U.S. patent application number 12/409950 was filed with the patent office on 2011-04-28 for composite airfoils having leading edge protection made using high temperature additive manufacturing methods.
Invention is credited to MICHAEL W. PERETTI, TIMOTHY TRAPP.
Application Number | 20110097213 12/409950 |
Document ID | / |
Family ID | 43898590 |
Filed Date | 2011-04-28 |
United States Patent
Application |
20110097213 |
Kind Code |
A1 |
PERETTI; MICHAEL W. ; et
al. |
April 28, 2011 |
COMPOSITE AIRFOILS HAVING LEADING EDGE PROTECTION MADE USING HIGH
TEMPERATURE ADDITIVE MANUFACTURING METHODS
Abstract
Composite airfoils including a leading edge, and a near net
shape metal leading edge protective strip operably connected to the
leading edge, the protective strip made by providing a high
temperature additive manufacturing device; providing a tooling
system including a mandrel; a metallic cladding; and at least one
cooling channel applying a metallic deposit to the mandrel having
the metallic cladding using the high temperature additive
manufacturing device; and concurrently removing heat from the
mandrel using the at least one cooling channel.
Inventors: |
PERETTI; MICHAEL W.;
(CINCINNATI, OH) ; TRAPP; TIMOTHY; (CINCINNATI,
OH) |
Family ID: |
43898590 |
Appl. No.: |
12/409950 |
Filed: |
March 24, 2009 |
Current U.S.
Class: |
416/241A |
Current CPC
Class: |
F04D 29/324 20130101;
F01D 5/282 20130101; B33Y 80/00 20141201; F05D 2240/303 20130101;
F05D 2300/603 20130101; F05D 2230/31 20130101; B23P 15/04 20130101;
F04D 29/023 20130101; F05D 2300/133 20130101 |
Class at
Publication: |
416/241.A |
International
Class: |
F01D 5/14 20060101
F01D005/14 |
Claims
1. A composite airfoil comprising: a leading edge; and a near net
shape metal leading edge protective strip operably connected to the
leading edge, the protective strip made by providing a high
temperature additive manufacturing device; providing a tooling
system comprising: a mandrel; a metallic cladding; and at least one
cooling channel applying a metallic deposit to the mandrel having
the metallic cladding using the high temperature additive
manufacturing device; and concurrently removing heat from the
mandrel using the at least one cooling channel.
2. The airfoil of claim 1 wherein the metallic deposit comprises
titanium or a titanium alloy.
3. The airfoil of claim 2 wherein the high temperature additive
manufacturing device is capable of carrying out a process selected
from the group consisting of plasma transferred arc deposition,
laser cladding, gas metal arc welding, ultrasonic welding, electron
beam free-form fabrication, and shaped metal deposition.
4. The airfoil of claim 3 comprising removing heat from the mandrel
by passing a cooling medium through the at least one cooling
channel.
5. The airfoil of claim 4 wherein the high temperature additive
manufacturing device has an operating temperature above about
3000.degree. C.
6. The airfoil of claim 5 wherein the metallic deposit comprises a
thermal conductivity and wherein the mandrel comprises a thermal
conductivity at least twice the thermal conductivity of the
metallic deposit.
7. The airfoil of claim 6 wherein the metallic cladding comprises
the same material as the metallic deposit.
8. The airfoil of claim 7 comprising finishing the near net shape
airfoil metal leading edge protective strip to a final
dimension.
9. The airfoil of claim 8 wherein the metallic cladding comprises a
thickness of from about 2 microns to about 2 mm.
10. The airfoil of claim 9 wherein the airfoil comprises a blade or
a vane.
11. A turbine engine comprising: a composite airfoil having a
leading edge; and a near net shape metal leading edge protective
strip operably connected to the leading edge, the protective strip
made by providing a high temperature additive manufacturing device;
providing a tooling system comprising: a mandrel; a metallic
cladding; and at least one cooling channel applying a metallic
deposit to the mandrel having the metallic cladding using the high
temperature additive manufacturing device; and concurrently
removing heat from the mandrel using the at least one cooling
channel.
12. The engine of claim 11 wherein the metallic deposit comprises
titanium or a titanium alloy.
13. The engine of claim 12 wherein the airfoil comprises a blade or
a vane.
14. The engine of claim 13 wherein the high temperature additive
manufacturing device is capable of carrying out a process selected
from the group consisting of plasma transferred arc deposition,
laser cladding, gas metal arc welding, ultrasonic welding, electron
beam free-form fabrication, and shaped metal deposition.
15. The engine of claim 14 comprising removing heat from the
mandrel by passing a cooling medium through the at least one
cooling channel.
16. The engine of claim 15 wherein the high temperature additive
manufacturing device has an operating temperature above about
3000.degree. C.
17. The engine of claim 16 wherein the metallic deposit comprises a
thermal conductivity and wherein the mandrel comprises a thermal
conductivity at least twice the thermal conductivity of the
metallic deposit.
18. The engine of claim 17 wherein the metallic cladding comprises
the same material as the metallic deposit.
19. The engine of claim 18 comprising finishing the near net shape
airfoil metal leading edge protective strip to a final
dimension.
20. The engine of claim 19 wherein the metallic cladding comprises
a thickness of from about 2 microns to about 2 mm.
Description
TECHNICAL FIELD
[0001] Embodiments described herein generally relate to composite
airfoils having leading edge protection made using high temperature
additive manufacturing methods.
BACKGROUND OF THE INVENTION
[0002] Many modern turbine engine airfoils, such as blades and
vanes, are constructed of a composite laminate or molded fiber.
Airfoil metal leading edge (herein "MLE") protective strips can be
used to protect composite airfoils from impact and erosion damage
that can often occur in the engine environment. In conventional
practices, a v-shaped protective metallic strip is often wrapped
around the leading edge and sides of the airfoil to provide such
protection.
[0003] While MLE protective strips can be made from a variety of
materials, titanium and titanium alloys are often utilized due to
their favorable weight and mechanical properties. However, hot
forming methods must be used to fabricate these titanium
components. Hot forming typically involves multiple steps with
intermediate chemical milling or machining. This can lead to high
tooling costs, high yield losses, and environmentally unfriendly
processing. These drawbacks are especially true when fabricating
thin, complex geometries, such as MLE protective strips.
[0004] Additive manufacturing involves the buildup of a metal part
or preform to make a net, or near net shape (NNS) component. This
approach can make complex components from expensive materials for a
reduced cost and with improved manufacturing efficiency. Generally,
a freestanding component is built from a computer aided design
(CAD) model. However, when the component has a thin and/or complex
shape, it can be beneficial to build up the component on a tool for
support.
[0005] When a high temperature, melt-based process, such as plasma
transferred arc or laser cladding, is used as the additive method
to make a NNS component, the tool must perform several functions:
it must give shape to the part, it must control heat input to
provide a uniform microstructure over the entire length of the
component with the desired grain size, and it must conduct heat
away from the deposit rapidly enough to prevent fusion of the
deposited component to the tool. Additionally, the tool must not
cause any contamination of the metallic deposit, as contamination
can have a disastrous affect on the physical and mechanical
properties of the component. This is especially true when working
with titanium and titanium alloys.
[0006] More specifically, when titanium or titanium alloy is
deposited, the risk of contamination of the deposit by the tooling
is high due to the high melting point and reactive nature of
titanium. Current practice utilizes a monolithic tool made from the
same alloy that is being deposited (e.g. titanium or titanium
alloy). While this approach helps mitigate the issue of
contamination, it results in a very narrow process window for
making a sound deposit without fusion of the deposit to the tool.
This is because titanium is a relatively poor heat conductor when
compared to other heat sink materials (e.g. refractory metals, mild
steel, copper).
[0007] Accordingly, there remains a need for airfoil leading edge
protection made using manufacturing methods that address and
overcome the previously discussed issues associated with current
MLE protective strip manufacturing.
BRIEF DESCRIPTION OF THE INVENTION
[0008] Embodiments herein generally relate to composite airfoils
comprising: a leading edge; and a near net shape metal leading edge
protective strip operably connected to the leading edge, the
protective strip made by providing a high temperature additive
manufacturing device; providing a tooling system comprising: a
mandrel; a metallic cladding; and at least one cooling channel
applying a metallic deposit to the mandrel having the metallic
cladding using the high temperature additive manufacturing device;
and concurrently removing heat from the mandrel using the at least
one cooling channel.
[0009] Embodiments herein also generally relate to turbine engines
comprising: a composite airfoil having a leading edge; and a near
net shape metal leading edge protective strip operably connected to
the leading edge, the protective strip made by providing a high
temperature additive manufacturing device; providing a tooling
system comprising: a mandrel; a metallic cladding; and at least one
cooling channel applying a metallic deposit to the mandrel having
the metallic cladding using the high temperature additive
manufacturing device; and concurrently removing heat from the
mandrel using the at least one cooling channel.
[0010] These and other features, aspects and advantages will become
evident to those skilled in the art from the following
disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] While the specification concludes with claims particularly
pointing out and distinctly claiming the invention, it is believed
that the embodiments set forth herein will be better understood
from the following description in conjunction with the accompanying
figures, in which like reference numerals identify like
elements.
[0012] FIG. 1 is a schematic representation of one embodiment of a
composite fan blade for a gas turbine engine in accordance with the
description herein; and
[0013] FIG. 2 is a schematic cross-sectional representation of a
portion of one embodiment of a high temperature additive
manufacturing system in accordance with the description herein.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Embodiments described herein generally relate to composite
airfoils having leading edge protection made using high temperature
additive manufacturing methods.
[0015] FIG. 1 is a composite fan blade 10 for a gas turbine engine
having a composite airfoil 12 generally extending in a chordwise
direction C from a leading edge 16 to a trailing edge 18. Airfoil
12 extends radially outward in a spanwise direction S from a root
20 to a tip 22 generally defining its span and having a suction
side 24 and a pressure side 26. Airfoil 12 can be constructed from
plies of composite material as is known in the art. Embodiments
herein describe methods and tooling for making a titanium or
titanium alloy metal leading edge (MLE) protective strip 28 for
adhesion to airfoil leading edge 16. Though embodiments herein
focus on composite fan blades, the methods, tooling and MLE
protective strips herein are suitable for use with any composite
airfoil, including blades and vanes.
[0016] MLE protective strip 28 can be made using high temperature
additive manufacturing processes. As used herein, "high temperature
additive manufacturing" refers to processes including plasma
transferred arc deposition, laser cladding, gas metal arc welding,
ultrasonic welding, electron beam free-from fabrication, shaped
metal deposition, and the like. Such processes have operating
temperatures in excess of about 3000.degree. C., which in the
present case, is well above the melting point of the titanium or
titanium alloy metallic deposit. To overcome the previously
described issues common to such processes when working with high
melting point and/or reactive materials, unique tooling must be
employed. FIG. 2 is a schematic representation of a high
temperature additive manufacturing system comprising tooling system
30 suitable for use in conjunction with high temperature additive
manufacturing of titanium and titanium alloys.
[0017] More particularly, tooling system 30 includes a mandrel 32,
a metallic cladding 34, and at least one cooling channel 36 for use
with a high temperature additive manufacturing device 38. Mandrel
32 can receive a metallic deposit 40 and can have a shape
corresponding to the desired shape of MLE protective strip 28.
Mandrel 32 can be single-use or reusable, and can be made from any
metallic or nonmetallic material. To help prevent contamination of
metallic deposit 40, mandrel 32 should have a thermal conductivity
that is at least about two times the thermal conductivity of the
metallic deposit. This difference in thermal conductivity can also
allow mandrel 32 to serve as a heat sink, thereby providing a
larger process window for making a sound deposit without fusion to
the mandrel when compared to current practices. Some examples of
suitable "metallic materials" for mandrel 32 include, but should
not be limited to, titanium, titanium alloy, molybdenum, tungsten,
mild steel, and copper, while some examples of suitable nonmetallic
materials include, but should not be limited to, graphite, silicon
carbide, and carbon-carbon composite.
[0018] Metallic cladding (or "cladding") 34 comprises a thin layer
of the titanium or titanium alloy in metallic deposit 40 applied to
mandrel 32. Cladding 34 serves to further prevent contamination of
metallic deposit 40. Cladding 34 can be applied to mandrel 32 by a
variety of methods, including plasma spray, roll bonding, plasma
transferred arc deposition, arc weld overlay (shielded metal arc
welding (SMAW), gas metal arc welding (GMAW), gas tungsten arc
welding (GTAW)), flame spray, and physical vapor deposition (PVD).
The thickness of cladding 34 can range from about 2 microns to
about 2 mm, and in one embodiment, from about 2 microns to about 1
mm. Conventional heat transfer modeling can be used to determine
the optimized coating thickness for the particular cladding
material being used.
[0019] In addition to cladding 34, active cooling of mandrel 32 may
be desired to remove heat and further help prevent fusion of MLE
protective strip 28 to mandrel 32 and cladding 34. Active cooling
can also be used help control grain size of the deposit material
and optimize the mechanical and corrosion performance of MLE
protection strip 28. Active cooling may be accomplished through the
use of at least one cooling channel 36 in association with mandrel
32. Such cooling channels 36 can be attached to mandrel 32,
embedded into mandrel 32 (as shown in FIG. 2), machined into
mandrel 32, or some combination thereof. An active cooling medium
can then be passed through cooling channel 36 (as indicated by
arrows) to remove heat from mandrel 32. The active cooling medium
can be a liquid, such as water or glycol, or a gas, such as argon,
nitrogen, air, or helium.
[0020] In use, high temperature additive manufacturing device 38
can be positioned above tooling system 30 for providing metallic
deposit 40. The application of metallic (titanium or titanium
alloy) deposit 40 to mandrel 32 can be accomplished using
conventional techniques as described previously. Once cooled to
about ambient temperatures, the resulting near net shape MLE
protective strip 28 can be processed further. In one embodiment,
MLE protective strip 28 may be finished to final dimensions using
conventional methods (e.g. machining) before being removed from
mandrel 32 and attached to airfoil leading edge 16. In another
embodiment, any required finishing operations can be carried out
after protective strip 28 is attached to airfoil leading edge 16.
MLE protective strip 28 can then be operably connected to airfoil
leading edge 16 using a variety of conventional methods.
[0021] The embodiments herein offer benefits over conventional MLE
protective strip manufacturing technologies. More particularly,
additive manufacturing allows for the leading edge protective strip
to be built up to near net shape, thereby reducing material input,
material waste, and overall manufacturing time. Applying only the
amount of material needed to complete the component conserves
expensive raw materials, and material removal and finishing needs
(e.g. machining) are drastically reduced. Moreover, additive
manufacturing allows for flexibility in changing or updating the
design of the MLE protective strip quickly and at a low cost when
compared to conventional machining methods. Furthermore, utilizing
additive manufacturing processes allows the MLE protective strip to
be functionally graded in composition to tailor the properties and
structure, thereby allowing advanced design capability.
[0022] This written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to make and use the invention. The patentable
scope of the invention is defined by the claims, and may include
other examples that occur to those skilled in the art. Such other
examples are intended to be within the scope of the claims if they
have structural elements that do not differ from the literal
language of the claims, or if they include equivalent structural
elements with insubstantial differences from the literal language
of the claims.
* * * * *