Effective parameters on the final properties of NiTi-based alloys manufactured by powder metallurgy methods: A review

Abstract NiTi alloys have recently attracted significant attention in aerospace and biomedical applications due to their excellent properties such as high corrosion resistance, proper biocompatibility, superior mechanical properties, and particular functional features like their shape memory effect and superelasticity. Among different manufacturing processes, special attention has been paid to powder metallurgy (PM) techniques such as additive manufacturing (AM) methods due to their advantages. A summary of all PM methods and their pros and cons are provided. This paper provides a comprehensive review of effective parameters on the microstructure and final properties of NiTi manufactured parts through PM methods. The warm and cold green compactions are compared, whereas the effect of alloying elements on the properties is discussed. Besides, the results of employing different processing parameters such as sintering time, temperature, atmosphere, heating rate, building orientation, and energy density are reviewed. In the end, two novel functional structures are considered, and the corresponding studies are summarized. The main objective of this research is to wrap up the main and novel achievements of the recent works on the correlation between process parameters and properties of NiTi parts manufactured by PM processes to give the readers a better understanding of this issue.