High strength biomedical Ti–13Mo–6Sn alloy: Processing routes, microstructural evolution and mechanical behavior

Abstract

Metastable β titanium alloys have been widely used in aerospace and biomedical applications thanks to their enhanced specific mechanical strength, low elastic modulus, high corrosion resistance and unique biocompatibility. To optimize the mechanical behavior of metastable β Ti–Mo–Sn based alloys requires an in-depth understanding of the relationship between processing routes and resulting microstructures. This study focused on an investigation into phase transformations involving solute partitioning and its effect on the mechanical behavior of Ti–13Mo–6Sn alloy. Despite the low diffusivity of the alloying elements Mo and Sn in Ti, they affect solute partitioning to form ωiso and α phases. The refinement of α phase precipitation is strongly influenced by the heating rate applied to reach the aging temperature. Moreover, grain boundary α phase precipitation and precipitate-free zones are of paramount importance to the intergranular fracture mode in tensile tests. The results of this investigation also indicate that low elastic modulus (66 GPa) and adequate ultimate tensile strength (740 MPa) are achieved in Ti–Mo–Sn alloys.