Research progress of NiTi alloys fabricated by additive manufacturing

As a kind of shape memory alloys, the NiTi alloys show the excellent shape memory effect, superelasticity, corrosion resistance, and biocompatibility, which have been widely used in the biomedical, aerospace, and micro electro mechanical fields. Additive manufacturing (AM) as the new processing method can enhance the manufacturing efficiency of the NiTi alloys and broaden the applications. The research progress of the NiTi alloys fabricated by additive manufacturing was reviewed in this paper, including the selections of raw materials and process, the microstructural characteristics of molten pool, grain, precipitates, and defects, the effects of raw materials, processing parameters, and heat treatment on the mechanical properties, phase transformation temperature, shape memory effect, superelasticity, and surface quality. Finally, the research status of the NiTi alloys fabricated by additive manufacturing was summarized, and the perspectives for the future research in this area were presented.