The current research status and development of elastocaloric refrigeration based on NiTi alloys

Elastocaloric refrigeration technology is a solid-state alternative to the traditional vapor compression technology. It is considered to be highly efficient, energy-saving and environmentally friendly. Out of the materials with elastocaloric effect, NiTi shape memory alloy is the most researched due to its excellent comprehensive mechanical and functional properties. However, it has some problems like large superelastic hysteresis, relatively high transformation stress and poor cyclic stability, which hinder its commercial application. This article explains the mechanism of elastocaloric effect and its characterization methods. Relevant research progress including the effects of considering elemental doping, mechanical processing, heat treatment, surface finishing, optimization of preparation methods and gradient structure on elastocaloric effect in NiTi alloy are summarized. In addition, the development and current status of elastocaloric refrigeration based on NiTi alloy are analyzed in this paper.