| Abstract |
| Changes in B2-B19` and B2-B19 martensitic transformation start temperature(Ms and Ms`) of Ti-Ni-Cu shape memory alloys whose Cu-content is more than 5at% by thermal cyclings have been investigated by means of electrical resistivity measurements and thermal cycling tests under constant load. For thermal cyclings under no applied stress, Ms decreased in the solution treated Ti-45Ni-5Cu alloy, while Ms` kept almost constant in Ti-35Ni-l5Cu and Ti-30Ni-20Cu alloys. Ms in the thermo-mechanically treated Ti-45Ni-5Cu alloy, however, did not change. For thermal cyclings under applied stress of 40 MPa. Ms decreased in the solution treated Ti-45Ni-5Cu alloy, while Ms` increased slightly in the solution treated Ti-35Ni-l5Cu and Ti-30Ni-20Cu alloys. For thermal cyclings under applied stress of 120 MPa, Ms kept almost constant in the solution treated 5at%Cu alloy, while Ms` increased in the solution treated l5at%Cu and 20at%Cu alloys. |
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| Key Words |
| Ti-Ni-Cu shape memory alloys, Thermal cycling effect, Substructural refinement effect, Martensitic transformation temperature, Thermo-mechanical treatment |
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