Effect of electropulsing treatment on the recovery of AZ31B magnesium alloy

Electropulsing treatment (EPT) is a potential annealing method with advantages of performance improvement and equipment simplification. In the current paper, the effect of EPT on the recovery of AZ31B magnesium alloy during a two-stage plastic deformation process was studied. The tensile properties, residual stress, microstructure, and recovery kinetics were evaluated. The residual stress decreased and the cumulative elongation increased slightly, whereas the yield strength retained relatively high after EPT. A typical recovery process was observed. Moreover, the recovery kinetics was accelerated by the improved pulse current density, which led to lower residual stress and higher cumulative elongation. Thus, satisfactory recovery can be achieved by adjusting the pulse current during EPT. Analysis of the full width at half maximum (FWHM) and kernel average misorientation (KAM) indicated that the dislocation density decreased after EPT. Therefore, the pulse current has a significant impact on the dislocation mobility and annihilation, accounting for the recovery behavior of AZ31B magnesium alloy. A model of the recovery kinetics was established to demonstrate the effect of the pulse current on recovery evolution in AZ31B magnesium alloy.