U.S. patent application number 17/325779 was filed with the patent office on 2021-09-02 for splatter shield systems and methods for additive manufacturing.
This patent application is currently assigned to Hamilton Sundstrand Corporation. The applicant listed for this patent is Hamilton Sundstrand Corporation. Invention is credited to Diana Giulietti, Alexander Madinger, Sergey Mironets, Dmitri Novikov.
Application Number | 20210268587 17/325779 |
Document ID | / |
Family ID | 1000005599439 |
Filed Date | 2021-09-02 |
United States Patent
Application |
20210268587 |
Kind Code |
A1 |
Mironets; Sergey ; et
al. |
September 2, 2021 |
SPLATTER SHIELD SYSTEMS AND METHODS FOR ADDITIVE MANUFACTURING
Abstract
A splatter shield system for an additive manufacturing machine
includes one or more splatter shields configured to cover at least
a portion of a build area during energy application such that the
at least one splatter shield is positioned between an energy source
of an additive manufacturing machine and the build area during
energy application. The one or more splatter shields are
transparent to an energy source (e.g., a laser) of the additive
manufacturing system such that energy application occurs through
the splatter shield.
Inventors: |
Mironets; Sergey;
(Charlotte, NC) ; Madinger; Alexander;
(Chesterfield, MO) ; Giulietti; Diana;
(Manchester, CT) ; Novikov; Dmitri; (Avon,
CT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hamilton Sundstrand Corporation |
Charlotte |
NC |
US |
|
|
Assignee: |
Hamilton Sundstrand
Corporation
Charlotte
NC
|
Family ID: |
1000005599439 |
Appl. No.: |
17/325779 |
Filed: |
May 20, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15820236 |
Nov 21, 2017 |
11027336 |
|
|
17325779 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B33Y 30/00 20141201;
B22F 2201/10 20130101; B33Y 50/02 20141201; B23K 26/342 20151001;
B22F 10/10 20210101; B33Y 10/00 20141201; B22F 12/00 20210101; B33Y
40/00 20141201; B29C 64/35 20170801; B29C 64/153 20170801 |
International
Class: |
B22F 12/00 20060101
B22F012/00; B33Y 30/00 20060101 B33Y030/00; B33Y 40/00 20060101
B33Y040/00; B33Y 50/02 20060101 B33Y050/02; B33Y 10/00 20060101
B33Y010/00 |
Claims
1. A method, comprising: placing a splatter shield over a build
area of an additive manufacturing machine between an energy source
and the build area during energy application, wherein the splatter
shield is transparent to the energy source and is positioned to
prevent splatter from energy application.
2. The method, of claim 1, further comprising providing uniformly
flowing inert gas between the splatter shield and the build
area.
3. The method of claim 1, further comprising cleaning the splatter
shield during recoating of the build area.
4. The method of claim 1, further comprising controlling a gap size
between build area and the splatter shield.
5. The method of claim 4, wherein the gap size is controlled to
minimize overall inert gas flow, and/or to direct inert gas flow at
an interface of a laser beam and powder bed, and/or to flush out
particles and/or condensate towards exhaust vents.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 15/820,236, filed Nov. 21, 2017, the entire content of
which is incorporated herein in its entirety.
BACKGROUND
1. Field
[0002] The present disclosure relates to additive manufacturing
systems and methods.
2. Description of Related Art
[0003] During Laser Powder Bed Fusion (LPBF) a shield gas, such as
Argon, is utilized to prevent material from oxidation. However,
"dead zones" exist where material gets partially oxidized,
resulting in inferior mechanical properties, because of non-uniform
gas coverage.
[0004] Also, during manufacturing, an ample amount of metal
particles eject at the laser weld pool, become airborne, and get
deposited back on top of powder bed along with product of metal
evaporation (aka condensate). Chemical composition of the ejected
particles and condensate exhibits much higher level of impurities
than in a virgin powder.
[0005] As a result of powder recoating motion, contaminated powder
gets spread across the entire build area and fused into parts. The
level of contamination increases with powder reuse/recycling.
[0006] Such conventional methods and systems have generally been
considered satisfactory for their intended purpose. However, there
is still a need in the art for improved additive manufacturing
systems and methods. The present disclosure provides a solution for
this need.
SUMMARY
[0007] A splatter shield system for an additive manufacturing
machine includes one or more splatter shields configured to cover
at least a portion of a build area during energy application such
that the at least one splatter shield is positioned between an
energy source of an additive manufacturing machine and the build
area during energy application. The one or more splatter shields
are transparent to an energy source (e.g., a laser) of the additive
manufacturing system such that energy application occurs through
the splatter shield.
[0008] The one or more splatter shields can include a plate shape.
The one or more splatter shields can be connected to and movable
with a recoater system.
[0009] In certain embodiments, the one or more splatter shields can
include two splatter shields, one on each side of the recoater
system. For example, the recoater system can include at least one
of a hopper, a roller recoater, or a knife recoater.
[0010] The one or more splatter shields can be made of at least one
of sapphire, quartz, or transparent polycrystalline ceramic. In
certain embodiments, the energy source can be a laser. Any other
suitable material suitably transparent for any other suitable
energy application (e.g., electron beam) is contemplated
herein.
[0011] The splatter shield can be placed proximate the build area
to form a gas flow channel for an inert gas to uniformly flow over
the build area between the splatter shield and the build area. For
example, the splatter shield can be separated by less than an inch.
The system can include a controller configured to control movement
of the recoater system, wherein the controller is configured to
place the one or more splatter shields over the build area during
energy application.
[0012] The system can include a splatter shield cleaning system
configured to clean the one or more splatter shields. The splatter
shield cleaning system can be configured to clean at least part of
the one or more splatter shields during a recoating process. The
splatter shield cleaning system can include a scraper configured to
scrape an underside of the splatter shield as the shield moves over
the scraper during the recoating process.
[0013] In accordance with at least one aspect of this disclosure, a
method can include placing a splatter shield over a build area of
an additive manufacturing machine between an energy source and the
build area during energy application. The splatter shield is
transparent to the energy source and is positioned to prevent
splatter from energy application.
[0014] The method can include providing uniformly flowing inert gas
between the splatter shield and the build area. The method can
include cleaning the splatter shield during recoating of the build
area.
[0015] The method can include controlling a gap size between build
area and the splatter shield. The gap size is controlled to
minimize overall inert gas flow, and/or to direct inert gas flow at
an interface of a laser beam and powder bed, and/or to flush out
particles and/or condensate towards exhaust vents.
[0016] These and other features of the systems and methods of the
subject disclosure will become more readily apparent to those
skilled in the art from the following detailed description taken in
conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] So that those skilled in the art to which the subject
disclosure appertains will readily understand how to make and use
the devices and methods of the subject disclosure without undue
experimentation, embodiments thereof will be described in detail
herein below with reference to certain figures, wherein:
[0018] FIG. 1 is a perspective view of an embodiment of a system in
accordance with this disclosure, showing the system in a first
position and energy being applied to a build area;
[0019] FIG. 2 is a schematic side view of the embodiment of FIG. 1,
showing a gas flowing between the shield and the build area.
[0020] FIG. 3 is a perspective view and a zoomed view thereof of
the embodiment of FIG. 1 in a recoating process, moving from left
to right to recoat the build area; and
[0021] FIG. 4 is a perspective view of an embodiment of a system in
accordance with this disclosure, showing the system in a second
position and energy being applied to a build area.
DETAILED DESCRIPTION
[0022] Reference will now be made to the drawings wherein like
reference numerals identify similar structural features or aspects
of the subject disclosure. For purposes of explanation and
illustration, and not limitation, an illustrative view of an
embodiment of a system in accordance with the disclosure is shown
in FIG. 1 and is designated generally by reference character 100.
Other embodiments and/or aspects of this disclosure are shown in
FIGS. 2-4. The systems and methods described herein can be used to
enhance environment control and build quality in an additive
manufacturing system, for example, or for any other purpose.
[0023] Referring to FIG. 1, a splatter shield system 100 for an
additive manufacturing machine includes one or more splatter
shields 101 configured to cover at least a portion of a build area
103 (e.g., a powder bed) during energy application (e.g., as shown
in FIG. 1) such that the at least one splatter shield 101 is
positioned between an energy source 105 of an additive
manufacturing machine and the build area 103 during energy
application. The one or more splatter shields 101 are transparent
to an energy source (e.g., a laser) of the additive manufacturing
system such that energy application occurs through the splatter
shield 101.
[0024] The one or more splatter shields 101 can include a plate
shape or any other suitable shape. The one or more splatter shields
101 can be sized to cover the entire build area 103 or any suitable
portion thereof. The one or more splatter shields 101 can be
connected to and movable with a recoater system 107 of the additive
manufacturing machine.
[0025] In certain embodiments, the one or more splatter shields 101
can include two splatter shields 101 as shown, one on each side of
the recoater system 107. For example, the recoater system 107 can
include at least one of a hopper 109, a roller recoater (not
shown), or one or more knife recoaters 111 (e.g., one on each side
of the hopper 109 as shown).
[0026] The one or more splatter shields 101 can be made of at least
one of sapphire, quartz, or transparent polycrystalline ceramic
(e.g., aluminum oxynitride). In certain embodiments, the energy
source 105 can be a laser 113. Any other suitable material (e.g., a
glass or other ceramic) suitably transparent for any other suitable
energy application (e.g., electron beam) is contemplated
herein.
[0027] Referring additionally to FIG. 2, the splatter shield 101
can be placed proximate the build area 103 to form a gas flow
channel 213 for an inert gas 215 (e.g., argon from a gas source
217) to uniformly flow over the build area 103 between the splatter
shield 101 and the build area 103. For example, the splatter shield
101 can be separated by less than an inch from the build area 103.
Any other suitable distance is contemplated herein (a few
millimeters from the powder bed).
[0028] Gas flow can be considered when selecting the distance from
the build area 103 powder bed that the shields 101 are positioned.
In accordance with certain embodiments, gas can be pumped through
the flow channel 213, and can be laminar because of the relatively
small volume. In certain embodiments, the gas flow can act like an
air knife and clean the splatter shield 101 while keeping the build
environment inert and pulling condensate or ejecta out of the build
area 103
[0029] Referring additionally to FIGS. 3 and 4, the system 100 can
include a controller 119 configured to control movement of the
recoater system 107. The controller 119 can also be configured to
place the one or more splatter shields 101 over the build area 103
during energy application (e.g., as shown in FIGS. 1 and 4). The
controller 119 can include any suitable hardware and/or software as
appreciated by those having ordinary skill in the art and can be
configured to execute any suitable method and/or portion thereof in
accordance with this disclosure.
[0030] In certain embodiments, the system 100 can include a
splatter shield cleaning system 121 that is configured to clean the
one or more splatter shields 101. The splatter shield cleaning
system 121 can be configured to clean at least part of the one or
more splatter shields 101 during a recoating process (e.g., as
shown in FIG. 3). The splatter shield cleaning system 121 can
include a scraper 123 (e.g., one or more brushes, blades, or other
suitable device) configured to scrape an underside of the splatter
shield 101 as the shield 101 moves over the scraper 123 during the
recoating process (e.g., as shown in FIG. 3).
[0031] While embodiments show two shields 101, one shield 101 can
be used and the recoater can cycle back and forth each time and
come to rest on the same side each time. As is appreciated by those
having ordinary skill in the art in view of this disclosure, two
shields 101 can allow the other shield 101 to be cleaned while the
other is in use.
[0032] In accordance with at least one aspect of this disclosure, a
method can include placing a splatter shield 101 over a build area
103 of an additive manufacturing machine between an energy source
105 and the build area 103 during energy application. The splatter
shield 101 is transparent to the energy source 105 and is
positioned to prevent splatter from energy application.
[0033] The method can include providing uniformly flowing inert gas
between the splatter shield and the build area. The method can
include cleaning the splatter shield during recoating of the build
area. The method can include activating the energy source 105 when
the shield 101 is positioned over the build area 103.
[0034] The method can include controlling a gap size between build
area 103 and the splatter shield 101. The gap size is controlled to
minimize overall inert gas flow, and/or to direct inert gas flow at
an interface of a laser beam and powder bed, and/or to flush out
particles and/or condensate towards exhaust vents.
[0035] Embodiments utilize transparent splatter shields 101 in
close proximity to a powder bed surface to facilitate a
continuously sealed environment, providing the benefits of uniform
gas flow coverage and preventing ejected particles from getting
redeposited. Using two shields 101 can facilitate dual powder
recoating in both directions for time efficiency. The gap (flow
channel 213) between the shield 101 and the powder bed can be
optimized for allowing adequate, uniform, shield gas flow across
the build area 103. In certain embodiments, the volume under the
shield 101 can be controlled by utilizing vacuum partial
pressure.
[0036] In certain cases, the working surface of the transparent
shields 101 will get progressively contaminated. In certain
embodiments, automatic shield replacement stations can be utilized
to remove the used transparent shields 101 and install clean
shields 101. Alternatively, since only one shield 101 is used per
layer (e.g., either left or right as shown), the unused shields 101
can go through a cleaning process (e.g., using cleaning system 121
or any other suitable system or process). The shield 101 can
provide a sealed environment for the powder bed below it but not
impede the energy source (e.g., laser) that will be passing through
it.
[0037] In certain embodiments, one or more shields 101 can be fixed
to the left and right sides of an existing recoater of a laser
powder bed fusion device. As appreciated by those having ordinary
skill in the art, a recoater spreads a thin layer of powder across
the top of previously selectively-fused layers, building the object
up additively.
[0038] As shown in FIG. 3, the recoater 107 can spread powder from
left to right of the bed shown FIG. 1, and then the left ceramic
plate would be covering the build area (novel). The energy source
can then fuse the deposited powder to a substrate through the
shield 101. When the layer is complete, the recoater would spread
the next layer from right to left, and then the right plate would
cover the build area. This process can be repeated until the part
is complete.
[0039] Using the one or more shields 101 can confine the
redeposited particles to a close proximity to melt pool, for
example, which minimizes the spread of the redeposited particles on
the top of powder bed surface. Some of the ejected particles and/or
condensate may attach to the one or more shields 101 and can be
removed by a cleaning system as disclosed herein.
[0040] Embodiments provide benefits such as creating a "sealed"
build environment and catching ejected particles, for example. The
sealed build environment minimizes the adverse effect of
non-uniform flow of shield gas. Catching ejected particles from the
melt pool (as well as melt pool condensate) and limiting the area
of spread of particles (e.g., to the melt pool) can prevent the
formation of harmful material contamination. This can improve
microstructure/properties of the final part, e.g., high temperature
ductility and notch sensitivity at elevated temperatures, and
provide the opportunity for utilizing additively build aerospace
quality alloys for demanding applications.
[0041] Moreover, a controlled gap between the powder bed and the
one or more shields 101 can be used to minimize the overall inert
gas flow, to direct the inert gas flow at the interface of laser
beam and powder bed, and to effectively flush out the condensate
towards exhaust vents. As a result, a sieved recycled powder will
have fewer ejected particles/contaminants allowing for a greater
number of powder reuses that will minimize the overall cost.
[0042] As will be appreciated by those skilled in the art, aspects
of the present disclosure may be embodied as a system, method or
computer program product. Accordingly, aspects of the present
invention may take the form of an entirely hardware embodiment, an
entirely software embodiment (including firmware, resident
software, micro-code, etc.) or an embodiment combining software and
hardware aspects that may all generally be referred to herein as a
"circuit," "module" or "system." Furthermore, aspects of the
present invention may take the form of a computer program product
embodied in one or more computer readable medium(s) having computer
readable program code embodied thereon.
[0043] Any combination of one or more computer readable medium(s)
may be utilized. The computer readable medium may be a computer
readable signal medium or a computer readable storage medium. A
computer readable storage medium may be, for example, but not
limited to, an electronic, magnetic, optical, electromagnetic,
infrared, or semiconductor system, apparatus, or device, or any
suitable combination of the foregoing. More specific examples (a
non-exhaustive list) of the computer readable storage medium would
include the following: an electrical connection having one or more
wires, a portable computer diskette, a hard disk, a random access
memory (RAM), a read-only memory (ROM), an erasable programmable
read-only memory (EPROM or Flash memory), an optical fiber, a
portable compact disc read-only memory (CD-ROM), an optical storage
device, a magnetic storage device, or any suitable combination of
the foregoing. In the context of this document, a computer readable
storage medium may be any tangible medium that can contain, or
store a program for use by or in connection with an instruction
execution system, apparatus, or device.
[0044] A computer readable signal medium may include a propagated
data signal with computer readable program code embodied therein,
for example, in baseband or as part of a carrier wave. Such a
propagated signal may take any of a variety of forms, including,
but not limited to, electro-magnetic, optical, or any suitable
combination thereof. A computer readable signal medium may be any
computer readable medium that is not a computer readable storage
medium and that can communicate, propagate, or transport a program
for use by or in connection with an instruction execution system,
apparatus, or device.
[0045] Program code embodied on a computer readable medium may be
transmitted using any appropriate medium, including but not limited
to wireless, wireline, optical fiber cable, RF, etc., or any
suitable combination of the foregoing.
[0046] Computer program code for carrying out operations for
aspects of the present invention may be written in any combination
of one or more programming languages, including an object oriented
programming language such as Java, Smalltalk, C++ or the like and
conventional procedural programming languages, such as the "C"
programming language or similar programming languages. The program
code may execute entirely on the user's computer, partly on the
user's computer, as a stand-alone software package, partly on the
user's computer and partly on a remote computer or entirely on the
remote computer or server. In the latter scenario, the remote
computer may be connected to the user's computer through any type
of network, including a local area network (LAN) or a wide area
network (WAN), or the connection may be made to an external
computer (for example, through the Internet using an Internet
Service Provider).
[0047] Aspects of the present invention may be described above with
reference to flowchart illustrations and/or block diagrams of
methods, apparatus (systems) and computer program products
according to embodiments of the invention. It will be understood
that any method and/or portion thereof can be implemented by
computer program instructions. These computer program instructions
may be provided to a processor of a general purpose computer,
special purpose computer, or other programmable data processing
apparatus to produce a machine, such that the instructions, which
execute via the processor of the computer or other programmable
data processing apparatus, create means for implementing the
functions/acts specified in any flowchart and/or block diagram
block or blocks.
[0048] These computer program instructions may also be stored in a
computer readable medium that can direct a computer, other
programmable data processing apparatus, or other devices to
function in a particular manner, such that the instructions stored
in the computer readable medium produce an article of manufacture
including instructions which implement the function/act specified
in the flowchart and/or block diagram block or blocks.
[0049] The computer program instructions may also be loaded onto a
computer, other programmable data processing apparatus, or other
devices to cause a series of operational steps to be performed on
the computer, other programmable apparatus or other devices to
produce a computer implemented process such that the instructions
which execute on the computer or other programmable apparatus
provide processes for implementing the functions/acts specified
herein.
[0050] Any suitable combination(s) of any disclosed embodiments
and/or any suitable portion(s) thereof is contemplated therein as
appreciated by those having ordinary skill in the art.
[0051] The embodiments of the present disclosure, as described
above and shown in the drawings, provide for improvement in the art
to which they pertain. While the subject disclosure includes
reference to certain embodiments, those skilled in the art will
readily appreciate that changes and/or modifications may be made
thereto without departing from the spirit and scope of the subject
disclosure.
* * * * *