US3622391A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of stripping aluminide coating from cobalt and nickel base alloys
Assignee: Alloy Surfaces Co Inc
•
Filing: 1969-04-04
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Granted: 1971-11-23
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Expires: 1989-04-04
Abstract
Abstract An improved stripping process for removing as produced aluminide coatings and exposed aluminide coatings from cobalt base and nickel base superalloys, using 1/2 to 5 percent of hydrofluoric acid or an acid fluoride having at least one mole of hydrofluoric acid, 3 to 20 percent of nitric acid and water, permissibly including a low foaming or nonfoaming wetting agent. The temperature of treatment is 50* to 115* F., preferably 60* to 100* F. for a time of at least 15 minutes. The treating solution can incorporate a thickening agent and a solubilizing agent for the thickening agent so as to produce a paste, and the paste can be applied locally for selective stripping.
Inventors
- 👤 Alfonso L Baldi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:17
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/44
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
15 words
A process of claim 1, in which the temperature is between 60* and 100* F.
Claim 2
Dependent Claim
11 words
A process of claim 1, which comprises agitating the treating agent.
Claim 3
Dependent Claim
13 words
A process of claim 1, which comprises agitating the alloy parts being treated.
Claim 4
Dependent Claim
28 words
A process of claim 1, in which the compound containing free hydrofluoric acid is a bifluoride of the class consisting of ammonium bifluoride, sodium bifluoride, and potassium bifluoride.
Claim 5
Dependent Claim
19 words
A process of claim 1, which comprises incorporating a low foaming or nonfoaming wetting agent in the treating agent.
Claim 6
Dependent Claim
22 words
A process of claim 1, which comprises subsequent to stripping rinsing the superalloy parts, drying them and dry blasting with an abrasive.
Claim 7
Dependent Claim
84 words
A process of claim 1, which comprises degreasing the superalloy parts, blasting them with an abrasive, treating the parts with the stripping agent, rinsing the parts in water, neutralizing the parts with an alkali solution, rinsing the parts in water, drying the parts, blasting the parts with abrasive, stripping the parts in the stripping agent for at least 15 minutes, reblasting the parts with abrasive, rinsing the parts in water, neutralizing with alkali, rinsing in water, drying the parts and blasting them with abrasive.
Claim 8
Dependent Claim
17 words
A process of claim 1, in which the treating agent is in the form of a paste.
Claim 9
Dependent Claim
30 words
A process of claim 9, which comprises locally applying the paste to a portion of the surface of the coating in order to selectively strip the coating at that location.
References Cited (Backward Citations)
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Cited
US2287111A
Cited
US2711364A
Cited
US2904413A
Cited
US2724667A
Cited
US2981609A
Cited
US3155556A
Cited
US3275560A
Cited
US3458353A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-22 | 1975-05-24 | 1975-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-22 | 1979-05-24 | 1979-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-22 | 1983-05-24 | 1983-11-23 | $7700.00 | Window Closed / Lapsed |