The measure
taken may be controlled (e.g., manually and/or automatically, e.g.,
by at least one controller), during and/or after the 3D
printing.
[0346] In some embodiments, one or more calibration structures are
used in conjunction with a (e.g., thermal) detector to characterize
one or more optical elements at varied conditions (e.g., energy
density, power, focus, pulse frequency, wavelength) of an energy
source. The relative positions of the calibration structures may
vary among each other, relative to the center of the platform
(e.g., to calibrate the energy beam along the platform. The
characterization can include a trajectory (e.g., path), footprint
(e.g., its area, shape (e.g., astigmatism), size, and/or focus),
power per unit area, fluence, Andrew Number, hatch spacing, scan
speed, scan direction, charge, and/or an irradiating energy beam.
Characterization of the one or more optical elements can be based
on (i) the measured irradiating energy beam characteristics, and/or
(ii) when the energy source and the irradiating energy beam are
operated in a controlled manner for calibration (e.g., compared
against a benchmark). An optical element benchmark operation can
occur before, during and/or following a 3D printing process (e.g.,
a build cycle). An optical element benchmark operation can comprise
irradiating one or more calibration structures for a predetermined
time. Irradiating for a predetermined time can comprise a plurality
of times (e.g., at least about 1 second (sec), 2 sec, 4 sec, 8 sec,
16 sec, 32 sec, 64 sec, 128 sec or 256 sec). Irradiating for a
predetermined multiplicity of times can comprise at most about 256
sec, 128 sec, 64 sec, 32 sec, 16 sec, 8 sec, 4 sec, 2 sec, or 1
sec. Irradiating for a predetermined time can be in between any of
the aforementioned times (from about 1 sec to about 256 sec, from
about 1 sec to about 64 sec, or from about 64 sec to about 256
sec).
[0347] The irradiating energy may be continuous or pulsing. The
irradiating energy may be projected onto one or more positions of
the one or more calibration structures. The irradiating energy beam
may follow on a path (e.g., a predetermined path) along the one or
more calibration structures. The path may be confined to one
calibration structure. The path may include several (e.g., at least
two) calibration structures. For example, a first irradiation can
be made on a first calibration structure, a second irradiation
(e.g., following the first) can be made on a second calibration
structure, and a third irradiation can be made on a third
calibration structure. There can be at least 1, 2, 3, 4, 5, 6, 7,
8, 9, or 10 calibration structures. In some embodiments, at least
two of the calibration structures are different. In some
embodiments, at most two of the calibration structures are similar.
One or more (e.g., at least one) calibration structure may be
maintained at a (e.g., substantially) controlled condition (e.g.,
benchmark condition). The controlled condition can be different
from an ambient condition. The controlled condition can comprise a
controlled temperature and/or pressure. The controlled condition
can be maintained before, during and/or after irradiation from the
irradiating energy beam. The controlled condition can be maintained
by limiting the energy flux transmitted from the irradiating energy
beam. Limiting the energy flux can include controlling a dwell
time, average energy density, pulse duration, and/or
cross-sectional footprint of the irradiating energy beam on the
benchmark calibration structure. The irradiation can be for a
specified time (e.g., a dwell time) at a given (e.g., at least one)
location of the calibration structure. The dwell time on the
benchmark calibration structure can be fixed (e.g., the same for
multiple irradiated positions). The dwell time on the benchmark
calibration structure can vary (e.g., varied for multiple
irradiated positions). The irradiating can be at a controlled
focus. The controlled focus can (e.g., controllably) change during
the plurality of times (e.g., at different irradiated positions). A
dwell time for the (e.g., at least two) different calibration
structures can be the same. A dwell time for the different
calibration structures can be different. At least one (e.g., two or
more) calibration structures can vary from the controlled
condition. Varying from the controlled condition can comprise a
temperature and/or pressure that is at, above, or below an ambient
temperature and/or pressure. The one or more calibration structures
varying from the controlled condition can be caused by the
irradiating energy beam (e.g., via heating).
[0348] In some embodiments, the thermal lensing characteristic of
an optical element may be characterized using a benchmark
structure. In some embodiments, the characteristics of the energy
beam (as affected by thermal lensing) may be characterized using a
benchmark structure. The characterization may be done before a
printing operation (e.g., before formation a layer of transformed
material), or before a print cycle. The characterization may be
done in real-time during the printing. A detector can generate one
or more signals, which can characterize (e.g., via a graphical
representation) one or more characteristics of the energy beam. The
characteristics may (in turn) correspond to one or more benchmark
condition(s) of the benchmark calibration structure. The
calibration can include characterization of one or more (e.g.,
calibration structure) thermal emissions captured by a detector
before, during, and/or after directing the irradiating energy at
one or more calibration structures. For example, a benchmark
calibration curve can be generated, which curve represents a
magnitude (e.g., intensity) of the detected (e.g., thermal) signal
of irradiated positions of the benchmark calibration structure as a
function of the irradiating energy beam spot size. At times, each
irradiated position may be equidistant from another irradiated
position (e.g., when using a pulsing energy beam). The detector may
have a field of view such that only one irradiated position is
measured at a given time. A focal plane of the detector may
coincide with a surface (e.g., a top surface) of the calibration
structure. The detector may be stationary or mobile (e.g., having a
known trajectory). A timing of the detector signal capture, and a
spacing of the irradiated position(s), may be coordinated such that
a detector measurement does excludes a signal from more than one
irradiated position. For example, irradiated positions may be
spaced such that heat diffusing from a first irradiated position
does not have sufficient time to reach a (e.g., thermal) detector
field of view of a second irradiated position, prior to the
detector measurement of the second irradiated position. A spacing
between irradiated positions can depend upon one or more
characteristics of the irradiating energy beam (e.g., energy source
power, energy beam spot size), and/or material properties (e.g.,
thermal diffusion coefficient) of the benchmark structure. For
example, a benchmark dwell time of an irradiated position may be
0.5-2 ms, a benchmark spot size may be 500 microns (e.g., in
diameter), a (e.g., benchmark) spacing between irradiated positions
on the benchmark calibration structure may be 2000 microns, and an
interval between successive irradiated positions on the benchmark
calibration structure can be 2 ms, for a benchmark structure made
of a high melting temperature metal, such as Tungsten and/or
Tantalum. The benchmark structure and/or target structure may be
formed from a high melting point material. The high melting point
material may have a melting temperature of at least about
1500.degree. C., 2000.degree. C., 2500.degree. C., 3000.degree. C.,
3200.degree. C., 3400.degree. C., or 3500.degree. C., at ambient
pressure. The high melting point material may have a melting
temperature between any of the afore-mentioned melting
temperatures, at ambient pressure (e.g., from about 1500.degree. C.
to about 3500.degree. C., from about 2000.degree. C. to about
3500.degree. C., or from about 2500.degree. C. to about
3500.degree. C.). The benchmark and/or target structure may
comprise an elemental metal, metal alloy, ceramic, salt, or an
allotrope of elemental carbon. The benchmark and/or target
structure may comprise an oxide. In this manner a plurality of the
irradiated position(s) can be isolated (e.g., experience no heating
effect) from prior irradiated positions of the benchmark
calibration structure, and detected measurements thereof may be
solely representative of the state of the optical element and/or
the energy imparted by the irradiating energy beam at a given
irradiated position.
[0349] FIG. 39A shows an example of a calibration curve 3910 having
detected intensity 3990 as a function of irradiating energy beam
spot size (e.g., cross-sectional area at the benchmark calibration
structure surface) 3985. Irradiating energy beam spot sizes (e.g.,
a diameter thereof) can range from maximally focused (e.g., a
minimal waist of the energy beam) to maximally defocused. For
example, irradiating energy beam spot size can range from about 50
microns to about 1500 microns. The benchmark detector intensity
value for a given spot size can be generated by (e.g., an average
value of) a plurality of measurements of the benchmark calibration
structure in the benchmark condition(s). In the example of FIG. 39,
three measurements 3905 are taken at each of spot sizes 1-5, with
curve 3910 passing through the average value of the measurements at
each spot size.
[0350] The benchmark calibration curve can provide a baseline
operation characterization of one or more (e.g., all) optical
elements in an optical system (of a 3D printing system). The
baseline characterization can represent the performance of the
optical element(s) at one or more nominal conditions (e.g., a
condition devoid of thermal lensing). The benchmark calibration
curve can be used in a process of monitoring a state (e.g., a
condition thereof, for example, a magnitude of thermal lensing) of
the optical element(s) via the measured one or more irradiating
energy beam characteristics, for example, during, before, and/or
after a 3D printing process. For example, one or more measurements
of the irradiating energy beam using the benchmark calibration
structure and the heating irradiation structure(s) can be used to
monitor a (e.g., measured) spot size of the irradiating energy beam
compared against a controlled (e.g., nominal) spot size of the
irradiating energy beam. As described herein, an optical element in
a thermal lensing condition will focus radiation passing
therethrough in an altered manner (e.g., will have an altered
focus). By comparing (i) a (e.g., thermal) detected signal
generated by the irradiating energy beam at a given condition
incident on the benchmark calibration structure (e.g., during
and/or after a 3D printing process), against (ii) a benchmark
calibration curve comprising the expected signal from the
irradiating energy beam at the given condition, any change in the
irradiating energy beam (e.g., from a nominal, benchmark condition)
may be monitored (e.g., in real time). The measurement rate may be
from about 0.1 KHz to about 10000 KHz, from about 0.1 KHz to about
1000 KHz, or from about 1000 KHz to about 10000 KHz. The change may
be a change in the focal distance of a (e.g., at least one) optical
element. The change may be quantified, for example, by the
magnitude of change in the detected signal at the given condition,
with respect to the expected signal at the benchmark calibration
condition. The (e.g., quantified) change may be used to control one
or more characteristics of the irradiating energy beam (e.g., in
real time or before the printing), such as the beam spot size at
the target surface. A thermal lensing condition can be determined
(e.g., to be present) based on the quantified change in the
detected signal. A thermal lensing condition can be qualified as a
variance from a requested energy beam characteristic, e.g., a
change in a requested beam spot size at the target surface (e.g., a
threshold level change in beam spot size, e.g., as described
herein). Based on the detected change in the irradiating beam, a
position of one or more optical elements may be adjusted to vary
the cross-section of the transforming beam. For example, the
position of one or more optical elements may be adjusted to vary a
footprint of the transforming beam and/or its focus on the target
surface. The thermal condition can be controlled (e.g. mitigated).
For example, by varying at least one parameter of the printing. For
example, by varying at least one component of the printer. For
example, by varying the temperature and/or position of the at least
one optical element, varying the power of the energy source, and/or
varying at least one characteristic of the energy beam.
[0351] Real time as understood herein may be during at least part
of the printing. Real time may be during a print operation. Real
time may be during a print cycle. Real time may comprise: during
formation of a 3D object, a layer of hardened material as part of
the 3D object, a hatch line, or a melt pool.
[0352] In the example of FIG. 39A, a magnified box of the benchmark
calibration curve 3910 depicts (e.g., three) benchmark calibration
measurements 3915a, taken at benchmark conditions (e.g.,
irradiating energy dwell time, energy source power, controlled
irradiating energy spot size 3985a) on the benchmark calibration
structure at time "t1." In the example of FIG. 39 the calibration
measurement 3915a have corresponding (e.g., average) detector
signal value 3990a. FIG. 39A depicts a time "t2" (e.g., during
and/or after a 3D printing process) benchmark calibration
measurements 3915b, at (e.g., the same) benchmark conditions (e.g.,
irradiating energy dwell time, energy source power, controlled
irradiating energy spot size 3985a) on the benchmark calibration
structure. FIG. 39 depicts that while the benchmark conditions are
the same in time "t2" as at time "t1," including the controlled
irradiating energy spot size, the measured (e.g., average) detector
signal value is higher (e.g., by .DELTA.y, 3990b). By comparing the
measured detector signal value against a benchmark calibration
curve (e.g., determining .DELTA.y), a corresponding spot size of
the irradiating energy beam on the calibration surface can be
determined. As shown in the example of FIG. 39, the corresponding
spot size is 3985b is smaller than the controlled (e.g., nominal,
or commanded) spot size 3985a, by a value Ax. In this manner a
change in a condition (e.g., a focal length) of an optical element
can be detected and/or monitored. The change in the condition of
the optical element can be due to thermal lensing. A magnitude of
the effect (e.g., a magnitude of thermal lensing, a change in a
spot size of the irradiating energy beam) can be detected and/or
monitored (e.g., by correlating measurement(s) against a benchmark
calibration curve). The detected change in the optical element may
be used to control (e.g., regulate and/or direct) at least one
characteristic of the irradiating energy (e.g., such as described
herein). Controlling at least one characteristic of the irradiating
energy may comprise its power density, dwell time, translational
speed, focus, or cross section. The detected change in the optical
element may be used to adjust at least one characteristic of the
irradiating energy. Adjusting at least one characteristic of the
irradiating energy may comprise the position at which the
irradiating energy intersects the calibration structure and/or
target surface. Controlling may be done during, before, or after a
build of the 3D object. Controlling may be performed manually
and/or by a controller. At times, controlling may be performed by
the same controller. At times, controlling may be performed by
different controllers (e.g., that are operatively coupled).
Controlling may comprise calibrating, monitoring, or adjusting. At
least one controller may be a control system. The controller may
include a processing unit (e.g., CPU, GPU, and/or FPGA). Controller
may be programmable. The controller may operate upon request. The
controller may be any controller described herein.
[0353] A sensitivity of thermal lensing detection can vary
according to one or more calibration conditions. For example,
thermal lensing detection sensitivity can be (e.g., relatively)
high when performing (e.g., calibration) measurements corresponding
to a portion (or portions) of the benchmark calibration curve that
are substantially linear. Substantially linear can correspond to
(i) a substantially linear change in a detected signal intensity
for (ii) a substantially linear change in irradiating energy spot
size on the benchmark calibration structure. For example,
calibration measurements can be taken at a (e.g., substantially
maximal) defocus (e.g., rightmost portion of FIG. 39, 3910). In
this manner a change in a spot size of the irradiating energy beam
on the benchmark calibration structure (e.g., by .DELTA.x on FIG.
39A, 3985) can be readily detected and/or quantified according to a
change in the detected signal (e.g., by .DELTA.y on FIG. 39A, 3990)
during a calibration measurement. At times, calibration
measurements can be taken at conditions corresponding to a portion
(or portions) of the benchmark calibration curve that are
substantially nonlinear (e.g., the portion between locations 2 and
4 of FIG. 39, 3985). At times, calibration measurements can be
taken at conditions corresponding to a portion (or portions) of the
benchmark calibration curve that are substantially flat (e.g., the
region between locations 3 and 4 of FIG. 39A, 3985). At times
calibration measurements are taken at conditions corresponding to
at least 2, 3, or 5 regions of the benchmark calibration curve.
[0354] The calibration can comprise directing an irradiating energy
at the one or more calibration structures in a sequence. The
calibration structures may vary with respect to each other in
position and/or material. In some embodiments, the calibration
structures are made of (e.g., substantially) the same material. The
sequence can comprise an initial irradiated position (e.g., at
benchmark dwell time, energy source power, irradiating energy beam
spot size) on the benchmark calibration structure, a subsequent
(e.g., second, heating) irradiation position (and/or hatch) on a
(e.g., different, at least one or more) calibration structure
(e.g., a heating irradiation), and a further subsequent (e.g.,
third) irradiation position on the benchmark calibration structure.
A heating irradiation can comprise an irradiation pulse and/or
hatch on a calibration structure that is not a benchmark
calibration structure (e.g., a heat sink). A heating irradiation
can comprise a relatively high power (e.g., compared with a
benchmark power, for example greater than 200 W) energy source
setting, and/or a relatively high dwell time (e.g., from about 1
second to about 60 seconds). At times, a heating irradiation can be
of sufficient power and/or duration to induce a thermal lensing
condition in an optical element. At times a heating irradiation can
fail to induce a thermal lensing condition in an optical element.
The irradiation on the benchmark calibration structure can be an
irradiated position by the irradiating energy beam on the benchmark
calibration structure. The irradiation on the different calibration
structure(s) (e.g., heating irradiation) can be before, during,
and/or after a 3D printing process. The initial irradiated position
can comprise more than one position (e.g., 2, 3, 5, 8, or 10
positions). At least two of the irradiated positions may comprise
irradiation from irradiating energy beams having different
cross-sectional area (e.g., spot size) at the surface of the
benchmark calibration structure. In some embodiments, irradiating
energy beams of different cross-sectional area can provide
different detector sensitivities in a calibration process. For
example, in the example of FIG. 39A a detector sensitivity (e.g.,
of 3990) is higher with respect to the curve 3910 at a region near
position 4 than at a region near position 5. In some embodiments, a
lower detector sensitivity can provide an improved measurement
sensitivity (e.g., improved resolution regarding the spot size of
the irradiating energy beam). An energy source power and/or a dwell
time of the irradiating energy may be controlled (e.g., manually
and/or automatically, e.g., using a controller) to remain
substantially constant for each irradiated position of the
benchmark calibration structure. The controlled power (e.g.,
benchmark power) can be of at least about 50 W, 100 W, 135 W, 150
W, 185 W, 200 W, 400 W, 750 W, or 1000 W. The controlled power can
be of at most about 1000 W, 750 W, 400 W, 200 W, 185 W, 150 W, 135
W, 100 W, or 50 W. The controlled power can be in between any of
the aforementioned powers (from about 50 W to about 1000 W, from
about 500 W to about 1000 W, or from about 50 W to about 500 W).
The controlled dwell time (e.g., benchmark dwell time) can be about
0.1 milliseconds (ms), 0.3 ms, 0.8 ms, 1 ms, 2 ms, or 5 ms. The
controlled dwell time can be at most about 5 ms, 2 ms, 1 ms, 0.8
ms, 0.3 ms, or 0.1 ms. The controlled dwell time can be in between
any of the afore-mentioned dwell times (from about 0.1 ms to about
5 ms, from about 2 ms to about 5 ms, from about 0.1 ms to about 2
ms).
[0355] In some cases, a layer of the 3D object can be formed within
at most about 1 hour (h), 30 minutes (min), 20 min, 10 min, 5 min,
1 min, 40 seconds (s), 20 s, 10 s, 9 s, 8 s, 7 s, 6 s, 5 s, 4 s, 3
s, 2 s, or 1 s. A layer of the 3D object can be formed within at
least about 30 minutes (min), 20 min, 10 min, 5 min, 1 min, 40
seconds (s), 20 s, 10 s, 9 s, 8 s, 7 s, 6 s, 5 s, 4 s, 3 s, 2 s, or
1 s. A layer of the 3D can be formed within any time between the
aforementioned time scales (e.g., from about 1 h to about 1 s, from
about 10 min to about 1 s, from about 40 s to about 1 s, from about
10 s to about 1 s, or from about 5 s to about 1 s).
[0356] The final form of the 3D object can be retrieved soon after
cooling of a final material layer. Soon after cooling may be at
most about 1 day, 12 hours (h), 6 h, 5 h, 4 h, 3 h, 2 h, 1 h, 30
minutes, 15 minutes, 5 minutes, 240 s, 220 s, 200 s, 180 s, 160 s,
140 s, 120 s, 100 s, 80 s, 60 s, 40 s, 20 s, 10 s, 9 s, 8 s, 7 s, 6
s, 5 s, 4 s, 3 s, 2 s, or 1 s. Soon after cooling may be between
any of the aforementioned time values (e.g., from about is to about
1 day, from about is to about 1 hour, from about 30 minutes to
about 1 day, or from about 20 s to about 240 s). In some cases, the
cooling can occur by method comprising active cooling by convection
using a cooled gas or gas mixture comprising argon, nitrogen,
helium, neon, krypton, xenon, hydrogen, carbon monoxide, carbon
dioxide, or oxygen. Cooling may be cooling to a temperature that
allows a person to handle the 3D object. Cooling may be cooling to
a handling temperature. The 3D object can be retrieved during a
time period between any of the aforementioned time periods (e.g.,
from about 12 h to about 1 s, from about 12 h to about 30 min, from
about 1 h to about 1 s, or from about 30 min to about 40 s).
[0357] The generated 3D object can require very little or no
further processing after its retrieval. In some examples, the
diminished further processing or lack thereof, will afford a 3D
printing process that requires smaller amount of energy and/or less
waste as compared to commercially available 3D printing processes.
The smaller amount can be smaller by at least about 1.1, 1.3, 1.5,
2, 3, 4, 5, 6, 7, 8, 9, or 10. The smaller amount may be smaller by
any value between the aforementioned values (e.g., from about 1.1
to about 10, or from about 1.5 to about 5). Further processing may
comprise trimming, as disclosed herein. Further processing may
comprise polishing (e.g., sanding). For example, in some cases the
generated 3D object can be retrieved and finalized without removal
of transformed material and/or auxiliary features. The 3D object
can be retrieved when the three-dimensional part, composed of
hardened (e.g., solidified) material, is at a handling temperature
that is suitable to permit the removal of the 3D object from the
material bed without substantial deformation. The handling
temperature can be a temperature that is suitable for packaging of
the 3D object. The handling temperature a can be at most about
120.degree. C., 100.degree. C., 80.degree. C., 60.degree. C.,
40.degree. C., 30.degree. C., 25.degree. C., 20.degree. C.,
10.degree. C., or 5.degree. C. The handling temperature can be of
any value between the afore-mentioned temperature values (e.g.,
from about 120.degree. C. to about 20.degree. C., from about
40.degree. C. to about 5.degree. C., or from about 40.degree. C. to
about 10.degree. C.).
[0358] The methods and systems provided herein can result in fast
and efficient formation of 3D objects. In some cases, the 3D object
can be transported within at most about 120 min, 100 min, 80 min,
60 min, 40 min, 30 min, 20 min, 10 min, or 5 min after the last
layer of the object hardens (e.g., solidifies). In some cases, the
3D object can be transported within at least about 120 min, 100
min, 80 min, 60 min, 40 min, 30 min, 20 min, 10 min, or 5 min after
the last layer of the object hardens. In some cases, the 3D object
can be transported within any time between the above-mentioned
values (e.g., from about 5 min to about 120 min, from about 5 min
to about 60 min, or from about 60 min to about 120 min). The 3D
object can be transported once it cools to a temperature of at most
about 100.degree. C., 90.degree. C., 80.degree. C., 70.degree. C.,
60.degree. C., 50.degree. C., 40.degree. C., 30.degree. C.,
25.degree. C., 20.degree. C., 15.degree. C., 10.degree. C., or
5.degree. C. The 3D object can be transported once it cools to a
temperature value between the above-mentioned temperature values
(e.g., from about 5.degree. C. to about 100.degree. C., from about
5.degree. C. to about 40.degree. C., or from about 15.degree. C. to
about 40.degree. C.). Transporting the 3D object can comprise
packaging and/or labeling the 3D object. In some cases, the 3D
object can be transported directly to a consumer.
[0359] Systems and methods presented herein can facilitate
formation of custom or stock 3D objects for a customer. A customer
can be an individual, a corporation, organization, government,
non-profit organization, company, hospital, medical practitioner,
engineer, retailer, any other entity, or individual. The customer
may be one that is interested in receiving the 3D object and/or
that ordered the 3D object. A customer can submit a request for
formation of a 3D object. The customer can provide an item of value
in exchange for the 3D object. The customer can provide a design or
a model for the 3D object. The customer can provide the design in
the form of a stereo lithography (STL) file. The customer can
provide a design where the design can be a definition of the shape
and dimensions of the 3D object in any other numerical or physical
form. In some cases, the customer can provide a 3D model, sketch,
or image as a design of an object to be generated. The design can
be transformed in to instructions usable by the printing system to
additively generate the 3D object. The customer can provide a
request to form the 3D object from a specific material or group of
materials (e.g., a material as described herein). In some cases,
the design may not contain auxiliary features or marks of any past
presence of auxiliary support features.
[0360] In response to the customer request the 3D object can be
formed or generated with the printing method, system and/or
apparatus as described herein. In some cases, the 3D object can be
formed by an additive 3D printing process. Additively generating
the 3D object can comprise successively depositing and melting a
powder comprising one or more materials as specified by the
customer. The 3D object can subsequently be delivered to the
customer. The 3D object can be formed without generation or removal
of auxiliary features (e.g., that is indicative of a presence or
removal of the auxiliary support feature). Auxiliary features can
be support features that prevent a 3D object from shifting,
deforming, or moving during formation.
[0361] The 3D object (e.g., solidified material) that is generated
for the customer can have an average deviation value from the
intended dimensions of at most about 0.5 microns (.mu.m), 1 .mu.m,
3 .mu.m, 10 .mu.m, 30 .mu.m, 100 .mu.m, 300 .mu.m, or less. The
deviation can be any value between the afore-mentioned values
(e.g., from about 0.5 .mu.m to about 300 .mu.m, from about 10 .mu.m
to about 50 .mu.m, from about 15 .mu.m to about 85 .mu.m, from
about 5 .mu.m to about 45 .mu.m, or from about 15 .mu.m to about 35
.mu.m). The 3D object can have a deviation from the intended
dimensions in a specific direction, according to the formula
Dv+L/K.sub.Dv, wherein Dv is a deviation value, L is the length of
the 3D object in a specific direction, and K.sub.Dv is a constant.
Dv can have a value of at most about 300 .mu.m, 200 .mu.m, 100
.mu.m, 50 .mu.m, 40 .mu.m, 30 .mu.m, 20 .mu.m, 10 .mu.m, 5 .mu.m, 1
.mu.m, or 0.5 .mu.m. Dv can have a value of at least about 0.5
.mu.m, 1 .mu.m, 3 .mu.m, 5 .mu.m, 10 .mu.m, 20 .mu.m, 30 .mu.m, 50
.mu.m, 70 .mu.m, 100 .mu.m, or 300 .mu.m. Dv can have any value
between the aforementioned values (e.g., from about 0.5 .mu.m to
about 300 .mu.m, from about 10 .mu.m to about 50 .mu.m, from about
15 .mu.m to about 85 .mu.m, from about 5 .mu.m to about 45 .mu.m,
or from about 15 .mu.m to about 35 .mu.m). K.sub.dv can have a
value of at most about 3000, 2500, 2000, 1500, 1000, or 500.
K.sub.dv can have a value of at least about 500, 1000, 1500, 2000,
2500, or 3000. K.sub.dv can have any value between the
aforementioned values (e.g., from about 3000 to about 500, from
about 1000 to about 2500, from about 500 to about 2000, from about
1000 to about 3000, or from about 1000 to about 2500).
[0362] The intended dimensions can be derived from a model design.
The 3D part can have the stated accuracy value immediately after
its formation, without additional processing or manipulation.
Receiving the order for the object, formation of the object (e.g.,
comprising 10,000 layers), and delivery of the object to the
customer can take at most about 7 days, 6 days, 5 days, 3 days, 2
days, 1 day, 12 hours, 6 hours, 5 hours, 4 hours, 3 hours, 2 hours,
1 hour, 30 min, 20 min, 10 min, 5 min, 1 min, 30 seconds, or 10
seconds. In some cases, the 3D object can be additively generated
in a period between any of the afore-mentioned time periods (e.g.,
from about 10 seconds to about 7 days, from about 10 seconds to
about 12 hours, from about 12 hours to about 7 days, or from about
12 hours to about 10 minutes). The time can vary based on the
physical characteristics of the object, including the size and/or
complexity of the object.
[0363] In some applications, the rate of printing (e.g.,
transforming) is at least about 5 cubic centimeters per hour
(cm.sup.3/hr), 10 cm.sup.3/hr, 20 cm.sup.3/hr, 30 cm.sup.3/hr, 40
cm.sup.3/hr, 50 cm.sup.3/hr, 100 cm.sup.3/hr, 150 cm.sup.3/hr, 200
cm.sup.3/hr, 250 cm.sup.3/hr, 300 cm.sup.3/hr, 400 cm.sup.3/hr, 500
cm.sup.3/hr or 1,000 cm.sup.3/hr. The rate of printing (e.g.,
transforming) may range between any of the afore-mentioned values
(e.g., from about 5 cm.sup.3/hr to about 1,000 cm.sup.3/hr, from
about 5 cm.sup.3/hr to about 200 cm.sup.3/hr, from about 200
cm.sup.3/hr to about 1,000 cm.sup.3/hr, or from about 5 cm.sup.3/hr
to about 200 cm.sup.3/hr).
[0364] The system and/or apparatus can comprise a controlling
mechanism (e.g., a controller). The methods, systems, and/or
apparatuses disclosed herein may incorporate a controller mechanism
that controls one or more of the components described herein. The
controller may comprise a computer-processing unit (e.g., a
computer) coupled to any of the systems and/or apparatuses, or
their respective components (e.g., the energy source(s)). The
computer can be operatively coupled through a wired and/or through
a wireless connection. In some cases, the computer can be on board
a user device. A user device can be a laptop computer, desktop
computer, tablet, smartphone, or another computing device. The
controller can be in communication with a cloud computer system
and/or a server. The controller can be programmed to selectively
direct the energy source(s) to apply energy to the at least a
portion of the target surface at a power per unit area. The
controller can be in communication with the scanner configured to
articulate the energy source(s) to apply energy to at least a
portion of the target surface at a power per unit area.
[0365] The controller may control the layer dispensing mechanism
and/or any of its components. The controller may control the
platform. The control may comprise controlling (e.g., directing
and/or regulating) the speed (velocity) of movement. The movement
may be horizontal, vertical, and/or in an angle. The controller may
control the level of pressure (e.g., vacuum, ambient, or positive
pressure) in the material removal mechanism material dispensing
mechanism, and/or the enclosure (e.g., chamber). The pressure level
(e.g., vacuum, ambient, or positive pressure) may be constant or
varied. The pressure level may be turned on and off manually and/or
by the controller. The controller may control the force generating
mechanism. For example, the controller may control the amount of
magnetic, electrical, pneumatic, and/or physical force generated by
force generating mechanism. For example, the controller may control
the polarity type of magnetic, and/or electrical charge generated
by the force generating mechanism. The controller may control the
timing and the frequency at which the force is generated. The
controller may control the direction and/or rate of movement of the
translating mechanism. The controller may control the cooling
member (e.g., external, and/or internal). In some embodiments, the
external cooling member may be translatable. The movement of the
layer dispensing mechanism or any of its components may be
predetermined. The movement of the layer dispensing mechanism or
any of its components may be according to an algorithm. The control
may be manual and/or automatic. The control may be programmed
and/or be effectuated a whim. The control may be according to an
algorithm. The algorithm may comprise a printing algorithm, or
motion control algorithm. The algorithm may take into account the
model of the 3D object.
[0366] The controller may comprise a processing unit. The
processing unit may be central. The processing unit may comprise a
central processing unit (herein "CPU"). The controllers or control
mechanisms (e.g., comprising a computer system) may be programmed
to implement methods of the disclosure. The controller may control
at least one component of the systems and/or apparatuses disclosed
herein. FIG. 7 is a schematic example of a computer system 700 that
is programmed or otherwise configured to facilitate the formation
of a 3D object according to the methods provided herein. The
computer system 700 can control (e.g., direct and/or regulate)
various features of printing methods, apparatuses and systems of
the present disclosure, such as, for example, regulating force,
translation, heating, cooling and/or maintaining the temperature of
a powder bed, process parameters (e.g., chamber pressure), scanning
route of the energy source, position and/or temperature of the
cooling member(s), application of the amount of energy emitted to a
selected location, or any combination thereof. The computer system
700 can be part of, or be in communication with, a printing system
or apparatus, such as a 3D printing system or apparatus of the
present disclosure. The computer may be coupled to one or more
mechanisms disclosed herein, and/or any parts thereof. For example,
the computer may be coupled to one or more sensors, valves,
switches, motors, pumps, or any combination thereof.
[0367] The computer system 700 can include a processing unit 706
(also "processor," "computer" and "computer processor" used
herein). The computer system may include memory or memory location
702 (e.g., random-access memory, read-only memory, flash memory),
electronic storage unit 704 (e.g., hard disk), communication
interface 703 (e.g., network adapter) for communicating with one or
more other systems, and peripheral devices 705, such as cache,
other memory, data storage and/or electronic display adapters. The
memory 702, storage unit 704, interface 703, and peripheral devices
705 are in communication with the processing unit 706 through a
communication bus (solid lines), such as a motherboard. The storage
unit can be a data storage unit (or data repository) for storing
data. The computer system can be operatively coupled to a computer
network ("network") 701 with the aid of the communication
interface. The network can be the Internet, an Internet and/or
extranet, or an intranet and/or extranet that is in communication
with the Internet. The network in some cases is a telecommunication
and/or data network. The network can include one or more computer
servers, which can enable distributed computing, such as cloud
computing. The network, in some cases with the aid of the computer
system, can implement a peer-to-peer network, which may enable
devices coupled to the computer system to behave as a client or a
server.
[0368] The processing unit can execute a sequence of
machine-readable instructions, which can be embodied in a program
or software. The instructions may be stored in a memory location,
such as the memory 702. The instructions can be directed to the
processing unit, which can subsequently program or otherwise
configure the processing unit to implement methods of the present
disclosure. Examples of operations performed by the processing unit
can include fetch, decode, execute, and write back. The processing
unit may interpret and/or execute instructions. The processor may
include a microprocessor, a data processor, a central processing
unit (CPU), a graphical processing unit (GPU), a system-on-chip
(SOC), a co-processor, a network processor, an application specific
integrated circuit (ASIC), an application specific instruction-set
processor (ASIPs), a controller, a programmable logic device (PLD),
a chipset, a field programmable gate array (FPGA), or any
combination thereof. The processing unit can be part of a circuit,
such as an integrated circuit. One or more other components of the
system 700 can be included in the circuit.
[0369] The storage unit 704 can store files, such as drivers,
libraries, and saved programs. The storage unit can store user
data, e.g., user preferences and user programs. The computer system
in some cases can include one or more additional data storage units
that are external to the computer system, such as located on a
remote server that is in communication with the computer system
through an intranet or the Internet.
[0370] The computer system can communicate with one or more remote
computer systems through the network. For instance, the computer
system can communicate with a remote computer system of a user
(e.g., operator). Examples of remote computer systems include
personal computers (e.g., portable PC), slate or tablet PC's (e.g.,
Apple.RTM. iPad, Samsung.RTM. Galaxy Tab), telephones, Smart phones
(e.g., Apple.RTM. iPhone, Android-enabled device, Blackberry.RTM.),
or personal digital assistants. The user can access the computer
system via the network.
[0371] Methods as described herein can be implemented by way of
machine (e.g., computer processor) executable code stored on an
electronic storage location of the computer system, such as, for
example, on the memory 702 or electronic storage unit 704. The
machine executable or machine-readable code can be provided in the
form of software. During use, the processor 706 can execute the
code. In some cases, the code can be retrieved from the storage
unit and stored on the memory for ready access by the processor. In
some situations, the electronic storage unit can be precluded, and
machine-executable instructions are stored on memory.
[0372] The code can be pre-compiled and configured for use with a
machine have a processer adapted to execute the code, or can be
compiled during runtime. The code can be supplied in a programming
language that can be selected to enable the code to execute in a
pre-compiled or as-compiled fashion.
[0373] The processing unit may include one or more cores. The
computer system may comprise a single core processor, multi core
processor, or a plurality of processors for parallel processing.
The processing unit may comprise one or more central processing
unit (CPU) and/or a graphic processing unit (GPU). The multiple
cores may be disposed in a physical unit (e.g., Central Processing
Unit, or Graphic Processing Unit). The processing unit may include
one or more processing units. The physical unit may be a single
physical unit. The physical unit may be a die. The physical unit
may comprise cache coherency circuitry. The multiple cores may be
disposed in close proximity. The physical unit may comprise an
integrated circuit chip. The integrated circuit chip may comprise
one or more transistors. The integrated circuit chip may comprise
at least 0.2 billion transistors (BT), 0.5 BT, 1 BT, 2 BT, 3 BT, 5
BT, 6 BT, 7 BT, 8 BT, 9 BT, 10 BT, 15 BT, 20 BT, 25 BT, 30 BT, 40
BT, or 50 BT. The integrated circuit chip may comprise at most 7
BT, 8 BT, 9 BT, 10 BT, 15 BT, 20 BT, 25 BT, 30 BT, 40 BT, 50 BT, 70
BT, or 100 BT. The integrated circuit chip may comprise any number
of transistors between the afore-mentioned numbers (e.g., from
about 0.2 BT to about 100 BT, from about 1 BT to about 8 BT, from
about 8 BT to about 40 BT, or from about 40 BT to about 100 BT).
The integrated circuit chip may have an area of at least 50
mm.sup.2, 60 mm.sup.2, 70 mm.sup.2, 80 mm.sup.2, 90 mm.sup.2, 100
mm.sup.2, 200 mm.sup.2, 300 mm.sup.2, 400 mm.sup.2, 500 mm.sup.2,
600 mm.sup.2, 700 mm.sup.2, or 800 mm.sup.2. The integrated circuit
chip may have an area of at most 50 mm.sup.2, 60 mm.sup.2, 70
mm.sup.2, 80 mm.sup.2, 90 mm.sup.2, 100 mm.sup.2, 200 mm.sup.2, 300
mm.sup.2, 400 mm.sup.2, 500 mm.sup.2, 600 mm.sup.2, 700 mm.sup.2,
or 800 mm.sup.2. The integrated circuit chip may have an area of
any value between the afore-mentioned values (e.g., from about 50
mm.sup.2 to about 800 mm.sup.2, from about 50 mm.sup.2 to about 500
mm.sup.2, or from about 500 mm.sup.2 to about 800 mm.sup.2). The
close proximity may allow substantial preservation of communication
signals that travel between the cores. The close proximity may
diminish communication signal degradation. A core as understood
herein is a computing component having independent central
processing capabilities. The computing system may comprise a
multiplicity of cores, which are disposed on a single computing
component. The multiplicity of cores may include two or more
independent central processing units. The independent central
processing units may constitute a unit that read and execute
program instructions. The multiplicity of cores can be parallel
cores. The multiplicity of cores can function in parallel. The
multiplicity of cores may include at least 2, 10, 40, 100, 400,
1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, or 10000
cores. The multiplicity of cores may include at most 1000, 2000,
3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000, or 40000 cores.
The multiplicity of cores may include cores of any number between
the afore-mentioned numbers (e.g., from 2 to 40000, from 2 to 400,
from 400 to 4000, from 2000 to 4000, or from 4000 to 10000 cores).
The processor may comprise low latency in data transfer (e.g., from
one core to another). Latency may refer to the time delay between
the cause and the effect of a physical change in the processor
(e.g., a signal). Latency may refer to the time elapsed from the
source (e.g., first core) sending a packet to the destination
(e.g., second core) receiving it (also referred as two-point
latency). One point latency may refer to the time elapsed from the
source (e.g., first core) sending a packet (e.g., signal) to the
destination (e.g., second core) receiving it, and the designation
sending a packet back to the source (e.g., the packet making a
round trip). The latency may be sufficiently low to allow a high
number of floating point operations per second (FLOPS). The number
of FLOPS may be at least about 1 Tera Flops (T-FLOPS), 2 T-FLOPS, 3
T-FLOPS, 5 T-FLOPS, 6 T-FLOPS, 7 T-FLOPS, 8 T-FLOPS, 9 T-FLOPS, or
10 T-FLOPS. The number of flops may be at most about 5 T-FLOPS, 6
T-FLOPS, 7 T-FLOPS, 8 T-FLOPS, 9 T-FLOPS, 10 T-FLOPS, 20 T-FLOPS,
30 T-FLOPS, 50 T-FLOPS, 100 T-FLOPS, 1 P-FLOPS, 2 P-FLOPS, 3
P-FLOPS, 4 P-FLOPS, 5 P-FLOPS, 10 P-FLOPS, 50 P-FLOPS, 100 P-FLOPS,
1 EXA-FLOP, 2 EXA-FLOPS or 10 EXA-FLOPS. The number of FLOPS may be
any value between the afore-mentioned values (e.g., from about 0.1
T-FLOP to about 10 EXA-FLOPS, from about 0.1 T-FLOPS to about 1
T-FLOPS, from about 1 T-FLOPS to about 4 T-FLOPS, from about 4
T-FLOPS to about 10 T-FLOPS, from about 1 T-FLOPS to about 10
T-FLOPS, or from about 10 T-FLOPS to about 30 T-FLOPS, from about
50 T-FLOPS to about 1 EXA-FLOP, or from about 0.1 T-FLOP to about
10 EXA-FLOPS). The FLOPS can be measured according to a benchmark.
The benchmark may be a HPC Challenge Benchmark. The benchmark may
comprise mathematical operations (e.g., equation calculation such
as linear equations), graphical operations (e.g., rendering), or
encryption/decryption benchmark. The benchmark may comprise a High
Performance UNPACK, matrix multiplication (e.g., DGEMM), sustained
memory bandwidth to/from memory (e.g., STREAM), array transposing
rate measurement (e.g., PTRANS), RandomAccess, rate of Fast Fourier
Transform (e.g., on a large one-dimensional vector using the
generalized Cooley-Tukey algorithm), or Communication Bandwidth and
Latency (e.g., MPI-centric performance measurements based on the
effective bandwidth/latency benchmark). UNPACK refers to a software
library for performing numerical linear algebra on a digital
computer. DGEMM refers to double precision general matrix
multiplication. STREAM. PTRANS. MPI refers to Message Passing
Interface.
[0374] The computer system may include hyper-threading technology.
The computer system may include a chip processor with integrated
transform, lighting, triangle setup, triangle clipping, rendering
engine, or any combination thereof. The rendering engine may be
capable of processing at least about 10 million polygons per
second. The rendering engines may be capable of processing at least
about 10 million calculations per second. As an example, the GPU
may include a GPU by Nvidia, ATI Technologies, S3 Graphics,
Advanced Micro Devices (AMD), or Matrox. The processing unit may be
able to process algorithms comprising a matrix or a vector. The
core may comprise a complex instruction set computing core (CISC),
or reduced instruction set computing (RISC).
[0375] The computer system may include an electronic chip that is
reprogrammable (e.g., field programmable gate array (FPGA)). For
example, the FPGA may comprise Tabula, Altera, or Xilinx FPGA. The
electronic chips may comprise one or more programmable logic blocks
(e.g., an array). The logic blocks may compute combinational
functions, logic gates, or any combination thereof. The computer
system may include custom hardware. The custom hardware may
comprise an algorithm.
[0376] The computer system may include configurable computing,
partially reconfigurable computing, reconfigurable computing, or
any combination thereof. The computer system may include a FPGA.
The computer system may include an integrated circuit that performs
the algorithm. For example, the reconfigurable computing system may
comprise FPGA, CPU, GPU, or multi-core microprocessors. The
reconfigurable computing system may comprise a High-Performance
Reconfigurable Computing architecture (HPRC). The partially
reconfigurable computing may include module-based partial
reconfiguration, or difference-based partial reconfiguration.
[0377] The computing system may include an integrated circuit that
performs the algorithm (e.g., control algorithm). The physical unit
(e.g., the cache coherency circuitry within) may have a clock time
of at least about 0.1 Gigabits per second (Gbit/s), 0.5 Gbit/s, 1
Gbit/s, 2 Gbit/s, 5 Gbit/s, 6 Gbit/s, 7 Gbit/s, 8 Gbit/s, 9 Gbit/s,
10 Gbit/s, or 50 Gbit/s. The physical unit may have a clock time of
any value between the afore-mentioned values (e.g., from about 0.1
Gbit/s to about 50 Gbit/s, or from about 5 Gbit/s to about 10
Gbit/s). The physical unit may produce the algorithm output in at
most 0.1 microsecond (.mu.s), 1 .mu.s, 10 .mu.s, 100 .mu.s, or 1
millisecond (ms). The physical unit may produce the algorithm
output in any time between the above-mentioned times (e.g., from
about 0.1 .mu.s, to about 1 ms, from about 0.1 .mu.s, to about 100
.mu.s, or from about 0.1 .mu.s to about 10 .mu.s). In some
instances, the controller may use calculations, real time
measurements, or any combination thereof to regulate the energy
beam(s). In some instances, the real-time measurements (e.g.,
temperature measurements) may provide input at a rate of at least
about 0.1 KHz, 1 KHz, 10 KHz, 100 KHz, 1000 KHz, or 10000 KHz). In
some instances, the real-time measurements may provide input at a
rate between any of the above-mentioned rates (e.g., from about 0.1
KHz to about 10000 KHz, from about 0.1 KHz to about 1000 KHz, or
from about 1000 KHz to about 10000 KHz). The memory bandwidth of
the processing unit may be at least about 1 gigabytes per second
(Gbytes/s), 10 Gbytes/s, 100 Gbytes/s, 200 Gbytes/s, 300 Gbytes/s,
400 Gbytes/s, 500 Gbytes/s, 600 Gbytes/s, 700 Gbytes/s, 800
Gbytes/s, 900 Gbytes/s, or 1000 Gbytes/s. The memory bandwidth of
the processing unit may be at most about 1 gigabytes per second
(Gbytes/s), 10 Gbytes/s, 100 Gbytes/s, 200 Gbytes/s, 300 Gbytes/s,
400 Gbytes/s, 500 Gbytes/s, 600 Gbytes/s, 700 Gbytes/s, 800
Gbytes/s, 900 Gbytes/s, or 1000 Gbytes/s. The memory bandwidth of
the processing unit may any value between the aforementioned values
(e.g., from about 1 Gbytes/s to about 1000 Gbytes/s, from about 100
Gbytes/s to about 500 Gbytes/s, from about 500 Gbytes/s to about
1000 Gbytes/s, or from about 200 Gbytes/s to about 400
Gbytes/s).
[0378] Aspects of the systems, apparatuses, and/or methods provided
herein, such as the computer system, can be embodied in
programming. Various aspects of the technology may be thought of as
"product," "object," or "articles of manufacture" typically in the
form of machine (or processor) executable code and/or associated
data that is carried on or embodied in a type of machine-readable
medium. Machine-executable code can be stored on an electronic
storage unit, such memory (e.g., read-only memory, random-access
memory, flash memory) or a hard disk. The storage may comprise
non-volatile storage media. "Storage" type media can include any or
all of the tangible memory of the computers, processors or the
like, or associated modules thereof, such as various semiconductor
memories, tape drives, disk drives, external drives, and the like,
which may provide non-transitory storage at any time for the
software programming.
[0379] The memory may comprise a random-access memory (RAM),
dynamic random-access memory (DRAM), static random-access memory
(SRAM), synchronous dynamic random-access memory (SDRAM),
ferroelectric random-access memory (FRAM), read only memory (ROM),
programmable read only memory (PROM), erasable programmable read
only memory (EPROM), electrically erasable programmable read only
memory (EEPROM), a flash memory, or any combination thereof. The
flash memory may comprise a negative-AND (NAND) or NOR logic gates.
The storage may include a hard disk (e.g., a magnetic disk, an
optical disk, a magneto-optic disk, a solid-state disk, etc.), a
compact disc (CD), a digital versatile disc (DVD), a floppy disk, a
cartridge, a magnetic tape, and/or another type of
computer-readable medium, along with a corresponding drive.
[0380] All or portions of the software may at times be communicated
through the Internet or various other telecommunication networks.
Such communications, for example, may enable loading of the
software from one computer or processor into another, for example,
from a management server or host computer into the computer
platform of an application server. Thus, another type of media that
may bear the software elements includes optical, electrical, and
electromagnetic waves, such as used across physical interfaces
between local devices, through wired and optical landline networks
and over various air-links. The physical elements that carry such
waves, such as wired or wireless links, optical links, or the like,
also may be considered as media bearing the software. As used
herein, unless restricted to non-transitory, tangible "storage"
media, terms such as computer or machine "readable medium" refer to
any medium that participates in providing instructions to a
processor for execution.
[0381] Hence, a machine-readable medium, such as
computer-executable code, may take many forms, including but not
limited to, a tangible storage medium, a carrier wave medium, or
physical transmission medium. Non-volatile storage media include,
for example, optical or magnetic disks, such as any of the storage
devices in any computer(s) or the like, such as may be used to
implement the databases, etc. shown in the drawings. Volatile
storage media include dynamic memory, such as main memory of such a
computer platform. Tangible transmission media include coaxial
cables, wire (e.g., copper wire), and/or fiber optics, including
the wires that comprise a bus within a computer system.
Carrier-wave transmission media may take the form of electric or
electromagnetic signals, or acoustic or light waves such as those
generated during radio frequency (RF) and infrared (IR) data
communications. Common forms of computer-readable media therefore
include for example: a floppy disk, a flexible disk, hard disk,
magnetic tape, any other magnetic medium, a CD-ROM, DVD or DVD-ROM,
any other optical medium, punch cards paper tape, any other
physical storage medium with patterns of holes, a RAM, a ROM, a
PROM and EPROM, a FLASH-EPROM, any other memory chip or cartridge,
a carrier wave transporting data or instructions, cables or links
transporting such a carrier wave, or any other medium from which a
computer may read programming code and/or data. The memory and/or
storage may comprise a storing device external to and/or removable
from device, such as a Universal Serial Bus (USB) memory stick, or
a hard disk. Many of these forms of computer readable media may be
involved in carrying one or more sequences of one or more
instructions to a processor for execution.
[0382] The computer system can include or be in communication with
an electronic display that comprises a user interface (UI) for
providing, for example, a model design or graphical representation
of a 3D object to be printed. Examples of UI's include, without
limitation, a graphical user interface (GUI) and web-based user
interface. The computer system can monitor and/or control various
aspects of the 3D printing system. The control may be manual and/or
programmed. The control may rely on feedback mechanisms that have
been pre-programmed. The feedback mechanisms may rely on input from
sensors (described herein) that are connected to the control unit
(e.g., control system or control mechanism e.g., computer). The
computer system may store historical data concerning various
aspects of the operation of the 3D printing system. The historical
data may be retrieved at predetermined times and/or at a whim. The
historical data may be accessed by an operator and/or by a user.
The historical and/or operative data may be provided in an output
unit such as a display unit. The output unit (e.g., monitor) may
output various parameters of the 3D printing system (as described
herein) in real time or in a delayed time. The output unit may
output the current 3D printed object, the ordered 3D printed
object, or both. The output unit may output the printing progress
of the 3D printed object. The output unit may output at least one
of the total time, time remaining, and time expanded on printing
the 3D object. The output unit may output (e.g., display, voice,
and/or print) the status of sensors, their reading, and/or time for
their calibration or maintenance. The output unit may output the
type of material(s) used and various characteristics of the
material(s) such as temperature and flowability of the
pre-transformed material. The output unit may output the amount of
oxygen, water, and pressure in the printing chamber (e.g., the
chamber where the 3D object is being printed). The computer may
generate a report comprising various parameters of the 3D printing
system, method, and or objects at predetermined time(s), on a
request (e.g., from an operator), and/or at a whim. The output unit
may comprise a screen, printer, or speaker. The control system may
provide a report. The report may comprise any items recited as
optionally output by the output unit.
[0383] The system and/or apparatus described herein (e.g.,
controller) and/or any of their components may comprise an output
and/or an input device. The input device may comprise a keyboard,
touch pad, or microphone. The output device may be a sensory output
device. The output device may include a visual, tactile, or audio
device. The audio device may include a loudspeaker. The visual
output device may include a screen and/or a printed hard copy
(e.g., paper). The output device may include a printer. The input
device may include a camera, a microphone, a keyboard, or a touch
screen. The system and/or apparatus described herein (e.g.,
controller) and/or any of their components may comprise Bluetooth
technology. The system and/or apparatus described herein (e.g.,
controller) and/or any of their components may comprise a
communication port. The communication port may be a serial port or
a parallel port. The communication port may be a Universal Serial
Bus port (i.e., USB). The system and/or apparatus described herein
(e.g., controller) and/or any of their components may comprise USB
ports. The USB can be micro or mini USB. The USB port may relate to
device classes comprising 00h, 01h, 02h, 03h, 05h, 06h, 07h, 08h,
09h, 0Ah, 0Bh, 0Dh, 0Eh, 0Fh, 10h, 11h, DCh, E0h, EFh, FEh, or FFh.
The system and/or apparatus described herein (e.g., controller)
and/or any of their components may comprise a plug and/or a socket
(e.g., electrical, AC power, DC power). The system and/or apparatus
described herein (e.g., controller) and/or any of their components
may comprise an adapter (e.g., AC and/or DC power adapter). The
system and/or apparatus described herein (e.g., controller) and/or
any of their components may comprise a power connector. The power
connector can be an electrical power connector. The power connector
may comprise a magnetically coupled (e.g., attached) power
connector. The power connector can be a dock connector. The
connector can be a data and power connector. The connector may
comprise pins. The connector may comprise at least 10, 15, 18, 20,
22, 24, 26, 28, 30, 40, 42, 45, 50, 55, 80, or 100 pins.
[0384] The systems, methods, and/or apparatuses disclosed herein
may comprise receiving a request for a 3D object (e.g., from a
customer). The request can include a model (e.g., CAD) of the
desired 3D object. Alternatively, or additionally, a model of the
desired 3D object may be generated. The model may be used to
generate 3D printing instructions. The 3D printing instructions may
exclude the 3D model. The 3D printing instructions may be based on
the 3D model. The 3D printing instructions may take the 3D model
into account. The 3D printing instructions may be based on
simulations. The 3D printing instructions may use the 3D model. The
3D printing instructions may comprise using an algorithm (e.g.,
embedded in a software) that takes into account the 3D model.
EXAMPLES
[0385] The following are illustrative and non-limiting examples of
methods of the present disclosure.
Example 1
[0386] In a 28 cm diameter by 30 cm height container at ambient
temperature, Inconel 718 powder of average particle size 35 .mu.m
was deposited to form a powder bed. The container was disposed in
an enclosure to separate the powder bed from the ambient
environment. The enclosure was purged with Argon gas for 30
minutes. Two rectangular targets having dimensions of 15 mm by 12
mm were formed from the Inconel 718 powder. An 800 W fiber laser
beam irradiating through an optical window was used to perform a
sequence of irradiations on a first one of the targets, the
sequence including irradiation times of 0.5, 1, 2, 4, 8, and 16
seconds. In between each irradiation of the first target of the
sequence, two irradiations of the second target were performed, the
two irradiations having nominal spot sizes at a surface of the
second target of 75-100 .mu.m, and 500 .mu.m, respectively. Each
irradiation had a duration of 5 ms. An InGaAs detector, comprising
optical filters limiting detected radiation to a wavelength band of
1400-1700 nanometers, was used to detect each irradiation of the
rectangular target during the irradiation duration. A detector
signal was generated that was plotted as a function of the nominal
spot size (e.g., as in FIG. 39A).
[0387] While preferred embodiments of the present invention have
been shown, and described herein, it will be obvious to those
skilled in the art that such embodiments are provided by way of
example only. It is not intended that the invention be limited by
the specific examples provided within the specification. While the
invention has been described with reference to the afore-mentioned
specification, the descriptions and illustrations of the
embodiments herein are not meant to be construed in a limiting
sense. Numerous variations, changes, and substitutions will now
occur to those skilled in the art without departing from the
invention. Furthermore, it shall be understood that all aspects of
the invention are not limited to the specific depictions,
configurations, or relative proportions set forth herein which
depend upon a variety of conditions and variables. It should be
understood that various alternatives to the embodiments of the
invention described herein may be employed in practicing the
invention. It is therefore contemplated that the invention shall
also cover any such alternatives, modifications, variations, or
equivalents. It is intended that the following claims define the
scope of the invention and that methods and structures within the
scope of these claims and their equivalents be covered thereby.
* * * * *