Strong Plasticity Enhancement of a Covering Mg-Based Material: Influence of Organizational Characteristics on the Strength and Plasticity of AZ31/WE43/AZ31 Laminated Metal Composites

Abstract

To enhance the mechanical properties of the WE43 rare-earth magnesium alloy, three-layer AZ31/WE43/AZ31 laminated metal composites (LMCs) are fabricated via a stacked rolling process. LMCs with varying microstructures are produced by annealing at temperatures ranging from 350 to 500 °C. Microstructural characterization and mechanical properties are evaluated using electron backscatter diffraction, scanning electron microscopy, energy-dispersive spectroscopy, and uniaxial tensile testing. The asynchronous recrystallization behavior of the AZ31 and WE43 layers leads to decoupled changes in strength and ductility. Analysis of the yield strength contributions reveals that grain boundary strengthening and dislocation strengthening are the dominant strengthening mechanisms. Plastic deformation analysis indicates that the outer AZ31 layers enhance the overall ductility of the LMCs by promoting microcrack toughening and increasing the crack accommodation capacity of the WE43 core. The AZ31/WE43/AZ31 LMCs annealed at 400 °C for 30 min exhibit the optimal combination of mechanical properties. Compared to the monolithic WE43 alloy, these LMCs demonstrate a modest increase in strength and a 44% improvement in ductility.