The effect of electropulsing treatment (EPT) on the microstructure and mechanical properties of aged Mg-9Al-1Zn alloy strip was studied. EPT was found to accelerate tremendously the β phase spheroidization in the aged Mg-9Al-1Zn alloy. This improved microstructure exhibits excellent mechanical properties, that is, increasing elongation to failure significantly without loss of tensile strength. The spheroidization of the β phase during EPT was attributed to the reduction of the nucleation thermodynamic barrier and enhancement of atomic diffusion.

The effect of electropulsing treatment (EPT) on the solution behavior of aged Mg alloy AZ61 strip was investigated using scanning electron microscope (SEM) and x-ray diffraction (XRD). It was found that EPT accelerated tremendously the dissolution of β phase into α matrix in an aged Mg alloy AZ61 strip. The dissolution of β phase took place in less than 4 s at relatively low temperature under EPT, compared with that in conventional heat treatment. A mechanism for rapid solid solution process during EPT was proposed based on the coupling of the thermal and athermal effects. The results in this investigation indicated that EPT played an important role in the nonequilibrium microstructural evolution in the alloy. It is supposed that EPT can provide a highly efficient approach for solid solution treatment of the alloy.