Selective Laser Melting of NiTi shape memory components
H. Meier, C. Haberland, J. Frenzel, R. Zarnetta.
Innovative Developments in Design and Manufacturing: Advanced Research in Virtual and Rapid Prototyping, 233-238, (2009)
Near-net-shape processing is a promising method for the production of Nickel-Titanium (NiTi) shape memory components. Generally, processing of NiTi shape memory alloys (SMAs) is not easy because all types of microstructural defects and smallest compositional variances strongly affect the shape memory properties. In the present work, we show how NiTi SMAs can be produced by Selective Laser Melting (SLM) starting from pre-alloyed powders. We focus on the effect of SLM processing on microstructures and phase transformation behavior. It was found that laser processing results in a slight evaporation of Nickel. This is associated with the formation of Ti2Ni particles and with an increase of transformation temperatures. We show that SLM NiTi can provide a distinct shape memory effect with a high cyclic stability. The present work demonstrates that SLM has a considerable potential for processing of NiTi based shape memory alloys.