Zhang Qiubo, Gallant Max C, Chen Yi, Song Zhigang, Liu Yang, Zheng Qi, Chen Linfeng, Bustillo Karen C, Huang Yu, Persson Kristin A, Zheng Haimei
Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, USA.
Nature. 2025 Oct;646(8084):323-330. doi: 10.1038/s41586-025-09530-w. Epub 2025 Sep 24.
Kinetically trapping the high-temperature states through rapid cooling solidification is widely used for the synthesis of high-entropy alloys (HEAs), especially those with intrinsically immiscible elemental combinations. However, strategies need to be developed to overcome the fundamental limitations of rapid cooling solidification in controlling the crystallinity, structure and morphology of HEAs. Here we introduce an isothermal solidification strategy for the synthesis of HEAs by rapidly altering the metal alloy composition through liquid-liquid interface reactions at low temperatures, for example, from 25 °C to 80 °C. We use gallium (Ga)-based metal as the sacrificial reagent and mixing medium. By directing the reactions to the interfaces between the Ga-based liquid metal and an aqueous metal ion solution, the foreign metal ions can be reduced at the interfaces and incorporated into the liquid metal quickly. HEAs with various crystallinity (single crystal, mesocrystal, polycrystal and amorphous), morphology (zero, two and three dimensions) and compositions can be achieved through the isothermal solidification. Ga can be completely consumed, resulting in Ga-free HEAs. If desired, Ga can be one of the metal elements in the final products. In situ liquid phase transmission electron microscopy (TEM) studies and theoretical analysis show the isothermal solidification mechanisms. Our direct observations show the enhanced mixing of liquid metal elements and the solidification process with fluctuating nucleation dynamics. The isothermal solidification marks a powerful strategy for HEA synthesis through an unexplored pathway of kinetically trapping the high-entropy states.
通过快速冷却凝固动力学捕获高温状态被广泛用于合成高熵合金（HEA），特别是那些具有本质上互不相溶元素组合的合金。然而，需要开发策略来克服快速冷却凝固在控制高熵合金的结晶度、结构和形态方面的基本限制。在此，我们介绍一种通过在低温下（例如从25°C到80°C）通过液-液界面反应快速改变金属合金成分来合成高熵合金的等温凝固策略。我们使用镓（Ga）基金属作为牺牲试剂和混合介质。通过将反应引导至Ga基金属液态与金属离子水溶液之间的界面，外来金属离子可在界面处被还原并迅速掺入液态金属中。通过等温凝固可以实现具有各种结晶度（单晶、中晶、多晶和非晶）、形态（零维、二维和三维）和成分的高熵合金。Ga可以被完全消耗，从而得到无Ga的高熵合金。如果需要，Ga可以是最终产物中的金属元素之一。原位液相透射电子显微镜（TEM）研究和理论分析揭示了等温凝固机制。我们的直接观察显示了液态金属元素的增强混合以及具有波动形核动力学的凝固过程。等温凝固标志着一种通过动力学捕获高熵状态的未探索途径来合成高熵合金的有力策略。
