Influence of oxygen content on microstructure and mechanical properties of Ti-Nb-Ta-Zr alloy

Abstract

The influence of oxygen content on microstructure and mechanical properties of Ti-22.5Nb-0.7Ta-2Zr (at.%) alloy was investigated in this work. According to experiments, the grains were refined apparently when the oxygen content was between 1.5% and 2.0%. The ultimate tensile strength (UTS) increased and elongation decreased with increasing oxygen content. But at the content of 1.0%, the elongation was nearly the same to that of the original alloy (about 16%). The elastic modulus remained comparatively low (<65. GPa) when the content was lower than 1.5%, and then increased dramatically. Therefore, there existed the best oxygen content-1.0%, at which fine grains were obtained, as well as UTS of 750. MPa, elongation of 16% and elastic modulus of 65. GPa. The Ti-22.5Nb-0.7Ta-2Zr-1.0O alloy maintained typical ductile fracture characteristics of beta titanium alloy, and had a little superelasticity. © 2010 Elsevier Ltd.