New flexible alloy maintains shape memory more than 10 million times

BBC : Shape-memory alloys are metals that can be deformed and then return to their original shape. Some have already found their way into a variety of regular uses, but they all suffer from a high rate of fatigue, which gives them a short useful lifespan. A new alloy developed by Manfred Wuttig of the University of Maryland, College Park, and his colleagues has a lifespan significantly longer than any previous memory alloy. The team subjected 1-cm squares of the material to over 10 million shape distortions caused by both temperature changes and mechanical stresses. The key to the longer life is that as the metal crystallizes, the nickel, titanium, and copper atoms align in a way that lets them easily switch between two different configurations. A lifespan of 10 million cycles should enable a significant number of possible applications.