A Molecular Dynamics Study on the Effect of Interfacial Layer Composition on the Tensile Mechanical Behavior of Al/Mg Layered Composites

Four interfacial configurations were constructed via molecular dynamics simulations: an interface-free model, a single Mg2Al3 layer, a single Mg17Al12 layer, and a Mg17Al12/Mg2Al3 composite bilayer. This study aimed to clarify how interfacial phase compositions govern the tensile properties and failure mechanisms of Al/Mg layered composites under in-plane interfacial tension. The results show that the Mg17Al12 monolayer model exhibits the best performance, with a tensile strength of 1.702 GPa, representing a 31% improvement compared to the model without an interfacial layer. The composite bilayer model yields a 14% improvement, whereas the Mg2Al3 monolayer model shows a slight decrease in strength. Failure analysis revealed crack initiation at the matrix grain boundaries in the interface-free and Mg2Al3 monolayer models, but within the interfacial region in the Mg17Al12 monolayer and composite bilayer models. This study reveals the differences in the deformation mechanisms between composite and single interfacial layers, providing a theoretical reference for interface optimization design.