Diverse yielding regimes of two Mg-Al composite structures predicted by molecular dynamics simulations

Abstract

Small-size amorphous metals exhibit unique physical properties and excellent plasticity. We report results from molecular dynamics simulations of tensile behaviors of two magnesium-aluminum composite structures (Mg-Al CSs) that are separately bonded by amorphous Mg2Al3 and Mg17Al12 via metallurgical reaction. The yielding behaviors of these two Mg-Al CSs are investigated in comparison with pure amorphous MgxAly, Mg and Al single crystals, another Mg-Al CSs, and MgxAly/Mg-Mg CSs. The yielding stresses and strains of the Mg2Al3/Mg-Al and Mg17Al12/Mg-Al CSs are comparable, but all smaller than those of the base materials. The different yielding regimes of these two Mg-Al CSs finally lead to the diverse rupture positions. These results give insights into the possibility of improving the tensile properties of Mg-Al CSs by fabricating the Mg/Al bonded interface to be amorphous Mg2Al3 and Mg17Al12.