Ductile-to-brittle transition in aluminum alloys

作者：Dengshan Zhou, Xiuzhen Zhang, Xueyong Pang, Zitong Zhao, Xinren Chen, Shaolou Wei, Chao Yang, Wu Gong, Stefanus Harjo, Rongguang Li, Deliang Zhang, Gaowu Qin · 发表于：Materials Research Letters · 年份：2026 · DOI：10.1080/21663831.2026.2646271 · 被引用次数：1 · 研究领域：Microstructure and mechanical properties、Aluminum Alloy Microstructure Properties、High-Velocity Impact and Material Behavior

Here we exploited room (298 K) – and cryogenic (77 K) – temperature mechanical behaviors of binary Al-Mg alloys across a wide range of magnesium concentration (i.e. 2.8–13.1 at.%). We observed ductile-to-brittle transition at 77 K as Mg content increases from 7.5 to 13.1 at.%, with a significant reduction from 161 J to 14 J in impact energy. Through detailed theoretical calculations and experimental observation, this composition-dependent transition is discovered to be primarily associated with Mg segregation-induced grain boundary (GB) expansion and charge density depletion at the GB. This finding not only addresses the surging need for durable low-temperature lightweight materials, but also provides an insight in designing superlight aerospace structural materials capable of withstanding the harsh environments encountered for space exploration.