Effects of thermomechanical processings on fatigue properties of Ti-29Nb-13Ta-4.6Zr for biomedical applications

Abstract

Fatigue properties of Ti-29Nb-13Ta-4.6Zr underwent various thermomechanical processings were investigated in order to establish the optimal thermomechanical processing conditions for getting excellent fatigue properties. Precipitated α phase in Ti-29Nb-13Ta-4.6Zr aged at 673 K for 259.2 ks after cold rolling presents very fine needlelike phase as compared with precipitated α phase in Ti-29Nb-13Ta-4.6Zr aged at 673 K for 259.2 ks after solution treatment at 1063 K for 3.6 ks or aged at 723 K for 259.2 ks after cold rolling. Ti-29Nb-13Ta-4.6Zr aged at 723 K for 259.2 ks after cold rolling shows the greatest fatigue strength in both low cycle fatigue and high cycle fatigue life regions and the fatigue limit, which is around 770 MPa, is nearly equal to that of hot-rolled Ti-6Al-4V ELI with equiaxed α structure.