A review of shape memory alloys: origins, occurrence, properties, and their applications

Abstract

Shape memory alloys (SMAs) are an important set of materials that find widespread applications due to their ‘shape retaining’ abilities when heated above a certain critical temperature in the fields of automotive engineering, aerospace, medical, robotics, structural engineering, spintronics, non-conventional energy resources, etc. The present paper discusses SMAs, detailing their origin and their classifications. Furthermore, the various properties of SMAs are discussed along with a study of nitinol, an extremely popular SMA used in many applications. A detailed study of SMA applications in the domains of aerospace and robotics has been presented in this paper. The motivation for this review work on SMAs is to understand the properties, characteristics and behavior of SMAs and utilize it in developing mechanisms for a diverse range of applications. SMAs are one of the most prominent research fields for engineers and scientists across the globe and significant progress has been made in recent years.