Effect of Sn and Zr content on superelastic properties of Ti-Mo-Sn-Zr biomedical alloys

The effects of Sn and Zr content on the shape memory and superelastic properties of Ti-3Mo-(1−8)Sn-(0−10)Zr alloys were investigated over a wide alloy composition range. Ti-3Mo-5.5Sn-9Zr, Ti-3Mo-6Sn-7Zr, Ti-3Mo-6.5Sn-5Zr, and Ti-3Mo-7Sn-3Zr alloys exhibited superelasticity, and large shape recovery strains of over 4% were obtained. The critical stress for slip of the Ti-3Mo-6Sn-5Zr alloy was evaluated as 652 MPa. Moreover, the stress hysteresis between the stress for inducing the martensitic transformation and for the reverse martensitic transformation decreased with increasing Sn content or decreasing Zr content.