关键词: Mg-Li合金, 轧制工艺, 微观组织, 力学性能

Abstract: A novel Mg-14Li-0.18Al-0.5Ca-0.5Y alloy was designed and subjected to three different rolling processes: single-pass cold rolling with 10% reduction, single-pass cold rolling with 30% reduction, and single-pass hot rolling with 30% reduction. Effects of these rolling methods on the microstructure and mechanical properties of the as-cast alloy were systematically investigated using OM, SEM/EDS, XRD, and a universal tensile testing machine. The results indicate that the as-cast Mg-14Li-0.18Al-0.5Ca-0.5Y alloy primarily consists of β-Li matrix, Al₂Y, and (Mg, Al)₂Ca phases. After single-pass cold rolling with 10% reduction, the number of (Mg, Al)₂Ca and Al₂Y particles in the alloy increases significantly, and fine and dispersed AlLi phase is distributed within the grains. Under single-pass cold rolling with 30% reduction, the (Mg, Al)₂Ca and Al₂Y particles are elongated along the rolling direction, forming a banded structure, and the number of AlLi particles in the alloy increases. Under single-pass hot rolling with 30% reduction, the high temperature promotes the diffusion of Al, Li, and other elements, leading to extensive precipitation of AlLi and Al₂Y phases. Among these, after single-pass cold rolling with 30% reduction, both strength and ductility of the alloy are improved simultaneously, and when the total reduction is 80%, the comprehensive mechanical properties of the alloy are the best, with tensile strength and total elongation at break of 220 MPa and 24%, respectively.

Key words: Mg-Li alloy, rolling process, microstructure, mechanical properties