Effect of Zr Addition on Mechanical Properties of Ti-Nb-Zr Alloys for Biomedical Applications

Artificial bone implant is concerned to improve their substantial features such as biocompatibility and mechanical properties. Ti-Nb alloys were considered to be one of the competitive materials because of their good biocompatibility and pseudoelasticity. In a present work, the effect of Zr addition as a third element on mechanical properties and pseudoelasticity of Ti-Nb alloys with Nb-content of 22-23at% were investigated by using cycling tests. The alloy ingots were fabricated by an arc melting method. The ingots were homogenization treated at 1273 K for 3.6ks followed by cold-rolled to a reduction ratio of 90% in thickness. All specimens were heat-treated at 873 K and some of them were aging treated at temperature ranging from 573 to 673 K after heat-treatment. Pseudoelasticity and mechanical behavior were evaluated by cycling test at room temperature. The results suggested that psuedoelasticity was confirmed in specimens without aging treatment irrespective of alloy compositions. Maximum recovery strain recovery increases with increasing Zr content. From all information acquired, it can be concluded that Ti-22Nb-(3-4)Zr(at.%) and Ti-23Nb-(2-3)Zr(at.%) alloys are the most optimum for artificial bone.