US3955935A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ductile corrosion resistant chromium-aluminum coating on superalloy substrate and method of forming
Assignee: Motors Liquidation Co
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Filing: 1974-11-27
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Granted: 1976-05-11
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Expires: 1994-11-27
Abstract
Abstract A long lived, ductile, corrosion resistant coating on a superalloy body, such as a turbine vane, preferably cobalt base, is formed by electrophoretically depositing a mixture of elemental aluminum powder and chromium-aluminum alloy powder on a superalloy substrate, and diffusing the "green" coating into the substrate. By electrodepositing on and diffusing into the alloy substrate a specified mixture of aluminum and chromium-aluminum alloy, the outward diffusion of chromium and nickel from the substrate and resultant agglomeration of precipitated carbides in the diffusion layer are minimized so that ductility of the aluminum-chromium rich coating is improved.
Inventors
- 👤 Quentin O. Shockley
- 👤 James O. Hodshire
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:51
CPC Classifications
B; B23; B23P; B23P15/00; B23P15/04; C; C25; C25D; C25D13/00; C25D13/02; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/923; Y10S428/924; Y10S428/926; Y10S428/9335; Y10S428/939; Y10T; Y10T428/00; Y10T428/12; Y10T428/12014; Y10T428/12028; Y10T428/12063; Y10T428/12493; Y10T428/12736; Y10T428/1275; Y10T428/12986
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
261 words
A metod of forming a ductile, corrosion resistant coating on a cobalt base superalloy or nickel base superalloy substrate comprising: electrophoretically codepositing a mixture containing, on a proportional weight basis, 3 to 4 parts elemental aluminum powder and one part of an alloy powder consisting essentially by weight of 70 to 80% chromium and the balance aluminum on a surface portion of a preformed article, made of a high temperature resistant alloy taken from the group consisting of cobalt base alloys and nickel base alloys, to form a porous coating of said mixture on said article and heating said article and coating at a temperature of about 1,900° F. in a protective atmosphere for at least about five hours whereby the aluminum and the chromium-aluminum alloy, interdiffuse with said substrate to form a ductile, corrosion resistant coating, said cobalt base alloys consisting essentially by weight of 50 to 75% cobalt, 20 to 30% chromium, up to about 101/2% nickel, up to 11% tungsten, up to 7% by weight total of one or more of titanium, boron, silicon, iron, tantalum and columbium, and minor amounts of carbon, manganese and silicon, and said nickel base alloys consisting essentially by weight of 40 to 80% nickel, 5 to 20% chromium, up to 10% molybdenum, up to 5.5% titanium, up to 6.5% aluminum, up to 3% columbium, up to 9% tantalum, up to 13.5% tungsten, up to 2% hafnium, up to 1% rhenium, up to 1.5% vanadium, up to 20% cobalt, up to 3% iron, and minor amounts of carbon, boron, zirconium, silicon and manganese.
Claim 2
Dependent Claim
261 words
A metod of forming a ductile, corrosion resistant coating on a cobalt base superalloy or nickel base superalloy substrate comprising: electrophoretically codepositing a mixture containing, on a proportional weight basis, 3 to 4 parts elemental aluminum powder and one part of an alloy powder consisting essentially by weight of 70 to 80% chromium and the balance aluminum on a surface portion of a preformed article, made of a high temperature resistant alloy taken from the group consisting of cobalt base alloys and nickel base alloys, to form a porous coating of said mixture on said article and heating said article and coating at a temperature of about 1,900° F. in a protective atmosphere for at least about five hours whereby the aluminum and the chromium-aluminum alloy, interdiffuse with said substrate to form a ductile, corrosion resistant coating, said cobalt base alloys consisting essentially by weight of 50 to 75% cobalt, 20 to 30% chromium, up to about 101/2% nickel, up to 11% tungsten, up to 7% by weight total of one or more of titanium, boron, silicon, iron, tantalum and columbium, and minor amounts of carbon, manganese and silicon, and said nickel base alloys consisting essentially by weight of 40 to 80% nickel, 5 to 20% chromium, up to 10% molybdenum, up to 5.5% titanium, up to 6.5% aluminum, up to 3% columbium, up to 9% tantalum, up to 13.5% tungsten, up to 2% hafnium, up to 1% rhenium, up to 1.5% vanadium, up to 20% cobalt, up to 3% iron, and minor amounts of carbon, boron, zirconium, silicon and manganese.
Claim 3
Independent Claim
176 words
A method of forming a ductile, corrosion resistant coating on a cobalt base superalloy substrate comprising: electrophoretically codepositing a mixture containing, on a proportional weight basis, 3 to 4 parts elemental aluminum powder and one part of an alloy powder consisting essentially by weight of 70 to 80% chromium and the balance aluminum on a surface portion of a preformed article, made of a high temperature resistant cobalt base alloy to form a porous coating of said mixture on said article and heating said article and coating at a temperature of about 1,900° F. in a hydrogen atmosphere for at least about five hours whereby the aluminum and the chromium-aluminum alloy interdiffuse with said substrate to form a ductile, corrosion resistant coating, said cobalt base alloy consisting essentially by weight of 50 to 75% cobalt, 20 to 30% chromium, up to about 101/2% nickel, up to 11% tungsten, up to 7% by weight total of one or more of titanium, boron, silicon, iron, tantalum and columbium, and up to 1% each of carbon, manganese and silicon.
Claim 4
Independent Claim
176 words
A method of forming a ductile, corrosion resistant coating on a cobalt base superalloy substrate comprising: electrophoretically codepositing a mixture containing, on a proportional weight basis, 3 to 4 parts elemental aluminum powder and one part of an alloy powder consisting essentially by weight of 70 to 80% chromium and the balance aluminum on a surface portion of a preformed article, made of a high temperature resistant cobalt base alloy to form a porous coating of said mixture on said article and heating said article and coating at a temperature of about 1,900° F. in a hydrogen atmosphere for at least about five hours whereby the aluminum and the chromium-aluminum alloy interdiffuse with said substrate to form a ductile, corrosion resistant coating, said cobalt base alloy consisting essentially by weight of 50 to 75% cobalt, 20 to 30% chromium, up to about 101/2% nickel, up to 11% tungsten, up to 7% by weight total of one or more of titanium, boron, silicon, iron, tantalum and columbium, and up to 1% each of carbon, manganese and silicon.
Claim 5
Dependent Claim
222 words
A heat and corrosion resistant article comprising a cobalt base alloy or nickel base alloy substrate and an aluminum-chromium diffusion coating 1/2 to 5 mils in thickness on said substrate, the diffusion coating being the diffusion product of heating, at about 1,900° F. in a protective atmosphere, the substrate and a powder metal mixture electrophoretically applied thereto, the metal content of the mixture initially consisting essentially, on a proportional weight basis, of 3 to 4 parts aluminum powder and one part of an alloy powder consisting essentially by weight of 70 to 80% chromium and the balance aluminum, said cobalt base alloy consisting essentially by weight of 50 to 75% cobalt, 20 to 30% chromium, up to about 101/2% nickel, up to 11% tungsten, up to 7% by weight total of one or more of titanium, boron, silicon, iron, tantalum and columbium, and minor amounts of carbon, manganese and silicon, and said nickel base alloy consisting essentially by weight of 40 to 80% nickel, 5 to 20% chromium, up to 10% molybdenum, up to 5.5% titanium, up to 6.5% aluminum, up to 3% columbium, up to 9% tantalum, up to 13.5% tungsten, up to 2% hafnium, up to 1% rhenium, up to 1.5% vanadium, up to 20% cobalt, up to 3% iron, and minor amounts of carbon, boron, zirconium, silicon and manganese.
Claim 6
Dependent Claim
222 words
A heat and corrosion resistant article comprising a cobalt base alloy or nickel base alloy substrate and an aluminum-chromium diffusion coating 1/2 to 5 mils in thickness on said substrate, the diffusion coating being the diffusion product of heating, at about 1,900° F. in a protective atmosphere, the substrate and a powder metal mixture electrophoretically applied thereto, the metal content of the mixture initially consisting essentially, on a proportional weight basis, of 3 to 4 parts aluminum powder and one part of an alloy powder consisting essentially by weight of 70 to 80% chromium and the balance aluminum, said cobalt base alloy consisting essentially by weight of 50 to 75% cobalt, 20 to 30% chromium, up to about 101/2% nickel, up to 11% tungsten, up to 7% by weight total of one or more of titanium, boron, silicon, iron, tantalum and columbium, and minor amounts of carbon, manganese and silicon, and said nickel base alloy consisting essentially by weight of 40 to 80% nickel, 5 to 20% chromium, up to 10% molybdenum, up to 5.5% titanium, up to 6.5% aluminum, up to 3% columbium, up to 9% tantalum, up to 13.5% tungsten, up to 2% hafnium, up to 1% rhenium, up to 1.5% vanadium, up to 20% cobalt, up to 3% iron, and minor amounts of carbon, boron, zirconium, silicon and manganese.
Claim 7
Dependent Claim
150 words
A heat and corrosion resistant article comprising a heat resistant cobalt base alloy substrate and an aluminumchromium diffusion coating 1/2 to 5 mils in thickness on said substrate, the diffusion coating being the diffusion product of heating at about 1,900° F. in a hydrogen atmosphere, the substrate and a powder metal mixture electrophoretically applied thereto, the metal content of the mixture initially consisting essentially, on a proportional weight basis, of 3 to 4 parts aluminum powder and one part of an alloy powder consisting essentially by weight of 70% to 80% chromium and the balance aluminum, and said cobalt base alloy consisting essentially by weight of 50 to 75% cobalt, 20 to 30% chromium, up to about 101/2 % nickel, up to 11% tungsten, up to 7% by weight total of one or more of titanium, boron, silicon, iron, tantalum and columbium, and minor amounts of carbon, manganese and silicon.
Claim 8
Dependent Claim
150 words
A heat and corrosion resistant article comprising a heat resistant cobalt base alloy substrate and an aluminumchromium diffusion coating 1/2 to 5 mils in thickness on said substrate, the diffusion coating being the diffusion product of heating at about 1,900° F. in a hydrogen atmosphere, the substrate and a powder metal mixture electrophoretically applied thereto, the metal content of the mixture initially consisting essentially, on a proportional weight basis, of 3 to 4 parts aluminum powder and one part of an alloy powder consisting essentially by weight of 70% to 80% chromium and the balance aluminum, and said cobalt base alloy consisting essentially by weight of 50 to 75% cobalt, 20 to 30% chromium, up to about 101/2 % nickel, up to 11% tungsten, up to 7% by weight total of one or more of titanium, boron, silicon, iron, tantalum and columbium, and minor amounts of carbon, manganese and silicon.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-05-11 | 1979-11-10 | 1980-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-11 | 1983-11-10 | 1984-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-11 | 1987-11-10 | 1988-05-11 | $7700.00 | Window Closed / Lapsed |