Synergistic control of microstructure and plasticity in hot-rolled Ti/Mg laminated composite plates by matrix composition and interfacial oxidation

Ti/Mg laminated composites were fabricated by hot-roll bonding at 400 °C with reduction ratios of 35% to 45%, using pure Mg and AZ31 alloy as base layer and TA1 pure titanium as the cladding layer. This study systematically investigates the synergistic effect of matrix composition and interfacial oxidation on the interfacial microstructure and mechanical properties of the Ti/Mg laminated composites. Initial bonding was achieved via mechanical interlocking under rolling pressure, which was enhanced at higher reduction ratios, resulting in improved tensile-shear strength. At the pure Mg/Ti interface, a MgTiO 3 -reinforced crystalline-amorphous composite structure formed via a Ti-Mg-O ternary reaction, which effectively hindering crack propagation and conferred superior tensile-shear and uniaxial tensile properties. In contrast, at the AZ31/Ti interface, the presence of Al promoted the formation of a multi-element amorphous transition zone rich in Al and O. While this improved the bending strength to some extent, it also induced high interfacial brittleness and unstable shear fracture. This work demonstrates that the O-dominated diffusion pathway achieves a better strength-toughness balance than the Al-dominated multi-element mechanism, providing crucial theoretical insights and experimental support for the interface design and performance optimization of Ti/Mg laminated composites.