On the printability and transformation behavior of nickel-titanium shape memory alloys fabricated using laser powder-bed fusion additive manufacturing

© 2018 Laser powder-bed fusion (L-PBF) additive manufacturing is regarded as an attractive alternative for producing parts with complex geometries for nickel-titanium shape memory alloys (NiTi SMAs). These alloys are known to pose challenges when processed using traditional subtractive or formative manufacturing technologies. Although L-PBF of NiTi has been investigated in some previous research efforts, very little emphasis has been placed on the manufacturability (or printability) of NiTi, where we use printability to refer to the capability of producing parts free of macroscopic defects. The current study elucidates challenges related to the printability of NiTi SMAs using L-PBF, and its interaction with their phase transformation behavior, responsible for their functional properties. More specifically, we conduct experiments and employ machine learning classification techniques to identify an adequate design parameter and an empirical rule for determining the printability of NiTi. Our results indicate that the linear energy density E L is a better design parameter for identifying satisfactory printability, while volumetric energy density, E V , is more relevant in controlling the transformation behavior of the processed material.

Mahmoudi, M., Tapia, G., Franco, B., Ma, J., Arroyave, R., Karaman, I., & Elwany, A

On the printability and transformation behavior of nickel-titanium shape memory alloys fabricated using laser powder-bed fusion additive manufacturing Academic Article