Fatigue Properties of TiNi Shape Memory Alloy

Abstract

The rotating-bending fatigue tests on a TiNi shape-memory alloy wire were carried out in air and in water and low-cycle fatigue was investigated. The fatigue life in water shortened with increasing temperature but did not depend on frequency. The temperature of the wire in air increased with increasing frequency and the fatigue life shortened. The fatigue equation was proposed to describe the fatigue life depending on strain amplitude, temperature and frequency. The fatigue life was estimated well by the proposed equation. The shape memory processing temperature did not affect the fatigue life.