U.S. patent application number 15/182456 was filed with the patent office on 2017-12-14 for thermal control for additive manufacturing.
This patent application is currently assigned to Hamilton Sundstrand Corporation. The applicant listed for this patent is Eric Karlen. Invention is credited to Eric Karlen.
Application Number | 20170355019 15/182456 |
Document ID | / |
Family ID | 60573547 |
Filed Date | 2017-12-14 |
United States Patent
Application |
20170355019 |
Kind Code |
A1 |
Karlen; Eric |
December 14, 2017 |
THERMAL CONTROL FOR ADDITIVE MANUFACTURING
Abstract
An additive manufacturing system for building a product includes
a base plate for mounting the product thereon, and at least one
heating element shaped to at least partially conform to the product
and configured to apply heat to at least a portion of the product
as the product is additively manufactured to reduce thermal
gradients in the product.
Inventors: |
Karlen; Eric; (Rockford,
IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Karlen; Eric |
Rockford |
IL |
US |
|
|
Assignee: |
Hamilton Sundstrand
Corporation
Charlotte
NC
|
Family ID: |
60573547 |
Appl. No.: |
15/182456 |
Filed: |
June 14, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B29C 64/295 20170801;
B22F 2003/1056 20130101; B22F 3/1055 20130101; B33Y 30/00 20141201;
Y02P 10/295 20151101; B33Y 10/00 20141201; Y02P 10/25 20151101;
B22F 2999/00 20130101; B22F 2999/00 20130101; B22F 3/1055 20130101;
B22F 2202/07 20130101; B22F 2999/00 20130101; B22F 3/1055 20130101;
B22F 2203/03 20130101; B22F 2203/11 20130101 |
International
Class: |
B22F 3/105 20060101
B22F003/105; B33Y 10/00 20060101 B33Y010/00; B33Y 30/00 20060101
B33Y030/00 |
Claims
1. An additive manufacturing system for building a product,
comprising: a base plate for mounting the product upon; and at
least one heating element shaped to at least partially conform to
the product and configured to apply heat to at least a portion of
the product as the product is additively manufactured to reduce
thermal gradients in the product.
2. The system of claim 1, wherein the base plate is configured to
be heated.
3. The system of claim 1, wherein the heating element includes an
electric coil.
4. The system of claim 1, wherein the heating element is conformal
to an outer shape of the product.
5. The system of claim 1, further comprising a thermal imaging
device positioned to view the product within the heating element
for thermal monitoring of the product as it is additively
manufactured.
6. The system of claim 5, further comprising a control unit
operatively connected to the thermal imaging device and the heating
element to control the heating element as a function of feedback
from the thermal imaging device to reduce thermal gradients in the
product.
7. The system of claim 1, further comprising an energy applicator
positioned to apply energy within the heating element for
layer-wise powder fusion.
8. A method for additively manufacturing a product, comprising:
additively manufacturing a product on a base plate and within a
heating element; and applying heat to a portion of the product
during additive manufacturing to reduce thermal gradients in the
product, wherein heating the product occurs within a heating
element configured to at least partially conform to the
product.
9. The method of claim 8, wherein additive manufacturing the
product includes depositing powder within the heating element.
10. The method of claim 9, further comprising applying energy from
an energy applicator to the powder within the heating element to
sinter the powder within the heating element.
11. The method of claim 8, further comprising controlling the
heating element as a function of feedback from a thermal imaging
device to reduce thermal gradients in the product.
12. The method of claim 8, further comprising heating the base
plate that the product is mounted on.
Description
BACKGROUND
1. Field
[0001] The present disclosure relates to additive manufacturing,
more specifically to thermal control for additive
manufacturing.
2. Description of Related Art
[0002] All welding and joining processes create non-uniform
residual stress distributions as a result of the intense heat
input. Residual stresses due to thermal expansion and contraction
of the solidified material can cause distortion of an additively
manufactured part. Distortion can occur during the additive
manufacturing process and/or during the heat treatment cycles after
building. The residual stress in the part can relax during heat
treatment causing significant distortion to occur.
[0003] As such, thermal management is required to prevent thermal
contraction/shrinkage from occurring during the process. Thermal
contraction can lead to layer misregistration where the layer being
fused does not dimensionally correlate to the previous layer.
Traditional additive manufacturing processes and systems do not
control such non-uniform residual stresses.
[0004] 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 thermal control for
additive manufacturing. The present disclosure provides a solution
for this need.
SUMMARY
[0005] An additive manufacturing system for building a product
includes a base plate for mounting the product upon, and at least
one heating element shaped to at least partially conform to the
product and configured to apply heat to at least a portion of the
product as the product is additively manufactured to reduce thermal
gradients in the product (e.g., due to non-uniform heating/cooling
of the product during sintering).
[0006] The heating element can be conformal to an outer shape of
the product. The heating element can include an electric coil or
any other suitable heating element.
[0007] In certain embodiments, the base plate can be configured to
be heated. The system can include a thermal imaging device (e.g.,
an IR camera) positioned to view the product within the heating
element for thermal monitoring of the product as it is additively
manufactured.
[0008] The system can include a control unit operatively connected
to the thermal imaging device and the heating element to control
the heating element as a function of feedback from the thermal
imaging device to prevent non-uniform heating of the product. In
certain embodiments, the system can include an energy applicator
positioned to apply energy within the heating element for
layer-wise powder fusion.
[0009] A method for additively manufacturing a product includes
additively manufacturing a product on a base plate and within a
heating element, and applying heat to a portion of the product
during additive manufacturing to reduce thermal gradients in the
product, wherein heating the product occurs within a heating
element configured to at least partially conform to the product. In
certain embodiments, additive manufacturing the product can include
depositing powder within the heating element.
[0010] The method can further include applying energy from an
energy applicator to the powder within the heating element to
sinter the powder within the heating element. In certain
embodiments, the method can include controlling the heating element
as a function of feedback from a thermal imaging device to prevent
non-uniform heating of the product. The method can include heating
the base plate.
[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 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, embodiments thereof will be described in detail
herein below with reference to certain figures, wherein:
[0013] FIG. 1 is a perspective exploded view of an embodiment of a
system in accordance with this disclosure.
DETAILED DESCRIPTION
[0014] 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.
The systems and methods described herein can be used to reduce
defects due to non-uniform heating/cooling during additive
manufacturing.
[0015] Referring to FIG. 1, an additive manufacturing system 100
for building a product 102 includes a base plate 101 for mounting
the product 102 upon and at least one heating element 103 shaped to
at least partially conform to the product 102 (e.g., completely
around, adjacent one or more lateral sides or portions thereof) and
configured to apply heat to at least a portion of the product 102
as the product 102 is additively manufactured to reduce thermal
gradients within the product 102. Any suitable number of heating
elements 103 can be utilized. It should be understood that the
heating element 103 may not actually increase temperatures within
the product 102, but instead slow a rate of cooling of the product
102. In so doing, the heating element 103 may reduce thermal
gradients in the product 102 (e.g., due to non-uniform
heating/cooling of the product 102 during the additive
manufacturing process)
[0016] In certain embodiments, the heating element 103 can be
conformal to the outer shape of the product 102 such that it
surrounds the product 102, for example. The heating element can
include an electric coil (e.g., an induction coil) or any other
suitable heating element that extends along a build axis.
[0017] In certain embodiments, the base plate 101 can be configured
to be heated (e.g., via one or more heating elements disposed
within the base plate 101). For example, the base plate 101 can
include a resistive heating arrangement with heating elements
attached to the bottom of the base plate 101 or embedded within the
base plate 101 (e.g., using additive manufacturing techniques).
Certain embodiments of the base plate 101 can have integral heat
pipes that define heating channels for a heating fluid to be pumped
through to stabilize temperature. In certain embodiments, a part
may be used as the base for deposition to create features or shapes
instead of manufacturing the entire part through additive
manufacturing methods.
[0018] The system 100 can include a thermal imaging device 105
(e.g., an IR camera) positioned to view within the heating element
103 for thermal monitoring of the product 102 as it is additively
manufactured. In certain embodiments, the system 100 can include an
energy applicator 109 (e.g., a laser) positioned to apply energy
within the heating element 103 for layer-wise powder fusion. While
embodiments can be used with directed energy deposition or blown
powder deposition processes (e.g., for metals), it is contemplated
that molten material deposition (e.g., for thermoplastics) can also
be utilized within the heating element.
[0019] As shown, the system 100 can include a control unit 107
operatively connected to the thermal imaging device 105, the
heating element 103, the base plate 101, and/or the energy
applicator 109 to control the heating element 103 and/or the energy
applicator 109 and/or the base plate 101 as a function of feedback
from the thermal imaging device 105 to prevent non-uniform heating
and/or reduce thermal gradients within the product 102. For
example, if a local hot spot is detected, the control unit 107 can
cause the heating element 103 to apply more heat to the product 102
being built.
[0020] In accordance with at least one aspect of this disclosure, a
method for additively manufacturing a product 102 includes
additively manufacturing a product 102 on a base plate 101 and
within a heating element 103. The method also includes applying
heat to the product 102 during additive manufacturing to prevent
non-uniform heating of the product 102.
[0021] In certain embodiments, additive manufacturing the product
102 can include depositing powder within the heating element 103.
For example, powder can be dropped or sprayed (e.g., via a cold
spray process) in any suitable manner. The heating element 103 can
be progressively submerged in powder, or powder can be deposited
only within the confines of the heating element 103 such as on the
product 102 only, for example. It is contemplated that any other
suitable method to place powder within the heating element 103 is
contemplated herein.
[0022] The method can further include applying energy from an
energy applicator 109 to the powder within the heating element 103
to sinter the powder within the heating element 103. In certain
embodiments, the method can include controlling the heating element
103 as a function of feedback from a thermal imaging device 105 to
prevent non-uniform heating of the product 102. The method can also
include heating the base plate 101.
[0023] As described above, embodiments include a heating element
that can be nearly conformal to the finished part. The heating
element 103 extends in the z-axis (i.e., the axis in which the part
is being built). Multiple heating elements 103 could be used as
needed to optimize the thermal management throughout the production
of a part. Also, the power settings for the heating element 103
could be varied as needed using pre-established parameters to
create a smaller or larger induced magnetic field. The base plate
101 can also be utilized as the starting surface for manufacturing
of the part. To maintain a uniform temperature, the base plate 101
can be heated.
[0024] Embodiments as described above allow for improved distortion
control, consistent registration between layers, minimized
temperature differences within part, reduced risk of solidification
cracking or issues with solidification (e.g., during a laser fusion
additive manufacturing process).
[0025] The methods and systems of the present disclosure, as
described above and shown in the drawings, provide for additive
manufacturing systems with superior properties as described above.
While the apparatus and methods of the subject disclosure have been
shown and described with reference to 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.
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