A Multiscale Investigation into the Electroplastic Effects in Copper : Experiments and Crystal Plasticity Modeling

Wu, Kaiwei and Sun, Xiaochuan and Liu, Bowen and Li, Quan and Wen, Wei and Shi, Qiwei and Xu, Zhutian and Peng, Linfa and Wang, Huamiao and Zhang, Yin and Forest, Samuel (2026) A Multiscale Investigation into the Electroplastic Effects in Copper : Experiments and Crystal Plasticity Modeling. Journal of the Mechanics and Physics of Solids, 212: 106597. ISSN 0022-5096

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Abstract

Electroplastic effects in metals show measurable changes in the exerted force in deformation processes under certain electric current conditions, holding potential to facilitate metal forming. However, the application of these effects is hindered by the so far unclear image of the underlying mechanisms, and the corresponding contributions are debatable. This work aims to quantitatively elucidate the athermal mechanisms of electroplasticity in copper with experimental and computational methods combined. Temperature-controlled pulsed-current electricity-assisted deformation (EAD) tests were conducted to emphasize athermal contributions, while large-area EBSD, two-beam TEM, and high-resolution EBSD (HR-EBSD) measurements were used to characterize texture evolution, slip systems, and semi-quantitative dislocation density. Then, a crystal plasticity model, incorporating electroplasticity-related mechanisms with thermodynamic evolution formulas, was applied to support a mechanism-focused interpretation of the observed electroplastic responses from dislocation behaviors. Analysis reveals that the reduced work hardening observed in the stress-strain curves originates from fluctuations in the local response. These fluctuations exhibit a characteristic two-stage behavior, consisting of a “rapid drop” followed by a “slow decline” of stress response. The associated changes in maximum flow stress and macroscopic work-hardening rate arise from the cumulative effect of EAD-induced softening during current pulses, which is linked to the recovery of statistically stored dislocations (SSDs). By quantitatively connecting short-term information to macroscopic stress-strain evolution within an electricity-coupled crystal plasticity framework and comparing with experimental textures and dislocation densities, this work provides mechanistic interpretations of athermal mechanisms and consolidate the understanding of electroplasticity in metals.