Effect of Annealing Temperature on the Microstructure and Mechanical Properties of the Al/Mg–8Li–3Al–1Zn/Al Composite Plates Fabricated by Hot Rolling

Al/Mg–Li/Al composite plates were fabricated by hot rolling with 50% thickness reduction at 673 K and annealed at 473–673 K for 1 h. The microstructure and mechanical properties of the composite plates under different annealing temperatures were investigated. The results show that the composite plates with a good bonding interface are fabricated. The diffusion layer consisting of Al3Mg2, Al12Mg17, AlLi, and MgLiAl2 has formed at the interface after annealing at and above 623 K, while the interfacial bonding strength increases with the annealing temperature. The microhardness of the interface increases rapidly when the annealing temperature is above 573 K. The elongation of the composite plate increases with annealing temperature. The tensile strength decreases when annealing temperature is above 573 K.