Microstructure of NiTi superelastic alloy manufactured by selective laser melting

Nitinol is used in dental tools for its superelasticity, shape memory and biocompatibility. Selective laser melting (SLM) on a powder bed potential process manufacturing such as tools. Microstructural studies are conducted NiTi-SLM using parallel strip strategy 90° beam rotation. The multi-scale (nano-, micro- mesoscopic) microstructure revealed. Similar “cast” type features found. SLM melt casted “micro-mold”. Fine micro-grains with random crystallographic orientation formed near the mold walls served seats rapid growth of columnar dendritic grains along 〈0 0 1〉 direction epitaxial relationships. curves towards center “micro-mold”, coinciding beam. It proposed that processing resembles “Metallic Self Micro-Mold Casting” (MSµMC) and/or “Self Micro-Molding” (S2M).