Microstructure and mechanical properties of Mg-5Li-1Al sheets processed by cross accumulative roll bonding

Mg-5Li-1Al alloy was processed by cross accumulative roll bonding (CARB). The processed Mg-5Li-1Al sheet possesses ultra-fine grains, and its strength increases both in the rolling direction (RD) and transverse direction (TD) with the elongation remaining 16˜18%. The proper CARB processing is helpful to improve the isotropy of mechanical properties of Mg-5Li-1Al sheet. At the same time, the CARB process has a beneficial effect on improving the plasticity of Mg-5Li-1Al sheet. With the change of the direction between the CARB passes, the basal texture of Mg-5Li-1Al sheet is weakened, and the non-basal texture is strengthened. Both prismatic slip and pyramidal slip are initiated. The dominant deformation mechanism changes from twin deformation to slip deformation, and finally shear deformation. The grain refinement mechanism changes from twin dynamic recrystallization to continuous dynamic recrystallization, and finally rotational dynamic recrystallization.