Laser powder bed fusion of a Fe–Mn–Si shape memory alloy

Abstract

The iron-based Fe–17Mn–5Si–10Cr–4Ni shape memory alloy (SMA) has been manufactured by laser powder bed fusion (LPBF) for the first time. High strength, elongation and ductility are observed after annealing. In addition, pronounced shape memory effect (SME) and pseudo-elasticity (PE), which exceed those measured for the conventionally fabricated Fe–17Mn–5Si–10Cr–4Ni-1(V,C) alloy containing VC precipitates, are achieved. The texture generated during the LPBF process brings to SME and PE highly dependent on the orientation of the loading direction with respect to the build direction. Improved strain recovery is observed when the loading direction is parallel to the build direction due to an increased amount of (101) orientated grains with high Schmid factor and low yield strength for phase transformation. Pronounced shape recovery is also obtained in more complex geometries successfully fabricated with the same manufacturing technique.