Flow behavior and dynamic transformation of titanium alloy Ti62A during deformation at different temperatures and strain rates

Abstract

The effect of deformation temperature and strain rate on the hot deformation behavior and dual-phase microstructure evolution of the titanium alloy Ti62A was examined using electron backscatter diffraction. In general, the activation energy of Ti62A during steady-state deformation in the (α + β) phase is 295 kJ mol−1. The primary recovery mechanisms of the β phase during hot deformation are dynamic recovery and dynamic recrystallization (DRX). Moreover, discontinuous DRX occurs at low temperatures and high strain rates, whereas continuous DRX occurs at high temperatures and low strain rates. Furthermore, high strain rates in the (α + β) phase and high deformation temperatures are advantageous to dynamic phase changes during dynamic transformation (DT). The β phase penetrates the lamellar α s phase, causing fragmentation and spheroidization of the α s phase. Finally, DT begins more easily in the fine α s phase than in the coarse α p phase.