Residual stress is caused by non–uniform deformation caused by non–uniform force, heat and composition, which is of great significance in engineering applications. It is assumed that the residual stress is always the upper limit of the elastic limit, so the reduction of the flow stress will reduce the residual elastic stress. It is particularly important to control the flow stress in metal materials. Compared with traditional methods, the use of electropulsing treatment (EPT) technology stands out due to its energy–efficient, highly effective, straightforward and pollution–free characteristics. However, there are different opinions about the mechanism of reducing flow stress through EPT due to the conflation of the effects from pulsed currents. Herein, a clear correlation is identified between induced stress levels and the application of pulsed electrical current. It was found that the decrease in flow stress is positively correlated with the current density and the duration of electrical contact and current action time. We first systematically and comprehensively summarize the influence mechanisms of EPT on dislocations, phase, textures and recrystallization. An analysis of Joule heating, electron wind effect, and thermal–induced stress within metal frameworks under the influence of pulsed currents was conducted. And the distribution of electric, thermal and stress fields under EPT are discussed in detail based on a finite element simulation (FES). Finally, some new insights into the issues and challenges of flow stress drops caused by EPT are proposed, which is critically important for advancing related mechanism research and the revision of theories and models.

In this article, a novel forming and sintering method is introduced for the forming of micro-components in which the loose powders are loaded directly into the die, followed by simultaneous electrical forming and electric-sintering (called coupled multi-fields activation). In the study, Φ1.0 mm × 1.0 mm sized cylinders were formed with 316 L stainless steel powders and the coupled multi-fields activations were enabled with a Gleeble-1500D thermal simulation machine. Sintered sample with relative density of 99.20% has been fabricated at a sintering temperature of 900°C, heating rate of 50°C/s, and pressure of 250 MPa. The study showed that the deformation and breakage of the particles during the combined forming and sintering under the electric field are two critical mechanisms that prescribe the densification process. Due to the deformation and breakage of the particles, an increase and then subsequent disappearance of the interface areas among the particles were observed, which proved to be vital to the densification of the powders and hence, vital to the density that was produced. Based on the experimental observation, a three-stage-sintering model has been established to describe the process of the densification of 316 L stainless steel powders when being formed/sintered under coupled multi-fields activations.