Recent Development of TiNi-Based Shape Memory Alloys with High Cycle Stability and High Transformation Temperature

TiNi-based shape memory alloys (SMAs) attract a lot of attention from engineering and biomedical fields because of their superior functional properties, such as their unique shape memory effect, superelasticity, and excellent biocompatibility. Most of the unique properties result from martensitic transformation, which can be thermally induced or stress induced. In recent years, with the development of understanding of martensitic transformation, significant progress has been made and several novel TiNi-based SMAs have been developed, including alloys with slim hysteresis and stable functional properties and high-temperature SMAs with extremely large recovery strain and stress. In this work, the most recent developments in TiNi-based SMAs are presented in terms of a strategy to develop high-performance alloys with particular microstructures, alloying effects, and functional properties.