Effects of recrystallization and element diffusion behavior on interfacial bonding quality and mechanical properties of aluminum laminated composites

Abstract

For aluminum laminated composites (ALCs), interlayer bonding strength plays a crucial role in its performance. In this work, 7050/Al/7A52 and 7A62/Al/7A52 ALC were studied to explore the effects of recrystallization and element diffusion on interfacial bonding quality and mechanical properties. The results show that attributed to the deformation localization occurs at the 7A52/pure Al interface, continuous dynamic recrystallization (CDRX), discontinuous dynamic recrystallization (DDRX) and geometric dynamic recrystallization (GDRX) coexist, while only DDRX exists at the bonding interfaces of 7050/pure Al and 7A62/pure Al. Among them, 7A62/pure Al interface has the most obvious element diffusion behavior among the three kinds of interfaces. Notably, recrystallization would have a higher effect on improving bonding quality, which causes the 7A52/pure Al interface of the composites more difficult to delaminate during the tensile test. Besides, the enhancement of element diffusion depth at the 7A62/pure Al interface promotes the bonding strength of 7A62/Al/7A52 ALC to increase by 21.0% compared with that of 7050/Al/7A52 ALC. After the dynamic impact test, the peak flow stress and energy absorption value of 7A62/Al/7A52 ALC reached 567.1 MPa and 72.2 MJ/m3, and the interface remains intact. However, due to the existence of huge strength deviation in the 7A62/pure Al interface, it is more prone to fail during the tensile process, resulting in a decrease in the elongation of the composites.