Microstructure, mechanical properties, and electrical conductivity of Mg-8Li-2Y-Zn/Al multilayered composites fabricated by cross asynchronous accumulative roll bonding.

Abstract

Mg-Li alloy is a material with great potential for development but its application in multiple fields is limited due to disadvantages, such as low strength and poor molding properties. In this study, Mg-8Li-2Y-Zn/Al multilayered composites were prepared by the Al layer cladding Mg-Li alloys using a cross asynchronous accumulative roll banding (CAARB) method, and the changes in microstructural characterization, mechanical properties, and electrical conductivity after rolling were evaluated. The results showed that the asynchronous rolling introduced additional shear variables, which provided the conditions for the aluminum layers to fracture to form wave patterns and improve the formability of the composites. The change in the rolling direction caused the grain orientation to be dispersed along the TD direction. The microhardness and tensile strength of the Mg-8Li-2Y-Zn/Al composites increased during the CAARB and reached a maximum after four cycles. In addition, calculations based on the skin depth indicate that the addition of Al layers benefits the composites in terms of improved electrical conductivity. Overall, the addition of Al layers allows more flexibility in the design and extension of Mg-Li alloys, and these findings provide insights into the control of microstructure and improvement of properties of Al/Mg-Li multilayered composites using the CAARB process.