Nanostructure Of β-type Titanium Alloys Through Severe Plastic Deformation

A novel β-type titanium alloy Ti–29Nb–13Ta–4.6Zr (TNTZ) has been developed and extensively researched to achieve highly desirable mechanical properties such as a high strength while maintaining a low Young’s modulus that is close to that of bone, as an alternative candidate for conventional titanium metallic biomaterials such as Ti-6Al-4V ELI. Therefore, strengthening by grain refinement and increasing dislocation density is expected to provide TNTZ high mechanical strength while keeping a low Young’s modulus because they keep the original β phase. In this case, severe plastic deformation, such as high-pressure torsion (HPT) processing, is a potential treatment for obtaining these properties. Furthermore, HPT processing is effective for producing ultrafine-grained TNTZ having high dislocation density in single β structure. The obtained promising results, which are a tensile strength of around 1100 MPa and a Young's modulus of around 60 GPa, motivated that the above mentioned mechan