Alloys, Shape Memory

Abstract

A shape memory alloy is a metallic substance that has a memory for shape combined with superelasticity. The mechanisms of a nickel‐titanium alloy’s shape memory effect and superelasticity are described based on thermally induced or stress induced martensite phase transformations. The thermomechanical characteristics, corrosion properties, and biocompatibility of Ni‐Ti shape memory alloys are reviewed for the design of shape memory devices. Manufacturing methods, including refining, processing, shape memory programming, and transformation temperature range measuring methods are summarized for practical applications. Finally, some applications in medical devices are reviewed as examples of current trends in the use of shape memory alloys.