Method of manufacturing high-temperature shape memory alloys
US5641364A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 27, 1995 |
| Grant date | Jun 24, 1997 |
| Priority date | — |
| Expiry date | Oct 27, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22F1/006
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method of manufacturing a high-temperature shape memory alloy includes the steps of cold-working a high-temperature shape memory alloy, in which a reverse martensite transformation start temperature (As) in a first heating after cold working reaches 350.degree. C. or above. Thereafter, the cold-worked alloy undergoes a first heat treatment for a period of time within the incubation time required for recrystallization or less, and at a temperature higher than a reverse martensite transformation finish temperature (Af). Finally, the resultant alloy is annealed with a second heat treatment, at a temperature which is not less than the plastic strain recovery temperature and not more than the recrystallization temperature. Specifically, the first heat treatment is performed for a period of three minutes or less at a temperature which exceeds 500.degree. C. and which is lower than the melting point of the alloy. The composition of the high-temperature shape memory alloy is Ti.sub.50 Ni.sub.50-x Pd.sub.x (x being 35 to 50 at %), Ti.sub.50-x Ni.sub.50 Zr.sub.x (x being 22 to 30 at %), Ti.sub.50-x Ni.sub.50 Hf.sub.x (x being 20 to 30 at %) or the like.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.