US3753791A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat-treatment of zinc/aluminium alloys
Assignee: Imperial Smelting Corp Ltd
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Filing: 1971-01-04
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Granted: 1973-08-21
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Expires: 1991-01-04
Abstract
Abstract Zinc/aluminium alloys containing 18 to 40 percent aluminium are rendered superplastic by annealing in the single-phase solid region, cooling to below 275* C at not more than 10* C per minute, and, simultaneously with and/or subsequently to cooling, working to at least 90 percent reduction above 200* C at least half of which working is carried out below 275* C. Optionally the alloy is cooled below 200* C and then reheated to the given range for some or all of the working.
Inventors
- 👤 C Swanson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 10:19
CPC Classifications
C; C22; C22F; C22F1/00; C22F1/16; C22F1/165; Y; Y10; Y10S; Y10S420/00; Y10S420/902
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
20 words
A process as claimed in claim 1, wherein some of said total reduction is carried out at above 275* C.
Claim 2
Dependent Claim
20 words
A process as claimed in claim 1, wherein all of said total reduction is carried out at below 275* C.
Claim 3
Dependent Claim
45 words
A process as claimed in claim 3, wherein cooling is effected to below 200* C, the body of alloy is reheated to above 200* C and below 275* C and subsequently at least part of said total reduction is carried out at below 275* C.
Claim 4
Dependent Claim
18 words
A process as claimed in claim 4, wherein all of said total reduction is effected after said reheat.
Claim 5
Dependent Claim
21 words
A process as claimed in claim 1, wherein at least half of said total reduction is carried out below 250* C.
Claim 6
Dependent Claim
16 words
A process as claimed in claim 1, wherein the heat-treatment period is at least 3 hours.
Claim 7
Dependent Claim
19 words
A process as claimed in claim 1, wherein the cooling rate is from 3* to 5* C per minute.
Claim 8
Dependent Claim
13 words
A process as claimed in claim 1, wherein working is effected by rolling.
Claim 9
Dependent Claim
17 words
A process as claimed in claim 1, wherein a subsequent working step is provided below 200* C.
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) | 1976-08-20 | 1977-02-19 | 1977-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-20 | 1981-02-19 | 1981-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-20 | 1985-02-19 | 1985-08-21 | $7700.00 | Window Closed / Lapsed |