Multi-scale interface strengthening mechanism of Mg/Al clad plates achieved by prefabricated corrugated rolling

Abstract

To address the issue of low interfacial bonding strength in Mg/Al clad plates, a prefabricated corrugated rolling (PCR) process is proposed. A combined approach of finite element simulation and experimental methods is employed to investigate the stress-strain evolution during rolling, as well as the effects of PCR process on the microstructure and mechanical properties of the clad plates. The results indicate that the bonding strength is significantly enhanced by the PCR process, with the trough, waist, and peak regions reaching 111.27, 110.43, and 108.55 MPa, respectively-approximately 34% higher than the FR plate. The PCR process introduces an inhomogeneous stress state during rolling, the trough region experiences compressive stress for the longest duration, triggering severe plastic deformation at the interface and matrix. The waist region generates the highest equivalent strain under the synergistic effect of compressive and shear stress. The peak region enhances the interface deformation effect by virtue of transverse metal flow. This complex stress strain state promotes grain refinement of the Mg and Al matrices, increases the dynamic recrystallization fraction of the Mg side and elevates the dislocation density of the Al side. Furthermore, it induces the formation of dislocation structures in the Mg side near-interface region and a nanocrystalline transition layer in the Al side near-interface region, achieving multi-scale reinforcement of interface microstructure. The PCR process can optimize the microstructural evolution of the interface by regulating stress distribution, providing a new insight for improving the performance of layered metal composites.