The Effect of Oxygen on the Phase Composition and Heat Treatment Behavior of Ti-V Alloys

Titanium and its alloys possess high specific strength, excellent corrosion resistance and good biocompatibility [1] [2]. Since oxygen is an unavoidable impurity in such materials, it has been adopted as an alloying element in the development of low-cost titanium alloys. Therefore, it is important to investigate the role of oxygen in these alloys, especially in beta-type alloys. In the present study, the effects of oxygen on the electrical resistivity, Vickers hardness and heat treatment behavior of a Ti-20mass%V alloy which is the lowest concentration for which the fully retained beta phase is obtained were assessed. The electrical resistivity and Vickers hardness of solution-treated and quenched specimens increased with increasing oxygen content, due to the dissolution of oxygen into the beta phase and solid solution hardening, respectively. Upon isothermal aging at 673 K, the addition of O accelerated a-phase precipitation. The addition of O was found to suppress the appearance of the athermal. phase in the solution-treated and quenched state.