Effect of Sn on elastic modulus and magnetic susceptibility of Zr-16Nb-xTi (x=4 wt%, 6 wt%) alloys

Low elastic modulus and magnetic susceptibility play a vital role in the design of biomedical alloys. However, many existing bio-alloys do not meet these requirements, which is the main reason for limiting their application areas. Therefore, we present a method that proper Sn addition can lower elastic modulus and magnetic susceptibility in this study. The microstructure, mechanical properties and magnetic susceptibility of Zr-16Nb- x Ti- y Sn ( x =4 wt%, 16 wt%; y =4 wt%, 6 wt%) alloys were studied. With increasing Sn addition, the fractions of β and α ″ martensite phases are increasing and decreasing, respectively. Elastic modulus, mechanical strength and elongation are roughly increasing with higher Sn compositions except Zr-16Nb-4Ti-6Sn. The increased Sn concentration from 4 wt% to 6 wt% can reduce magnetic susceptibility, especially in Zr-16Nb-16Ti alloy. These evolutions are closely correlated with the change in microstructural characteristics as phase fractions of β and α ″ martensite phases of alloys, which can be ascribed fundamentally to the difference in Sn concentrations. Among these alloys, the Zr-16Nb-4Ti-6Sn alloy shows the best combination of mechanical properties and magnetic susceptibility.