High-density electric current pulses increase the plasticity and reduce the yield stress of metals with negligible heat generation. This effect has great potential for the development of energy-saving technologies for processing hard-to-deform metallic materials. Despite the long history of the study of 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 home-made experimental setup. The electroplasticity of the wire in the delivery state and after annealing is compared. It is shown that for a constant tensile stress, the incremental plastic deformation of the wire decreases with each successive pulse. This effect is stronger for annealed wires because they have a lower dislocation density and therefore a lower plasticity resource. The Joule heat release in the specimen and the 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.

The effect of electroplasticity (EE) is used to increase the deformability of metals and alloys, save the energy used to deform them, and reduce tool wear. Despite the practical importance of EE, there is no consensus in the literature on its physical nature, and further research is needed to elucidate it. In this work, the tensile deformation of aluminum and copper wires stimulated by the repetitive electric pulses is experimentally investigated. Copper and aluminum have low and high stacking fault energy, respectively, and it is interesting to compare the behavior of these metals during electrically assisted plastic deformation. Joule heat release is precisely controlled in the experiments. Both metals show qualitatively similar behavior, with the increment in plastic deformation decreasing with pulse number at fixed tensile stress. This result supports the dislocation mechanism of EE in these metals.

The healing of cracks in metals and alloys by means of exposure to strong pulsed electromagnetic fields is of considerable interest, since it allows to increase the reliability and service life of structural materials and products made of them. In spite of practical importance, the methodology of selection of the parameters of the electric pulse treatment, which would allow to heal the defects, has not been developed yet. Healing of long macrocracks in thin plates by welding of their edges under electric pulse action is of particular difficulty. The present work is devoted to the study of the possibility of selecting the parameters of electric pulse treatment for such a case. The mechanism of healing of macrocracks in flat specimens is considered. The proposed multistage method of electric pulse treatment allowed to heal a significant length of macrocrack in a steel plate. The conducted studies of microstructure of cross-sections of AISI201 stainless steel samples confirm that healing occurs by the mechanism of welding of crack edges by molten material. The electric pulse creates at the tip of the crack significant compressive stress and high temperature, causing the melting of steel. The experiments showed significant heterogeneity of healing along the macrocrack front and in depth, however, the quality of healing improved with increasing distance from the plate surface. In the healed region along the crack edges, a zone with elongated grains surrounding a central zone with equiaxed grains is observed, which reflects the kinetics of cooling of the molten region of the specimen exposed to the current pulse.