Breaking Mg matrix composite property trade-offs via in-situ interface reaction and heterogeneous structure design

Many properties of Mg matrix composites are mutually incompatible, and even completely repel each other. Here, we constructed a magnetic layered component in Mg matrix composite reinforced with reduced graphene oxide (RGO) through an in-situ interface reaction strategy, achieving simultaneous improvement in the strength, ductility, and electromagnetic shielding performance of the composite. The magnetic component is generated by the in-situ reaction of Fe₂O₃ nanoparticles encapsulated on RGO with the Mg matrix. The superior strength-ductility synergy originates from layered heterostructure, which actives non-basal dislocations and enables a stable microcrack-multiplication. The heterogeneous layered structure strengthens the multi-level reflection of electromagnetic wave (EMW) inside the composite. The in-situ interfacial reaction introduces abundant of heterogeneous interfaces into the composites, which improves the interfacial polarization loss ability of the composites. The magnetic RGO layer can provide shape anisotropy that breaks the Snoek limit, thus improving the magnetic loss ability of composite in high-frequency electromagnetic fields. The synergistic action of multiple EMW loss mechanisms improves the electromagnetic shielding performance of composite. The current study emphasizes the influence of interface structure on the mechanical and functional properties of composites, and presents a promising approach for the development of structure/functional integrated composites with enhanced properties.