Additive Manufacturing of NiTi Shape Memory Alloys with Biomedical Applications

Abstract

This study focuses on the laser powder bed fusion processing of NiTi alloys and the feasibility of fabricating very thin stent structures for biomedical applications. A comprehensive correlation between the process and the material’s-structure and properties is established to facilitate the fabrication of NiTi alloys with tailored properties. In the first step, the impact of LPBF processing parameters and post-treatments on evolving the microstructure, texture, superelasticity, and asymmetry is examined. Subsequently, the feasibility of manufacturing very thin mesh structured stents is scrutinized followed by in-depth investigations into differently designed stents considering properties such as surface characteristics, mechanical properties, superelasticity, and recoverability. The obtained results and the represented discussions offer imperative insights, helping to better understand the complexity of the LPBF process and the present challenging aspects. Moreover, detailed contributions are made with the goal of paving the road ahead for the production of patient-specific NiTi stents with enhanced properties.