Electroplasticity Mechanism Study Based on Dislocation Behavior of Al6061 in Tensile Process

Abstract

The effects of electric current on dislocation motion is the fundamental mechanism for the electroplastic effect. The difficulty of the research lies in how to design macro-experiments that can reflect the micro-evolution mechanism of dislocations. As a macroscopic manifestation of the interaction between dislocations and interstitial atoms, the Portevin-le Chateliar (PLC) effect provides a satisfying entry point for solving the above problems. Experiments of Al6061 in tensile process show that the current causes an increase of the pinning strength and a reduction of the time for dislocations to escape from the pinning. Further microscopic characterization reveals that the current leads to the dissolution of the precipitated phase and promotes the dislocation motion by activating the second slip system. Those changes are closely related to the thermal and athermal effects of the current. Based on the observation results in this paper, the contradictions in the existing literature can be well explained.