Effect of annealing process on the interfacial microstructure evolution and mechanical properties of 7050 aluminum alloy clad plates

In this research, aluminum alloy thick plates are produced by vacuum roll cladding (VRC) technology. And the annealing experiments with different annealing temperature and holding time are carried out for the clad plates. The results show that the tensile strength and elongation of the bonding interface are positively correlated with the annealing temperature and holding time. The fracture mode of the bond interface gradually changes from brittle fracture to ductile fracture. The Mg and O elements diffuse at the interface during the annealing process, and the Al2O3 gradually evolves into MgO (mainly) and MgAl2O4. After holding at 470 degrees C for 24 h, the tensile strength of the interface is 427 MPa, which fully reaches the level of the matrix. Therefore, the dissolution and evolution of interfacial oxide contribute to the recovery of mechanical properties at the bonding interface.