Effect of annealing temperature on tensile fracture behavior of AZ31/6061 explosive composite plate

In this study, the first evaluated and analyzed the local strain evolution and macro fracture morphology of AZ31/6061 explosive composite plate during uniaxial tension by the digital image correlation (DIC) method. The materials used are double-layer AZ31/6061 composite plates prepared by the explosive welding process. In order to meet the subsequent forming requirements, annealing at different temperatures is carried out. The fracture damage mechanism of AZ31/6061 explosive clad plate was comprehensively studied through mechanical tests at different annealing temperatures, microstructure characterization and fracture behavior analysis during the tensile process. The results showed that the thickness of the intermetallic compound at the interface increased with the increase of temperature, and the interface bonding strength reached the highest at 150 °C. Under the condition of 200 °C/2 h annealing, the composite plate has the best comprehensive properties, the tensile strength is 253.51 MPa, and the failure elongation is 25.16%. Combined with the SEM observation of tensile fracture and the evolution of strain distribution measured by digital image correlation (DIC), it is shown that the composite plate is mainly a brittle fracture mechanism before annealing and a ductile-brittle mixed fracture mechanism after annealing. Revealed the effect of temperature on the interfacial strengthening mechanism and fracture behavior of Mg/Al composite plate during fracture.