US4032359A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Removal of aluminium rich coatings from heat resisting alloys
Assignee: Rolls Royce PLC
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Filing: 1975-08-04
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Granted: 1977-06-28
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Expires: 1995-08-04
Abstract
Abstract A solution for removing a diffused aluminium coating from a component made of nickel or cobalt base high temperature alloy, consisting of Nitric Acid 57%, Sulphuric Acid 29% and Water 14%. The solution removes all but traces of nickel or cobalt-rich aluminides and does not attack the substrate material. If said traces have to be removed also, there is used an etching solution consisting of Ferric Chloride Solution 85%, Sulphuric Acid 10% and Hydrofluoric Acid 5%.
Inventors
- 👤 Maurice Fisher
- 👤 Michael Kruger
- 👤 Terence Walter Maber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:29
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/44
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
60 words
A method of removing an aluminide coating from a component made of a material based on an element selected from the group consisting of nickel and cobalt, comprising the step of immersing said component in a solution consisting essentially of, by volume: ______________________________________
Nitric Acid 50-70% (Sp. Gr. 1.42)
Sulfuric Acid 25-50% (Sp. Gr. 1.84)
Water Remainder (if any).
______________________________________
Claim 2
Independent Claim
60 words
A method of removing an aluminide coating from a component made of a material based on an element selected from the group consisting of nickel and cobalt, comprising the step of immersing said component in a solution consisting essentially of, by volume: ______________________________________
Nitric Acid 50-70% (Sp. Gr. 1.42)
Sulfuric Acid 25-50% (Sp. Gr. 1.84)
Water Remainder (if any).
______________________________________
Claim 3
Independent Claim
56 words
A method of removing an aluminide coating from a component made of a material based on an element selected from the group consisting of nickel and cobalt, comprising the step of immersing said component in a solution consisting essentially of, by volume: ______________________________________
Nitric Acid 50-70% (Sp. Gr. 1.42)
Sulfuric Acid 30-50% (Sp. Gr. 1.84).
______________________________________
Claim 4
Independent Claim
56 words
A method of removing an aluminide coating from a component made of a material based on an element selected from the group consisting of nickel and cobalt, comprising the step of immersing said component in a solution consisting essentially of, by volume: ______________________________________
Nitric Acid 50-70% (Sp. Gr. 1.42)
Sulfuric Acid 30-50% (Sp. Gr. 1.84).
______________________________________
Claim 5
Independent Claim
60 words
A method of removing an aluminide coating from a component made of a material based on an element selected from the group consisting of nickel and cobalt, comprising the step of immersing said component in a solution consisting essentially of, by volume: ______________________________________
Nitric Acid 50-70% (Sp. Gr. 1.42)
Sulfuric Acid 25-35% (Sp. Gr. 1.84)
Water Remainder (if any).
______________________________________
Claim 6
Independent Claim
60 words
A method of removing an aluminide coating from a component made of a material based on an element selected from the group consisting of nickel and cobalt, comprising the step of immersing said component in a solution consisting essentially of, by volume: ______________________________________
Nitric Acid 50-70% (Sp. Gr. 1.42)
Sulfuric Acid 25-35% (Sp. Gr. 1.84)
Water Remainder (if any).
______________________________________
Claim 7
Dependent Claim
31 words
The method of claim 2 wherein said solution consists essentially of, by volume: ______________________________________
Nitric Acid 50-60% (Sp. Gr. 1.42)
Sulfuric Acid 25-30% (Sp. Gr. 1.84)
Water Remainder (if any).
______________________________________
Claim 8
Dependent Claim
53 words
The method of claim 1 comprising the further step of removing said component from said solution after a predetermined time, and immersing said component in a further solution consisting essentially of, by volume: ______________________________________
Ferric Chloride Solution
75-90% (Sp. Gr. 1.3)
Sulfuric Acid 5-20% (Sp. Gr. 1.84)
Hydrofluoric Acid
3-7% (60% w/w).
______________________________________
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) | 1980-06-27 | 1980-12-27 | 1981-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-27 | 1984-12-27 | 1985-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-27 | 1988-12-27 | 1989-06-28 | $7700.00 | Window Closed / Lapsed |