US5843244A
Expired / Lapsed
US
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Shape memory alloy treatment
Assignee: Cordis Corp
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Filing: 1996-06-13
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Granted: 1998-12-01
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Expires: 2016-06-13
Abstract
Abstract A method of treating a component formed from a Ni--Ti based shape memory alloy, so that the component exhibits superelasticity, comprises cold working the component, annealing the alloy while the component is restrained in the configuration resulting from the cold working step, and exposing the component to a temperature that is less than the solvus temperature of the alloy and greater than the temperature to which it is exposed in the annealing step to cause the A f temperature to be reduced.
Inventors
- 👤 Alan Pelton
- 👤 Thomas Duerig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:22
CPC Classifications
C; C22; C22F; C22F1/00; C22F1/006; A; A61; A61F; A61F2/00; A61F2/82
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
165 words
A method of treating a component formed from a Ni--Ti based shape memory alloy so that the component exhibits superelasticity and to impart a desired shape to the component and thereafter lower the component's Af, which comprises: (a) cold working the component, the component comprising greater than 50.5 at. % nickel; (b) restraining the alloy to a desired shape and heat treating the alloy at a temperature that is less than solvus temperature of the alloy, to cause dislocations in the alloy resulting from the cold working step to combine; and (c) after heat treating the component in the restrained desired shape in step (b), removing the restraint and thereafter heat treating the component at a temperature that is greater than the temperature to which it is exposed in step (b) and less than the solvus temperature of the alloy, causing the component to retain the desired shape and causing the Af temperature to be reduced so that said component is superelastic at body temperature.
Claim 2
Independent Claim
165 words
A method of treating a component formed from a Ni--Ti based shape memory alloy so that the component exhibits superelasticity and to impart a desired shape to the component and thereafter lower the component's Af, which comprises: (a) cold working the component, the component comprising greater than 50.5 at. % nickel; (b) restraining the alloy to a desired shape and heat treating the alloy at a temperature that is less than solvus temperature of the alloy, to cause dislocations in the alloy resulting from the cold working step to combine; and (c) after heat treating the component in the restrained desired shape in step (b), removing the restraint and thereafter heat treating the component at a temperature that is greater than the temperature to which it is exposed in step (b) and less than the solvus temperature of the alloy, causing the component to retain the desired shape and causing the Af temperature to be reduced so that said component is superelastic at body temperature.
Claim 3
Dependent Claim
38 words
A method as claimed in claim 1, further including the step of annealing the component prior to step (a) and wherein the amount of cold work imparted to the component in step (a) is greater than about 10%.
Claim 4
Dependent Claim
26 words
A method as claimed in claim 1, in which the component is exposed to elevated temperature in step (c) for not more than about 10 minutes.
Claim 5
Dependent Claim
26 words
A method as claimed in claim 3, in which the component is exposed to elevated temperature in step (c) for not more than about 5 minutes.
Claim 6
Dependent Claim
25 words
A method as claimed in claim 1, in which the component is exposed to elevated temperature in step (c) for at least about 30 seconds.
Claim 7
Dependent Claim
24 words
A method as claimed in claim 1, in which step (b) is carried out more than once but before step (c) is carried out.
Claim 8
Dependent Claim
16 words
A method as claimed in claim 1, in which the alloy is a thermally unstable alloy.
Claim 9
Dependent Claim
23 words
A method as claimed in claim 1, in which the heat treatment of step (c) is performed at a temperature above 510° 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) | 2001-11-30 | 2002-06-01 | 2002-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-11-30 | 2006-06-01 | 2006-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-11-30 | 2010-06-01 | 2010-12-01 | $7700.00 | Window Closed / Lapsed |