Microstructure evolution and mechanical properties of as-rolled Mg-Al-Ca-Mn alloy sheet with Al2Ca phase and Mg2Ca phase

作者：M.Q. Zhang, T. Nakata, Xu Cheng, Guoyuan Tang, Kun-kun Deng, Tao Liu, Kai Cui, Xiaojun Wang, Gen‐Shuh Wang, S. Kamado, Lin Geng · 发表于：Journal of Materials Research and Technology · 年份：2025 · DOI：10.1016/j.jmrt.2025.07.130 · 被引用次数：8 · 研究领域：Magnesium Alloys: Properties and Applications、Aluminum Alloys Composites Properties、Aluminum Alloy Microstructure Properties

In this study, Mg-Al-Ca-Mn alloy sheets containing distinct Laves phases (Al 2 Ca phase and Mg 2 Ca phase) were fabricated via composition modulation and hot rolling to systematically investigate the microstructure evolution and mechanical properties. At the initial rolling stages, microstructure examination revealed that the {10 2} tensile twin and the {10 1}-{10 2} double twin mainly occurred in the original grains, in which the Mg-1.0Al-3.0Ca-0.4Mn (wt.%) alloy with high {10 2} tensile twin ratio exhibited broad transverse direction (TD)-split texture. With increasing accumulative reduction, the original grains with crystal orientation near [11 0]//TD were gradually rotated to [10 0]//TD around the [0001] axis, facilitating the in-situ conversion from sub-grains to dynamic recrystallized (DRXed) grains via the continuous DRX (CDRX) mechanism. Ultimately, the alloys exhibited a typical bimodal microstructure consisting of DRXed grains and un-DRXed grains. The micron-sized Al 2 Ca phases with high elastic modulus stimulated DRX by the particle stimulated nucleation (PSN) mechanism, leading to a moderate DRX ratio with 46% for the Mg-5.0Al-2.0Ca-0.4Mn (wt.%) alloy. The nano-sized Guinier Preston (G.P.) zones and Al 2 Ca precipitates could effectively restrict the non-basal dislocation slips, resulting in a low DRX ratio with 21% for the Mg-1.0Al-3.0Ca-0.4Mn (wt.%) alloy. Consequently, the alloy containing Al 2 Ca phase exhibited higher ductility than that containing Mg 2 Ca p...