U.S. patent application number 17/729649 was filed with the patent office on 2022-08-11 for powder evacuation systems.
This patent application is currently assigned to Hamilton Sundstrand Corporation. The applicant listed for this patent is Hamilton Sundstrand Corporation. Invention is credited to Lawrence Binek, David W. Morganson.
Application Number | 20220250325 17/729649 |
Document ID | / |
Family ID | |
Filed Date | 2022-08-11 |
United States Patent
Application |
20220250325 |
Kind Code |
A1 |
Morganson; David W. ; et
al. |
August 11, 2022 |
POWDER EVACUATION SYSTEMS
Abstract
An additive manufacturing system includes a build chamber
housing a recoater and a sintering laser. A build plate is moveable
within the build chamber to accommodate growth of a part formed by
the recoater and the sintering laser. At least one powder
evacuation cavity at least partially surrounds a build volume of
the build chamber. The build volume of the build chamber is defined
between the build plate and the recoater and is configured to hold
a sintered part and unsintered powder during an additive
manufacturing build in the build chamber.
Inventors: |
Morganson; David W.;
(Marlborough, CT) ; Binek; Lawrence; (Glastonbury,
CT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hamilton Sundstrand Corporation |
Charlotte |
NC |
US |
|
|
Assignee: |
Hamilton Sundstrand
Corporation
Charlotte
NC
|
Appl. No.: |
17/729649 |
Filed: |
April 26, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16166911 |
Oct 22, 2018 |
11318676 |
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17729649 |
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International
Class: |
B29C 64/35 20060101
B29C064/35; B33Y 10/00 20060101 B33Y010/00; B33Y 30/00 20060101
B33Y030/00; B33Y 40/00 20060101 B33Y040/00; B33Y 50/02 20060101
B33Y050/02; B29C 64/364 20060101 B29C064/364; B29C 64/153 20060101
B29C064/153; B29C 64/393 20060101 B29C064/393 |
Claims
1. A method of managing feedstock powder comprising: forming a part
from feedstock powder in a powder bed within a build volume;
evacuating unsintered feedstock powder from the build volume,
wherein the unsintered feedstock powder flows into at least one
evacuation cavity at least partially surrounding the build
volume.
2. The method as recited in claim 1, wherein evacuating unsintered
feedstock powder includes opening at least one gating valve to
place the at least one powder evacuation cavity in fluid
communication with the build volume.
3. The method as recited in claim 1, wherein evacuating unsintered
feedstock powder includes vibrating the build volume sub- or
ultrasonically to facilitate flow of powder from the build volume
into the at least one powder evacuation cavity.
4. The method as recited in claim 3, wherein at least one of:
vibrating includes vibrating in a direction lateral to build
direction in the build volume; and/or vibrating includes vibrating
the build volume sub- or ultrasonically.
5. The method as recited in claim 1, further comprising dosing
feedstock powder into the build volume from a dosing chamber,
wherein the dosing chamber and the at least one powder evacuation
cavity are distinct and separate from one another.
6. The method as recited in claim 5, further comprising recycling
feedstock powder from the at least one evacuation cavity to the
dosing chamber through a closed loop recycling system for re-use of
the unsintered feedstock powder.
7. The method as recited in claim 6, wherein recycling the
feedstock powder includes maintaining the closed loop recycling
system under a controlled atmosphere.
8. The method as recited in claim 1, further comprising
automatically controlling the at least one evacuation cavity to
automatically initiate powder removal from the build volume after
completing a build.
9. The method as recited in claim 1, wherein evacuating unsintered
feedstock powder from the build volume is performed after forming
the part
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a divisional of U.S. patent application Ser. No.
16/166,911 filed Oct. 22, 2018 the content of which is incorporated
by reference herein in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0002] The present disclosure relates to additive manufacturing,
and more particularly to management of stock powder such as used in
laser sintering for additive manufacturing.
2. Description of Related Art
[0003] Powder evacuation and removal at the end of an additive
manufacturing build is a highly manual operation in conventional
additive manufacturing systems. This powder removal is
non-standardized and the quality of the procedure is a function of
the operator's diligence.
[0004] The conventional techniques have been considered
satisfactory for their intended purpose. However, there is an ever
present need for improved feedstock powder management. This
disclosure provides a solution for this need.
SUMMARY OF THE INVENTION
[0005] An additive manufacturing system includes a build chamber
housing a recoater and a sintering laser. A build plate is moveable
within the build chamber to accommodate growth of a part formed by
the recoater and the sintering laser. At least one powder
evacuation cavity at least partially surrounds a build volume of
the build chamber. The build volume of the build chamber is defined
between the build plate and the recoater and is configured to hold
a sintered part and unsintered powder during an additive
manufacturing build in the build chamber.
[0006] The at least one powder evacuation cavity can be selectively
in fluid communication with the build volume through at least one
gating valve. An oscillation transducer can be operatively
connected to the build volume to vibrate the build volume sub- or
ultrasonically to facilitate flow of powder from the build volume
into the at least one powder evacuation cavity. The oscillation
transducer can be configured to vibrate in a direction lateral to
the build direction in the build volume. The at least one
evacuation cavity can include a single evacuation cavity that
surrounds the build volume peripherally.
[0007] A dosing chamber can be operatively connected to supply
feedstock powder to the build volume. The dosing chamber and the at
least one powder evacuation cavity can be distinct and separate
from one another. The at least one powder evacuation cavity and the
dosing chamber can be operatively connected to one another by a
recycling system configured to recycle used feedstock powder from
the at least one powder evacuation cavity through a recycling
process for re-use in the dosing chamber. The build chamber, the at
least one evacuation cavity, the recycling system, and the dosing
chamber can all be part of a controlled atmosphere closed loop.
[0008] A controller can be operatively connected to the build
plate, the recoater, and the sintering laser to control additive
manufacture of a part in the build volume. The controller can be
operatively connected to the at least one evacuation cavity to
automatically initiate powder removal from the build volume after
completing a build.
[0009] A method of managing feedstock powder includes forming a
part from feedstock powder in a powder bed within a build volume.
The method includes evacuating unsintered feedstock powder from the
build volume (e.g. after forming the part), wherein the unsintered
feedstock powder flows into at least one evacuation cavity at least
partially surrounding the build volume.
[0010] Evacuating unsintered feedstock powder can include opening
at least one gating valve to place the at least one powder
evacuation cavity in fluid communication with the build volume.
Evacuating unsintered feedstock powder can include vibrating the
build volume sub- or ultrasonically to facilitate flow of powder
from the build volume into the at least one powder evacuation
cavity. Vibrating the build volume can include vibrating the build
volume in a direction lateral to build direction in the build
volume. The method can include dosing feedstock powder into the
build volume from a dosing chamber, wherein the dosing chamber and
the at least one powder evacuation cavity are distinct and separate
from one another. The method can include recycling feedstock powder
from the at least one evacuation cavity to the dosing chamber
through a closed loop recycling system for re-use of the unsintered
feedstock powder. Recycling the feedstock powder can include
maintaining the closed loop recycling system under a controlled
atmosphere. The method can include automatically controlling the at
least one evacuation cavity to automatically initiate powder
removal from the build volume after completing a build.
[0011] 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 of the
preferred embodiments taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] 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, preferred embodiments thereof will be described in
detail herein below with reference to certain figures, wherein:
[0013] FIG. 1 is a schematic side elevation view of an exemplary
embodiment of an additive manufacturing system constructed in
accordance with the present disclosure, showing a part being
sintered from feedstock powder in the build volume;
[0014] FIG. 2 is a schematic side elevation view of the system of
FIG. 1, showing feedstock powder evacuated through the evacuation
cavity, recycled, and returned to the dosing chamber for use in
another build; and
[0015] FIG. 3 is a schematic plan view of the build volume and
evacuation cavity of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] 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, a partial view of an exemplary
embodiment of an additive manufacturing system in accordance with
the disclosure is shown in FIG. 1 and is designated generally by
reference character 100. Other embodiments of systems in accordance
with the disclosure, or aspects thereof, are provided in FIGS. 2-3,
as will be described. The systems and methods described herein can
be used to improve handling of feedstock powder, and particularly
to improve automation of removal of feedstock powder from a build
chamber after a build.
[0017] The system 100 includes a build chamber 102 housing a
recoater 104 and a sintering laser 106. A build plate 108 is
moveable within the build chamber 102 to accommodate growth of a
part 110 formed by the recoater 104 and the sintering laser 106. At
each stage during the build, the recoater 104 deposits a thin layer
of feedstock powder in the build volume 112, and the sintering
laser selectively sinters a portion of the thin layer of feedstock
powder 114 onto the part 110. As each new layer is sintered, the
part 110 grows in a build direction D, i.e., vertically as oriented
in FIGS. 1-2, as the unsintered feedstock powder 114 accumulates
around the part 110 in the build volume 112. The build volume 112
of the build chamber 112 is defined between, i.e. vertically
between as oriented in FIG. 1, the build plate 108 and the recoater
104 and is configured to hold a sintered part 110 and unsintered
feedstock powder 114 during an additive manufacturing build in the
build chamber 102.
[0018] At least one powder evacuation cavity 116 at least partially
surrounds the build volume 112 of the build chamber 102. As shown
in FIG. 3, there is one evacuation cavity 112 that completely
surrounds the build volume 112 peripherally, however those skilled
in the art will readily appreciate that any suitable number of
evacuation cavities can be arranged at least partially around the
periphery of the build volume 112 without departing from the scope
of this disclosure.
[0019] The powder evacuation cavity 116 is selectively in fluid
communication with the build volume 112 through a plurality of
gating valves 120. An oscillation transducer 122 is operatively
connected to the build volume 112 to vibrate the build volume 112
sub- or ultrasonically to facilitate flow of unsintered feedstock
powder 114 from the build volume 112, through the gating valves 120
into the at least one powder evacuation cavity 120. The oscillation
transducer can be incorporated in the actuator for moving the build
plate 108 in the build direction D, for example, and is configured
to vibrate in a direction d that is lateral to the build direction
D in the build volume 112.
[0020] A dosing chamber 124 is operatively connected to supply
feedstock powder 114 to the build volume 112. The dosing chamber
124 and the powder evacuation cavity 116 are distinct and separate
chambers from one another. The powder evacuation cavity 112 and the
dosing chamber 124 are operatively connected to one another by a
recycling system 126 configured to recycle used feedstock powder
114 from the powder evacuation cavity 116 through a recycling
process, e.g., including filtering and straining, for re-use in the
dosing chamber 124 for building a subsequent part 110. The build
chamber 102, the evacuation cavity 116, the recycling system 126,
and the dosing chamber 124 can all be part of a controlled
atmosphere closed loop so that the feedstock powder 114 can be
isolated from the ambient atmosphere. FIG. 1 shows the feedstock
powder 114 that is unsintered in the build chamber 112 during a
build of the part 110, and FIG. 2 shows the recycled feedstock
powder 114 returned to the dosing chamber 124 after evacuation from
the build volume 112 through the powder evacuation cavity 116 for
use in a subsequent build.
[0021] A controller 128 is operatively connected to the build plate
108, the recoater 104, and the sintering laser 106 to control
additive manufacture of a part 110 in the build volume 112. The
controller 128 is operatively connected to the evacuation cavity
112 to automatically initiate powder removal, e.g., by opening the
gating valves 120, from the build volume 112 after completing a
build. It is also contemplated that the build plate 108 can provide
the gating, e.g., wherein the gating valves 120 are simply ports
connecting between the build volume 112 and the evacuation cavity
110 that are positioned so that the controller 128 can cause
over-traveling of the build plate 108 below the ports to open the
pathway from the build volume 112 to the evacuation cavity 110.
[0022] A method of managing feedstock powder includes forming a
part, e.g., part 110, from feedstock powder, e.g., feedstock powder
114, in a powder bed within a build volume, e.g., build volume 112.
The method includes evacuating unsintered feedstock powder from the
build volume after forming the part, wherein the unsintered
feedstock powder flows into at least one evacuation cavity, e.g.,
evacuation cavity 116, at least partially surrounding the build
volume.
[0023] Evacuating unsintered feedstock powder can include opening
at least one gating valve, e.g., gating valves 120, to place the at
least one powder evacuation cavity in fluid communication with the
build volume. The method can include dosing feedstock powder into
the build volume from a dosing chamber, e.g., dosing chamber 124,
wherein the dosing chamber and the at least one powder evacuation
cavity are distinct and separate from one another. The method can
include recycling feedstock powder from the at least one evacuation
cavity to the dosing chamber through a closed loop recycling
system, e.g., recycling system 126, for re-use of the unsintered
feedstock powder. Recycling the feedstock powder can optionally
include maintaining the closed loop recycling system under a
controlled atmosphere. The method can include automatically
controlling the at least one evacuation cavity to automatically
initiate powder removal from the build volume after completing a
build.
[0024] A powder evacuation system as disclosed herein can remove
feedstock powder from the build chamber by agitating the
un-sintered powder feedstock using sub- to ultrasonic frequencies.
Once the part build has completed, the oscillation transducer
engages causing the static feedstock powder in the build volume to
flow into one or more evacuation cavities that are located around
the build plate platform in its most retracted state, i.e. its
lowest position as oriented in FIGS. 1 and 2. The feedstock powder
that has been evacuated in this manner can be collected and
reprocessed in existing closed-loop powder circuits.
[0025] This process removes considerable lead time in post
processing after a build. Powder removal in conventional systems is
a highly manual operation which is not standardized or quality
controlled. By having a reliable automated process for powder
extraction, such as disclosed herein, post processing efforts are
reduced and better controlled. Operators can be spared from
exposure to free powder and the powder that has been evacuated from
the build can be easily reintroduced into the feedstock supply
without risking contamination.
[0026] The methods and systems of the present disclosure, as
described above and shown in the drawings, provide for feedstock
powder management with superior properties including automatic
removal of unsintered feedstock powder, and facilitated recycling
of the feedstock powder. While the apparatus and methods of the
subject disclosure have been shown and described with reference to
preferred embodiments, those skilled in the art will readily
appreciate that changes and/or modifications may be made thereto
without departing from the scope of the subject disclosure.
* * * * *