A review of studies on the electroplastic effect on the deformation process in various conductive materials and alloys for the last decade has been carried out. Aspects, such as the mode and regimes of electric current, the practical methods of its introduction into materials with different deformation schemes, features of deformation behavior accompanied by a pulsed current of different materials, structural changes caused by the combined action of deformation and current, the influence of structural features on the electroplastic effect, changes in the physical, mechanical, and technological properties of materials subjected to plastic deformation under current, possible mechanisms and methods of physical and computer modeling of the electroplastic effect, and potential and practical applications of the electroplastic effect are considered. The growing research interest in the manifestation of the electroplastic effect in such new modern materials as shape-memory alloys and ultrafine-grained and nanostructured alloys is shown. Various methods of modeling the mechanisms of electroplasticity, especially at the microlevel, are becoming the most realistic approach for the prediction of the deformation behavior and physical and mechanical properties of various materials. Original examples of the practical application of electropulse methods in the processes of drawing, microstamping, and others are given.

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.

Analysis of scanning electron microscopy images was used to study the changes in the crystal size distribution of ZnO, which occurred during its processing in an aqueous medium at 220–255 °C and an equilibrium vapor pressure in an autoclave. The results were compared with those of ZnO placed in a die for treatment under similar conditions supplemented with mechanical pressure application in the cold sintering process. In both cases, ZnO was treated in the presence of an activating additive: either zinc acetate or ammonium chloride. During autoclaving, a powder consisting of fine ZnO monocrystals was obtained, while the cold sintering process led to ceramics formation. Under vapor pressure and mechanical pressure, the aqueous medium affected ZnO transformation by the same mechanism of solid-phase mobility activation due to the additives’ influence. The higher the content of additives in the medium, and the higher the mechanical pressure, the more pronounced activating effect was observed. Mass transfer during the cold sintering process occurred mainly by the coalescence of crystals, while without mechanical pressure, the predominance of surface spreading was revealed. In the initial ZnO powder, the average crystal size was 0.193 μm. It grew up to 0.316–0.386 μm in a fine-crystalline powder formed in the autoclave and to an average grain size of 0.244–0.799 μm in the ceramics, which relative density reached 0.82–0.96. A scheme explaining the influence of an aqueous medium on the solid-phase mobility of ZnO structure was proposed. It was found that the addition of 7.6 mol% ammonium chloride to the reaction medium causes the processes of compaction and grain growth similar to those observed in ZnO Cold Sintering Process with the addition of 0.925 mol% zinc acetate.

The problem of the real existence of the electroplastic effect during deformation of metallic materials of different nature is still relevant. At the same time, the influence of structure refinement is not considered enough. In this work, the deformation behavior of ultrafine-grained (UFG) titanium Grade 4 is compared with that of coarse-grained (CG) titanium under tension with pulse current of the low duty cycle. The deformation curves of both structure states are presented for different regimes of pulsed current and thermal heating from an external source. Structure studies by optical and scanning electron microscopy, as well as microhardness measurements have been carried out. It is shown that Grade 4 titanium under tension accompanied by pulsed current exhibits electroplastic effect (EPE) in the form of a flow stress reduction. EPE in UFG state is much stronger than in CG state. An increase in the density and duration of the current pulse leads to a multiple decrease in the flow stresses in CG and UFG titanium. The contribution in the flow stress reduction from heating by an external source was less than that from tension with pulse current at the same temperatures. The impact of pulsed current during tension does not influence microhardness and grain size.

The effect of a pulsed current on titanium tensile deformation obtained by postdeformation annealing after cold rolling of the coarse-grained and ultrafine

The deformation behavior of duplex stainless steel under tension and bending, accompanied by a pulsed current and when heated by an external source, is investigated. The stress–strain curves are compared at the same temperatures. The contribution to the decrease in flow stresses is greater when using a multi-pulse current at the same temperature, compared to external heating. This confirms the presence of an electroplastic effect. An increase in the strain rate by an order of magnitude reduces the contribution of the electroplastic effect from single pulses to the reduction in flow stresses by 20%. An increase in the strain rate by an order of magnitude reduces the contribution of the electroplastic effect from single pulses to the reduction in flow stresses by 20%. However, in the case of a multi-pulse current, the strain rate effect is not observed. Introducing a multi-pulse current during bending reduces the bending strength by a factor of two and the springback angle to 6.5.