Abstract: Selective laser melting NiTi shape memory alloy which has ambient temperature sensing capability is the basic of a metal material 4D printing technology, according to the technical requirements for selective laser melting the powder properties, studying the effect of NiTi powder gas atomization process on the selective laser melting moldability and alloys’ superelastic is great significant. By comparing the influence of vacuum inert gas atomization (VIGA) and electrode induction melting gas atomization (EIGA) process on the performance of NiTi alloy powder, such as the impurity content, fluidity, spherical degree. The VIGA process which used crucible melting resulting in impurity content is higher than EIGA process, and fine powder size distribution biased side, easy to form satellite powder, resulting in poor powder flow, and powder spreading difficulties in the printing process and difficult to mold, more than of that, increasing the oxygen content results in balling in the SLM process, prone to cracking and so on, hence the NiTi alloy powder prepared by VIGA process is poor moldability in SLM process. EIGA prepared NiTi powder hold homogeneous particle size distribution, good fluidity and low oxygen content, satisfying selective laser melting technique NiTi alloy powder characteristics requirements. Comparison of surface topography and powder samples prepared from two printing processes, forming a superelastic NiTi shape memory alloy sample having a complete ecovery properties.

Key words: selective laser melting, NiTi shape mempry alloy powder, VIGA, EIGA