Superplastic behaviour and microstructure evolution of a fine-grained TA15 titanium alloy.

Zhao, Zhanglong; Guo, Hongzhen; Chen, Li; Yao, Zekun

The fine-grained microstructure of TA15 titanium alloy was prepared through two-step forging technology combined with high and low temperatures, and a transnormal superplastic elongation of more than 2000% was obtained. The superplastic behaviour and microstructure evolution were systematically researched at different temperatures and strain rates through superplastic tensile test. The results indicate that the fine-grained TA15 alloy exhibits superplasticity at temperatures of 760–980°C and initial strain rates from 1.1 × 10−2 to 5.5 × 10−5 s−1. The optimal superplastic conditions are 940°C and 3.3 × 10−4 s−1, in which the average elongation is 2526% and the maximum elongation is 2743%. During superplastic deformation, dynamic recovery and recrystallization occur obviously, and the corporate effect of strain hardening and recrystallization softening decides the superplastic ability directly.

Rare Metals, 2009, Vol 28, Issue 5, p523

1001-0521

Academic Journal

10.1007/s12598-009-0101-8