Influence of single and double aging treatment on microstructures and mechanical properties of cold rolled Ti–30Nb–5Ta–6Zr alloy

Abstract

A new β type Ti–30Nb–5Ta–6Zr alloy with low Young’s modulus, high tensile strength, good plasticity and biocompatibility was designed according to d-electron alloy design method. The influence of single and double aging time on microstructures and mechanical properties of the cold rolled and then soluted alloy was investigated. It was found that the cold rolled Ti–30Nb–5Ta–6Zr alloy is composed of single β phase after solution treatment at 750°C. With increasing single aging time that varied from 2 to 8 h at 450 and 500°C, the size and quantity of acicular α phase increased gradually, as well as the strength and elastic modulus. As compared with single aging process, the acicular α phase became coarsen with increasing double aging time that varied from 0·5 to 2 h, while the quantity of α phase decreased. The strength and elastic modulus of the alloy decreased, and the ductility was improved after double aging treatment. Ti–30Nb–5Ta–6Zr alloy obtained excellent integrated mechanical properties through first aging at low temperature for long time and then second aging at high temperature for short time.