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US 4,067,752 AGranted
Austenitic aging of metallic compositions
AssigneeRaychem Corporation
InventorsGreville B. Brook, Peter L. Brooks, Roger F. Iles
Life of this patent
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AssigneeRaychem Corporation
InventorsGreville B. Brook, Peter L. Brooks, Roger F. Iles
Estimating the term…
Some metallic compositions that undergo a reversible transformation between austenitic and martensitic states as a result of being heated or cooled through critical temperature ranges may lose a portion or all of the ability to revert from martensite to austenite. That loss can be inhibited by "aging" the composition prior to its conversion to the martensitic state by holding it at a temperature at which it exists in the austenitic state. The time required to significantly inhibit loss of reversibility may vary as the nature of the composition changes. For a specific composition, the time required typically is shortened as the holding temperature is raised. The ability of a composition to respond to preconditioning methods by which its A.sub.s temperature can be elevated may also be improved by aging in the austenitic state prior to attempting preconditioning.
A metallic composition having a substantially reduced tendency to lose reversibility between its martensitic and austenitic state as compared with its normal tendency to do so at a given temperature.
An alloy comprising copper and a metal selected from a group consisting of zinc and aluminum, said alloy having a substantially reduced tendency to lose reversibility between its martensitic and austenitic state as compared with its normal tendency to do so at a given temperature.
A method of inhibiting loss of reversibility between the martensitic and austenitic states in a metallic composition comprising holding said composition at a temperature above the M.sub.s temperature while in the austenitic state for a time sufficient to reduce said loss, said holding temperature being one at which there is no significant transformation of the metallic composition to a phase that undergoes no reversible austenite-martensite transformation.
An alloy comprising copper and a metal selected from the group consisting of zinc and aluminum having a substantially reduced tendency to lose reversibility between its martensitic and austenitic state, said alloy being the product of the process comprising holding said composition at a temperature above the M.sub.s temperature while in the austenitic state for a time sufficient to reduce said tendency to lose reversibility, said holding temperature being one at which there is no significant transformation of the alloy to a phase that undergoes no reversible austenite-martensite transformation.
Dependencies are inferred from the claim text.