Abstract
The effect of the alloy compositions on the cyclic bending fatigue behaviors of the Ti–Ni base shape memory alloy wires was investigated using a rotary bending fatigue tester specially designed for wires. The fatigue test results were discussed in connection with the static tensile properties. The results were summarized as follows. (1) The martensite inducing stress increased with the increasing of the Ni-content. (2) The fatigue life decreased with the increasing of the test temperature and the Ni-content. (3) The fracture pattern resulted from the rotary bending fatigue test has changed from the dimple pattern under the room temperature and small cyclic strain to the quasi-cleavage fracture under the high temperature and large cyclic strain.
