Influence of Grain Size on Electrically Assisted Tensile Behavior of Ti-6Al-4V Alloy

The effect of grain size and current density on deformation behavior during electrically assisted tension of Ti-6Al-4V alloy was investigated. The microstructural variations under different conditions were observed by optical microscope, SEM and TEM. The dislocation density was quantified by x-ray diffraction technique. The decrease in grain size could increase the elongation growth and stress reduction during electrically assisted tension. Fine grain size specimens can reach higher temperature than coarse grain specimens. With increasing current density, wider and deeper dimples on the fracture surfaces were observed, and less dislocation density and pileups were found in comparison with room-temperature tension without current. The dislocation density has a 62.1% reduction at 10.48 A/mm² compared with room-temperature tension for 9.2 μm grain size specimens.