|About this Abstract
||2023 TMS Annual Meeting & Exhibition
||Additive Manufacturing and Innovative Powder/Wire Processing of Multifunctional Materials
||Controlling Martensitic Transformation Characteristics in Defect-free NiTi Shape Memory Alloys Fabricated Using Laser Powder Bed Fusion
||Ibrahim Karaman, L. Xue, Kadri C Atli, Chen Zhang, Alaa Elwany, Raymundo Arroyave
|On-Site Speaker (Planned)
Laser Powder Bed Fusion (L-PBF) was utilized to fabricate fully dense, near-equiatomic and Ni-rich NiTi shape memory alloys (SMAs) which exhibited tensile ductility up to 16%, shape memory strain of 6%, and tensile superelasticity up to 6%. The selection of optimum processing parameters that yielded fully dense parts was guided by a process optimization framework based on an analytical model to predict the melt pool dimensions. The framework also included single-track experiments to validate the model predictions and a criterion for the maximum allowable hatch spacing to prevent the formation of porosity. This framework allowed for constructing L-PBF processing maps for NiTi SMAs and revealed that fully dense parts could be printed over a wide range of process parameters. The flexibility of parameter selection to print defect-free NiTi SMAs and composition control by preferential evaporation of Ni opens the possibility to print functional NiTi SMA parts without post-processing.