High-Temperature NiTi-based Shape Memory Alloys Prepared By Laser-Powder-Bed-Fusion

Additive Manufacturing methods like laser-powder-bed-fusion are a promising preparation route for NiTi-based shape memory alloys as this class of material could benefit from the process inherent freeform capabilities to design a new generation of high-temperature transforming actuators. Powder quality and characteristics are crucial in achieving a stable high-temperature transformation, as it is sensitively affected by chemical composition and impurities. In addition, transformation temperatures can be shifted up by applying a stress to the material according to Clausius-Clapeyron’s law.In this study we report on the capabilities of NiTi-based Shape Memory Alloys powders processed by additive manufacturing for the realization of high temperature actuators. Particular emphasis is placed on the material transformation behaviour at high stresses. Differential Scanning Calorimetry, Scanning Electron Microscopy as well as mechanical tests in tensile and compression mode are performed to access microstructure, thermal properties and shape memory performance.