Direct rapid prototyping of shape memory alloy with linear superelasticity via plasma arc deposition

Abstract Recently, additive manufacturing (AM) technology has drawn significant attention to fabricate shape memory alloys. In this study, plasma arc deposition (PAD), an AM technology, has been successfully applied to prepare the Ti 51 Ni 49 alloy directly and rapidly at the first time. The synthesized PAD Ti 51 Ni 49 alloy consisting of TiNi (B2), TiNi (B19′) and Ti 2 Ni phase, exhibited primary TiNi columnar dendrites structure with a certain number of Ti 2 Ni phases distributed in the interdendritic regions. The as-deposited Ti 51 Ni 49 alloy displayed a two-step phase transformation evidently (B2→ R → B19’) during cooling process, and special linear superelasticity (up to 4.5%) with narrow hysteresis due to Ti 2 Ni phase embedded in TiNi matrix phase. This work suggests that the PAD is an effective technology to directly and rapidly synthesize shape memory alloy.