U.S. patent application number 13/735342 was filed with the patent office on 2014-07-10 for recoating process and recoated turbine blade.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. The applicant listed for this patent is GENERAL ELECTRIC COMPANY. Invention is credited to Michael Anthony DEPALMA, III, Mark Lawrence HUNT, Gareth William David LEWIS, Jonathan Matthew LOMAS, Christopher Edward THOMPSON, John D. WARD, JR..
Application Number | 20140193664 13/735342 |
Document ID | / |
Family ID | 51061175 |
Filed Date | 2014-07-10 |
United States Patent
Application |
20140193664 |
Kind Code |
A1 |
THOMPSON; Christopher Edward ;
et al. |
July 10, 2014 |
RECOATING PROCESS AND RECOATED TURBINE BLADE
Abstract
Recoating process and recoated turbine blade are disclosed. The
recoating process includes providing a coated turbine blade, then
removing a portion of the thermal barrier coating system to form a
partially-stripped turbine blade, then applying a bond recoat to
the stripped region of the partially-stripped turbine blade; and
then applying a thermal barrier recoat to the bond recoat to form a
recoated turbine blade. The recoated turbine blade comprises the
bond coating portion abutting the bond recoat, the thermal barrier
coating portion abutting the thermal barrier recoat, and the
stepped configuration. The coated turbine blade has a thermal
barrier coating system positioned on a substrate. The
partially-stripped turbine blade has a stripped region, a bond
coating portion, a thermal barrier coating portion, and a stepped
configuration.
Inventors: |
THOMPSON; Christopher Edward;
(Greenville, SC) ; WARD, JR.; John D.; (Woodruff,
SC) ; HUNT; Mark Lawrence; (Simpsonville, SC)
; LOMAS; Jonathan Matthew; (Simpsonville, SC) ;
LEWIS; Gareth William David; (Greenville, SC) ;
DEPALMA, III; Michael Anthony; (Simpsonville, SC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GENERAL ELECTRIC COMPANY |
Schenectady |
NY |
US |
|
|
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
51061175 |
Appl. No.: |
13/735342 |
Filed: |
January 7, 2013 |
Current U.S.
Class: |
428/633 ;
427/142 |
Current CPC
Class: |
F01D 5/005 20130101;
F05D 2230/31 20130101; Y10T 428/12618 20150115; F01D 5/288
20130101 |
Class at
Publication: |
428/633 ;
427/142 |
International
Class: |
F01D 5/28 20060101
F01D005/28 |
Claims
1. A recoating process, comprising: providing a coated turbine
blade, the coated turbine blade having a thermal barrier coating
system positioned on a substrate; then removing a portion of the
thermal barrier coating system to form a partially-stripped turbine
blade having a stripped region; then applying a bond recoat to the
stripped region of the partially-stripped turbine blade; and then
applying a thermal barrier recoat to the bond recoat to form a
recoated turbine blade.
2. The recoating process of claim 1, wherein the thermal barrier
coating system includes a thermal barrier coating and a bond
coat.
3. The recoating process of claim 1, wherein the removing is by
water-jet stripping.
4. The recoating process of claim 1, wherein the partially-stripped
turbine blade comprises a bond coat portion and a thermal barrier
coating portion prior to the applying of the bond recoat and the
applying of the thermal barrier recoat.
5. The recoating process of claim 1, wherein the partially-stripped
turbine blade comprises a bond coat portion and is substantially
devoid of a thermal barrier coating of the thermal barrier coating
system prior to the applying of the bond recoat and applying of the
thermal barrier recoat.
6. The recoating process of claim 1, wherein the partially-stripped
turbine blade has a stepped configuration.
7. The recoating process of claim 1, comprising inspecting the
partially-stripped turbine blade prior to applying the bond
recoat.
8. The recoating process of claim 1, wherein the applying of the
bond recoat to the partially-stripped turbine blade includes
applying a first bond recoat to the substrate and applying a second
bond recoat to the first bond recoat.
9. The recoating process of claim 1, wherein the applying of the
bond recoat is devoid of masking.
10. The recoating process of claim 1, wherein the applying of the
bond recoat to the partially-stripped turbine blade does not apply
the bond recoat outside of the stripped region of the
partially-stripped turbine blade.
11. The recoating process of claim 1, wherein the applying of the
bond recoat to the partially-stripped turbine blade applies the
bond recoat outside of the stripped region of the
partially-stripped turbine blade.
12. The recoating process of claim 1, wherein the applying of the
thermal barrier recoat is devoid of masking.
13. The recoating process of claim 1, wherein the applying of the
thermal barrier recoat to the partially-stripped turbine blade does
not apply the thermal barrier recoat outside of the stripped region
of the partially-stripped turbine blade.
14. The recoating process of claim 1, wherein the applying of the
thermal barrier recoat to the partially-stripped turbine blade
applies the thermal barrier recoat outside of the stripped region
of the partially-stripped turbine blade.
15. The recoating process of claim 1, wherein the recoated turbine
blade comprises the bond recoat, and the bond recoat abuts a bond
coating portion of the thermal barrier coating system.
16. The recoating process of claim 1, wherein the recoated turbine
blade comprises the thermal barrier recoat, and the thermal barrier
recoat abuts a thermal barrier coating portion of the thermal
barrier coating system.
17. The recoating process of claim 1, wherein the recoated turbine
blade has a stepped configuration.
18. The recoating process of claim 1, wherein the removing of the
portion of the thermal barrier coating system from the coated
turbine blade is performed without removal of the coated turbine
blade from a turbine system.
19. A recoating process, comprising: providing a coated turbine
blade, the coated turbine blade having a thermal barrier coating
system positioned on a substrate; then removing a portion of the
thermal barrier coating system to form a partially-stripped turbine
blade having a stripped region, a bond coating portion, a thermal
barrier coating portion, and a stepped configuration; then applying
a bond recoat to the stripped region of the partially-stripped
turbine blade; and then applying a thermal barrier recoat to the
bond recoat to form a recoated turbine blade; wherein the recoated
turbine blade comprises the bond coating portion abutting the bond
recoat, the thermal barrier coating portion abutting the thermal
barrier recoat, and the stepped configuration.
20. A recoated turbine blade, comprising: a substrate; a bond coat
portion abutting a bond recoat; a thermal barrier coating portion
abutting a thermal barrier recoat; and a stepped configuration of
the bond coating portion, the bond coating, the thermal barrier
portion, and the thermal barrier coating on the substrate; wherein
the bond coat portion and the thermal barrier coating portion
include post-operational features.
Description
FIELD OF THE INVENTION
[0001] The present invention is directed to manufacturing processes
and manufactured components. More particularly, the present
invention is directed to recoating turbine blades and recoated
turbine blades.
BACKGROUND OF THE INVENTION
[0002] Gas turbine blades are affected by operational use.
Extremely high temperatures and long cycle times result in
properties that can benefit from repair or replacement. For
example, extremely high temperatures and exposure to certain
materials, such as fuel, can result in oxidation, can result in
fatigue, can result in damage, or other undesirable features. To
reduce or eliminate such effects, turbine blades are replaced or
repaired at periodic intervals.
[0003] Replacement of turbine blades can be expensive. Removal of
the turbine blades for replacement from service can result in
operational downtime that can reduce overall operational
efficiency. As such, any reduction of such downtime can result in
substantial improvements in overall operational efficiency of
turbine systems utilizing turbine blades. Similarly, full stripping
of coatings on turbine blades can be expensive due to time and
materials expended in the stripping process and the recoating
process.
[0004] Also, using more than one thermal barrier coating on a
turbine blade can be undesirable aesthetically. For example,
turbine blades with multiple thermal barrier coatings may have
regions that look different from other regions. Individuals may
improperly perceive that such differences relate to the quality or
other properties of the turbine blade. Such improper perceptions
can result in decreased use and/or sales of such turbine
blades.
[0005] A recoating process and recoated turbine blade that do not
suffer from one or more of the above drawbacks would be desirable
in the art.
BRIEF DESCRIPTION OF THE INVENTION
[0006] In an exemplary embodiment, a recoating process includes
providing a coated turbine blade, then removing a portion of the
thermal barrier coating system to form a partially-stripped turbine
blade having a stripped region, then applying a bond recoat to the
stripped region of the partially-stripped turbine blade, and then
applying a thermal barrier recoat to the bond recoat to form a
recoated turbine blade. The coated turbine blade has a thermal
barrier coating system positioned on a substrate.
[0007] In another exemplary embodiment, a recoating process
includes providing a coated turbine blade having a thermal barrier
coating system positioned on a substrate, then removing a portion
of the thermal barrier coating system to form a partially-stripped
turbine blade having a stripped region, a bond coating portion, a
thermal barrier coating portion, and a stepped configuration, then
applying a bond recoat to the stripped region of the
partially-stripped turbine blade, and then applying a thermal
barrier recoat to the bond recoat to form a recoated turbine blade.
The recoated turbine blade includes the bond coating portion
abutting the bond recoat, the thermal barrier coating portion
abutting the thermal barrier recoat, and the stepped
configuration.
[0008] In another exemplary embodiment, a recoated turbine blade
includes a substrate, a bond coat portion abutting a bond recoat, a
thermal barrier coating portion abutting a thermal barrier recoat,
a stepped configuration of the bond coating portion, the bond
coating, the thermal barrier portion, and the thermal barrier
coating on the substrate. The bond coat portion and the thermal
barrier coating portion include post-operational features.
[0009] Other features and advantages of the present invention will
be apparent from the following more detailed description of the
preferred embodiment, taken in conjunction with the accompanying
drawings which illustrate, by way of example, the principles of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a flow diagram of an exemplary recoating
process.
[0011] FIG. 2 is a schematic view of a thermal barrier coating
system of a coated turbine blade during a removing step of an
exemplary recoating process according to the disclosure.
[0012] FIG. 3 is a schematic view of the coated turbine blade of
FIG. 2.
[0013] FIG. 4 is a schematic view of a thermal barrier coating
system of a coated turbine blade during a removing step of an
exemplary recoating process according to the disclosure.
[0014] FIG. 5 is a schematic view of the coated turbine blade of
FIG. 4.
[0015] FIG. 6 is a schematic view of a thermal barrier coating
system of a coated turbine blade during a recoating step of an
exemplary recoating process according to the disclosure.
[0016] FIG. 7 is a schematic view of the coated turbine blade of
FIG. 6.
[0017] FIG. 8 is a schematic view of a thermal barrier coating
system of a coated turbine blade during a recoating step of an
exemplary recoating process according to the disclosure.
[0018] FIG. 9 is a schematic view of the coated turbine blade of
FIG. 8.
[0019] Wherever possible, the same reference numbers will be used
throughout the drawings to represent the same parts.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Provided is an exemplary recoating process and recoated
turbine blade. Embodiments of the present disclosure, for example,
in comparison to processes and coated articles without partial
stripping and partial recoating, permit operational downtime to be
reduced, permit selective repair and replacement of turbine blades,
permit conserved use of materials in recoating turbine blades,
permit materials to be inspected after removal of a thermal barrier
coating and/or bond coat prior to recoating (for example,
permitting inspection of a base material), permit damage from
complete stripping to be reduced or eliminated, or a combination
thereof.
[0021] FIG. 1 schematically shows a recoating process 100. The
recoating process 100 includes providing a coated turbine blade 201
(step 102), as is further described in the embodiments shown in
FIGS. 2-5, removing a portion of a thermal barrier coating system
203 (step 104), as is further described in the embodiments shown in
FIGS. 2-5, applying a bond recoat 601 (step 106), as is further
described in the embodiments shown in FIGS. 6-7, and applying a
thermal barrier recoat 801 to the bond recoat 601 (step 108), as is
further described in the embodiments shown in FIGS. 8-9.
[0022] The coated turbine blade 201 is any suitable blade, bucket,
vane, or air foil. Referring to FIG. 2, the coated turbine blade
201 has a thermal barrier coating system 203 positioned on a
substrate 205. The substrate 205 is any suitable metal material,
metallic material, alloy, superalloy, or combination thereof.
Suitable alloys include, but are not limited to, nickel-based
alloys and cobalt-based alloys.
[0023] The thermal barrier coating system 203 is any suitable
material(s) capable of providing thermal resistance for the coated
turbine blade 201. In one embodiment, the thermal barrier coating
system 203 includes a bond coating 202 and a thermal barrier
coating 204. The bond coat 202 includes one or more bond coat
materials, such as, MCrAlY (where M is a metal element), NiCrAlY,
CoNiCrAlY, FeNiCrAlY, or a combination thereof. The thermal barrier
coating 204 includes ceramics, yttria-stabilized zirconia,
gadolinium zirconate, rare earth zirconates, or a combination
thereof.
[0024] The removing of the portion of the thermal barrier coating
203 (step 104) forms a partially-stripped turbine blade 209 having
a stripped region 211, for example, as is shown in FIGS. 2 and 4.
As used herein, the term "partially-stripped" refers to having a
portion but not all of the thermal barrier coating system 203 being
removed. The portion includes part or all of the thermal barrier
coating 204. In one embodiment, the portion includes part of the
bond coating 202. In one embodiment, the removing (step 104) is by
a stripping method, for example, water-jet stripping, grit-blast
stripping, acid stripping, or a combination thereof. The removing
(step 104) is a single-step process or a multiple-step process (for
example, with an individual step for stripping the all or a portion
of thermal barrier coating portion 204 and an individual step for
stripping a portion of the bond coating 202). In one embodiment,
the removing (step 104) is performed without removal of the coated
turbine blade 201 from a turbine system (not shown) or after
removal of the coated turbine blade 201, such as, a power
generation system or a turbine engine.
[0025] The stripped region 211 extends into the partially-stripped
turbine blade 209, for example, into a thermal barrier coating
portion 207 of the partially-stripped turbine blade 209 and a bond
coat portion 213 of the partially-stripped turbine blade 209. In
one embodiment, the stripped region 211 has a stepped
configuration, for example, as a plurality of cascading layers
arranged in a step-like manner.
[0026] As shown in FIGS. 2-3, in one embodiment, the
partially-stripped turbine blade 209 includes the bond coat portion
213 and the thermal barrier coating portion 207 prior to the
applying of the bond recoat 601 (step 106) (as shown if FIGS. 6-7)
and the applying of the thermal barrier recoat 801 (step 108) (as
shown in FIGS. 8-9). As is shown in FIGS. 4-5, in one embodiment,
the partially-stripped turbine blade 209 includes the bond coat
portion 213 and is substantially devoid of the thermal barrier
coating portion 207 (see FIGS. 2-3) and/or the thermal barrier
coating 204 of the thermal barrier coating system 203 prior to the
applying of the bond recoat 601 (step 106) and applying of the
thermal barrier recoat 801 (step 108).
[0027] In one embodiment, the method 100 includes one or more
inspection steps (not shown). The inspection steps are prior to the
removing (step 104) and/or after the removing (step 104) but prior
to the applying of the bond recoat 601 (step 106). The one or more
inspection steps are by any suitable inspection techniques.
Suitable techniques include, but are not limited to,
non-destructive techniques and destructive techniques. The one or
more inspection steps identify regions to be removed and/or
recoated, for example, due to identifiable surface features.
[0028] The bond recoat 601 and the thermal barrier recoat 801 are
applied to the partially-stripped turbine blade 209 to
predetermined regions by any suitable processes. The bond recoat
601 includes material similar to, compatible with, or identical to
the bond coating 202. The thermal barrier recoat 801 includes
material similar to, compatible with, or identical to the thermal
barrier coating 204. Suitable processes for applying the bond
recoat 601 and/or the thermal barrier recoat 801 include, but are
not limited to, air plasma spray, high-velocity oxy-fuel spray,
suspension thermal spray, chemical vapor deposition, electron beam
physical vapor deposition, physical vapor deposition, other
suitable application processes, or a combination thereof.
[0029] As shown in FIGS. 6-7, the applying of the bond recoat 601
(step 106) is to the stripped region 211 of the partially-stripped
turbine blade 209. In one embodiment, the applying of the bond
recoat 601 (step 106) includes applying a first bond recoat to the
substrate and applying a second bond recoat to the first bond
recoat. Any suitable number of recoat steps are used. In one
embodiment, the applying of the bond recoat 601 (step 106) is
devoid of masking. In one embodiment, the applying of the bond
recoat 601 (step 106) to the partially-stripped turbine blade 209
does not apply the bond recoat 601 outside of the stripped region
211 of the partially-stripped turbine blade 209. In another
embodiment, the applying of the bond recoat 601 (step 106) to the
partially-stripped turbine blade 209 applies the bond recoat 601
outside of the stripped region 211 of the partially-stripped
turbine blade 209.
[0030] As shown in FIGS. 8-9, the applying of the thermal barrier
recoat 801 (step 108) forms a recoated turbine blade 901. In one
embodiment, the applying of the thermal barrier recoat 801 (step
108) is devoid of masking. In one embodiment, the applying of the
thermal barrier recoat 801 (step 108) to the partially-stripped
turbine blade 209 does not apply the thermal barrier recoat 801
outside of the stripped region 211 of the partially-stripped
turbine blade 209. In another embodiment, the applying of the
thermal barrier recoat 801 (step 108) to the partially-stripped
turbine blade 209 applies the thermal barrier recoat 801 outside of
the stripped region 211 of the partially-stripped turbine blade
209.
[0031] After the applying of the bond recoat 601 (step 106) and the
applying of the thermal barrier recoat 801 (step 108), the recoated
turbine blade 901 is formed. In one embodiment, the recoated
turbine blade 901 includes the bond recoat 601 (see FIG. 8), and
the bond recoat 601 abuts the bond coating portion 213 (see FIG. 8)
of the thermal barrier coating system 203. In a further embodiment,
the bond coating portion 213 differs from the bond recoat 601 by
being post-operational, thereby having been oxidized, heat-exposed
(for example, to a temperature above 1,500.degree. F.),
fuel-exposed, otherwise impacted by operational use, or a
combination thereof.
[0032] In one embodiment, the recoated turbine blade 901 includes
the thermal barrier recoat 801, and the thermal barrier recoat 801
abuts the thermal barrier coating portion 207 of the thermal
barrier coating system 203. In a further embodiment, the thermal
barrier coating portion 207 differs from the thermal barrier recoat
801 by being post-operational, thereby having been oxidized,
heat-exposed (for example, to a temperature above 1,500.degree.
F.), fuel-exposed, otherwise impacted by operational use, or a
combination thereof.
[0033] The arrangement within the recoated turbine blade 901 of the
bond coat portion 213, the bond recoat 601, the thermal barrier
coating portion 207 (if present), and the thermal barrier recoat
801 is any suitable configuration. Suitable configurations include,
but are not limited to, a stepped configuration as is described
above, an overlapping configuration, a tapered configuration with a
blending of materials between layers, having mismatched layers (for
example, the bond coat portion 213 and the bond recoat 601 being
slightly out of relative alignment and/or the thermal barrier
coating portion 207 and the thermal barrier recoat 801 being
slightly out of relative alignment), any other suitable
configuration, or a combination thereof.
[0034] While the invention has been described with reference to a
preferred embodiment, it will be understood by those skilled in the
art that various changes may be made and equivalents may be
substituted for elements thereof without departing from the scope
of the invention. In addition, many modifications may be made to
adapt a particular situation or material to the teachings of the
invention without departing from the essential scope thereof.
Therefore, it is intended that the invention not be limited to the
particular embodiment disclosed as the best mode contemplated for
carrying out this invention, but that the invention will include
all embodiments falling within the scope of the appended
claims.
* * * * *