Effect of Zr addition on mechanical properties and corrosion behavior of Ti-6Al-7Nb- x Zr ( x=0, 5, 10, 15, 20 wt%) alloy

The effects of Zr addition on mechanical properties and corrosion properties of hot-rolled Ti-6Al-7 Nb- x Zr ( x = 0, 5, 10, 15, 20 wt%) (TANZ) alloys were investigated. As the Zr content increases, the phase evolution of alloy is alpha phase -* alpha + alpha '' phase -* alpha + metastable beta + alpha '' phase. The results show that the simultaneous existence of initial alpha phase and metastable phase was beneficial to increase the uniform elongation and work hardening ability of the alloy. Ti-6Al-7 Nb-20Zr alloy exhibit the best combined mechanical properties, including tensile strength of 862 MPa, uniform elongation of 9.1%, and total elongation of 16.8%. Compared with Ti-6Al-7 Nb alloy, the improvement is 96%, 98%, and 65%, respectively. At the same time, the addition of Zr improves the passivation ability of the alloy and the corrosion resistance of the alloy. This study illustrates the broad application potential of titanium alloys in the field of medical device manufacturing.