The effect of pulsed current on the shear deformation behavior of Ti-6Al-4V alloy.

Pulse current-assisted forming is a new technology to improve the plastic deformability of titanium alloy. In this work, Shearing tests of Ti-6Al-4V alloy were conducted using hat-shaped specimens under pulsed current (electroplastic shearing) and constant temperature (isothermal shearing). The actual deformation in shear zone of electroplastic shearing was larger than that of isothermal shearing. The shear load is also decreased by the pulsed current. Microstructure variation in the shear zone was investigated by scanning electron microscopy. An evident straight shear band was observed in the electroplastic shearing specimens. The deformation model of shear zone was established. Intracrystalline deformation was markedly easier for the grains with the pulsed current and induced larger deformation of the grains along the shear direction. Microcracks were observed in the shear zone of isothermal shearing, but none were found in the shear zone of electroplastic shearing. Evident crack healing was found in the crack tip of the shear zone of electroplastic shearing.