US4933239A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Aluminide coating for superalloys
Assignee: RTX Corp
•
Filing: 1989-03-06
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Granted: 1990-06-12
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Expires: 2009-03-06
Abstract
Abstract A protective coating system for superalloys is described. The coating is an active element enriched aluminide, and can be formed by aluminizing an overlay coated superalloy, wherein during the aluminizing process, aluminum diffuses completely through the overlay coating and into the substrate. The coating system exhibits desirable oxidation resistance and resistance to thermal fatigue cracking, due to the presence of oxygen active elements in the overlay.
Inventors
- 👤 Walter E. Olson
- 👤 Dinesh K. Gupta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:20
CPC Classifications
C; C23; C23C; C23C10/00; C23C10/02; C23C10/28; C23C10/34; C23C10/36; C23C10/48; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12014; Y10T428/12028; Y10T428/12063; Y10T428/1209; Y10T428/12493; Y10T428/12736; Y10T428/1275; Y10T428/12771; Y10T428/12806; Y10T428/12826; Y10T428/12861; Y10T428/12931; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
86 words
An article having resistance to oxidation and thermal mechanical fatigue comprising a substrate selected from the group consisting of nickel and cobalt base superalloys, and a coating 0.001-0.005 inches thick diffused with the substrate, wherein the coating has an outer zone and a diffusion zone inward thereof, the outer zone consisting essentially of, by weight percent, 21-35 Al, 0.1-5 Y, 0.1-7 Si, 0.1-2 Hf, 5-30 Cr, 10-40 Co, and the balance nickel, and the diffusion zone having a lesser concentration of aluminum than the outer zone.
Claim 2
Dependent Claim
86 words
An article having resistance to oxidation and thermal mechanical fatigue comprising a substrate selected from the group consisting of nickel and cobalt base superalloys, and a coating 0.001-0.005 inches thick diffused with the substrate, wherein the coating has an outer zone and a diffusion zone inward thereof, the outer zone consisting essentially of, by weight percent, 21-35 Al, 0.1-5 Y, 0.1-7 Si, 0.1-2 Hf, 5-30 Cr, 10-40 Co, and the balance nickel, and the diffusion zone having a lesser concentration of aluminum than the outer zone.
Claim 3
Dependent Claim
19 words
The article of claim 1 wherein the aluminum concentration in the diffusion zone decreases as a function of thickness.
Claim 4
Dependent Claim
117 words
A process for producing a coated nickel or cobalt base superalloy article having resistance to oxidation and thermal fatigue, comprising the steps of: (a) applying a 0.0005-0.003 inch thick overlay coating to the superalloy surface, wherein said overlay coating contains yttrium, silicon and hafnium; and (b) diffusing aluminum through the overlay coating and into the superalloy substrate so as to form a coating characterized by an outer coating zone containing about 21-35 weight percent aluminum and a diffusion zone between the outer zone and the substrate, wherein the diffusion zone has a lesser concentration of aluminum than the outer zone and the combined thickness of the outer coating zone and the diffusion zone is about 0.001-0.005 inches.
Claim 5
Dependent Claim
117 words
A process for producing a coated nickel or cobalt base superalloy article having resistance to oxidation and thermal fatigue, comprising the steps of: (a) applying a 0.0005-0.003 inch thick overlay coating to the superalloy surface, wherein said overlay coating contains yttrium, silicon and hafnium; and (b) diffusing aluminum through the overlay coating and into the superalloy substrate so as to form a coating characterized by an outer coating zone containing about 21-35 weight percent aluminum and a diffusion zone between the outer zone and the substrate, wherein the diffusion zone has a lesser concentration of aluminum than the outer zone and the combined thickness of the outer coating zone and the diffusion zone is about 0.001-0.005 inches.
Claim 6
Dependent Claim
19 words
The process of claim 3, wherein the overlay is applied to a thickness of between 0.0005 and 0.0015 inches.
Claim 7
Dependent Claim
28 words
The process of claim 3, wherein the combined thickness of the outer zone and diffusion zone is at least about 100% greater than the initial overlay coating thickness.
Claim 8
Dependent Claim
31 words
The process of claim 3, wherein the overlay is applied by plasma spraying powder in such a manner that the powder particles are substantially molten when they strike the superalloy surface.
Claim 9
Dependent Claim
17 words
The process of claim 6, wherein said plasma spray powder contains at least 5 weight percent aluminum.
Claim 10
Dependent Claim
13 words
The article of claim 4, wherein the coating thickness is about 0.002-0.003 inches.
Claim 11
Dependent Claim
16 words
The process of claim 5, wherein the combined thickness of the coating is about 0.002-0.003 inches.
Claim 12
Dependent Claim
18 words
The process of claim 6, wherein the overlay coating is applied by a low pressure plasma spray process.
Claim 13
Dependent Claim
16 words
The process of claim 3 wherein the overlay coating is peened before the step of diffusing.
Claim 14
Dependent Claim
27 words
The process of claim 3, wherein the overlay coating applied in step (a) consists essentially of, by weight percent. 10-40Co, 5-30Cr, 5-15Al, 0.1-5Y, 0.1-7Si, 0.1-2Hf, balance Ni.
Claim 15
Dependent Claim
30 words
The process of claim 12, wherein the overlay coating consists essentially of, by weight percent, about 22 Co, 17 Cr, 12.5 Cr, 0.6 Y, 0.4 Si, 0.2 Hf, balance Ni.
Claim 16
Dependent Claim
25 words
The process of claim 12, wherein the combined amount of yttrium, silicon and hafnium in the overlay coating is between about 0.5 and 9 percent.
Claim 17
Dependent Claim
25 words
The process of claim 12, wherein the combined amount of yttrium, silicon and hafnium in the overlay coating is between about 0.5 and 6 percent.
Claim 18
Dependent Claim
23 words
The process of claim 12, wherein the combined amount of yttrium, silicon and hafnium in the overlay coating is between about 1.2 percent.
Claim 19
Dependent Claim
130 words
A process for producing a coated nickel or cobalt base superalloy article having resistance to oxidation and thermal fatigue, comprising the steps of: (a) applying a 0.0005-0.003 inch thick overlay coating to the superalloy surface, wherein said overlay coating contains at least two oxygen active elements in a combined amount between about 0.5 and 9 weight percent; and (b) diffusing aluminum through the overlay coating and into the superalloy substrate so as to form a coating characterized by an outer coating zone containing about 21-35 weight percent aluminum and a diffusion zone between the outer zone and the substrate, wherein the diffusion zone has a lesser concentration of aluminum than the outer zone and the combined thickness of the outer coating zone and the diffusion zone is about 0.001-0.005 inches.
Claim 20
Dependent Claim
130 words
A process for producing a coated nickel or cobalt base superalloy article having resistance to oxidation and thermal fatigue, comprising the steps of: (a) applying a 0.0005-0.003 inch thick overlay coating to the superalloy surface, wherein said overlay coating contains at least two oxygen active elements in a combined amount between about 0.5 and 9 weight percent; and (b) diffusing aluminum through the overlay coating and into the superalloy substrate so as to form a coating characterized by an outer coating zone containing about 21-35 weight percent aluminum and a diffusion zone between the outer zone and the substrate, wherein the diffusion zone has a lesser concentration of aluminum than the outer zone and the combined thickness of the outer coating zone and the diffusion zone is about 0.001-0.005 inches.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-11 | 1993-12-11 | 1994-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-11 | 1997-12-11 | 1998-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-11 | 2001-12-11 | 2002-06-12 | $7700.00 | Window Closed / Lapsed |