Production, microstructure and mechanical properties of cold-rolled Ti-Nb-Mo-Zr alloys for orthopedic applications

The microstructure and mechanical properties of two new metastable β Ti alloys were studied and the influence of the degree of deformation by cold rolling after homogenization heat treatment was also investigated. Both Ti-29Nb-2Mo-6Zr and Ti-24Nb-4Mo-3Zr alloys present a β microstructure after solution heat treatment at 1000 °C for 24 h followed by water quenching whereas ulterior cold rolling induces the precipitation of α” martensite. The results indicate that both alloys are promising alternatives to the widely used Ti-6Al-4V. Young's modulus decreases and hardness increases with the degree of deformation. A thickness reduction of 90% maximizes the hardness/Young's modulus ratio and optimizes the required mechanical properties for orthopedic implants.