Effect of electropulsing on dislocation mobility of titanium sheet

To investigate the effect of the electropulsing on dislocation mobility, specimens cut from the cold-rolled titanium sheet were treated by high density electropulsing with the maximum current density of 7.22, 7.64, 7.96 kA/mm(2), pulse period 110 mu s. The internal friction and elastic modulus were measured by a dynamic mechanical analyzer (DMA). When strain amplitude lowers a certain critical one, the damping of the electropulsed titanium sheet is lower than that of the cold-rolled one. When the strain amplitude exceeds the critical one, the damping of the electropulsed titanium sheet is extraordinarily higher than that of the cold-rolled or conventional annealed one. Furthermore, it is found that the damping peak of the electropulsed titanium sheet shifts to lower temperature compared with the conventional annealed one. It is demonstrated that the electropulsing treatment can decrease dislocation tangles and enhance dislocation mobility.