Influence of Nb addition on microstructural evolution and compression mechanical properties of Ti-Zr alloys

In order to expand the application horizon of Ti-Zr based alloys, the influence of Nb content on phase composition, microstructural evolution and biomechanical properties is systematically studied. The phase and microstructural characterization of the as-cast alloys is carried out by X-ray diffraction, optical microscopy and transmission electron microscopy. The results reveal that Nb-containing Ti-Zr alloys transformed from single alpha phase -> alpha + alpha '' + beta phase -> single beta phase -> double beta phases with increasing Nb content. In the case of beta-type alloys, the addition of Nb improves the bonding energy between atoms, reduces the grain size, increases the elastic modulus, improves the yield strength and renders superior work-hardening behavior. Moreover, the current study provides mechanistic insights into microstructural evolution and strengthening of Nb-containing Ti-Zr alloys with increasing Nb content. Herein, the addition of 5 at.% Nb resulted in an abnormal work hardening during compression deformation under the synergistic influence of stress-induced martensite transformation of beta phase and stress-induced twinning of alpha phase. Moreover, the biomechanical properties are evaluated to demonstrate the potential of Nb-containing Ti-Zr alloys in biological applications. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

The influence of Nb content on phase composition, microstructural evolution, and biomechanical properties of Ti-Zr based alloys was systematically studied. The addition of Nb improved the bonding energy between atoms, reduced the grain size, increased the elastic modulus, improved the yield strength, and showed superior work-hardening behavior. The study also demonstrated the potential of Nb-containing Ti-Zr alloys in biological applications, especially with the addition of 5 at.% Nb resulting in abnormal work hardening during compression deformation.