U.S. patent application number 15/237921 was filed with the patent office on 2016-12-08 for hybrid additive manufacturing methods using hybrid additively manufactured features for hybrid components.
This patent application is currently assigned to General Electric Company. The applicant listed for this patent is General Electric Company. Invention is credited to Srikanth Chandrudu Kottilingam, Benjamin Paul Lacy, David Edward Schick.
Application Number | 20160354843 15/237921 |
Document ID | / |
Family ID | 55023853 |
Filed Date | 2016-12-08 |
United States Patent
Application |
20160354843 |
Kind Code |
A1 |
Lacy; Benjamin Paul ; et
al. |
December 8, 2016 |
HYBRID ADDITIVE MANUFACTURING METHODS USING HYBRID ADDITIVELY
MANUFACTURED FEATURES FOR HYBRID COMPONENTS
Abstract
A hybrid additive manufacturing method comprises building an
additive structure on a pre-sintered preform base, wherein building
the additive structure comprises iteratively fusing together a
plurality of layers of additive material with at least a first
layer of additive material joined to the pre-sintered preform base,
and wherein the pre-sintered preform base comprises an initial
shape. The hybrid additive manufacturing method further comprises
modifying the initial shape of the pre-sintered preform base
comprising the additive structure into a modified shape comprising
the additive structure, and, joining the pre-sintered preform base
in its modified shape to a component.
Inventors: |
Lacy; Benjamin Paul; (Greer,
SC) ; Kottilingam; Srikanth Chandrudu; (Simpsonville,
SC) ; Schick; David Edward; (Greenville, SC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
General Electric Company |
Schenectady |
NY |
US |
|
|
Assignee: |
General Electric Company
Schenectady
NY
|
Family ID: |
55023853 |
Appl. No.: |
15/237921 |
Filed: |
August 16, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14574557 |
Dec 18, 2014 |
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15237921 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B23K 26/0006 20130101;
B23K 10/027 20130101; B33Y 80/00 20141201; B22F 7/08 20130101; B23K
2103/18 20180801; C22C 19/07 20130101; B22F 2005/005 20130101; B22F
2301/15 20130101; B23K 2103/05 20180801; B23K 2103/08 20180801;
B22F 5/009 20130101; B22F 7/062 20130101; B33Y 10/00 20141201; C22C
19/057 20130101; Y02P 10/25 20151101; B23K 2103/26 20180801; B23K
26/342 20151001; F01L 9/02 20130101; B22F 3/1055 20130101; B22F
5/04 20130101; B23K 2103/10 20180801; F01D 9/02 20130101; B22F 3/24
20130101; B22F 7/06 20130101; C22C 19/058 20130101; B23K 2103/14
20180801 |
International
Class: |
B22F 7/08 20060101
B22F007/08; B33Y 80/00 20060101 B33Y080/00; C22C 19/05 20060101
C22C019/05; B22F 3/105 20060101 B22F003/105; B23K 10/02 20060101
B23K010/02; B33Y 10/00 20060101 B33Y010/00; B23K 26/342 20060101
B23K026/342 |
Goverment Interests
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH &
DEVELOPMENT
[0001] This invention was partially made with government support
under government contract No. DE-FC26-05NT42643 awarded by the
Department of Energy. The government has certain rights to this
invention.
Claims
1. (canceled)
2. (canceled)
3. (canceled)
4. (canceled)
5. (canceled)
6. (canceled)
7. (canceled)
8. (canceled)
9. (canceled)
10. (canceled)
11. A hybrid additively manufactured feature comprising: a
pre-sintered preform base comprising a modified shape different
than an initial shape; and, an additive structure joined to the
pre-sintered preform base, wherein the additive structure was built
on the pre-sintered preform while in its initial shape by fusing
together a plurality of layers of additive material with at least a
first layer of additive material joined to the pre-sintered preform
base while in its initial shape.
12. The hybrid additively manufactured feature of claim 11, wherein
the modified shape comprises a non-planar surface.
13. The hybrid additively manufactured feature of claim 12, wherein
the initial shape comprised a planar surface.
14. The hybrid additively manufactured feature of claim 12, wherein
the non-planar surface comprises a curved surface.
15. The hybrid additively manufactured feature of claim 11, wherein
the additive structure comprises one or more cooling feature
extensions.
16. A hybrid component comprising: a pre-sintered preform base
joined to a component, the pre-sintered preform base comprising a
modified shape different than an initial shape; and, an additive
structure joined to the pre-sintered preform base, wherein the
additive structure was built on the pre-sintered preform base while
in its initial shape by fusing together a plurality of layers of
additive material with at least a first layer of additive material
joined to the pre-sintered preform base while in its initial
shape.
17. The hybrid component of claim 16, wherein the modified shape
comprises a non-planar surface.
18. The hybrid component of claim 16, wherein the component
comprises a turbine component.
19. The hybrid component of claim 18, wherein the turbine component
comprises a nozzle, and wherein the pre-sintered preform base is
joined to an interior surface of the nozzle.
20. The hybrid component of claim 16, wherein the additive
structure comprises one or more cooling feature extensions.
Description
BACKGROUND OF THE INVENTION
[0002] The subject matter disclosed herein relates to additive
manufacturing and, more specifically, to hybrid additive
manufacturing methods using hybrid additively manufactured features
for hybrid components.
[0003] Additive manufacturing processes generally involve the
buildup of one or more materials to make a net or near net shape
object, in contrast to subtractive manufacturing methods. Though
"additive manufacturing" is an industry standard term (ASTM F2792),
additive manufacturing encompasses various manufacturing and
prototyping techniques known under a variety of names, including
freeform fabrication, 3D printing, rapid prototyping/tooling, etc.
Additive manufacturing techniques are capable of fabricating
complex components from a wide variety of materials. Generally, a
freestanding object can be fabricated from a computer aided design
(CAD) model. One exemplary additive manufacturing process uses an
energy beam, for example, an electron beam or electromagnetic
radiation such as a laser beam, to sinter or melt a powder
material, creating a solid three-dimensional object in which
particles of the powder material are bonded together. Different
material systems, for example, engineering plastics, thermoplastic
elastomers, metals, and ceramics may be used. Laser sintering or
melting is one exemplary additive manufacturing process for rapid
fabrication of functional prototypes and tools. Applications can
include patterns for investment casting, metal molds for injection
molding and die casting, molds and cores for sand casting, and
relatively complex components themselves. Fabrication of prototype
objects to facilitate communication and testing of concepts during
the design cycle are other potential uses of additive manufacturing
processes. Likewise, components comprising more complex designs,
such as those with internal passages that are less susceptible to
other manufacturing techniques including casting or forging, may be
fabricated using additive manufacturing methods.
[0004] Laser sintering can refer to producing three-dimensional
(3D) objects by using a laser beam to sinter or melt a fine powder.
Specifically, sintering can entail fusing (agglomerating) particles
of a powder at a temperature below the melting point of the powder
material, whereas melting can entail fully melting particles of a
powder to form a solid homogeneous mass. The physical processes
associated with laser sintering or laser melting include heat
transfer to a powder material and then either sintering or melting
the powder material. Although the laser sintering and melting
processes can be applied to a broad range of powder materials, the
scientific and technical aspects of the production route, for
example, sintering or melting rate, and the effects of processing
parameters on the microstructural evolution during the layer
manufacturing process can lead to a variety of production
considerations. For example, this method of fabrication may be
accompanied by multiple modes of heat, mass and momentum transfer,
and chemical reactions.
[0005] Laser sintering/melting techniques can specifically entail
projecting a laser beam onto a controlled amount of powder material
(e.g., a powder metal material) on a substrate (e.g., build plate)
so as to form a layer of fused particles or molten material
thereon. By moving the laser beam relative to the substrate along a
predetermined path, often referred to as a scan pattern, the layer
can be defined in two dimensions on the substrate (e.g., the "x"
and "y" directions), the height or thickness of the layer (e.g.,
the "z" direction) being determined in part by the laser beam and
powder material parameters. Scan patterns can comprise parallel
scan lines, also referred to as scan vectors or hatch lines, and
the distance between two adjacent scan lines may be referred to as
hatch spacing, which may be less than the diameter of the laser
beam so as to achieve sufficient overlap to ensure complete
sintering or melting of the powder material. Repeating the movement
of the laser along all or part of a scan pattern may facilitate
further layers of material to be deposited and then sintered or
melted, thereby fabricating a three-dimensional object.
[0006] For example, laser sintering and melting techniques can
include using continuous wave (CW) lasers, such as Nd: YAG lasers
operating at or about 1064 nm. Such embodiments may facilitate
relatively high material deposition rates particularly suited for
repair applications or where a subsequent machining operation is
acceptable in order to achieve a finished object. Other laser
sintering and melting techniques may alternatively or additionally
be utilized such as, for example, pulsed lasers, different types of
lasers, different power/wavelength parameters, different powder
materials or various scan patterns to facilitate the production of
one or more three-dimensional objects. However, the base shape of
the three-dimensional object may be limited to relatively planar
(e.g., flat) structures. Such shapes may not match up with
non-planar (e.g., curved) components that the three-dimensional
object may eventually be joined to.
[0007] Accordingly, alternative hybrid additive manufacturing
methods using hybrid additively manufactured features for hybrid
components would be welcome in the art.
BRIEF DESCRIPTION OF THE INVENTION
[0008] In one embodiment, a hybrid additive manufacturing method is
disclosed. The hybrid additive manufacturing method comprises
building an additive structure on a pre-sintered preform base,
wherein building the additive structure comprises iteratively
fusing together a plurality of layers of additive material with at
least a first layer of additive material joined to the pre-sintered
preform base, and wherein the pre-sintered preform base comprises
an initial shape. The hybrid additive manufacturing method further
comprises modifying the initial shape of the pre-sintered preform
base comprising the additive structure into a modified shape
comprising the additive structure, and, joining the pre-sintered
preform base in its modified shape to a component.
[0009] In another embodiment, a hybrid additively manufactured
feature is disclosed. The hybrid additively manufactured feature
comprises a pre-sintered preform base comprising a modified shape
different than an initial shape, and, an additive structure joined
to the pre-sintered preform base, wherein the additive structure
was built on the pre-sintered preform while in its initial shape by
fusing together a plurality of layers of additive material with at
least a first layer of additive material joined to the pre-sintered
preform base while in its initial shape.
[0010] In yet another embodiment, a hybrid component is disclosed.
The hybrid component comprises a pre-sintered preform base joined
to a component. The pre-sintered preform base comprises a modified
shape different than an initial shape. The hybrid component further
comprises an additive structure joined to the pre-sintered preform
base, wherein the additive structure was built on the pre-sintered
preform base while in its initial shape by fusing together a
plurality of layers of additive material with at least a first
layer of additive material joined to the pre-sintered preform base
while in its initial shape.
[0011] These and additional features provided by the embodiments
discussed herein will be more fully understood in view of the
following detailed description, in conjunction with the
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The embodiments set forth in the drawings are illustrative
and exemplary in nature and not intended to limit the inventions
defined by the claims. The following detailed description of the
illustrative embodiments can be understood when read in conjunction
with the following drawings, where like structure is indicated with
like reference numerals and in which:
[0013] FIG. 1 illustrates a hybrid additive manufacturing method
according to one or more embodiments shown or described herein;
[0014] FIG. 2 is an additive structure on a pre-sintered preform
base comprising an initial shape according to one or more
embodiments shown or described herein;
[0015] FIG. 3 is an additive structure on a pre-sintered preform
base after modifying its shape according to one or more embodiments
shown or described herein;
[0016] FIG. 4 is an exploded view of a hybrid additively
manufactured feature being joined to a component according to one
or more embodiments shown or described herein;
[0017] FIG. 5 is a schematic view of a hybrid component according
to one or more embodiments shown or described herein; and,
[0018] FIG. 6 is a perspective view of a hybrid component according
to one or more embodiments shown or described herein.
DETAILED DESCRIPTION OF THE INVENTION
[0019] One or more specific embodiments of the present invention
will be described below. In an effort to provide a concise
description of these embodiments, all features of an actual
implementation may not be described in the specification. It should
be appreciated that in the development of any such actual
implementation, as in any engineering or design project, numerous
implementation-specific decisions must be made to achieve the
developers' specific goals, such as compliance with system-related
and business-related constraints, which may vary from one
implementation to another. Moreover, it should be appreciated that
such a development effort might be complex and time consuming, but
would nevertheless be a routine undertaking of design, fabrication,
and manufacture for those of ordinary skill having the benefit of
this disclosure.
[0020] When introducing elements of various embodiments of the
present invention, the articles "a," "an," "the," and "said" are
intended to mean that there are one or more of the elements. The
terms "comprising," "including," and "having" are intended to be
inclusive and mean that there may be additional elements other than
the listed elements.
[0021] Referring now to FIG. 1, a hybrid additive manufacturing
method 100 is illustrated. Referring additionally to FIGS. 2-6, the
hybrid additive manufacturing method 100 can generally comprise
making a hybrid additively manufactured feature 5 comprising an
additive structure 20 built on a pre-sintered preform base 10,
which in turn can be modified into a modified shape 12. The hybrid
additively manufactured feature 5 with its modified shape 12 can
subsequently be joined to a component 30 (e.g., turbine component)
to form a hybrid component 1. By modifying the pre-sintered preform
base 10 into a modified shape 12 (e.g., curved shape) with the
additive structure 20 built thereon, the hybrid additively
manufactured feature 5 can be joined to a curved or otherwise
non-planar surface 31 of a component 30. The hybrid additive
manufacturing method 100 can thereby facilitate the joining of
additively manufactured structures 20 (e.g., cooling features) to
curved or complex components 30 (e.g., turbine components).
[0022] Specifically, the hybrid additive manufacturing method 100
can first comprise building an additive structure 20 on a
pre-sintered preform base 10 in step 110, wherein building the
additive structure 20 comprises iteratively fusing together a
plurality of layers of additive material with at least a first
layer of additive material joined to the pre-sintered preform base
10, and wherein the pre-sintered preform base 10 comprises an
initial shape 11.
[0023] The pre-sintered preform base 10 can generally comprise a
mixture of particles comprising a base alloy and a second alloy
that have been sintered together at a temperature below their
melting points to form an agglomerate and somewhat porous mass.
Suitable particle size ranges for the powder particles include 150
mesh, or even 325 mesh or smaller to promote rapid sintering of the
particles and minimize porosity in the pre-sintered preform 120 to
about 10 volume percent or less. In some embodiments, the density
of the pre-sintered preform 120 has a density of 90% or better. In
even some embodiments, the pre-sintered preform 120 has a density
of 95% or better.
[0024] The base alloy of the pre-sintered preform base 10 can
comprise any composition such as one similar to the substrate
(e.g., the turbine bucket shroud 108) to promote common physical
properties between the pre-sintered preform 120 and the substrate.
For example, in some embodiments, the base alloy (of the
pre-sintered preform 120) and the substrate (e.g., the turbine
bucket shroud 108) share a common composition (i.e., they are the
same type of material). Depending, for example, on the desired
application and/or build shape, in some embodiments, the base alloy
can comprise nickel-based superalloys such as MAR-M-247, Rene N4,
Rene N5, Rene 108, GTD-111.RTM., GTD-222.RTM., GTD-444.RTM., and
IN-738 or cobalt-based superalloys such as MAR-M-509 or FSX-414 as
discussed above. In some embodiments, the properties for the base
alloy include chemical and metallurgical compatibility with the
substrate (e.g., the turbine bucket shroud 108), such as high
fatigue strength, low tendency for cracking, oxidation resistance
and/or machinability.
[0025] In some embodiments, the base alloy may comprise a melting
point of within about 25.degree. C. of the melting temperature of
the component 30 and/or the additive structure 20 it will be joined
to. In some embodiments, the base alloy may comprise a
compositional range of, by weight, about 2.5 to 11% cobalt, 7 to 9%
chromium, 3.5 to 11% tungsten, 4.5 to 8% aluminum, 2.5 to 6%
tantalum, 0.02 to 1.2% titanium, 0.1 to 1.8% hafnium, 0.1 to 0.8%
molybdenum, 0.01 to 0.17% carbon, up to 0.08% zirconium, up to 0.60
silicon, up to 2.0 rhenium, the balance being nickel and incidental
impurities. In even some embodiments, the base alloy may comprise a
compositional range of, by weight, about 9 to 11% cobalt, 8 to 8.8%
chromium, 9.5 to 10.5% tungsten, 5.3 to 5.7% aluminum, 2.8 to 2.3%
tantalum, 0.9 to 1.2% titanium, 1.2 to 1.6% hafnium, 0.5 to 0.8%
molybdenum, 0.13 to 0.17% carbon, 0.03 to 0.08% zirconium, the
balance nickel and incidental impurities.
[0026] In even some embodiments, the base alloy may comprise
MAR-M-247. Such a base alloy may comprise a compositional range of,
by weight, about 59% nickel, about 10% tungsten, about 8.25%
chromium, about 5.5% aluminum, about 3% tantalum, about 1%
titanium, about 0.7% molybdenum, about 0.5% iron and about 0.015
percent boron. In some embodiments, the base alloy may comprise
MAR-M-509. Such a base alloy may comprise a compositional range of,
by weight, about 59% cobalt, about 23.5% chromium, about 10%
nickel, about 7% tungsten, about 3.5% tantalum, about 0.6% carbon,
about 0.5% zirconium and about 0.2% titanium.
[0027] It should be appreciated that while specific materials and
compositions have been listed herein for the composition of the
base alloy of the pre-sintered preform base 10, these listed
materials and compositions are exemplary only and non-limiting and
other alloys may alternatively or additionally be used.
Furthermore, it should be appreciated that the particular
composition of the base alloy for the pre-sintered preform base 10
may depend on the composition of the component 10 (e.g., a turbine
nozzle) and/or the additive material used in the additive structure
20.
[0028] As discussed above, the pre-sintered preform base 10 further
comprises a second alloy. The second alloy may also have a
composition similar to the substrate (e.g., the turbine bucket
shroud 108) but further contain a melting point depressant to
promote sintering of the base alloy and the second alloy particles
and enable bonding of the pre-sintered preform base 10 to the
component 30 at temperatures below the melting point of the
component. For example, in some embodiments the melting point
depressant can comprise boron and/or silicon.
[0029] In some embodiments, the second alloy may comprise a melting
point of about 25.degree. C. to about 50.degree. C. below the grain
growth or incipient melting temperature of the component 30. Such
embodiments may better preserve the desired microstructure of the
component 30 during the heating process. In some embodiments, the
second alloy may comprise a compositional range of, by weight,
about 9 to 10% cobalt, 11 to 16% chromium, 3 to 4% aluminum, 2.25
to 2.75% tantalum, 1.5 to 3.0% boron, up to 5% silicon, up to 1.0%
yttrium, the balance nickel and incidental impurities. For example,
in some embodiments the second alloy may comprise commercially
available Amdry DF4B nickel brazing alloy.
[0030] In even some embodiments, the second alloy may comprise MAR
M-509B commercially available from WESGO Ceramics. Such a second
alloy may comprise a compositional range of, by weight, about 22.9
to 24.75% chromium, 9.0 to 11.0% nickel, 6.5 to 7.6% tungsten, 3.0
to 4.0 percent tantalum, 2.6 to 3.16% boron, 0.55 to 0.65% carbon,
0.3 to about 0.6% zirconium, 0.15 to 0.3% titanium, up to 1.3%
iron, up to 0.4% silicon, up to 0.1% manganese, up to 0.02% sulfur
and the balance cobalt.
[0031] It should also be appreciated that while specific materials
and compositions have been listed herein for the composition of the
second alloy of the pre-sintered preform base 10, these listed
materials and compositions are exemplary only and non-limiting and
other alloys may alternatively or additionally be used.
Furthermore, it should be appreciated that the particular
composition of the second alloy for the pre-sintered preform base
10 may depend on the composition of the component 30 and/or the
additive material of the additive structure 20.
[0032] The pre-sintered preform base 10 can comprise any relative
amounts of the base alloy and the second alloy that are sufficient
to provide enough melting point depressant to ensure wetting and
bonding (e.g., diffusion/brazing bonding) of the particles of the
base alloy and the second alloy to each other and to the surface 31
of the component 30. For example, in some embodiments the second
alloy can comprise at least about 10 weight percent of the
pre-sintered preform base 10. In some embodiments the second alloy
can comprise no more than 70 weight percent of the pre-sintered
preform base 10.
[0033] In even some embodiments, the base alloy may comprise
commercially available MAR-M-247 and the second alloy may comprise
commercially available DF4B. In some embodiments, the base alloy
may comprise commercially available MAR-M-247 and the second alloy
may comprise commercially available AMS4782. In some embodiments,
the base alloy may comprise commercially available MAR-M-509 and
the second alloy may comprise MAR-M-509B. In such embodiments, the
ratio of base alloy to the second alloy may comprise from about 80%
-85% base alloy to about 20% -15% second alloy. Alternatively,
ratios of from about 90% -60% base alloy to about 10% -40% second
alloy may be used.
[0034] Such embodiments may provide a sufficient amount of melting
point depressant while limiting potential reduction of the
mechanical and environmental properties of the subsequent heating.
Furthermore, in these embodiments, the base alloy can comprise the
remainder of the pre-sintered preform base 10 (e.g., between about
30 weight percent and about 70 weight percent of the pre-sintered
preform). In even some embodiments, the particles of the base alloy
can comprise about 40 weight percent to about 70 weight percent of
the pre-sintered preform base 10 with the balance of the
composition comprising particles of the second alloy. It should be
appreciated that while specific relative ranges of the base alloy
and the second alloy have been presented herein, these ranges are
exemplary only and non-limiting and any other relative compositions
may also be realized such that a sufficient amount of melting point
depressant is provided as discussed above.
[0035] The pre-sintered preform base 10 can comprise any initial
shape 11 comprising any suitable geometry for the building of the
additive structure 20 thereon using an additive manufacturing
process as should be appreciated herein. For example, in some
embodiments, the initial shape 11 can comprise a planar (i.e.,
flat) surface such as illustrated in FIG. 2.
[0036] As stated above, an additive structure 20 is built on the
pre-sintered preform base in step 110. The additive structure 20
can be built by iteratively fusing together a plurality of layers
of additive material, wherein at least a first layer of the
material is joined to the pre-sintered preform base 10, in a
process also referred to as additive manufacturing.
[0037] As used herein, "iteratively fusing together a plurality of
layers of additive material" and "additive manufacturing" refers to
any process which results in a three-dimensional object and
includes a step of sequentially forming the shape of the object one
layer at a time. Additive manufacturing processes include, but are
not limited to, powder bed additive manufacturing and powder fed
additive manufacturing processes such as by using lasers or
electron beams for iteratively fusing together the powder material.
Additive manufacturing processes can include, for example, three
dimensional printing, laser-net-shape manufacturing, direct metal
laser sintering (DMLS), direct metal laser melting (DMLM),
selective laser sintering (SLS), plasma transferred arc, freeform
fabrication, and the like. One exemplary type of additive
manufacturing process uses a laser beam to fuse (e.g., sinter or
melt) a powder material (e.g., using a powder bed process).
Additive manufacturing processes can employ powder materials or
wire as a raw material. Moreover additive manufacturing processes
can generally relate to a rapid way to manufacture an object
(article, component, part, product, etc.) where a plurality of thin
unit layers are sequentially formed to produce the object. For
example, layers of a powder material may be provided (e.g., laid
down) and irradiated with an energy beam (e.g., laser beam) so that
the particles of the powder material within each layer are
sequentially fused (e.g., sintered or melted) to solidify the
layer.
[0038] The additive structure 20 built on the pre-sintered preform
base 10 can comprise a variety of different additive materials. For
example, the additive material can comprise any material that may
be fused (e.g., sintered) by a laser beam or other energy source.
In some embodiments, the additive material can comprise a powder
metal. Such powder metals can include, by non-limiting example,
cobalt-chrome alloys, aluminum and its alloys, titanium and its
alloys, nickel and its alloys, stainless steels, tantalum, niobium
or combinations thereof. In other embodiments, the additive
material may comprise a powder ceramic or a powder plastic. In some
embodiments, the additive material may be selected based at least
in part on the component 30 and/or the pre-sintered preform base 10
such as by matching or substantially matching all or some of those
materials.
[0039] The additive structure 20 built on the pre-sintered preform
base 10 in step 110 can comprise a variety of shapes and
configurations. For example, in some embodiments, the additive
structure 20 can comprise a plurality of pins, plates, or the like.
Such embodiments may provide for cooling features such as for
turbine components by drawing heat away from the external surface.
In some embodiments, the additive structure may comprise other
cooling features such as one or more parts of fluid flow passages.
In some embodiments, the additive structure 20 may comprise an part
of a larger structure that can be combined with other adjacent
additive structures 20 to form a larger feature. While specific
embodiments of additive structures 20 have been discussed and
illustrated herein, it should be appreciated that these are only
intended to be non-limiting examples and additional or alternative
embodiments may also be realized.
[0040] With continued reference to FIG. 1 and the exemplary
embodiments in FIGS. 2-6, the hybrid additive manufacturing method
100 can further comprise modifying the initial shape in step 120 of
the pre-sintered preform base 10 comprising the additive structure
20 (such as by applying a force 50) to modify it into a modified
shape 12. In some embodiments, the pre-sintered preform base 10 may
have its shape modified simply via gravity. In some embodiments,
gravity may be used in combination with elevated temperatures to
modify the shape in step 120. In some embodiments, any other
additional or alternative force 50 may be applied through any
suitable means such as, for example, via one or more vices, clamps,
presses, plates or the like.
[0041] Moreover, modifying the initial shape in step 120 can
comprise modifying the pre-sintered preform base 10 into any
modified shape 12 that is different than the initial shape 11. In
some embodiments, the modified shape 12 may comprise a non-planar
surface. For example, the non-planar surface may comprise a curved
shape such as illustrated in FIG. 3. In some embodiments, the
modified shape 12 may comprise one or more bends, warps,
oscillations or other non-planar deviations such as when compared
to a substantially planar initial shape 11. The pre-sintered
preform base 10 can be modified into any modified shape 12 that
substantially matches the surface 31 of the component 30 so that it
can be disposed against the surface 31 prior to joining. The
resulting hybrid additively manufactured feature 5 comprising the
pre-sintered preform base 10 with a modified shape 12 and the
additive structure 20 may be more susceptible to joining with a
component 30 with a non-planar surface than if the additive
structure 20 simply comprised a flat surface and was to be joined
directly.
[0042] The hybrid additive manufacturing method 100 can further
comprise joining the pre-sintered preform base 10 in its modified
shape 12 to a component 30 in step 130.
[0043] The component 30 can comprise any type of component that has
a surface 31 for which the pre-sintered preform base 10 can be
joined thereto, including when the surface 31 comprises a curved or
otherwise non-planar shape. For example, in some embodiments, the
component 30 may comprise a turbine component such as a nozzle as
illustrated in FIG. 6. Such components 30 can comprise any metal or
alloy substrate suitable for a braze application. Specifically, the
present disclosure is generally applicable to any metal or alloy
component 30 that may be brazed, particularly those components that
operate within environments characterized by relatively high
stresses and/or temperatures. Notable examples of such components
30 include turbine components such as turbine buckets (blades),
nozzles (vanes), shrouds, and other hot gas path and combustion
components of a turbine, such as an industrial gas or steam turbine
or an aircraft gas turbine engine.
[0044] For example, in some embodiments, the component 30 may
comprise a nickel-, cobalt, or iron-based superalloys. For example,
the component 30 may comprise nickel-based superalloys such as Rene
N4,Rene N5, Rene 108, GTD-111.RTM., GTD-222.RTM., GTD-444.RTM.,
IN-738 and MarM 247 or cobalt-based superalloys such as FSX-414.
The component 30 may be formed as an equiaxed, directionally
solidified (DS), or single crystal (SX) casting to withstand
relatively higher temperatures and stresses such as may be present
within a gas or steam turbine.
[0045] The surface 31 of the component 30 for which the
pre-sintered preform base 10 is to be joined to (as part of the
larger hybrid additively manufactured feature 5), can comprise any
surface 31 for which the additive structure 20 should be adjacent.
The surface 31 can comprise any shaped surface such as a curved
surface. Curved surfaces can include one or more curves, twists,
oscillations or any other planar or non-planar surfaces, or
combinations thereof. For example, the curved surface may comprise
a surface of a three dimensionally shaped airfoil. In some
particular embodiments, the surface 31 may comprise a mildly
non-planar surface such that a single pre-sintered preform base 10
can be modified (e.g., forced) to a shape to match the surface
31.
[0046] In some specific embodiments, including where the additive
structure 20 comprises one or more cooling feature extensions
(i.e., pins, walls, or the like that extend away from pre-sintered
preform base 10 and can draw away heat), the surface 31 of the
component 30 to be joined with the pre-sintered preform base 10 may
comprise an interior surface of a turbine component 30. In some
such embodiments, the surface 31 may comprise an interior surface
of a nozzle or other airfoil. While specific surfaces 31, locations
of surfaces 31, shapes of surfaces 31, and components 30 comprising
the surfaces 31 have been presented herein, it should be
appreciated that these are intended to be non-limiting examples
only; a plurality of other surfaces 31 and components 30 may
additionally or alternatively be realized in the scope of this
disclosure.
[0047] The heat applied in step 130 to join the pre-sintered
preform base 10 to the surface 31 of the component 30 can comprise
any suitable temperature, heat source, iterations, ramp rate, hold
time, cycle and any other relevant parameters to join (e.g., braze,
bond or the like) the materials together, such as by at least
partially melting the second alloy pre-sintered preform base 10
such that it subsequently solidifies and joins the base alloy of
the pre-sintered preform base 10 with the component 30.
[0048] For example, in some embodiments, to facilitate the joining
process, a non-oxidizing atmosphere within the furnace and a method
of inducing a pressure on pre-sintered preform base 10 and/or the
component 30 may be provided. To obtain a non-oxidizing atmosphere,
a vacuum may be formed in the furnace with a pressure of
approximately 0.067 Pascal (Pa) (0.5 milliTorr) or less. The
furnace may be heated to approximately 650.degree. C. (1200.degree.
F.) at a rate of approximately 14.degree. C./minute (25.degree.
F./minute). Once approximately 650.degree. C. (1200.degree. F.) is
attained, this temperature may be maintained for approximately 30
minutes. Then the furnace temperature may be increased to
approximately 980.degree. C. (1800.degree. F.) at a rate of
approximately 14.degree. C./minute (25.degree. F./minute). Once
approximately 980.degree. C. (1800.degree. F.) is attained, this
temperature may be maintained for approximately 30 minutes. Then
the furnace temperature may be increased to approximately 1204 to
1218.degree. C. (2200 to 2225.degree. F.) at a rate of
approximately 19.degree. C./minute (35.degree. F./minute). Once
approximately 1204 to 1218.degree. C. (2200 to 2225.degree. F.) is
attained, this temperature may be maintained for approximately 20
minutes. In even some embodiments, a cooling cycle sub-step may
include a controlled cooling of the brazing furnace with the
pre-sintered preform 120 and the substrate (e.g., turbine bucket
shroud 108) inside to approximately 1120.degree. C. (2050.degree.
F.) and maintaining that temperature for approximately 60 minutes.
Then the furnace may be further cooled to approximately 815.degree.
C. (1500.degree. F.). The furnace may finally be subsequently
cooled to approximately room temperature. While specific
temperatures, times and ramp rates are disclosed herein, it should
be appreciated that these are intended to be exemplary and
non-limiting.
[0049] As a result of joining the pre-sintered preform base 10 in
its modified shape 12 to the surface 31 of the component 30, the
hybrid additively manufactured feature 5 can be joined with the
component 30 to form an overall hybrid component 1 as illustrated
in FIGS. 5 and 6. The hybrid component 1 can comprise the additive
structure 20 joined to a non-planar surface 31 of the component 30
where building said additive structure 20 directly on the surface
may have been limited by access space or the like, or where if said
additive structure 20 was joined to a flat plate, said plate could
not have been joined to the curved component 30. For example, where
other additive manufacturing methods may only have facilitated
building features on a flat surface that could not conform and bond
with non-flat surfaces, the herein disclosed hybrid additive
manufacturing method builds features on ductile pre-sintered
preform so that said pre-sintered preform may conform and bond with
non-flat surfaces.
[0050] The hybrid component 1 may further comprise a variety of
types of components such as one or more of the turbine components
discussed herein. For example, the hybrid component 1 may comprise
a turbine component wherein the additive structure 20 built on the
pre-sintered preform base 20 (and subsequently joined to the
component 30 itself) provides one or more cooling features such as
through cooling pins, walls or the like. Such cooling features may
help to draw heat away from the exterior surface of the component
30 to help maintain said component 30 in a specified operating
temperature range. While specific components and features have been
disclosed herein, it should be appreciated that these embodiments
are intended to be non-limiting examples, and additional or
alternative configurations may also be realized.
[0051] While the invention has been described in detail in
connection with only a limited number of embodiments, it should be
readily understood that the invention is not limited to such
disclosed embodiments. Rather, the invention can be modified to
incorporate any number of variations, alterations, substitutions or
equivalent arrangements not heretofore described, but which are
commensurate with the spirit and scope of the invention.
Additionally, while various embodiments of the invention have been
described, it is to be understood that aspects of the invention may
include only some of the described embodiments. Accordingly, the
invention is not to be seen as limited by the foregoing
description, but is only limited by the scope of the appended
claims.
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