U.S. patent application number 16/776231 was filed with the patent office on 2020-09-10 for material deposition to form a sheet structure.
This patent application is currently assigned to United Technologies Corporation. The applicant listed for this patent is United Technologies Corporation. Invention is credited to William J. Brindley, Gary D. Roberge.
Application Number | 20200283910 16/776231 |
Document ID | / |
Family ID | 1000004856387 |
Filed Date | 2020-09-10 |
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United States Patent
Application |
20200283910 |
Kind Code |
A1 |
Roberge; Gary D. ; et
al. |
September 10, 2020 |
MATERIAL DEPOSITION TO FORM A SHEET STRUCTURE
Abstract
A method for forming a sheet structure includes providing a tool
having a formation surface corresponding to a shape of the sheet
structure. The method also includes depositing at least one layer
of material on the formation surface using a cold-spray deposition
technique. The method also includes removing the at least one layer
of material from the formation surface to create the sheet
structure.
Inventors: |
Roberge; Gary D.; (Tolland,
CT) ; Brindley; William J.; (Hebron, CT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
United Technologies Corporation |
Farmington |
CT |
US |
|
|
Assignee: |
United Technologies
Corporation
Farmington
CT
|
Family ID: |
1000004856387 |
Appl. No.: |
16/776231 |
Filed: |
January 29, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15388172 |
Dec 22, 2016 |
10648084 |
|
|
16776231 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C25D 7/00 20130101; F05D
2220/32 20130101; B22F 3/1055 20130101; C23C 24/04 20130101; F05D
2300/10 20130101; B33Y 80/00 20141201; B33Y 10/00 20141201; F01D
25/005 20130101; C23C 24/087 20130101; F05D 2230/31 20130101 |
International
Class: |
C23C 24/04 20060101
C23C024/04; C23C 24/08 20060101 C23C024/08; B33Y 10/00 20060101
B33Y010/00; C25D 7/00 20060101 C25D007/00; F01D 25/00 20060101
F01D025/00 |
Claims
1. A system for forming a sheet structure, comprising: a tool
having a formation surface corresponding to a desired shape of the
sheet structure; a cold-spray gun configured to output a gas
including particles of a material towards the formation surface at
a velocity sufficiently great to cause the particles of the
material to bond together; and a means for separating the material
from the formation surface to create the sheet structure.
2. The system of claim 1, wherein the sheet structure has a
thickness between 5 thousandths of an inch (0.127 millimeters) and
1 inch (25.4 millimeters).
3. The system of claim 1, further comprising a computer configured
to generate a model of the tool.
4. The system of claim 3, further comprising a robot configured to
create the tool based on the model of the tool.
5. The system of claim 4, further comprising an additive
manufacturing machine, wherein the robot is configured to form the
tool using the additive manufacturing machine.
6. The system of claim 1, further comprising an electroplating
machine configured to form an interface coating on the formation
surface via electroplating, such that the particles of the material
contact the interface coating on the formation surface.
7. The system of claim 1, wherein the means for separating the
material from the formation surface includes at least one of a
mechanical tool usable to pry the material from the formation
surface, a releasing agent configured to be applied between the
material and the formation surface to separate the material from
the formation surface, a heater configured to heat the formation
surface to a sufficient temperature to separate the material from
the formation surface, or an acid or other chemically reactive
material configured to be applied to at least one of the material
or the formation surface to etch the material from the formation
surface.
8. A sheet structure for use in an aircraft prepared by a method
comprising the steps of: providing a tool having a formation
surface corresponding to a shape of the sheet structure; depositing
at least one layer of material on the formation surface using a
cold-spray deposition technique; and removing the at least one
layer of material from the formation surface to create the sheet
structure.
9. The sheet structure of claim 8, wherein the sheet structure has
a thickness between 5 thousandths of an inch (0.127 millimeters)
and 1 inch (25.4 millimeters).
10. The sheet structure of claim 8, wherein the steps further
include forming the tool via additive manufacturing, preparing a
model of the tool using a computer, and controlling a robot to form
the tool based on the model of the tool.
11. The sheet structure of claim 8, wherein the steps further
include forming an interface coating on the formation surface via
electroplating, such that depositing the at least one layer of
material includes depositing the at least one layer of material on
the interface coating.
12. The sheet structure of claim 8, wherein removing the at least
one layer of material from the formation surface includes removing
the at least one layer via at least one of applying physical force
to the at least one layer of material in a direction away from the
formation surface, applying a releasing agent between the at least
one layer of material and the formation surface, increasing a
temperature of the tool, or etching the at least one layer of
material from the formation surface using an acid or other
chemically reactive material.
13. The sheet structure of claim 8, wherein the steps further
include removing a portion of the formation surface of the tool to
form a recess in the formation surface, wherein depositing the at
least one layer of material on the formation surface further
includes depositing a greater amount of material in the recess on
the formation surface such that the sheet structure has a greater
thickness at a location corresponding to the recess.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. application Ser.
No. 15/388,172, filed Dec. 22, 2016 for "MATERIAL DEPOSITION TO
FORM A SHEET STRUCTURE", which is hereby incorporated by reference
herein.
FIELD
[0002] The present disclosure is directed to a system and a method
for creation of a sheet structure using a cold-spray deposition
technique.
BACKGROUND
[0003] Gas turbine engines include multiple components, a portion
of which are formed as sheet structures. These sheet structures are
currently hot or cold formed using dies. The dies include a
relatively durable material that is capable of withstanding the
temperature, pressure, and other loads applied to the die via the
selected forming operation. The material used in the dies may be
relatively expensive. Furthermore, formation of dies is a
relatively time-consuming and expensive process. The lead time and
expense of forming the dies increases as the complexity, such as
complex contours and size, of the desired part increases.
SUMMARY
[0004] Disclosed herein is a method for forming a sheet structure.
The method includes providing a tool having a formation surface
corresponding to a shape of the sheet structure. The method also
includes depositing at least one layer of material on the formation
surface using a cold-spray deposition technique. The method also
includes removing the at least one layer of material from the
formation surface to create the sheet structure.
[0005] In any of the foregoing embodiments, the sheet structure has
a thickness between 5 thousandths of an inch (0.127 millimeters)
and 1 inch (25.4 millimeters).
[0006] Any of the foregoing embodiments may also include forming
the tool via additive manufacturing.
[0007] Any of the foregoing embodiments may also include preparing
a model of the tool using a computer, and controlling a robot to
form the tool based on the model of the tool.
[0008] Any of the foregoing embodiments may also include forming an
interface coating on the formation surface via electroplating, such
that depositing the at least one layer of material includes
depositing the at least one layer of material on the interface
coating.
[0009] In any of the foregoing embodiments, removing the at least
one layer of material from the formation surface includes removing
the at least one layer via at least one of applying physical force
to the at least one layer of material in a direction away from the
formation surface, applying a releasing agent between the at least
one layer of material and the formation surface, increasing a
temperature of the tool, or etching the at least one layer of
material from the formation surface using an acid or other
chemically reactive material.
[0010] Any of the foregoing embodiments may also include removing a
portion of the formation surface of the tool to form a recess in
the formation surface, wherein depositing the at least one layer of
material on the formation surface further includes depositing a
greater amount of material in the recess on the formation surface
such that the sheet structure has a greater thickness at a location
corresponding to the recess.
[0011] Also described is a system for forming a sheet structure.
The system includes a tool having a formation surface corresponding
to a desired shape of the sheet structure. The system also includes
a cold-spray gun configured to output a gas including particles of
a material towards the formation surface at a velocity sufficiently
great to cause the particles of the material to bond together. The
system also includes a means for separating the material from the
formation surface to create the sheet structure.
[0012] In any of the foregoing embodiments the sheet structure has
a thickness between 5 thousandths of an inch (0.127 millimeters)
and 1 inch (25.4 millimeters).
[0013] Any of the foregoing embodiments may also include a computer
configured to generate a model of the tool.
[0014] Any of the foregoing embodiments may also include a robot
configured to create the tool based on the model of the tool.
[0015] Any of the foregoing embodiments may also include an
additive manufacturing machine, wherein the robot is configured to
form the tool using the additive manufacturing machine.
[0016] Any of the foregoing embodiments may also include an
electroplating machine configured to form an interface coating on
the formation surface via electroplating, such that the particles
of the material contact the interface coating on the formation
surface.
[0017] In any of the foregoing embodiments, the means for
separating the material from the formation surface includes at
least one of a mechanical tool usable to pry the material from the
formation surface, a releasing agent configured to be applied
between the material and the formation surface to separate the
material from the formation surface, a heater configured to heat
the formation surface to a sufficient temperature to separate the
material from the formation surface, or an acid or other chemically
reactive material configured to be applied to at least one of the
material or the formation surface to etch the material from the
formation surface.
[0018] Also described is a sheet structure for use in an aircraft.
The sheet structure is prepared by a method that includes providing
a tool having a formation surface corresponding to a shape of the
sheet structure. The method also includes depositing at least one
layer of material on the formation surface using a cold-spray
deposition technique. The method also includes removing the at
least one layer of material from the formation surface to create
the sheet structure.
[0019] In any of the foregoing embodiments, the sheet structure has
a thickness between 5 thousandths of an inch (0.127 millimeters)
and 1 inch (25.4 millimeters).
[0020] In any of the foregoing embodiments, the steps further
include forming the tool via additive manufacturing, preparing a
model of the tool using a computer, and controlling a robot to form
the tool based on the model of the tool.
[0021] In any of the foregoing embodiments, the steps further
include forming an interface coating on the formation surface via
electroplating, such that depositing the at least one layer of
material includes depositing the at least one layer of material on
the interface coating.
[0022] In any of the foregoing embodiments, removing the at least
one layer of material from the formation surface includes removing
the at least one layer via at least one of applying physical force
to the at least one layer of material in a direction away from the
formation surface, applying a releasing agent between the at least
one layer of material and the formation surface, increasing a
temperature of the tool, or etching the at least one layer of
material from the formation surface using an acid or other
chemically reactive material.
[0023] In any of the foregoing embodiments, the steps further
include removing a portion of the formation surface of the tool to
form a recess in the formation surface, wherein depositing the at
least one layer of material on the formation surface further
includes depositing a greater amount of material in the recess on
the formation surface such that the sheet structure has a greater
thickness at a location corresponding to the recess.
[0024] The foregoing features and elements may be combined in
various combinations without exclusivity, unless expressly
indicated otherwise. These features and elements as well as the
operation thereof will become more apparent in light of the
following description and the accompanying drawings. It should be
understood, however, the following description and drawings are
intended to be exemplary in nature and non-limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Various features will become apparent to those skilled in
the art from the following detailed description of the disclosed,
non-limiting, embodiments. The drawings that accompany the detailed
description can be briefly described as follows:
[0026] FIG. 1 is a schematic cross-section of a gas turbine engine,
in accordance with various embodiments;
[0027] FIG. 2 is a flowchart illustrating a method for forming a
sheet structure usable in the gas turbine engine of FIG. 1 using a
cold-spray deposition technique, in accordance with various
embodiments;
[0028] FIG. 3 is a block diagram illustrating a system for forming
a sheet structure using a cold-spray deposition technique, in
accordance with various embodiments;
[0029] FIG. 4A is a drawing of a tool used for forming a sheet
structure using a cold-spray deposition technique, in accordance
with various embodiments;
[0030] FIG. 4B is a drawing of the tool of FIG. 4A having an
interface coating for receiving a cold-spray deposit, in accordance
with various embodiments;
[0031] FIG. 4C is a drawing of a sheet structure using the tool and
interface coating of FIG. 4B, in accordance with various
embodiments;
[0032] FIG. 5A is a drawing of a tool having a recess in a
formation surface for forming a sheet structure with a feature
having a greater thickness relative to other portions of the sheet
structure, in accordance with various embodiments;
[0033] FIG. 5B is a drawing of the sheet structure with the feature
formed using the tool of FIG. 5A, in accordance with various
embodiments;
[0034] FIG. 6 is a drawing of multiple portions of the sheet
structure of FIG. 5B having ribs of various shapes, in accordance
with various embodiments;
[0035] FIG. 7A is a drawing of a portion of an exhaust duct of an
aircraft, in accordance with various embodiments;
[0036] FIG. 7B is a drawing of two duct segments of the exhaust
duct of FIG. 7A formed using a cold-spray deposition technique and
having flanges for coupling purposes, in accordance with various
embodiments; and
[0037] FIG. 7C is a drawing of one of the duct segments of FIG. 7B
illustrating features of the duct segment and the corresponding
flange, in accordance with various embodiments.
DETAILED DESCRIPTION
[0038] All ranges and ratio limits disclosed herein may be
combined. It is to be understood that unless specifically stated
otherwise, references to "a," "an," and/or "the" may include one or
more than one and that reference to an item in the singular may
also include the item in the plural.
[0039] The detailed description of various embodiments herein makes
reference to the accompanying drawings, which show various
embodiments by way of illustration. While these various embodiments
are described in sufficient detail to enable those skilled in the
art to practice the disclosure, it should be understood that other
embodiments may be realized and that logical, chemical, and
mechanical changes may be made without departing from the spirit
and scope of the disclosure. Thus, the detailed description herein
is presented for purposes of illustration only and not of
limitation. For example, the steps recited in any of the method or
process descriptions may be executed in any order and are not
necessarily limited to the order presented. Furthermore, any
reference to singular includes plural embodiments, and any
reference to more than one component or step may include a singular
embodiment or step. Also, any reference to attached, fixed,
connected, or the like may include permanent, removable, temporary,
partial, full, and/or any other possible attachment option.
Additionally, any reference to without contact (or similar phrases)
may also include reduced contact or minimal contact. Cross hatching
lines may be used throughout the figures to denote different parts
but not necessarily to denote the same or different materials.
[0040] As used herein, "aft" refers to the direction associated
with the exhaust (e.g., the back end) of a gas turbine engine. As
used herein, "forward" refers to the direction associated with the
intake (e.g., the front end) of a gas turbine engine.
[0041] As used herein, "radially outward" refers to the direction
generally away from the axis of rotation of a turbine engine. As
used herein, "radially inward" refers to the direction generally
towards the axis of rotation of a turbine engine.
[0042] In various embodiments and with reference to FIG. 1, a gas
turbine engine 20 is provided. The gas turbine engine 20 may be a
two-spool turbofan that generally incorporates a fan section 22, a
compressor section 24, a combustor section 26 and a turbine section
28. Alternative engines may include, for example, an augmentor
section among other systems or features. In operation, the fan
section 22 can drive coolant (e.g., air) along a bypass flow path B
while the compressor section 24 can drive coolant along a core flow
path C for compression and communication into the combustor section
26 then expansion through the turbine section 28. Although depicted
as a two-spool turbofan gas turbine engine 20 herein, it should be
understood that the concepts described herein are not limited to
use with two-spool turbofans as the teachings may be applied to
other types of turbine engines including turbojet, turboprop,
turboshaft, or power generation turbines, with or without geared
fan, geared compressor or three-spool architectures.
[0043] The gas turbine engine 20 may generally comprise a low speed
spool 30 and a high speed spool 32 mounted for rotation about an
engine central longitudinal axis A-A' relative to an engine static
structure 36 or engine case via several bearing systems 38, 38-1,
and 38-2. It should be understood that various bearing systems 38
at various locations may alternatively or additionally be provided,
including for example, the bearing system 38, the bearing system
38-1, and the bearing system 38-2.
[0044] The low speed spool 30 may generally comprise an inner shaft
40 that interconnects a fan 42, a low pressure compressor 44 and a
low pressure turbine 46. The inner shaft 40 may be connected to the
fan 42 through a geared architecture 48 that can drive the fan 42
at a lower speed than the low speed spool 30. The geared
architecture 48 may comprise a gear assembly 60 enclosed within a
gear housing 62. The gear assembly 60 couples the inner shaft 40 to
a rotating fan structure. The high speed spool 32 may comprise an
outer shaft 50 that interconnects a high pressure compressor 52 and
high pressure turbine 54. A combustor 56 may be located between
high pressure compressor 52 and high pressure turbine 54. A
mid-turbine frame 57 of the engine static structure 36 may be
located generally between the high pressure turbine 54 and the low
pressure turbine 46. Mid-turbine frame 57 may support one or more
bearing systems 38 in the turbine section 28. The inner shaft 40
and the outer shaft 50 may be concentric and rotate via bearing
systems 38 about the engine central longitudinal axis A-A', which
is collinear with their longitudinal axes. As used herein, a "high
pressure" compressor or turbine experiences a higher pressure than
a corresponding "low pressure" compressor or turbine.
[0045] The airflow of core flow path C may be compressed by the low
pressure compressor 44 then the high pressure compressor 52, mixed
and burned with fuel in the combustor 56, then expanded over the
high pressure turbine 54 and the low pressure turbine 46. The
turbines 46, 54 rotationally drive the respective low speed spool
30 and high speed spool 32 in response to the expansion.
[0046] The gas turbine engine 20 may be, for example, a high-bypass
ratio geared engine. In various embodiments, the bypass ratio of
the gas turbine engine 20 may be greater than about six (6). In
various embodiments, the bypass ratio of the gas turbine engine 20
may be greater than ten (10). In various embodiments, the geared
architecture 48 may be an epicyclic gear train, such as a star gear
system (sun gear in meshing engagement with a plurality of star
gears supported by a carrier and in meshing engagement with a ring
gear) or other gear system. The geared architecture 48 may have a
gear reduction ratio of greater than about 2.3 and the low pressure
turbine 46 may have a pressure ratio that is greater than about
five (5). In various embodiments, the bypass ratio of the gas
turbine engine 20 is greater than about ten (10:1). In various
embodiments, the diameter of the fan 42 may be significantly larger
than that of the low pressure compressor 44, and the low pressure
turbine 46 may have a pressure ratio that is greater than about
five (5:1). The low pressure turbine 46 pressure ratio may be
measured prior to the inlet of the low pressure turbine 46 as
related to the pressure at the outlet of the low pressure turbine
46 prior to an exhaust nozzle. It should be understood, however,
that the above parameters are exemplary of various embodiments of a
suitable geared architecture engine and that the present disclosure
contemplates other gas turbine engines including direct drive
turbofans. A gas turbine engine may comprise an industrial gas
turbine (IGT) or a geared engine, such as a geared turbofan, or
non-geared engine, such as a turbofan, a turboshaft, or may
comprise any gas turbine engine as desired.
[0047] In various embodiments, the low pressure compressor 44, the
high pressure compressor 52, the low pressure turbine 46, and the
high pressure turbine 54 may comprise one or more stages or sets of
rotating blades and one or more stages or sets of stationary vanes
axially interspersed with the associated blade stages but
non-rotating about engine central longitudinal axis A-A'. The
compressor and turbine sections 24, 28 may be referred to as rotor
systems. Within the rotor systems of the gas turbine engine 20 are
multiple rotor disks, which may include one or more cover plates or
minidisks. Minidisks may be configured to receive balancing weights
or inserts for balancing the rotor systems.
[0048] Various components of gas turbine engine 20 may include one
or more sheet structures. A sheet structure may include a
relatively flat structure having a fairly broad surface relative to
its thickness. For example, a sheet structure may have a thickness
between 10 thousandths of an inch (0.0.254 millimeters) and 0.5
inches (12.7 millimeters), or between 15 thousandths of an inch
(0.0.381 millimeters) and 250 thousandths of an inch (6.35
millimeters).
[0049] Conventional processes for manufacturing such sheet
structures are relatively expensive and time-consuming. Referring
to FIG. 2, a method 200 for forming a sheet structure using a
cold-spray process is shown. Formation of a sheet structure using
the method 200 may be less expensive and less time-consuming than
conventional processes. In various embodiments, the method 200 may
be used to form sheet structures having a relatively large size.
For example, the method 200 may be used to form sheet structures
having a surface area of at least 1 inch squared (1 in..sup.2, 2.54
centimeters squared (cm.sup.2)), 10 in..sup.2 (25.4 cm.sup.2), 36
in..sup.2 (91.44 cm.sup.2), or 100 in..sup.2 (254 cm.sup.2).
[0050] In block 202, a computer is used to create a model of a
tool. A computer may include a processor, a memory, and input
device, and an output device. A computer may include one or more
computers having processors and one or more tangible,
non-transitory memories and be capable of implementing logic. The
processor(s) can be a general purpose processor, a digital signal
processor (DSP), an application specific integrated circuit (ASIC),
a field programmable gate array (FPGA), a graphical processing unit
(GPU), or other programmable logic device, discrete gate or
transistor logic, discrete hardware components, or any combination
thereof. The memory may be any non-transitory memory capable of
storing data. For example, the memory may store instructions to be
executed by the processor, may store modeling software, may store a
model of a component, or the like. The input device may include,
for example, a mouse, a keyboard, a microphone, or the like. The
output device may include, for example, a display, a speaker, an
input/output port, or the like.
[0051] The tool may include a formation surface on which a material
of the sheet structure is deposited. In that regard, the tool may
be modeled such that the formation surface corresponds to a desired
shape of the sheet structure. The tool may be modeled using any
three-dimensional modeling software such as SolidWorks.TM.,
available from Dassault Systemes of Velizy-Villacoublay,
France.
[0052] The tool may include any material having sufficient yield
strength to resist the formation in response to receiving spray
from a cold-spray gun. As will be described below, a cold-spray
deposition technique delivers material at a relatively low
temperature. Accordingly, the tool may include materials having a
relatively low thermal resistance, which may result in lower cost
of the tools. For example, the tool may include a metal, a plastic,
or another compound material such as nylon, polymers,
high-temperature resins, aluminum, low melt alloys, or the like. A
low melt alloy may include any metallic alloy that has a melting
temperature of 450 degrees Fahrenheit (450 degrees F., 233 degrees
Celsius (C)) or below. For example, a low melt alloy may include
one or more of bismuth, lead, tin, cadmium, indium, and the like.
Selection of a material for the tool may be based considering the
cost of the material of the tool and a durability of the tool.
[0053] In block 204, a robot is controlled to form the tool based
on the computer-generated model. The tool may be formed using
additive manufacturing, such as stereolithography. In that regard,
the robot may be an additive manufacturing device, such as a 3-D
printer, connected to the computer. The computer may be
electrically coupled to the additive manufacturing device such that
the device forms the tool based on the model. In various
embodiments, the robot may include a machine separate from the
additive manufacturing device and may independently control the
additive manufacturing device based on the computer-generated
model. In various embodiments, a user may receive the model from
the computer and may manually provide information corresponding to
the model to an additive manufacturing device.
[0054] In block 206, an interface coating may be applied to the
formation surface of the tool. The interface coating may include,
for example, a metal formed on the formation surface using
electroplating. The interface material may include, for example, an
epoxy or low melt alloy. In that regard, the interface coating may
provide various benefits such as erosion protection of the tool,
thermal protection of the tool, generation of a desired surface
finish or feature, facilitation of separation of the sheet
structure from the tool, and increased rigidity and resistance to
deformation resulting from contact with relatively high-velocity
spray from a cold-spray gun. In that regard, the formation surface
of the tool may include one or both of the interface material or
the material of the tool.
[0055] In various embodiments, it may be desirable to form one or
more features, such as ribs, in the sheet structure that have great
thickness relative to other portions of the sheet structure. In
order to form the feature, a portion of the formation surface may
be removed to form one or more recess in the formation surface in
block 208. In response to the sheet structure material being
cold-sprayed onto the formation surface, additional material may
collect in the recess such that the corresponding part of the sheet
structure has a greater thickness at the location corresponding to
the recess. In various embodiments, the tool may be formed to have
the recess such that removal of a portion of the formation surface
is optional.
[0056] In block 210, at least one layer of material may be
cold-sprayed onto the formation surface (or the interface coating)
using a cold-spray deposition technique that utilizes a cold-spray
gun. A cold-spray deposition technique is based on direct additive
deposition of fine metallic particles that are accelerated to
supersonic speeds using inert gas and a cold-spray gun. Inert gas
may include at least one of an inert gas, air, or a less reactive
gas, such as nitrogen. The cold-spray gun outputs a gas that
includes the metallic particles and the inert gas. The output gas
is directed towards the formation surface. The kinetic energy used
in the process enables bonding of the metallic particles to each
other on the formation surface of the tool, allowing the metallic
particles to bind together to form the sheet structure. In various
embodiments, the inert gas may be heated to a temperature that is
between 400 degrees F. (204.4 degrees C.) and 1000 degrees F.
(537.8 degrees C.). The temperature of the inert gas may, however,
remain significantly below the melting point of the material of the
metallic particles. In this context, significantly may refer to 5
percent (5%), or 15%, or 25%.
[0057] In various embodiments, it may be desirable for the sheet
structure to have a greater relative thickness at particular
locations. In that regard, the cold-spray gun may be used to apply
more of the metallic particles to the particular locations to
increase the thickness at the particular locations.
[0058] In various embodiments, the cold-spray gun may be controlled
by at least one of a computer or a robot. In that regard, the
computer or robot may be programmed to spray a predetermined amount
of the metallic particles at each location of the sheet structure.
The predetermined amount of the metallic particles sprayed at each
location may result in each location of the sheet structure
achieving the desired thickness.
[0059] Using a computer, and an electromechanical control system
that is controlled by the computer, to control the cold-spray gun
may result in a relatively accurate deposition of the metallic
particles. The computer (or a user) may control such deposition
factors as rate of discharge of the metallic particles, a distance
from the tool from which the cold-spray gun is used, and the rate
of movement of the cold-spray gun relative to the tool to adjust
the thickness of the sheet structure.
[0060] A cold-spray gun outputs a relatively narrow plume of the
output gas. This relatively narrow plume results in an ability to
precisely position the metallic particles where desired.
[0061] The metallic particles used to form the sheet structure may
include various metals and corresponding alloys such as, for
example, titanium, nickel, aluminum and titanium aluminide alloys,
cobalt alloys, or the like.
[0062] In block 212, the at least one layer of material
(corresponding to the sheet structure) may be removed from the
formation surface. This sheet structure may be removed in a variety
of manners. In various embodiments, the sheet structure may be
physically manipulated away from the formation surface by applying
a force to the sheet structure in a direction away from the
formation surface. In various embodiments, this physical
manipulation may be performed by a user grasping a portion of the
sheet structure, may be performed by a user using a tool, such as a
crowbar, to separate the sheet structure from the tool, or the
like. In various embodiments, the tool may be constructed such that
introduction of pressurized fluid causes flexure of the tool
(potentially including the formation surface), thus facilitating
release of the sheet structure. In various embodiments, water or
another fluid may be introduced between the formation surface and
the sheet structure via capillary action or other means. In that
regard, the fluid may be frozen (and thus expand), exerting a
separating force/pressure to facilitate release of the sheet
structure.
[0063] In various embodiments, a releasing agent may be applied
between the sheet structure and the tool to facilitate release of
the sheet structure from the formation surface. The release agent
may include, for example, Boron Nitride (i.e., a hexagonal boron
nitride). The release agent may be applied between the sheet
structure and the formation surface or between the formation
surface and the interface coating prior to cold-spray deposition of
the metallic particles or after cold-spray deposition of the
metallic particles. The properties of the release agent may result
in a weaker bond between the sheet structure and the tool, allowing
the sheet structure to be removed from the tool with relative ease.
In various embodiments, the release agent may be used and the sheet
structure may still be physically manipulated away from the
formation surface.
[0064] In various embodiments, the combination of the tool and the
sheet structure may be heated to such a temperature that the sheet
structure does not deform yet the tool, or interface coating,
deforms or de-bonds from the sheet structure, facilitating release
of the sheet structure. In various embodiments, the interface
coating may include an adhesive having a melting point above that
of the temperature of the cold-spray gas and below that of the
sheet structure. In that regard, the sheet structure and the
interface coating may be heated to the melting point of the
interface coating, facilitating release of the sheet structure. The
interface coating may then be reapplied to the tool prior to a new
sheet structure being formed on the tool.
[0065] In various embodiments, the sheet structure may be etched
from the tool. For example, an acid such as a Bronsted-Lowry acid
or another etching agent or chemically reactive material may be
applied to the tool, thereby etching the tool away from the sheet
structure.
[0066] In various embodiments, additional operations may be
performed on the sheet structure to complete the part after
separation from the tool. For example, the additional operations
may include machining of interfaces, welding of the part to
additional parts, forming an integral portion of the sheet
structure using a cold-spray deposition technique with a different
tool, or the like.
[0067] Turning now to FIG. 3, a system 300 for implementing the
method 200 of FIG. 2 is shown. The system 300 includes a computer
302 in communication with an additive manufacturing machine 304 and
a robot 306. In various embodiments, the robot 306 may not be
present in the system 300. In various embodiments, the tool may be
made using a machine different from the additive manufacturing
machine 304.
[0068] A user may create a model of a tool using the computer 302.
In various embodiments, the model may be received by the robot 306
and/or the additive manufacturing machine 304 which may, in turn,
form a tool 308. In various embodiments, a user may provide the
model to the robot 306 and/or the additive manufacturing machine
304. In various embodiments, a user may manually control the
additive manufacturing machine 304 to create the tool 308.
[0069] The tool 308 may then be provided to an electroplating
machine 310 or another device, which may apply an interface coating
312 on the tool 308. In various embodiments, the electroplating
machine 310 may not be present in the system 300 such that no
interface coating is applied. In various embodiments, the interface
coating 312 may be applied via brushing, spraying, or another
device. In various embodiments, the electroplating machine 310 may
be controlled by the computer 302 or by another computer or robot
to form the interface coating 312.
[0070] After the interface coating 312 is applied to the tool 308,
the combined tool 308 and interface coating 312 may be subjected to
spray from a cold-spray gun 314. The cold-spray gun 314 may direct
a gas with metallic particles 316 towards the tool 308 and the
interface coating 312. The gas with metallic particles 316 may hit
the interface coating 312 and may begin to form one or more layer
of material 318 on the interface coating 312. In various
embodiments, the cold-spray gun 314 may be controlled by the
computer 302 and/or by a robot 315. In various embodiments, the
cold-spray gun 314 may be controlled by a separate computer or may
be independently controlled.
[0071] After the material 318 has been applied to the interface
coating 312, the combined tool 308, interface coating 312, and
material 318 may be subjected to a separating means 320. The
separating means 320 may include any method or structure used to
separate the material 318 from the interface coating 312 as
described above with reference to block 212 of FIG. 2. The
separating means 320 may separate the material 318 from the
interface coating 312. The resulting material 318 may correspond to
a sheet structure 322.
[0072] Referring now to FIGS. 4A and 4B, an exemplary tool 400 and
sheet structure 401 is shown. The tool 400 has a formation surface
402. The formation surface 402 has a shape that corresponds to a
desired shape of the sheet structure 401. The tool 400 includes one
or more pockets 404 positioned within the tool 400 and having a
material that is different from the remaining material of the tool
400. The pockets 404 may be designed to reduce the likelihood of
deformation of the tool 400 due to impact with a relatively high
velocity gas from a cold-spray gun 410. In that regard, the pockets
404 may include a material having a yield strength that is greater
than that of the remaining portions of the tool 400. For example,
the pockets 404 may include an epoxy or a low melt alloy.
[0073] An interface coating 406 may be applied to the formation
surface 402 of the tool 400. The interface coating 406 may provide
benefits as described above with reference to FIG. 2.
[0074] A cold-spray gun 410 may deposit metallic particles onto the
interface coating 406 to form one or more layer of material 408. In
order to deposit metallic particles onto the interface coating 406,
the cold-spray gun 410 may move relative to the tool 400. For
example, the cold-spray gun 410 may move from a first location 412
to a second location 414, depositing metallic particles at desired
thicknesses along the way.
[0075] After the desirable amount of material 408 has been applied
to the interface coating 406, the material 408 may be separated
from the interface coating 406 in one or more manners as described
above with reference to FIG. 2.
[0076] Referring now to FIGS. 4A, 4B, and 4C, the material 408 that
is separated from the interface coating 406 may be the sheet
structure 401. As shown, the sheet structure 401 has a shape that
corresponds to the shape of the formation surface 402. The sheet
structure 401 may have a thickness 416 that corresponds to the
amount of metallic particles deposited on the interface coating
406. The cold-spray gun 410 may achieve the desired thickness 416
in one or more of a variety of manners. For example, the desired
thickness 416 may be achieved by making a predetermined number of
passes over the formation surface 402 with the cold-spray gun 410,
may be achieved by adjusting the rate of flow of gas exiting the
cold-spray gun 410, may be achieved by adjusting the rate at which
the cold-spray gun 410 moves relative to the formation surface 402,
or the like.
[0077] Turning now to FIGS. 5A and 5B, another tool 500 may include
a formation surface 502 on which at least one layer of material 508
is directly deposited to form a sheet structure 501. Stated
differently, the tool 500 may not include an interface coating. The
formation surface 502 may have a shape that is similar to the
formation surface 402 of FIG. 4A. However, it may be desirable for
the sheet structure 501 to have one or more feature 518 such as a
rib.
[0078] In order to form the feature 518, a portion 519 of the
formation surface 502 may be removed from the tool 500 to form a
recess 520. In various embodiments, a tool that includes an
interface coating may be manipulated such that a portion of the
interface coating and/or the formation surface 502 is removed from
the tool to form the feature on the sheet structure. In various
embodiments, the tool 500 may be formed with the recess 520 in
place such that the tool 500 may be used without removal of any of
the tool 500.
[0079] After the portion 519 of the formation surface 502 is
removed, a cold-spray gun 510 may deposit metallic particles on the
formation surface 502. In various embodiments, the cold-spray gun
510 may be manipulated across the formation surface 502 to deposit
additional material within the recess 520. In various embodiments,
the recess 520 may have particular features that facilitate bonding
of the metallic particles within the recess 520. For example, the
recess 520 may have an angle 522 that is greater than 90 degrees.
The angle 522 may allow the metallic particles to bond together and
entirely fill the recess 520.
[0080] In response to the sheet structure 501 being separated from
the formation surface 502, the metal that was deposited in the
recess 520 may form the feature 518 such as the rib. In various
embodiments, the recess 520 may not be completely filled by the
material. In that regard, the sheet structure 501 may have an
indentation, or a volume, where the recess 520 is not completely
filled.
[0081] Referring now to FIGS. 5A and 6, the sheet structure 501 may
be formed to have a variety of features by forming recesses 520 in
the tool 500. For example, the sheet structure 501 may have
straight ribs 600 extending in one direction or two directions
parallel to a surface of the sheet structure 501. The sheet
structure 501 may also be formed to have hexagonal ribs 602. The
sheet structure 501 may also be formed to have iso-grid ribs 604 or
circular ribs 606.
[0082] Referring now to FIGS. 7A, 7B, and 7C, the method 200 may be
used to form parts for an annular or other non-flat structure, such
as a portion of an exhaust duct 700. The exhaust duct 700 may
include a first duct segment 702, a second duct segment 704, a
third duct segment 706, and a fourth duct segment 708. Each of the
duct segments 702, 704, 706, 708 may be formed as a sheet structure
and may have a curved surface. Each of the duct segments 702, 704,
706, 708 may be coupled together to form the portion of the exhaust
duct 700.
[0083] In order to fasten each of the duct segments 702, 704, 706,
708 together, the ends of the duct segments 702, 704, 706, 708 may
be formed to have a flange that interfaces with a flange of an
adjacent duct segment 702, 704, 706, 708. For example, the fourth
duct segment 708 may include a flange 710 designed to interface
with a flange 712 of the third duct segment 706. The flange 710 and
the flange 712 may be coupled together via, for example, welding or
use of a fastener 714.
[0084] In order to provide an effective means of transitioning
structural stiffness between relatively thin deposited sheet
regions of the fourth duct segment 708 and the flange 710 (which is
relatively rigid) of the fourth duct segment 708, the fourth duct
segment 708 may be formed to have an increasing thickness towards
the flange 710. For example, the fourth duct segment 708 has a
first thickness 716 and a second thickness 718. The second
thickness 718 may be closer to the flange 710 than the first
thickness 716. The second thickness 718 may be greater than the
first thickness 716. The thickness of the fourth duct segment 708
may increase from the location of the first thickness 716 to the
flange 710. Such tapering can be performed using a known structural
practice and may be integrally formed into the fourth duct segment
708 via preferential deposition of material.
[0085] This increase in thickness may be formed in a variety of
manners. In various embodiments, a cold-spray gun may be controlled
to deposit the metallic particles at a faster rate as the
cold-spray gun approaches the flange 710, the cold-spray gun may be
controlled to make additional passes over the corresponding tool as
it approaches the flange 710, the cold-spray gun may be controlled
to reduce its rate of movement relative to the tool as it
approaches the flange 710, or the tool may be designed to have a
recess that corresponds to the increasing thickness of the fourth
duct segment 708.
[0086] In various embodiments, the flange 710 may be formed in a
variety of manners. For example, the tool may be designed to have a
recess that corresponds to the flange 710. As another example, the
fourth duct segment 708 may be initially formed without the flange
710 and used in conjunction with a separate tool to form the flange
710.
[0087] While the disclosure is described with reference to
exemplary embodiments, it will be understood by those skilled in
the art that various changes may be made and equivalents may be
substituted without departing from the spirit and scope of the
disclosure. In addition, different modifications may be made to
adapt the teachings of the disclosure to particular situations or
materials, without departing from the essential scope thereof. The
disclosure is thus not limited to the particular examples disclosed
herein, but includes all embodiments falling within the scope of
the appended claims.
[0088] Benefits, other advantages, and solutions to problems have
been described herein with regard to specific embodiments.
Furthermore, the connecting lines shown in the various figures
contained herein are intended to represent exemplary functional
relationships and/or physical couplings between the various
elements. It should be noted that many alternative or additional
functional relationships or physical connections may be present in
a practical system. However, the benefits, advantages, solutions to
problems, and any elements that may cause any benefit, advantage,
or solution to occur or become more pronounced are not to be
construed as critical, required, or essential features or elements
of the disclosure. The scope of the disclosure is accordingly to be
limited by nothing other than the appended claims, in which
reference to an element in the singular is not intended to mean
"one and only one" unless explicitly so stated, but rather "one or
more." Moreover, where a phrase similar to "at least one of a, b,
or c" is used in the claims, it is intended that the phrase be
interpreted to mean that a alone may be present in an embodiment, b
alone may be present in an embodiment, c alone may be present in an
embodiment, or that any combination of the elements a, b and c may
be present in a single embodiment; for example, a and b, a and c, b
and c, or a and b and c. Different cross-hatching is used
throughout the figures to denote different parts but not
necessarily to denote the same or different materials.
[0089] Systems, methods and apparatus are provided herein. In the
detailed description herein, references to "one embodiment", "an
embodiment", "an example embodiment", etc., indicate that the
embodiment described may include a particular feature, structure,
or characteristic, but every embodiment may not necessarily include
the particular feature, structure, or characteristic. Moreover,
such phrases are not necessarily referring to the same embodiment.
Further, when a particular feature, structure, or characteristic is
described in connection with an embodiment, it is submitted that it
is within the knowledge of one skilled in the art to affect such
feature, structure, or characteristic in connection with other
embodiments whether or not explicitly described. After reading the
description, it will be apparent to one skilled in the relevant
art(s) how to implement the disclosure in alternative
embodiments.
[0090] Furthermore, no element, component, or method step in the
present disclosure is intended to be dedicated to the public
regardless of whether the element, component, or method step is
explicitly recited in the claims. No claim element herein is to be
construed under the provisions of 35 U.S.C. 112(f), unless the
element is expressly recited using the phrase "means for." As used
herein, the terms "comprises", "comprising", or any other variation
thereof, are intended to cover a non-exclusive inclusion, such that
a process, method, article, or apparatus that comprises a list of
elements does not include only those elements but may include other
elements not expressly listed or inherent to such process, method,
article, or apparatus.
* * * * *