Effect of electropulsing treatment on microstructure and tensile fracture behavior of aged Mg-9Al-1Zn alloy strip

摘要

The effect of electropulsing treatment (EPT) on the microstructure, mechanical properties, and tensile fracture behavior of aged Mg-9Al-1Zn alloy strip at room temperature was investigated. The results indicated that EPT accelerated the spheroidizing and dissolution of β phase tremendously in the aged Mg-9Al-1Zn alloy strip. The EPT-induced microstructural change resulted in remarkably increasing elongation to failure, remained tensile strength unchanged. A mechanism for rapid spheroidizing and dissolution process of β phase during EPT was proposed based on the reduction of nucleation thermodynamic barrier and enhancement of atomic diffusion. Fracture analysis showed that with increase in frequency of EPT transgranular dimple fracture becomes predominant instead of the quasicleavage fracture.