Interfacial microstructure evolution for coordinated deformation of Mg/Al composite plates by asymmetrical rolling with differential temperature rolls

Abstract

In this work, Mg/Al composite plates with different thickness ratios were prepared by the asymmetrical rolling process with differential temperature rolls and isothermal symmetrical rolling. Microstructural evolution and mechanical properties of matrix and composite materials with different thicknesses were analyzed. Influence of thickness ratios on the coordinated deformability of heterogeneous metals and interface toughness under the action of temperature gradient and shear force was investigated. Results show that the relative deformation rates of matrix and composite materials converge gradually under the influence of work hardening of Mg/Al layer. The Mg layer is mainly DRXed grains and texture intensity gradually weakens with increasing thickness ratio. The Al layer is mostly dominated by subgrains and deformed grains, which have a strong correlation with thickness ratio. Strength and plasticity of composites first increase and then decrease with increasing thickness ratio. Fracture of composite plate occurs in intermetallic compounds (IMCs). Thickness of IMCs has a strong positive correlation with thickness ratio. When the thickness ratio of AZ31B/Al6061 for 5, the relative thickness of IMCs is the largest and the relative bonding strength is the smallest. When the thickness ratio of AZ31B/Al6061 for 3, there is no element aggregation in IMCs, and the comprehensive mechanical properties of composite plate are comparatively better.