Additive manufacturing of NiTiHf high temperature shape memory alloy.

A NiTi-20Hf high temperature shape memory alloy (HTSMA) was additively manufactured by selective laser melting (SLM) technique using NiTiHf powder. The thermomechanical and shape memory response were compared to the conventional vacuum induction skull melted counterpart. Transformation temperatures of the SLM material were found to be above 200 °C and slightly lower due to the additional oxygen pick up from the gas atomization and melting process. The shape memory response in compression was measured for stresses up to 500 MPa, and transformation strains were found to be very comparable (up to 1.26% for as-extruded; up to 1.52% for SLM). [ABSTRACT FROM AUTHOR]