U.S. patent application number 14/971292 was filed with the patent office on 2016-07-21 for method and equipment for repairing a component.
This patent application is currently assigned to ROLLS-ROYCE plc. The applicant listed for this patent is ROLLS-ROYCE plc. Invention is credited to Martyn Anthony JONES.
Application Number | 20160209131 14/971292 |
Document ID | / |
Family ID | 52630611 |
Filed Date | 2016-07-21 |
United States Patent
Application |
20160209131 |
Kind Code |
A1 |
JONES; Martyn Anthony |
July 21, 2016 |
METHOD AND EQUIPMENT FOR REPAIRING A COMPONENT
Abstract
A method of repairing a component having a metal part adhesively
bonded to a composite body includes thermally coupling a heatsink
to the metal part adjacent to a repair region of the metal part
which is to be repaired; and performing a metal deposition process
on the metal part in the repair region. During the metal deposition
process the heatsink acts to transfer thermal energy away from the
metal part caused by the metal deposition process. Equipment
repairs a component having a metal part adhesively bonded to a
composite body.
Inventors: |
JONES; Martyn Anthony;
(Derby, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ROLLS-ROYCE plc |
London |
|
GB |
|
|
Assignee: |
ROLLS-ROYCE plc
London
GB
|
Family ID: |
52630611 |
Appl. No.: |
14/971292 |
Filed: |
December 16, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F01D 5/005 20130101;
F28F 13/00 20130101; F05D 2300/603 20130101; Y02T 50/60 20130101;
F04D 29/324 20130101; F01D 25/285 20130101; B23K 2101/001 20180801;
B23K 2103/26 20180801; F01D 5/282 20130101; F05D 2220/36 20130101;
B23K 26/342 20151001; F05D 2230/31 20130101; F05D 2230/80 20130101;
F01D 5/147 20130101; B23P 6/007 20130101; C23C 26/00 20130101; Y02T
50/672 20130101; B23K 37/003 20130101; Y02T 50/673 20130101; F05D
2240/303 20130101 |
International
Class: |
F28F 13/00 20060101
F28F013/00; C23C 26/00 20060101 C23C026/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 15, 2015 |
GB |
1500636.4 |
Claims
1. A method of repairing a component having a metal part attached
to a composite body, the method comprising: thermally coupling a
heatsink to the metal part adjacent to a repair region of the metal
part which is to be repaired; and performing a metal deposition
process on the metal part in the repair region; wherein during the
metal deposition process the heatsink acts to transfer thermal
energy away from the metal part caused by the metal deposition
process.
2. A method according to claim 1, wherein the heatsink has a
heatsink base having a profile corresponding to that of the metal
part, wherein thermally coupling the heatsink to the metal part
includes placing the heatsink base against the metal part.
3. A method according to claim 2, wherein the heatsink base
comprises a recess for receiving the metal part.
4. A method according to claim 3, wherein the recess is in the form
of a channel.
5. A method according to claim 1, wherein the heatsink is a
liquid-cooled heatsink.
6. A method according to claim 5, wherein during the metal
deposition process a cooling liquid is used to transfer thermal
energy away from the heatsink.
7. A method according to claim 5, wherein during the metal
deposition process a cooling liquid is pumped past the
heatsink.
8. A method according to claim 1, wherein the heatsink defines an
opening, and wherein with the heatsink thermally coupled to the
metal part, at least a part of the repair region is exposed through
the opening.
9. A method according to claim 8, wherein the heatsink is thermally
coupled to the metal part such that it surrounds at least a part of
the repair region.
10. A method according to claim 8, wherein the metal deposition
process is performed through the opening.
11. A method according to claim 1, further comprising performing a
heat treatment process on the repair region after the metal
deposition process, wherein during the heat treatment process the
heatsink acts to transfer thermal energy away from the metal part
caused by the heat treatment process.
12. A method according to claim 11, wherein the heatsink is a
liquid-cooled heatsink, and wherein during the heat treatment
process a cooling liquid is used to transfer thermal energy from
the heatsink.
13. A method according to claim 11, wherein the heatsink is a
liquid-cooled heatsink, and wherein during the heat treatment
process a cooling liquid is pumped past the heatsink.
14. A method according to claim 11, wherein the heatsink defines an
opening, wherein with the heatsink thermally coupled to the metal
part, at least a part of the repair region is exposed through the
opening, and wherein the heat treatment process is performed
through the opening.
15. A method according to claim 1, wherein the component is a blade
or vane.
16. A method according to claim 15, wherein the metal part is a
metal leading edge, trailing edge or tip of the blade or vane.
17. Equipment for repairing a component having a metal part
adhesively bonded to a composite body, the equipment comprising: a
heatsink arranged to be thermally coupled to the metal part
adjacent to a repair region of the metal part which is to be
repaired; and metal deposition apparatus for performing a metal
deposition process on the metal part in the repair region.
18. Equipment according to claim 17, further comprising heat
treatment apparatus for performing a heat treatment process on the
repair region.
19. A heatsink for use in the method of claim 1.
20. A heatsink for use with the equipment of claim 17.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of
priority from British Patent Application Number 1500636.4 filed 15
Jan. 2015, the entire contents of which are incorporated by
reference.
BACKGROUND
[0002] 1. Field of the Disclosure
[0003] The disclosure relates to a method and equipment for
repairing a component having a metal part adhesively bonded to a
composite body. In particular, although not exclusively, the
disclosure relates to a method and equipment for repairing a fan
blade having a leading and/or trailing metal edge adhesively bonded
to a composite body.
[0004] 2. Description of the Related Art
[0005] Composite fan blades are known which comprise a composite
aerofoil body and leading and trailing protective metal edges
adhesively bonded to the composite aerofoil body. The composite
aerofoil body is typically made from a composite material such as a
glass or carbon fibre reinforced polymer (GFRP, CFRP), whilst the
leading and trailing protective metal edges are typically made from
titanium or steel. The leading and trailing metal edges are
provided to protect the edge of the composite aerofoil body from
impact damage and erosion. During use, impacts such as from bird
strikes and runway debris may damage the metal edges, and over time
small particulate matter may erode the metal edges, thereby
changing their profile.
[0006] It is desirable to repair the leading/trailing metal edges
of composite fan blades in order to extend their life. Impact
damage to the metal edges, such as chips or notches, can be
repaired by "dressing-out" the damaged area. This involves removing
material to create a smoother profile in order reduce stress
concentration areas. The metal edges can be re-profiled by using a
material removal process such as abrading. Whilst these methods of
repair may increase the life of the fan blade, they involve the
removal of metal and so there may no longer be sufficient metal
remaining after a number of repairs.
OBJECTS AND SUMMARY
[0007] It is therefore desirable to provide an improved method and
equipment for repairing a component having a metal part adhesively
bonded to a composite body.
[0008] According to an aspect there is provided a method of
repairing a component having a metal part attached (for example
adhesively bonded) to a composite body, the method comprising:
thermally coupling a heatsink to the metal part adjacent to a
repair region of the metal part which is to be repaired; and
performing a metal deposition process on the metal part in the
repair region; wherein during the metal deposition process the
heatsink acts to transfer (or dissipate) thermal energy away from
the metal part caused by the metal deposition process. The use of a
heatsink to transfer heat away from the metal part means that
during the metal deposition process the adhesive bond and/or the
resin of the composite body do not reach excessive temperatures.
This allows the metal part to be repaired using a material addition
process.
[0009] It should be appreciated that the order that the method
steps are presented in is not limiting and the steps could be
carried out in any particular order.
[0010] The heatsink may have a heatsink base having a profile
corresponding to that of the metal part, and thermally coupling the
heatsink to the metal part may include placing the heatsink base
against the metal part. The heatsink base may comprise a recess for
receiving the metal part. The recess may be in the form of a
channel. The channel may have a profile corresponding to the edge
of a fan blade, such as a leading edge or a trailing edge. The
heatsink may be a liquid-cooled heatsink, such as a water-cooled
heatsink. During the metal deposition process a cooling liquid,
such as water, may be used to transfer (or dissipate) thermal
energy away from the heatsink. This may increase the transfer rate
of heat away from the metal part. During the metal deposition
process a cooling liquid, such as water, may be pumped past the
heatsink. A cooling liquid may be pumped through, over, or across
the heatsink. In other embodiments other ways of causing a cooling
liquid, such as water, to flow past the heatsink may be used.
[0011] The heatsink may define an opening, and with the heatsink
thermally coupled to the metal part, at least a part of a repair
region may be exposed through the opening. The heatsink may be
thermally coupled to the metal part such that it surrounds at least
a part of a repair region. The metal deposition process may be
performed through the opening.
[0012] The heatsink may have one or more formations or features for
promoting heat transfer (or dissipation), such as heat transfer
fins.
[0013] The method may further comprise, after the metal deposition
process, performing a heat treatment process on the repair region,
wherein during the heat treatment process the heatsink acts to
transfer (or dissipate) thermal energy away from the metal part
caused by the heat treatment process. During the heat treatment
process, a cooling liquid, such as water, may be used to transfer
(or dissipate) thermal energy away from the heatsink. A cooling
liquid, such as water, may be pumped past the heatsink during the
heat treatment process. A cooling liquid may be pumped through,
over, or across the heatsink. In other embodiments other ways of
causing a cooling liquid, such as water, to flow past the heatsink
may be used. The heat treatment process may be performed through
the opening.
[0014] The component may be a blade or a vane. The metal part may
be a metal leading or trailing edge or tip.
[0015] According to another aspect there is provided equipment for
repairing a component having a metal part adhesively bonded to a
composite body, the equipment comprising: a heatsink arranged to be
thermally coupled to the metal part adjacent to a repair region of
the metal part which is to be repaired; and metal deposition
apparatus for performing a metal deposition process on the metal
part in the repair region.
[0016] The heatsink may have a heatsink base having a profile
corresponding to that of the metal part. The heatsink base may
comprise a recess for receiving the metal part. The recess may be
in the form of a channel. The heatsink may be a liquid-cooled
heatsink.
[0017] The heatsink may define an opening which is arranged such
that with the heatsink thermally coupled to the metal part, at
least a part of a repair region is exposed through the opening.
[0018] The equipment may further comprise heat treatment apparatus
for performing a heat treatment process on the repair region.
[0019] The disclosure also relates to a heatsink for use in the
method according to any statement herein, or according to the
equipment of any statement herein.
[0020] The disclosure may comprise any combination of the features
and/or limitations referred to herein, except combinations of such
features that are mutually exclusive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Embodiments will now be described, by way of example, with
reference to the accompanying drawings, in which:
[0022] FIG. 1 schematically shows perspective views of a composite
fan blade for a gas turbine engine, such as a jet engine;
[0023] FIG. 2 schematically shows a cross-sectional view of the
composite fan blade of FIG. 1;
[0024] FIG. 3 schematically shows a repair process in accordance
with an embodiment of the invention;
[0025] FIG. 4 schematically shows a perspective view of a heatsink
according to an embodiment; and
[0026] FIG. 5 schematically shows a perspective view of the
heatsink of FIG. 4 thermally coupled to the metal edge of the fan
blade of FIG. 1.
DETAILED DESCRIPTION OF EMBODIMENTS
[0027] FIGS. 1 and 2 show a composite fan blade 2 for a jet engine
(not shown). The fan blade 2 comprises a composite aerofoil body 4
and protective leading and trailing metal edges 6, 8 which are
adhesively bonded to the leading and trailing edges of the
composite aerofoil body 4. The trailing metal edge 8 further
extends around the tip of the composite aerofoil body 4 and is
adhesively bonded to it. In other embodiments, the leading metal
edge 6 may extend around the tip of the composite aerofoil body 4
instead. In yet a further embodiment a separate metal tip edge
could be provided that is adhesively bonded to the composite body
4. The composite aerofoil body 4 is made from a composite material,
for example, a glass or carbon fibre reinforced polymer (GFRP,
CFRP). The metal leading and trailing edges 6, 8 are made from
titanium. It should be appreciated that the metal edges could be
made from other suitable metals such as steel. The outer surfaces
of the composite aerofoil body 4 are provided with an adhesive
layer that is co-cured with the composite body 4. The pressure
surface is further provided with an additional elastic polyurethane
layer on top of the adhesive layer. Both surfaces are coated with a
polyurethane paint layer which provides a smooth aerodynamic
finish, and improves the aesthetic appearance. In use, the leading
metal edge 6 and the trailing metal edge 8 may become damaged from
either impacts, causing chips/notches, or erosion, causing a change
in the profile of the edge.
[0028] A method of repairing the leading/trailing metal edges 6, 8
of the composite fan blade 2 using a metal deposition process will
now be described with reference to FIG. 3.
[0029] The repair process 48 is initiated by an inspection process
50 in which the leading metal edge 6 and the trailing metal edge 8
are inspected for impact damage or erosion damage. If, upon
inspection, damaged is found, a 3D scan 52 is performed in which
the 3D geometry of the surface of the damaged metal edge 6, 8 is
mapped. This produces 3D data that is used to create a CAD/CAM
program 54 for the repair process. The metal edge 6, 8 is then
machined 56 in the region to be repaired, which may be a localized
repair region or may be the entire length of the metal edge 6, 8 if
the edge needs to be re-profiled. The machining process 56 is
performed in order to provide a suitable surface geometry for a
subsequent metal deposition process. A cleaning and etching process
58 is then performed which removes impurities such as oxides from
the repair region. A metal deposition process 60 is then carried
out on the repair region to add metal to the repair region so as to
restore the metal edge 6, 8 to its original profile.
[0030] In this embodiment the metal deposition process 60 is a
blown powder direct laser deposition process, in which a plurality
of layers of metal are deposited on top of one another to build-up
metal in the repair region. In this embodiment, the metal
deposition process 60 is used to fill-in notches/chips or to
re-profile the metal edge 6, 8, thus restoring the metal edge 6, 8
to its original profile. The metal deposition process 60 uses a
laser power in the region of 450 W, which causes the temperature of
the metal edge 6, 8 to be increased. In order to prevent the
temperature of the adhesive used to bond the metal edges 6, 8 to
the composite body 4 reaching unacceptably high levels (which may
be 120.degree. C.), a heatsink 14 is thermally coupled to the metal
edge 6, 8 during the metal deposition process 60. The heatsink 14
also acts to prevent the temperature of the composite body itself
reaching unacceptably high levels (which may be 80.degree. C.).
Temperatures beyond these levels may cause the adhesive and/or
composite material to degrade. The heatsink 14 will be described in
detail below with reference to FIGS. 4 and 5.
[0031] Following the metal deposition process 60, the repair region
(i.e. the metal deposited in the repair region) is subjected to a
heat treatment process 62 in which the temperature of the repair
region (i.e. the region in which the metal has been deposited) is
raised to approximately 600.degree. C. for one hour. The heat
treatment process 62 alleviates tensile stress within the deposited
metal and the surrounding area. This improves impact resistance and
prevents the interface between the original metal and the deposited
metal from cracking. Due to the high temperatures involved, the
heatsink 14 remains thermally coupled to the metal edge 6, 8 so as
to avoid the adhesive and the composite material from being
overheated. The heat treatment process 62 is followed by an etching
process 64 which removes impurities from the surface of the
deposited material, and there then follows a polishing process 68
which produces a smooth surface. The metal deposited in the repair
region is then peened 70, which reduces the likelihood of crack
propagation. In some embodiments, the peening process 70 may not be
required. The metal edge 6, 8 that has been repaired is then
inspected to ensure that the repair has been carried out
successfully.
[0032] FIG. 4 shows a perspective view of a heatsink 14 which can
be used in the repair process described above in order to assist in
the dissipation or transfer of thermal energy (i.e. heat) from the
metal edge 6, 8 being repaired. The use of the heatsink 14 prevents
the temperature of the adhesive bonding the metal edge 6, 8 to the
composite body 4 from reaching levels at which the adhesive bond
would be compromised. Further, the use of the heatsink 14 prevents
the temperature of the composite material of the composite body
from reaching levels at which the composite material itself would
be compromised. In this embodiment the heatsink 14 is a
liquid-cooled heatsink and therefore during use a liquid is used to
transfer thermal energy (i.e. heat) received by the heatsink away
from the heatsink 14 (and therefore away from the metal edge 6,
8).
[0033] The heatsink 14 is manufactured from a thermally conductive
metal such as copper and has a base 16 comprising a recess in the
form of an elongate channel 26. As will be described in detail
below, the inner profile of the channel 26 substantially
corresponds to the outer profile of the metal edge 6, 8. The
heatsink 14 also comprises an opening 28 that extends through the
heatsink 14 from an upper surface 30 and which opens into the
channel 26. The heatsink 14 is provided with two fluid passageways,
each having an inlet 22 and an outlet (not shown). The fluid
passageways are located on either side of the opening 28 and extend
through the heatsink 14 in the same general direction as the
direction of extent of the channel 26.
[0034] As shown in FIG. 5, in use, prior to the metal deposition
process 60, the heatsink 14 is located over the metal edge 6, 8
such that the region to be repaired or restored is accessible
through the opening 28. With the heatsink 14 located over the metal
edge 6, 8, the base 16 is in physical contact with the metal edge
6, 8 and is therefore thermally coupled to it. The inlet ports 22
are connected to respective inlet tubes 34 which are connected
together with a fluid coupling 38. The fluid coupling 38 is
connected to a fluid pump (not shown) for pumping cooling fluid,
such as water, through the heatsink 14. The outlet ports are
connected to respective outlet tubes 40 which are connected
together with a fluid coupling 42. The fluid coupling 42 is
connected to a heat exchanger (not shown) which is arranged to
extract heat from the cooling fluid so as to cool it. The pump may
be connected to the heat exchanger so as to form a closed
system.
[0035] During the metal deposition process 60 the pump is operated
to pump cooling liquid, such as water, through the fluid
passageways in the heatsink 14. The metal deposition process 60 is
performed through the access opening 28, specifically, metal powder
is deposited through the opening 28 and the laser is directed
through the opening 28. Heat generated by the metal deposition
process 60 is transferred away from the metal edge 6, 8 to the
heatsink 14 and the flow of cooling liquid acts to transfer the
heat away from the heatsink 14 to the cooling liquid. This forced
cooling effect efficiently cools the metal edge 6, 8, preventing
overheating of the adhesive and the composite material itself. This
allows a metal deposition process 60 to be performed on a region of
the fan blade which is sensitive to excessive temperatures. During
the heat treatment process 62 the pump is also operated to pump
cooling liquid through the heatsink 14, thereby efficiently
transferring thermal energy away from the metal edge 6, 8. As for
during the metal deposition process 60, this forced cooling
prevents overheating of the adhesive and the composite material
itself. Although the cooling liquid has been described as being
water, any other suitable liquid could be used. Further, although
it has been described that the cooling liquid is pumped through the
heatsink 14, it may be conveyed through the heatsink 14 using any
suitable means, for example under the force of gravity.
[0036] Once the repair process 48 has been completed, if there is a
second region that requires repair, the heatsink 14 can be
repositioned along the metal edge 6, 8 such that the second repair
region is accessible through the opening 28. The repair process 48
is then repeated on this second repair region.
[0037] In the foregoing description it has been described that the
metal deposition process 60 is blown powder direct laser
deposition. It should be appreciated that any suitable metal
deposition (i.e. metal additive) process could be used.
[0038] In the foregoing description it has been described that the
leading/and or trailing metal edge 6, 8 of a fan blade 2 is
repaired. It will be appreciated that the metal tip of the fan
blade may also be repaired using the same method. The metal tip of
the fan blade may either be formed by the leading/and or trailing
metal edge 6, 8 of a fan blade 2 or a separate component may be
provided.
[0039] In the embodiment described the heatsink has been described
as a liquid-cooled heatsink that is cooled with a cooling liquid
such as water. However, in other embodiments the heatsink could be
cooled by an airflow, either forced or driven by convection.
[0040] It has been described that the repair method is for
repairing the metal leading or trailing edge 6, 8 of a fan blade 2
for a jet engine. However, the method could be used to repair any
metal component adhesively bonded to a composite body. For example,
it could be used to repair a metal edge bonded to a composite wing
component. Further, the method could be used to repair non-aircraft
components, such as a metal part bonded to a composite body
component of a car.
* * * * *