The Estimation of Temperature Rise in Low-Cycle Fatigue of TiNi Shape-Memory Alloy

Abstract

A difference in fatigue strength depending on the rotational speed between air and water was found for the rotating-bending fatigue characteristics of a TiNi shape-memory alloy wire in our previous work. The heat transfer characteristics around a shape-memory alloy wire were measured using Reynold's analogy. The rise in temperature of the metal during the rotating-bending cycles was calculated considering the heat transfer result. As a result, the rotating-bending fatigue characteristics of a shape-memory alloy wire were explained well from the viewpoint of the heat transfer characteristics.