Effect of Reduction Ratio on Interfacial Evolution, Microstructure, and Mechanical Properties of Al/Mg/Al Laminated Composites

To study the effect of reduction ratio on the interfacial evolution, microstructure, and mechanical properties of Al/Mg/Al laminated composites, hot rolling experiments of Al/Mg/Al laminated composites with 30%, 40%, 50%, and 60% reduction ratios were carried out at 400 °C. The interfacial morphology, phase composition, microstructural evolution of the Mg layer, and the mechanical properties of the laminated composites were analyzed. The results showed that a continuous intermetallic compound layer mainly composed of Mg ₁₇ Al ₁₂ and Mg ₂ Al ₃ was formed at the Mg/Al interface at each reduction ratio. The peeling strength and mechanical strength of the laminated composites increased first and then decreased with the reduction ratio. The peeling strength reached a peak value of 23.04 N/mm, the ultimate tensile strength reached the highest value of 244.09 MPa, the yield ratio decreased to the lowest value of 0.72, and the plastic strain ratio ( r ) reached the highest value of 1.96 at 50% reduction ratio. At this time, the dynamic recrystallization of the Mg layer was the most complete, the grains were significantly refined and the texture was weak. In summary, the laminated composites showed a better match among interfacial bonding, microstructural evolution, and comprehensive mechanical properties under 50% reduction ratio at 400 °C.