US4036669A
Expired / Lapsed
US
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Mechanical preconditioning method
Assignee: Raychem Corp
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Filing: 1975-02-18
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Granted: 1977-07-19
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Expires: 1995-02-18
Abstract
Abstract Certain metallic compositions undergo a reversible transformation between an austenitic state and a martensitic state. The temperature at which these compositions begin to undergo the transition from martensite to austenite can be raised by deforming an article formed from the composition and maintaining it while in the deformed state at a temperature at which the composition would normally exist in the austenitic state.
Inventors
- 👤 Greville B. Brook
- 👤 Peter L. Brooks
- 👤 Roger F. Iles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:30
CPC Classifications
C; C22; C22C; C22C9/00; C22C9/04; C22F; C22F1/00; C22F1/006; F; F16; F16B; F16B2200/00; F16B2200/77
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
155 words
A method for expanding the hysteresis loop of an article comprised of a metallic composition capable of undergoing a reversible transformation between austenitic and martensitic states wherein the A s of the composition is elevated above its normal A s , said method comprising deforming the article from an original configuration into a second deformed configuration from which heat recovery towards said original configuration is desired, applying constraining means to said article and holding the article in said deformed configuration at a temperature above the temperature M s at which formation of martensite in the metallic composition is induced thermally in the absence of applied stress for a time sufficient to cause at least a portion of the deformation to be retained as heat recoverable strain, the recovery of which towards the original configuration begins above the normal A s of the metal composition, when the constraining means is removed and removing said constraining means.
Claim 2
Independent Claim
155 words
A method for expanding the hysteresis loop of an article comprised of a metallic composition capable of undergoing a reversible transformation between austenitic and martensitic states wherein the A s of the composition is elevated above its normal A s , said method comprising deforming the article from an original configuration into a second deformed configuration from which heat recovery towards said original configuration is desired, applying constraining means to said article and holding the article in said deformed configuration at a temperature above the temperature M s at which formation of martensite in the metallic composition is induced thermally in the absence of applied stress for a time sufficient to cause at least a portion of the deformation to be retained as heat recoverable strain, the recovery of which towards the original configuration begins above the normal A s of the metal composition, when the constraining means is removed and removing said constraining means.
Claim 3
Dependent Claim
16 words
A method according to claim 1 wherein the article is deformed while in the austenitic state.
Claim 4
Dependent Claim
29 words
A method according to claim 1 wherein the article is deformed at a temperature below the holding temperature and its temperature raised to the holding temperature while under constraint.
Claim 5
Dependent Claim
17 words
A method according to claim 3 wherein the article is deformed at about its M s temperature.
Claim 6
Dependent Claim
21 words
A method according to claim 3 wherein the article is deformed at a temperature within the M s -M f range.
Claim 7
Dependent Claim
21 words
A method according to claim 3 wherein the article is deformed at a temperature below the M s -M f range.
Claim 8
Dependent Claim
29 words
A method according to claim 1 wherein the temperature of the article is lowered to within the M s -M f range prior to removal of the constraining means.
Claim 9
Dependent Claim
26 words
A method according to claim 1 wherein the article is cooled to below the M s -M f range prior to removal of the constraining means.
Claim 10
Dependent Claim
23 words
A method according to claim 1 wherein the article is deformed while in the martensitic state and slowly heated to the holding temperature.
Claim 11
Dependent Claim
49 words
A method according to claim 1 wherein prior to its deformation, the article is held at a temperature above the M s temperature while in the austenitic state for a time sufficient to reduce the loss of reversibility between the martensitic and austenitic states and to improve its preconditionability.
Claim 12
Dependent Claim
18 words
A method according to claim 1 wherein the metallic composition is an alloy that forms an electron compound.
Claim 13
Dependent Claim
29 words
A method according to claim 11 wherein the alloy is a body centered cubic type analagous to beta-brass having a ratio of about 3 valence electrons to 2 atoms.
Claim 14
Dependent Claim
28 words
A method according to claim 1 wherein the metallic composition is a beta-phase alloy comprising copper and a metal selected from the group consisting of zinc and aluminum.
Claim 15
Dependent Claim
31 words
A method according to claim 13 wherein said metal is zinc and the alloy further contains a member selected from the group consisting of aluminum, manganese, silicon, tin and combinations thereof.
Claim 16
Dependent Claim
30 words
A method according to claim 13 wherein said metal is aluminum and wherein said alloy further contains a member selected from the group consisting of manganese, zinc and mixtures thereof.
Claim 17
Dependent Claim
30 words
A method according to claim 1 wherein the metallic composition is a beta-phase alloy comprising by weight 60-85% copper, 0-40% zinc, 0-5% silicon, 0-14% aluminum and 0-15 wt. % manganese.
References Cited (Backward Citations)
US3802930A
Cited
US3783037A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-07-18 | 1981-01-17 | 1981-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-18 | 1985-01-17 | 1985-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-18 | 1989-01-17 | 1989-07-19 | $7700.00 | Window Closed / Lapsed |