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US4410488A
Expired / Lapsed
US
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Powder metallurgical process for producing a copper-based shape-memory alloy
Assignee: BBC AG
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Filing: 1981-07-27
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Granted: 1983-10-18
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Expires: 2001-07-27
Abstract
Abstract Shape-memory alloys comprised of Cu/Al or Cu/Al/Ni are produced by a powder metallurgical process wherein a coarse-grained powder of pre-alloyed and/or pre-mixed powder alloys having a grain size of 0.05 to 0.8 mm is introduced into a metal container which is then evacuated, sealed, and hot isostatically pressed. The resulting billet is then hot worked. In another embodiment, the powder is first placed in a rubber tube and cold isostatically pressed. The billet is then placed in a cylinder having deformable walls, such as a copper cylinder, the cylinder is sealed, and the powder therein is then hot isostatically pressed, and the billet so prepared is subjected to a homogenization heat treatment and hot working.
Inventors
- 👤 Gernot Gessinger
- 👤 Oliver Mercier
- 👤 Helmut Riegger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:04
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/12; B22F3/16; C; C22; C22C; C22C1/00; C22C1/04; C22C1/0425; C22F; C22F1/00; C22F1/006
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
90 words
A process for producing a copper-based shape memory alloy by powder metallurgy, comprising: providing a coarse-grained alloy powder having a particle size of 0.2 to 0.8 mm grain diameter; introducing said powder into a container; evacuating said container; sealing said container under vacuum; hot isostatically pressing said powder at a pressure of 50 to 300 MPa in a temperature range from 750° to 950° C. for 1/5 to 5 hours, whereby a billet is formed; and subjecting said billet to hot working at a temperature of 750° to 850° C.
Claim 2
Dependent Claim
90 words
A process for producing a copper-based shape memory alloy by powder metallurgy, comprising: providing a coarse-grained alloy powder having a particle size of 0.2 to 0.8 mm grain diameter; introducing said powder into a container; evacuating said container; sealing said container under vacuum; hot isostatically pressing said powder at a pressure of 50 to 300 MPa in a temperature range from 750° to 950° C. for 1/5 to 5 hours, whereby a billet is formed; and subjecting said billet to hot working at a temperature of 750° to 850° C.
Claim 3
Dependent Claim
22 words
The process of claim 1 wherein said hot working operation is selected from the group consisting of forging, pressing, swaging, and rolling.
Claim 4
Dependent Claim
28 words
The process of claim 1 wherein an alloy powder having a composition the same as the final composition of the memory alloy is used as the raw material.
Claim 5
Dependent Claim
17 words
The process of claim 1 wherein 2 or more pre-alloy powders are used as the raw material.
Claim 6
Dependent Claim
23 words
The process of claim 1 wherein said container is made from a metal selected from the group consisting of stainless steel and copper.
Claim 7
Dependent Claim
43 words
The process of claim 1 comprising the additional preliminary step of introducing the alloy powder into a rubber or plastic tube and subjecting the powder to a cold isostatic pressing at a pressure of 300 to 800 MPa for 1 to 10 minutes.
Claim 8
Dependent Claim
45 words
The process of claim 1 or claim 6 wherein said billet is subjected to a homogenization annealing in a protective gas atmosphere at a temperature of 900° to 950° C. for 1 to 20 hours after said hot isostatic pressing and before said working operation.
Claim 9
Dependent Claim
39 words
The process of claim 1 wherein the alloy powder used as raw material has a composition corresponding to a shape-memory alloy having the following composition: aluminum: 10.5 to 15% by weight nickel: 0 to 6% by weight copper: balance.
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) | 1986-10-17 | 1987-04-18 | 1987-10-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-17 | 1991-04-18 | 1991-10-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-17 | 1995-04-18 | 1995-10-18 | $7700.00 | Window Closed / Lapsed |