The mechanism of electroplasticity of Ti6Al4V

Electroplasticity has been reported for Ti6Al4V alloy under in situ pulse electric current treatment during mechanical test. We reported in the study that the electoplasticity of Ti6Al4V can also be achieved with direct current treatment. The mechanism of electroplasticity was investigated. The direct current treatment causes the phase transition from α to β phase below the β-transus temperature. The α/β ratio 36:1 of the as-received material changed to 19:1 at 12000 A/cm² after 30 min, while to around 7:1 at 14000 A/cm² after 5 min. The α and β phases were characterized for composition with WDS, grain orientation and grain size with EBSD, and dislocation density with XRD. The average reductions in elastic modulus are 1.47 GPa and 2.18 GPa, respectively, at 12000 A/cm² and 14000 A/cm². The direct current treatment reduced the 0.2 %YS from 960 MPa to 840 MPa. The enhancement in electroplasticity by direct current treatment was attributed to the phase transformation from α to β phase.