Fast recrystallization and phase transformation in ECAP deformed Ti–6Al–4V alloy induced by pulsed electric current

Abstract

Abstract Ultrafine-grained Ti–6Al–4V alloy with high mechanical properties in both strength and elongation was prepared by equal channel angular pressing and following pulsed electric current treatment. The mechanical properties of Ti–6Al–4V alloy were investigated by tensile tests at room temperature. Elongation of the samples treated by pulsed electric current and annealing was considerably increased by 66.5% and 20.8%, respectively. The plasticity of ECAP deformed Ti–6Al–4V alloy was significantly improved by pulsed electric current while the strength still remained relatively high. Comparing with conventional equal channel angular pressing and following annealing process, uniform fully recrystallization microstructure with fine grains, increasing proportion of beta phase and decreasing dislocation density was obtained at a relatively low temperature during a short time with the help of pulsed electric current. This study proves that the pulsed electric current provoked a fast recrystallization and phase transformation process of a titanium alloy produced by equal channel angular pressing.