Interaction mechanism between twin boundary and crystalline/amorphous interface in dual-phase Mg alloys

The effect of the introduction of {101¯2} <101¯1> twin boundary (TB) on the mechanical behavior of dual-phase amorphous/crystalline (A/C) MgAl/Mg alloys is investigated by molecular dynamics simulation. The results show that the introduction of TB can activate dislocation slip and HCP→FCC phase transformation, which can significantly facilitate the synergy interaction between the crystalline and amorphous phases and enhance the plastic deformability of the dual-phase Mg alloys. However, TB increases the plasticity of dual-phase Mg alloys at the expense of strength. To design high performance Mg alloys, we also study the effect of the spacing between TB and ACI (STA) on the mechanical properties of the dual-phase Mg alloys. It is worth highlighting that the yield strength of the dual-phase Mg alloys increases with the increase of STA. The simulations indicate that the high-strength and high-plasticity dual-phase Mg alloys can be obtained by introducing TBs and optimizing STAs.