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摘要: 大量的研究表明多主元合金中广泛地存在对其性能提升有重要影响的化学短程序. 利用先进的透射电子显微成像技术可以在原子分辨率水平分析多主元合金中化学短程序的尺度、成分和构型.Abstract: Numerous studies indicates that multicomponent alloys extensively possess short-range order, which place a significant impact on their performance improvement. Employing advanced transmission electron microscopy, the size, composition and structure of short-range order in multicomponent alloys can be analyzed at atomic resolution.
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Key words:
- multicomponent alloys /
- short-range order /
- mechanical performance
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图 1 (a)沿着
$\langle 112 \rangle $ 晶带轴方向三元VCoNi合金的纳米束电子衍射图, 黄色圆圈圈出的为CSRO引起的额外的弥散衍射点. (b)使用额外的弥散衍射点拍摄的能量过滤暗场像. (c) CSRO尺寸分布的统计. (d)用高角环形暗场像表征CSRO. (e)原子级分辨率的能谱展示富V面−富Co/Ni面−富V面的三明治CSRO结构. (f)上半部为基于空间分布关联系数分析得到的各元素之间的近邻倾向, 其中该系数为正表示避免近邻, 为负表示倾向近邻; 下半部为基于蒙特卡洛模拟得出的系统能量在规避V−V近邻、倾向V−Co/Ni近邻构型时能量下降 -
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