Effect of Repetitive High-Density Current Pulses on Plastic Deformation of Copper Wires

High-density electric current pulses increase the plasticity and reduce the yield strength of metals with negligible heat generation. This effect has great potential for the development of energy-saving processing technologies for hard-to-deform metallic materials. Despite the long history of studying electroplasticity, there is still no consensus on the physical nature of this effect. In this paper, the effect of repetitive pulses applied at the same or gradually increasing tensile stress on the plastic deformation of copper wire is investigated using a homemade experimental setup. The electroplasticity of the wire in the delivery state and after annealing was compared. It is shown that at constant tensile stress, the incremental plastic deformation of the wire decreases with each successive pulse. This effect is stronger for annealed wire because it has a lower dislocation density and hence a lower plasticity resource. Joule heat release in the sample and heating due to plastic deformation are evaluated. The results obtained will be used to fit the parameters of the atomistic model being developed to describe the interaction of electron flow with dislocations.