US4010025A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oxidation and sinter-resistant metal powders and pastes
Assignee: Plessey Inc
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Filing: 1976-02-06
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Granted: 1977-03-01
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Expires: 1996-02-06
Abstract
Abstract A high density precious metal powder that resists sintering at 600 DEG C. and contains a very small percentage of titania or zirconia is produced by co-nucleation and precipitation of gold and titania from an ammoniacal solution at pH 3-4 with a bisulfite.
Inventors
- 👤 Anthony V. Fraioli
- 👤 John A. DeRosa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:49
CPC Classifications
B; B22; B22F; B22F9/00; B22F9/16; B22F9/18; B22F9/24; B01; B01J; B01J23/00; B01J23/70; B01J23/74; B01J23/755; C; C22; C22C; C22C1/00; C22C1/10; C22C1/1026; H; H01; H01B; H01B1/00; H01B1/02; H05; H05K; H05K1/00; H05K1/02; H05K1/09; H05K1/092
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
67 words
The method of preparing finely divided nickel powder of increased oxidation resistance comprising: forming an acidic solution of nickel and a minor proportion of a zirconium oxide precursor; forming a alkaline hydrazine reducing solution; adding said acidic nickel solution to said reducing solution very slowly under conditions of agitation; separating, washing and drying the resulting precipitate; firing said precipitate in a reducing atmosphere at about 450° C.
Claim 2
Independent Claim
67 words
The method of preparing finely divided nickel powder of increased oxidation resistance comprising: forming an acidic solution of nickel and a minor proportion of a zirconium oxide precursor; forming a alkaline hydrazine reducing solution; adding said acidic nickel solution to said reducing solution very slowly under conditions of agitation; separating, washing and drying the resulting precipitate; firing said precipitate in a reducing atmosphere at about 450° C.
Claim 3
Dependent Claim
16 words
The method as claimed in claim 1, wherein said zirconium oxide precursor is disulfato zirconic acid.
Claim 4
Dependent Claim
28 words
The method as claimed in claim 1, wherein the amount of said zirconium oxide precursor is sufficient to provide no more than about 2% zirconia in said powder
Claim 5
Dependent Claim
29 words
The method as claimed in claim 1, wherein said addition of said nickel solution is carried out at a rate of no more than about 10 ml. per minute.
References Cited (Backward Citations)
US2564331A
Cited
US3235515A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-02-29 | 1980-08-30 | 1981-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-29 | 1984-08-30 | 1985-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-29 | 1988-08-30 | 1989-03-01 | $7700.00 | Window Closed / Lapsed |