Additive Manufacturing Of NiTi-Based Shape Memory Alloys For Functional Components

Abstract

In recent years, Laser Powder Bed Fusion (LPBF) has attracted significant interest for the fabrication of NiTi-based shape memory alloys (SMA), enabling the production of complex geometries beyond conventional manufacturing. This study evaluates the potential of LPBF to produce NiTi components with stable pseudoelastic behavior at room temperature under both tensile and compressive loading. Solution annealing at 850 °C increased the critical stress for martensitic transformation, while aging treatments between 400 and 500 °C led to a significant reduction. Compression tests revealed the highest recoverable strain in the as-built condition, whereas tensile tests showed enhanced strain recovery after solution annealing followed by aging, with a pronounced dependence on build orientation. Beyond monolithic NiTi, the work also investigates the printability and functional performance of modified NiTi compositions, such as NiTi-Fe alloys, with the aim of developing architected SMA components for solid-state refrigeration applications.