| The effect of the thermal fatigue on the transformation temperature and shape recovery of Ti-Ni alloys was investigated utilizing thermal cycling tests, electrical resistivity measurements and the transmission electron microscopy. Three types of heat treatment were used, they were solution treatment at 950℃, aging treatment at 400℃ after the solution treatment and annealing at 400℃ of a 30% cold-worked specimen after the solution treatment(i.e., mechanical treatment). The mechanical treatment was found to be the most effective way to improve the shape memory effect and stabilization of the transformation temperature. Change of the M_s temperature was observed to a certain number of thermal cycles, and the M_s temperature was nearly constant after a critical number of thermal fatigue cycle. |
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