Effect of high-energy electro-pulses on the compression deformation behavior of Ti-6Al-4V alloy

Abstract

Compression tests of Ti–6Al–4V alloy were conducted using an electron universal testing machine with discharge voltages that range from 50 V to 70 V and strain rate of 0.01 s−1. Isothermal compression at equivalent temperatures was also performed on a universal testing machine with furnace, with the same strain rate. Results show that the deformability of Ti–6Al–4V alloy can be significantly improved by high-energy electro-pulses, and the deformation resistance and yield stress were also decreased. Moreover, the effect of high-energy electropulses on compression mechanical properties of Ti–6Al–4V alloy increased with increasing discharge voltage. However, elongation and deformation resistance of compressions with high-energy electro-pulses were higher than isothermal compressions at equivalent temperatures. This result proved that the deformability improvement of Ti–6Al–4V alloy by high-energy electro-pulses results from the joint effects of temperature and electro-plasticity. Fracture modes in different experimental conditions were analyzed by observing the fracture morphologies of specimens by using a scanning electron microscope. Under high-energy electro-pulses, the micro morphology of compression fracture changes from elongated oval to equiaxed dimples, and the fracture modes transfer from intergranular to transgranular fracture.