The critical roles of twinning and prismatic 〈a〉 slipping in affecting the dynamic recrystallization of hot-rolled Mg-Gd-Zr thick plate

作者：Sen Wang, Hucheng Pan, Zhihao Zeng, Zhen Pan, Sheng Wang, Dengshan Zhou, Zhuoran Zeng, Gaowu Qin · 发表于：Journal of Magnesium and Alloys · 年份：2025 · DOI：10.1016/j.jma.2025.07.016 · 被引用次数：16 · 研究领域：Magnesium Alloys: Properties and Applications、Aluminum Alloy Microstructure Properties、Aluminum Alloys Composites Properties

In this study, the typical Mg-14Gd-0.3Zr alloy was rolled at the high-temperature range of 450–500 °C. The rolled Mg alloy plate with thickness of 30 mm exhibits an ultra-high ultimate tensile strength of 428 MPa and elongation of 3.4 %, which has rarely been reported, and the strong fiber texture played a critical role in strengthening. The mechanisms underlying the evolution of texture during rolling were systematically investigated. At the early stage of rolling, alloys (450 °C and 475 °C) exhibited a [10 1 ¯ 0] texture due to twinning assisted by Prismatic 〈a〉 slipping. At 500 °C, the alloy underwent nearly complete dynamic recrystallization (DRX) process. With increasing the rolling reduction, the DRX occurred in the whole temperature range, exhibiting the typical [10 1 ¯ 0]–[11 2 ¯ 0] double fiber texture. For continuous DRX, Prismatic 〈a〉 dislocations accumulate to form grains with 30°[0001] grain boundaries, which exhibit a [10 1 ¯ 0] fiber texture. During discontinuous DRX, Prismatic 〈a〉 slip induced grain rotation around the [0001] axis, stabilizing either the 〈10 1 ¯ 0〉//RD (rolling direction) or 〈11 2 ¯ 0〉//RD orientations, leading to the formation of [10 1 ¯ 0]–[11 2 ¯ 0] double fiber texture. TEM observations confirmed that Prismatic 〈a〉 dislocations can accumulate to form sub-grain lamellae, which gradually transform into high-angle grain boundaries by absorbing more Prismatic 〈a〉 dislocations. First-principle calculation demonstrated that with increasing Gd co...