Oligocrystalline microstructure in an additively manufactured biocompatible Ti-Nb-Zr-Ta alloy

Abstract Oligocrystalline materials exhibit large grains typically spanning the entire sample in one dimension, which strongly reduces the area covered by grain boundaries. This microstructure increases the pseudoelasticity, fatigue lifetime and ductility of shape memory alloys. In this paper, we demonstrate a new processing route for obtaining parts with complex geometries and oligocrystalline microstructure in biocompatible Ti-35Nb-7Zr-5Ta alloy by combining additive manufacturing and heat treatment. Oligocrystallinity has a pronounced effect on the recoverable strain during uniaxial compression. This processing route is applicable to different types of alloys and allows the production of oligocrystalline parts with complex shapes and advanced functional properties.