US4086391A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alumina forming coatings containing hafnium for high temperature applications
Assignee: RTX Corp
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Filing: 1976-09-01
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Granted: 1978-04-25
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Expires: 1996-09-01
Abstract
Abstract Coatings are described which are particularly suited for the protection of nickel and cobalt superalloy articles at elevated temperatures. The protective nature of the coatings is due to the formation of an alumina layer on the surface of the coating which serves to reduce oxidation/corrosion. The coatings contain aluminum, chromium, and one metal chosen from the group consisting of nickel and cobalt or mixtures thereof. The coatings further contain a small controlled percentage of hafnium which serves to greatly improve the adherence and durability of the protective alumina film on the surface of the coating.
Inventors
- 👤 Charles Stanley Giggins, Jr.
- 👤 Bernard Henry Kear
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:43
CPC Classifications
C; C22; C22C; C22C19/00; C22C19/03; C22C19/05; C23; C23C; C23C30/00; C23C4/00; C23C4/04; C23C4/06; C23C4/073; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12014; Y10T428/12028; Y10T428/12063; Y10T428/12493; Y10T428/12535; Y10T428/12583; Y10T428/1259; Y10T428/1266; Y10T428/12667; Y10T428/12771; Y10T428/12861; Y10T428/12937
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
75 words
A method of protecting superalloy articles from oxidation/corrosion at elevated temperatures which comprises: applying a layer of material to the surface of the article, said material having a thickness of from 0.001 to 0.010 inches and consisting essentially of from about 10 to about 45 percent chromium, from about 6 to about 25 percent aluminum, from about 0.5 to about 3 percent hafnium, balance chosen from the group consisting of nickel, cobalt, and mixtures thereof.
Claim 2
Independent Claim
75 words
A method of protecting superalloy articles from oxidation/corrosion at elevated temperatures which comprises: applying a layer of material to the surface of the article, said material having a thickness of from 0.001 to 0.010 inches and consisting essentially of from about 10 to about 45 percent chromium, from about 6 to about 25 percent aluminum, from about 0.5 to about 3 percent hafnium, balance chosen from the group consisting of nickel, cobalt, and mixtures thereof.
Claim 3
Dependent Claim
17 words
A method as in claim 1 wherein the material contains from about 10 to about 35% Cr.
Claim 4
Dependent Claim
17 words
A method as in claim 1 wherein the material contains from about 10 to about 20% Al.
References Cited (Backward Citations)
US3528861A
Cited
US3914507A
Cited
US3961098A
Cited
US3918139A
Cited
US3951642A
Cited
US3976436A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-04-24 | 1981-10-24 | 1982-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-24 | 1985-10-24 | 1986-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-24 | 1989-10-24 | 1990-04-25 | $7700.00 | Window Closed / Lapsed |