Sinter-Based Additive Manufacturing of Ni-Ti Shape Memory Alloy

Abstract Additive manufacturing (AM) of Shape Memory Alloys (SMA) is an emerging technology that can open the route for numerous new applications in the fields of actuation, sensing, energy harvesting, and heat management. Currently, most AM processes of SMA rely on melting-based methods that locally melt the metallic feedstock of Ni-Ti. However, the repeated melting impairs the resulting microstructure, thus limiting the ability to undergo a reversible thermo-elastic martensitic transformation. Recent advances in sinter-based AM have the potential to facilitate the control over the final microstructure and properties of the printed SMA. Here, we present the production and characterization of Ni-Ti SMA produced via two sinter-based AM methods: 1. Lithography-based Metal Manufacturing (LMM), and 2. Moldjet, a unique modification of conventional metal injection molding.