Effects of pore structure characteristics on the mechanical behavior of Mg-Zn metallic glass under tensile and cyclic loading

Abstract

The effects of distribution and size of pores on the mechanical behavior of Mg70Zn30 metallic glasses (MGs) under tensile and cyclic loading are investigated by molecular dynamics simulation. It is found that the pores in Mg-Zn MGs not only reduces its elastic modulus, but also improves the plasticity and fatigue resistance. The AA11 pore distribution, having parallel pore stacking and the ratio of pore diameter (d) and separation (s) d/s = 1/1, shows a higher degree of strain aggregation and remarkable shear bands oriented perpendicular to the loading direction, while the AA13 pore distribution, having parallel pore stacking and d/s = 1/3, shows lower degree of strain aggregation and multiple shear bands along 45° direction. Pore distributions change the expansion mode of shear zones during the loading processes, which contributes to the optimal plasticity and fatigue resistance of AA13 pore distribution.