CA2110007A1 - Thermal barrier coating process - Google Patents
Thermal barrier coating processInfo
- Publication number
- CA2110007A1 CA2110007A1 CA002110007A CA2110007A CA2110007A1 CA 2110007 A1 CA2110007 A1 CA 2110007A1 CA 002110007 A CA002110007 A CA 002110007A CA 2110007 A CA2110007 A CA 2110007A CA 2110007 A1 CA2110007 A1 CA 2110007A1
- Authority
- CA
- Canada
- Prior art keywords
- substrate
- zirconia layer
- bondcoat
- zirconia
- barrier coating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 239000012720 thermal barrier coating Substances 0.000 title claims abstract description 20
- 238000000576 coating method Methods 0.000 title abstract description 16
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims abstract description 77
- 238000000034 method Methods 0.000 claims abstract description 35
- 230000008569 process Effects 0.000 claims abstract description 34
- 239000000758 substrate Substances 0.000 claims abstract description 27
- 238000000151 deposition Methods 0.000 claims abstract description 15
- 229910052751 metal Inorganic materials 0.000 claims abstract description 5
- 239000002184 metal Substances 0.000 claims abstract description 5
- 239000007921 spray Substances 0.000 claims description 4
- 229910052759 nickel Inorganic materials 0.000 claims description 3
- 229910045601 alloy Inorganic materials 0.000 claims 2
- 239000000956 alloy Substances 0.000 claims 2
- 229910000601 superalloy Inorganic materials 0.000 claims 1
- 239000010410 layer Substances 0.000 description 32
- 239000011248 coating agent Substances 0.000 description 10
- 238000005382 thermal cycling Methods 0.000 description 8
- 230000008021 deposition Effects 0.000 description 7
- 239000000919 ceramic Substances 0.000 description 6
- 239000000843 powder Substances 0.000 description 5
- 230000007704 transition Effects 0.000 description 5
- 230000008901 benefit Effects 0.000 description 4
- 238000002485 combustion reaction Methods 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 238000009718 spray deposition Methods 0.000 description 3
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 2
- 230000004888 barrier function Effects 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 229910002076 stabilized zirconia Inorganic materials 0.000 description 2
- RZVAJINKPMORJF-UHFFFAOYSA-N Acetaminophen Chemical group CC(=O)NC1=CC=C(O)C=C1 RZVAJINKPMORJF-UHFFFAOYSA-N 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- UOACKFBJUYNSLK-XRKIENNPSA-N Estradiol Cypionate Chemical compound O([C@H]1CC[C@H]2[C@H]3[C@@H](C4=CC=C(O)C=C4CC3)CC[C@@]21C)C(=O)CCC1CCCC1 UOACKFBJUYNSLK-XRKIENNPSA-N 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 239000012159 carrier gas Substances 0.000 description 1
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 description 1
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000005137 deposition process Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- -1 where M is Co Substances 0.000 description 1
- 229910052727 yttrium Inorganic materials 0.000 description 1
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 description 1
- RUDFQVOCFDJEEF-UHFFFAOYSA-N yttrium(III) oxide Inorganic materials [O-2].[O-2].[O-2].[Y+3].[Y+3] RUDFQVOCFDJEEF-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/02—Pretreatment of the material to be coated, e.g. for coating on selected surface areas
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/04—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the coating material
- C23C4/06—Metallic material
- C23C4/073—Metallic material containing MCrAl or MCrAlY alloys, where M is nickel, cobalt or iron, with or without non-metal elements
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/04—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the coating material
- C23C4/10—Oxides, borides, carbides, nitrides or silicides; Mixtures thereof
- C23C4/11—Oxides
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/12—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying
- C23C4/129—Flame spraying
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/12—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying
- C23C4/134—Plasma spraying
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Plasma & Fusion (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Other Surface Treatments For Metallic Materials (AREA)
- Coating By Spraying Or Casting (AREA)
- Turbine Rotor Nozzle Sealing (AREA)
Abstract
THERMAL BARRIER COATING PROCESS
ABSTRACT
A process of providing a thermal barrier coating on a metal substrate comprises the steps of:
a) applying a metallurgical bondcoat to the substrate;
b) depositing a first zirconia layer on the bondcoat;
c) depositing a second zirconia layer on the first zirconia layer; and d) controlling substrate temperature during steps b) and c) to provide the first zirconia layer with substantially zero porosity and to provide the second zirconia layer with between about 10% and 20% porosity.
A product produced by the process is also disclosed.
ABSTRACT
A process of providing a thermal barrier coating on a metal substrate comprises the steps of:
a) applying a metallurgical bondcoat to the substrate;
b) depositing a first zirconia layer on the bondcoat;
c) depositing a second zirconia layer on the first zirconia layer; and d) controlling substrate temperature during steps b) and c) to provide the first zirconia layer with substantially zero porosity and to provide the second zirconia layer with between about 10% and 20% porosity.
A product produced by the process is also disclosed.
Description
2110~0'7 T~IERMAL BARRIER COATING PROCESS
TECIINICAL EIELD
This invention relates to a proces~ for providing a thermal barrier coating on industrial gas turbine components such as combustion liners and transition pieces.
BACKGROUND PRIOR ART
Thermal barrier coating (TBC) systems are widely u~ed in high temperature applications to provide oxidation and thermal resistance protection to metallic sub~trates under high thermal gradient conditions. Conventional TBC's are applied by various powder ~pray deposition processes, and consist of an intermediate metallic bondcoat attached to the ~ubstrate and a topcoat of ~tabilized zirconia. The zirconia may be phase-stabilized with betw~:en 6 and 22 weight percent yttria, or alternatively, magnesia, ceria or similar oxides. The~e coatings typically exhibit an uncracked but porous mlcrostructure. This type of processing is done with minimal substrate preheat, and is limited to a maximum coating thickness of 25 to 30 mil. In addition, thermal cycling resistance is significantly reduced due to coating spallation via cracking and separation between the bondcoat and initial zirconia deposit at that interface. ~-More recently, superior adherence and thermal cycling resistance of zirconia to a bondcoat ha~ been achieved by virtue of a controlled microstructure. This i8 obtained by preheating the substrate to at lea~t 600F. before and during depo~ition of the zirconia, which produce~ a dense, columnar deposit which is precracked perpendicular to the interface. This readily allows the deposition and retention of a thick ceramic layer of up to 100 mil in thickne~s.
21100~17 Control of the initial zirconia layers deposited via this process i8 critical to the thermal cycling resistance of this TBC. In part, control is achieved through proce~s parameter optimization and per-pass powder injection rates which are generally lower than conventional processing.
Hence, thi~ coating has a higher thermal conductivity per unit thickness than the porous conventional coating described above, by as much as 30 to 50%. Therefore, this coating may have an effective thermal resistance only one-third that of its absolute thickness advantage.
Another process for applying a ceramic thermal barrier ~ ~ ~
to a metallic substrate i8 disclosed in U.S. Patent No. ~-4,503,130. This patent describes a process where graded ceramic/metallic layers are applied between the bondcoat and two upper layers of ceramic, one dense and one porous. ~-~
In U.S. Patent No. 4,613,259, apparatu3 is disclosed for controlling powder flow rate in a carrier gas. The apparatu~ i8 employed ~pecifically to control the production of graded ceramic/metallic layers on a substrate.
SUMMARY OF T~E INVENTION
The objective of this invention is to provide a ~`
superior TBC coating through plasma spray deposition of an initial zirconia deposit with a columnar microstructure achieved with controlled substrate preheat. This first or inner layer promotes good adherence, and is followed by a smooth, in-process transition to conditions which favor deposition of a controlled porosity, highly thermal resistivo zirconia outer layer.
A more specific ob~ective of this invention i~ to provide a cost-effective coating process for large ~urface area components such as industrial landbased gas turbine combu~tion liners and transition pieces, which typically , 2 ~
reguire TBC coatingc over 1500-2000 ~guare inches of surface area.
The advantage of this two-layer zirconia TBC
microstructure i5 that it maximizeC thermal cycling resistance and thermal re~i~tivity at an overall lower coating thicknes~. This will re~ult in reduced manufacturing cycle time and cost. Further reduction~ in cycle time may be achieved through increases in powder deposition rates, particularly for the outer zirconia layer, since a porou~ structure may be easier to achieve and control in this manner.
The coating process of this invention thus produces a ~ ~-thermally resistant surface layer compri&ed of two layers ~transitioned through grading of poro6ity) of 6tabilized zirconia ceramic attached to an oxidation and corrosion resistant metallic bondcoat, which iq itself metallurgically bonded to a metallic substrate.
More specifically, an air pla~ma ~pray process used to deposit the inner ~tabilized-zirconia Layer, however, i8 controlled to produce a dense, columnar micro6tructure which has lower thermal resi~tivity, but which is extremely well adhered to the metallic bondcoat and which al~o provides maximum thermal cycling resi~tance to the composite, multi-layered coating system. The outer stabilized zirconia layer is applied by the air plasma spray deposition process to produce a controlled micro~tructure containing minimal cracks and approximately lO to 20X poro~ity, which enhances thermal resistivity of the layer.
In accordance with the broader aspects of the invention, therefore, a process is provided for applying a thermal barrier coating to a metallic substrate which comprises the steps of:
a) applying a metallurgical bondcoat to the sub~trate;
21~'~
b) depositing a first zirconia layer on the bondcoat, the fir~t zirconia layer having a dense, c~lumnar micro~tructure; and c) depositing a ~econd zirconia layer on the fir~t zirconia layer, the second zirconia layer having a microstructure having a porosity of between 10 and 20%.
In another a~pect, the invention relates to a ga6 turbine component having a thermal barrier coating thereon, applied by the above described process.
By the above described invention, a superior thermal barrier coating is achieved which exhibits excellent adhesion, thermal cycling and oxidation resigtance, and ~-high thermal resi~tivity. ~ ;
Additional objects and advantages of the invention will become apparent from the detailed description which follows.
:::
BRIEF DESCRIPTION OF THE DRAWINGS
FIGURE 1 is a cro~s section of a metal ~ub6trate provided with a thermal barrier coating in accordance with a fir~t exemplary embodiment of the invention. -~
BEST MODE FOR CARRYING OUT THE INVENTION
With reference to the Figure, a sichematic illustration of an exemplary embodiment of the invention i~ shown to include a metallic substrate material 10 with a bondcoat 12 metallurgically bonded thereto. The substrate 10 may be, for example, a large ~uperalloy surface area component of an industrial gas turbine engine. More specifically, the ~ubstrate may be a combustion liner or a transition piece Iconnecting the combustion chamber to the turbine) or other large component which typically require~ a thermal barrier coating over 1500-2000 ~quare in~hes of ~urface area.
The metallic bondcoat 12 may be applied by a variety of thermal spray processes including air or vacuum plasma, or High Velocity Oxy-Fuel (HVOF) deposition to a ~uitable thicknes6, and may compri~e MCrAlY chemical compositions, where M is Co, Ni, Fe or combinations of these elements.
For example, one such bondcoat may comprise 10-30% weight Chromium, 3-13 wt.% aluminum, and 0.05 to 1.0 wt.% yttrium or other rare earth elements, and the balance M.
An inner stabilized zirconia deposit layer 14 i6 applied to the bondcoat 12 by an air plasma ~pray process.
The process is controlled (by substrate preheat) to produce a den~e (i.e., substantially zero porosity), columnar microstructure which has lower thermal resistivity, but which i8 extremely well adhered to the metallic bondcoat 12. In thi~ regard, it i8 not necessary in this proces6 to apply graded layers (transitioning from all metal to all non-metallic) to insure adherence between layer 14 and the metallic bondcoat 12. More specifically, the 6ubstrate temperature is initially elevated to a temperature in excess of 600F. and up to about 1200F. or higher to provide the den~e, columnar mlcrostructure. The thickness of thi~ inner layer 14 i B preferably between about 2 and about 20 mil, but may be greater. This inner layer 14 provides maximum thermal cycling resistance to the composite, multi-layered coating system.
Following the deposition of the inner layer 14, the proces~ is continued under conditions which favor the deposition of a controlled porosity, highly thermal resistive zirconia outer layer 16, having a thickness of between about 10 and about 45 mil. The outer zirconia layer 16 is also applied by the air plasma spray deposition process to produce a controlled microstructure containing minimal cracks and approximately a 10 to 20X porosity, which enhances the thermal resistivity of the iayer. This is achieved by permitting the substrate 10 to cool to a lower temperature, betwéen ambient and up to about 600F.
. 17MY04066 6 21~00~ ~
As a result of the continuity of the process, a transition zone between the inner and outer layers iB created which: ::
has a porocity of between 0 and about 10%.
~ By thu~ controlling the substrate heat beore and :~
during depo6it of the zirconia layer6 14 and 16, it i~
po~sible to control the density/poro6ity of the layer~ and thereby maximize the adherence of the inner layer 14 to the bondcoat 12, and at the ~ame time, maximize the thermal re~istivity of the outer layer 16.
The advantage of this two-layer zirconia TBC ~ :
microstructure is that it maximize6 thermal cycling re6i6tance and thermal re6istivity at a lower total coating thickness. This will result in reduced manufacturing cycle time and cost. Further reductions in cycl~! time may be achieved through increases in powder deposition rate6, particularly for the outer zirconia layer, ~ince a porou6 ~tructure may be easier to achieve and control in this manner.
While the invention ha~ been described with respect to what i~ pre~ently regarded as the mo6t practical . .
embodiments thereof, it will be under6tood by tho~e of --ordinary skill in the art that various alterations and modification6 may be made which nevertheless remain within the scope of the inventior.. a6 defined by the claims which follow.
TECIINICAL EIELD
This invention relates to a proces~ for providing a thermal barrier coating on industrial gas turbine components such as combustion liners and transition pieces.
BACKGROUND PRIOR ART
Thermal barrier coating (TBC) systems are widely u~ed in high temperature applications to provide oxidation and thermal resistance protection to metallic sub~trates under high thermal gradient conditions. Conventional TBC's are applied by various powder ~pray deposition processes, and consist of an intermediate metallic bondcoat attached to the ~ubstrate and a topcoat of ~tabilized zirconia. The zirconia may be phase-stabilized with betw~:en 6 and 22 weight percent yttria, or alternatively, magnesia, ceria or similar oxides. The~e coatings typically exhibit an uncracked but porous mlcrostructure. This type of processing is done with minimal substrate preheat, and is limited to a maximum coating thickness of 25 to 30 mil. In addition, thermal cycling resistance is significantly reduced due to coating spallation via cracking and separation between the bondcoat and initial zirconia deposit at that interface. ~-More recently, superior adherence and thermal cycling resistance of zirconia to a bondcoat ha~ been achieved by virtue of a controlled microstructure. This i8 obtained by preheating the substrate to at lea~t 600F. before and during depo~ition of the zirconia, which produce~ a dense, columnar deposit which is precracked perpendicular to the interface. This readily allows the deposition and retention of a thick ceramic layer of up to 100 mil in thickne~s.
21100~17 Control of the initial zirconia layers deposited via this process i8 critical to the thermal cycling resistance of this TBC. In part, control is achieved through proce~s parameter optimization and per-pass powder injection rates which are generally lower than conventional processing.
Hence, thi~ coating has a higher thermal conductivity per unit thickness than the porous conventional coating described above, by as much as 30 to 50%. Therefore, this coating may have an effective thermal resistance only one-third that of its absolute thickness advantage.
Another process for applying a ceramic thermal barrier ~ ~ ~
to a metallic substrate i8 disclosed in U.S. Patent No. ~-4,503,130. This patent describes a process where graded ceramic/metallic layers are applied between the bondcoat and two upper layers of ceramic, one dense and one porous. ~-~
In U.S. Patent No. 4,613,259, apparatu3 is disclosed for controlling powder flow rate in a carrier gas. The apparatu~ i8 employed ~pecifically to control the production of graded ceramic/metallic layers on a substrate.
SUMMARY OF T~E INVENTION
The objective of this invention is to provide a ~`
superior TBC coating through plasma spray deposition of an initial zirconia deposit with a columnar microstructure achieved with controlled substrate preheat. This first or inner layer promotes good adherence, and is followed by a smooth, in-process transition to conditions which favor deposition of a controlled porosity, highly thermal resistivo zirconia outer layer.
A more specific ob~ective of this invention i~ to provide a cost-effective coating process for large ~urface area components such as industrial landbased gas turbine combu~tion liners and transition pieces, which typically , 2 ~
reguire TBC coatingc over 1500-2000 ~guare inches of surface area.
The advantage of this two-layer zirconia TBC
microstructure i5 that it maximizeC thermal cycling resistance and thermal re~i~tivity at an overall lower coating thicknes~. This will re~ult in reduced manufacturing cycle time and cost. Further reduction~ in cycle time may be achieved through increases in powder deposition rates, particularly for the outer zirconia layer, since a porou~ structure may be easier to achieve and control in this manner.
The coating process of this invention thus produces a ~ ~-thermally resistant surface layer compri&ed of two layers ~transitioned through grading of poro6ity) of 6tabilized zirconia ceramic attached to an oxidation and corrosion resistant metallic bondcoat, which iq itself metallurgically bonded to a metallic substrate.
More specifically, an air pla~ma ~pray process used to deposit the inner ~tabilized-zirconia Layer, however, i8 controlled to produce a dense, columnar micro6tructure which has lower thermal resi~tivity, but which is extremely well adhered to the metallic bondcoat and which al~o provides maximum thermal cycling resi~tance to the composite, multi-layered coating system. The outer stabilized zirconia layer is applied by the air plasma spray deposition process to produce a controlled micro~tructure containing minimal cracks and approximately lO to 20X poro~ity, which enhances thermal resistivity of the layer.
In accordance with the broader aspects of the invention, therefore, a process is provided for applying a thermal barrier coating to a metallic substrate which comprises the steps of:
a) applying a metallurgical bondcoat to the sub~trate;
21~'~
b) depositing a first zirconia layer on the bondcoat, the fir~t zirconia layer having a dense, c~lumnar micro~tructure; and c) depositing a ~econd zirconia layer on the fir~t zirconia layer, the second zirconia layer having a microstructure having a porosity of between 10 and 20%.
In another a~pect, the invention relates to a ga6 turbine component having a thermal barrier coating thereon, applied by the above described process.
By the above described invention, a superior thermal barrier coating is achieved which exhibits excellent adhesion, thermal cycling and oxidation resigtance, and ~-high thermal resi~tivity. ~ ;
Additional objects and advantages of the invention will become apparent from the detailed description which follows.
:::
BRIEF DESCRIPTION OF THE DRAWINGS
FIGURE 1 is a cro~s section of a metal ~ub6trate provided with a thermal barrier coating in accordance with a fir~t exemplary embodiment of the invention. -~
BEST MODE FOR CARRYING OUT THE INVENTION
With reference to the Figure, a sichematic illustration of an exemplary embodiment of the invention i~ shown to include a metallic substrate material 10 with a bondcoat 12 metallurgically bonded thereto. The substrate 10 may be, for example, a large ~uperalloy surface area component of an industrial gas turbine engine. More specifically, the ~ubstrate may be a combustion liner or a transition piece Iconnecting the combustion chamber to the turbine) or other large component which typically require~ a thermal barrier coating over 1500-2000 ~quare in~hes of ~urface area.
The metallic bondcoat 12 may be applied by a variety of thermal spray processes including air or vacuum plasma, or High Velocity Oxy-Fuel (HVOF) deposition to a ~uitable thicknes6, and may compri~e MCrAlY chemical compositions, where M is Co, Ni, Fe or combinations of these elements.
For example, one such bondcoat may comprise 10-30% weight Chromium, 3-13 wt.% aluminum, and 0.05 to 1.0 wt.% yttrium or other rare earth elements, and the balance M.
An inner stabilized zirconia deposit layer 14 i6 applied to the bondcoat 12 by an air plasma ~pray process.
The process is controlled (by substrate preheat) to produce a den~e (i.e., substantially zero porosity), columnar microstructure which has lower thermal resistivity, but which i8 extremely well adhered to the metallic bondcoat 12. In thi~ regard, it i8 not necessary in this proces6 to apply graded layers (transitioning from all metal to all non-metallic) to insure adherence between layer 14 and the metallic bondcoat 12. More specifically, the 6ubstrate temperature is initially elevated to a temperature in excess of 600F. and up to about 1200F. or higher to provide the den~e, columnar mlcrostructure. The thickness of thi~ inner layer 14 i B preferably between about 2 and about 20 mil, but may be greater. This inner layer 14 provides maximum thermal cycling resistance to the composite, multi-layered coating system.
Following the deposition of the inner layer 14, the proces~ is continued under conditions which favor the deposition of a controlled porosity, highly thermal resistive zirconia outer layer 16, having a thickness of between about 10 and about 45 mil. The outer zirconia layer 16 is also applied by the air plasma spray deposition process to produce a controlled microstructure containing minimal cracks and approximately a 10 to 20X porosity, which enhances the thermal resistivity of the iayer. This is achieved by permitting the substrate 10 to cool to a lower temperature, betwéen ambient and up to about 600F.
. 17MY04066 6 21~00~ ~
As a result of the continuity of the process, a transition zone between the inner and outer layers iB created which: ::
has a porocity of between 0 and about 10%.
~ By thu~ controlling the substrate heat beore and :~
during depo6it of the zirconia layer6 14 and 16, it i~
po~sible to control the density/poro6ity of the layer~ and thereby maximize the adherence of the inner layer 14 to the bondcoat 12, and at the ~ame time, maximize the thermal re~istivity of the outer layer 16.
The advantage of this two-layer zirconia TBC ~ :
microstructure is that it maximize6 thermal cycling re6i6tance and thermal re6istivity at a lower total coating thickness. This will result in reduced manufacturing cycle time and cost. Further reductions in cycl~! time may be achieved through increases in powder deposition rate6, particularly for the outer zirconia layer, ~ince a porou6 ~tructure may be easier to achieve and control in this manner.
While the invention ha~ been described with respect to what i~ pre~ently regarded as the mo6t practical . .
embodiments thereof, it will be under6tood by tho~e of --ordinary skill in the art that various alterations and modification6 may be made which nevertheless remain within the scope of the inventior.. a6 defined by the claims which follow.
Claims (18)
1. A process of producing a thermal barrier coating on a metal substrate comprising the steps of:
a) applying a metallurgical bondcoat to the substrate;
b) depositing a first zirconia layer on the bondcoat, the first zirconia layer having a dense, columnar microstructure; and c) depositing a second zirconia layer on the first zirconia layer, the second zirconia layer having a microstructure with a porosity of between 10 and 20%.
a) applying a metallurgical bondcoat to the substrate;
b) depositing a first zirconia layer on the bondcoat, the first zirconia layer having a dense, columnar microstructure; and c) depositing a second zirconia layer on the first zirconia layer, the second zirconia layer having a microstructure with a porosity of between 10 and 20%.
2. The process of claim 1 wherein said bondcoat comprises an alloy of MCrAlY where M is one of Co, Ni, Fe or combinations thereof.
3. The process of claim 1 wherein steps b) and c) are carried out using an air plasma spray process.
4. The process of claim 1 wherein step a) is carried out using a thermal spray process.
5. The process of claim 1 wherein, during step b), the substrate is maintained at a temperature above 600°F.
6. The process of claim 1 wherein during step a), the substrate is maintained at a temperature of less than 600°F.
7. The process of claim 5 wherein during step a), the substrate is maintained at a temperature of less than 600°F.
8. The process of claim 2 wherein steps b) and c) are carried out using an air plasma spray process.
9. The process of claim 1 wherein the substrate is comprised of a superalloy.
10. The process of claim 1 wherein the first zirconia layer has a thickness of between about 2 and about 20 mil.
11. The process of claim 1 wherein the second zirconia layer has a thickness of between about 10 and about 45 mil.
12. A process of providing a thermal barrier coating on a metal substrate comprising the steps of:
a) applying a metallurgical bondcoat to the substrate;
b) depositing a first zirconia layer on the bondcoat;
c) depositing a second zirconia layer on the first zirconia layer; and d) controlling substrate temperature during steps b) and c) to provide said first zirconia layer with substantially zero porosity and to provide said second zirconia layer with about 10% porosity.
a) applying a metallurgical bondcoat to the substrate;
b) depositing a first zirconia layer on the bondcoat;
c) depositing a second zirconia layer on the first zirconia layer; and d) controlling substrate temperature during steps b) and c) to provide said first zirconia layer with substantially zero porosity and to provide said second zirconia layer with about 10% porosity.
13. The process of claim 12 wherein, during step b), the substrate is maintained at a temperature above 600°F.
14. The process of claim 12 wherein during step a), the substrate is maintained at a temperature of less than 600°F.
15. The process of claim 14 wherein during step a), the substrate is maintained at a temperature of less than 600°F.
16. The process of claim 12 wherein said bondcoat comprises an alloy of MCrAlY where M is one of Co, Ni, Fe or combinations thereof.
17. A gas turbine component having a surface provided with a thermal barrier coating in accordance with the process of claim 1.
18. The invention as defined in any of the preceding claims including any further features of novelty disclosed.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US99692092A | 1992-12-29 | 1992-12-29 | |
| US996,920 | 1992-12-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2110007A1 true CA2110007A1 (en) | 1994-06-30 |
Family
ID=25543430
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002110007A Abandoned CA2110007A1 (en) | 1992-12-29 | 1993-11-25 | Thermal barrier coating process |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0605196A1 (en) |
| JP (1) | JPH06235074A (en) |
| KR (1) | KR940014878A (en) |
| CA (1) | CA2110007A1 (en) |
| NO (1) | NO934862L (en) |
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| EP0705911B1 (en) * | 1994-10-04 | 2001-12-05 | General Electric Company | Thermal barrier coating |
| US5558922A (en) * | 1994-12-28 | 1996-09-24 | General Electric Company | Thick thermal barrier coating having grooves for enhanced strain tolerance |
| US5512382A (en) * | 1995-05-08 | 1996-04-30 | Alliedsignal Inc. | Porous thermal barrier coating |
| US6102656A (en) * | 1995-09-26 | 2000-08-15 | United Technologies Corporation | Segmented abradable ceramic coating |
| JPH1088368A (en) * | 1996-09-19 | 1998-04-07 | Toshiba Corp | Thermal insulation coating member and its production |
| US6057047A (en) * | 1997-11-18 | 2000-05-02 | United Technologies Corporation | Ceramic coatings containing layered porosity |
| US5876860A (en) * | 1997-12-09 | 1999-03-02 | N.V. Interturbine | Thermal barrier coating ceramic structure |
| US6106959A (en) * | 1998-08-11 | 2000-08-22 | Siemens Westinghouse Power Corporation | Multilayer thermal barrier coating systems |
| US6287644B1 (en) | 1999-07-02 | 2001-09-11 | General Electric Company | Continuously-graded bond coat and method of manufacture |
| US6716539B2 (en) * | 2001-09-24 | 2004-04-06 | Siemens Westinghouse Power Corporation | Dual microstructure thermal barrier coating |
| US7258934B2 (en) | 2002-09-25 | 2007-08-21 | Volvo Aero Corporation | Thermal barrier coating and a method of applying such a coating |
| JP4616648B2 (en) * | 2002-09-25 | 2011-01-19 | ボルボ エアロ コーポレイション | Thermal barrier coating and method of applying such a coating |
| SE527179C2 (en) * | 2003-12-05 | 2006-01-17 | Sandvik Intellectual Property | Thin film solar cell or thin film battery, comprising a zirconia coated ferritic chrome strip product |
| JP4645030B2 (en) * | 2003-12-18 | 2011-03-09 | 株式会社日立製作所 | Heat resistant member with thermal barrier coating |
| US7354663B2 (en) | 2004-04-02 | 2008-04-08 | Mitsubishi Heavy Industries, Ltd. | Thermal barrier coating, manufacturing method thereof, turbine part and gas turbine |
| US7597966B2 (en) * | 2005-06-10 | 2009-10-06 | General Electric Company | Thermal barrier coating and process therefor |
| US20070099013A1 (en) * | 2005-10-27 | 2007-05-03 | General Electric Company | Methods and apparatus for manufacturing a component |
| WO2007112783A1 (en) * | 2006-04-06 | 2007-10-11 | Siemens Aktiengesellschaft | Layered thermal barrier coating with a high porosity, and a component |
| US8372488B2 (en) * | 2006-05-01 | 2013-02-12 | General Electric Company | Methods and apparatus for thermal barrier coatings with improved overall thermal insulation characteristics |
| US7875370B2 (en) | 2006-08-18 | 2011-01-25 | United Technologies Corporation | Thermal barrier coating with a plasma spray top layer |
| DE102008007870A1 (en) | 2008-02-06 | 2009-08-13 | Forschungszentrum Jülich GmbH | Thermal barrier coating system and process for its preparation |
| US20090252985A1 (en) * | 2008-04-08 | 2009-10-08 | Bangalore Nagaraj | Thermal barrier coating system and coating methods for gas turbine engine shroud |
| EP2196559A1 (en) | 2008-12-15 | 2010-06-16 | ALSTOM Technology Ltd | Thermal barrier coating system, components coated therewith and method for applying a thermal barrier coating system to components |
| US20110033284A1 (en) * | 2009-08-04 | 2011-02-10 | United Technologies Corporation | Structurally diverse thermal barrier coatings |
| CN101698364B (en) * | 2009-11-03 | 2013-08-28 | 西安交通大学 | Thermal barrier coating and preparation technology thereof |
| RU2445199C2 (en) * | 2010-03-25 | 2012-03-20 | Общество с ограниченной ответственностью "Производственное предприятие Турбинаспецсервис" | Method of hardening turbo machine nozzle vane unit made from nickel and cobalt alloys |
| US9034479B2 (en) | 2011-10-13 | 2015-05-19 | General Electric Company | Thermal barrier coating systems and processes therefor |
| US9023486B2 (en) | 2011-10-13 | 2015-05-05 | General Electric Company | Thermal barrier coating systems and processes therefor |
| DE102012200560B4 (en) * | 2012-01-16 | 2014-08-21 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | A method of producing a ceramic layer on a surface formed of a Ni-based alloy and a ceramic layer article |
| US10280765B2 (en) | 2013-11-11 | 2019-05-07 | United Technologies Corporation | Article with coated substrate |
| JP6016861B2 (en) * | 2014-08-26 | 2016-10-26 | 三菱重工業株式会社 | Coating method for machine parts |
| DE102014222686A1 (en) * | 2014-11-06 | 2016-05-12 | Siemens Aktiengesellschaft | Double-layered thermal barrier coating by different coating methods |
| RU2702515C1 (en) * | 2018-06-06 | 2019-10-08 | Общество с ограниченной ответственностью "Научно-производственное предприятие "Уралавиаспецтехнология" | Method of nickel-based alloy part reinforcing treatment (versions) |
| RU2697758C1 (en) * | 2019-01-14 | 2019-08-19 | федеральное государственное бюджетное образовательное учреждение высшего образования "Уфимский государственный авиационный технический университет" | Method of applying heat-resistant coatings y-mo-o from vacuum-arc discharge plasma |
| CN113088859A (en) * | 2021-03-30 | 2021-07-09 | 潍柴动力股份有限公司 | Composite coating, piston, engine and vehicle |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4503130A (en) * | 1981-12-14 | 1985-03-05 | United Technologies Corporation | Prestressed ceramic coatings |
| EP0185603B1 (en) * | 1984-11-28 | 1989-11-08 | United Technologies Corporation | Improved durability metallic-ceramic turbine air seals |
| US4588607A (en) * | 1984-11-28 | 1986-05-13 | United Technologies Corporation | Method of applying continuously graded metallic-ceramic layer on metallic substrates |
| US4613259A (en) * | 1984-11-28 | 1986-09-23 | United Technologies Corporation | Apparatus for controlling powder flow rate in a carrier gas |
| US4880614A (en) * | 1988-11-03 | 1989-11-14 | Allied-Signal Inc. | Ceramic thermal barrier coating with alumina interlayer |
| IL99473A0 (en) * | 1990-09-20 | 1992-08-18 | United Technologies Corp | Columnar ceramic thermal barrier coating with improved adherence |
| GB9204791D0 (en) * | 1992-03-05 | 1992-04-22 | Rolls Royce Plc | A coated article |
-
1993
- 1993-11-25 CA CA002110007A patent/CA2110007A1/en not_active Abandoned
- 1993-12-22 EP EP93310442A patent/EP0605196A1/en not_active Withdrawn
- 1993-12-24 JP JP5325561A patent/JPH06235074A/en not_active Withdrawn
- 1993-12-28 NO NO934862A patent/NO934862L/en unknown
- 1993-12-28 KR KR1019930030354A patent/KR940014878A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| NO934862L (en) | 1994-06-30 |
| JPH06235074A (en) | 1994-08-23 |
| KR940014878A (en) | 1994-07-19 |
| EP0605196A1 (en) | 1994-07-06 |
| NO934862D0 (en) | 1993-12-28 |
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