Effect of Annealing Temperature on Interface structure of Mg/Al Laminated Composites Rolled under LSDR Principle

Mg/Al laminated composites were prepared based on lattice severe deformation rolling（LSDR） principle.The thickness,composition and morphological characteristics of the interfacial layer were studied at 200℃-400℃annealing temperatures,and tensile tests were carried out.The results show that the thickness of diffusion layer increases with the increase of annealing temperature.When the annealing temperature reaches 300℃,the interface is composed of two layers,including Mg₁₇Al₁₂ phase near the magnesium alloy side and Mg₂Al₃ phase near the aluminum alloy side,and the growth rate of Mg₂Al₃ phase is faster than that of Mg₁₇Al₁₂ phase as the temperature increases.The interfacial layers are continuously distributed along the rolling direction（RD） and transverse direction（TD）.The tensile strength and elongation of Mg/Al laminated composites along RD and TD increase at first and then decrease with the increase of annealing temperature.The optimal mechanical performance is obtained when the annealing temperature is 300℃.The tensile strength along the RD and TD are 242 MPa and 247 MPa,respectively,and the elongation is more than 14%,which is obviously higher than that of the plates without annealing.The research results provide experimental reference for preparing high quality Mg/Al laminated composites based on LSDR principle.