Effect of recovering damage and improving microstructure in the titanium alloy strip under high-energy electropulses

The effect of electropulsing treatment (EPT) on the microstructure improvement and damage recovery of cold-tension Ti-6Al-4V alloy strips was investigated. The results showed that the ductility and subsequent formability of the titanium alloy were improved noticeably by EPT, which originated from the rapid recrystallization and microcracks healing at a relative low temperature. Cold-rolling was introduced as a comparison, which brought in similar damage pressing but worsens materials ductility by work hardening. The rapid recrystallization process of Ti-6Al-4V alloy under EPT was attributed to the enhancement of nucleation rate and atomic diffusion resulting from the coupling of the thermal and athermal effects. Thermal compressive effect and pinch effect of electropulses were utilized to discuss the damage healing. Therefore, it is supposed that EPT provides a highly-efficiency and energy-saving method for enhancing ductility of titanium alloy by improving microstructure and recovering damage. (C) 2014 Elsevier B.V. All rights reserved.