Abstract In a Co–Al–W base superalloy, two types of topologically close-packed (TCP) phases, μ and Laves phases, were investigated by high-resolution transmission electron microscopy, scanning transmission electron microscopy and energy dispersive X-ray spectroscopy. It is found that an intergrowth structure of Laves within μ phases can be formed and both have a completely coherent interface relationship. With the aid of image simulation, both μ and Laves phases are identified as the quaternary compounds containing Co, Cr, W and Mo. Compared to Co7W6-type μ phase, W1 and W3-sites are the preferred sites of substitution by Mo atoms and Co1-site is a preferred site of substitution by Cr atoms in the quaternary μ phase, leading to the atomic displacement and an alteration of lattice parameter. In contrast to Co2W-type Laves phase, the newly formed quaternary Laves phase can maintain the C14-type Laves structure although Co and W are substituted partially by Cr and Mo respectively.

中文翻译：

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Co-Al-W 基高温合金 μ 相内 Laves 的共生结构

摘要 在 Co-Al-W 基高温合金中，通过高分辨率透射电子显微镜、扫描透射电子显微镜和能量色散 X 射线光谱研究了两种拓扑密堆积 (TC​​P) 相 μ 和 Laves 相。发现可以在μ相内形成Laves的共生结构，并且两者具有完全一致的界面关系。借助图像模拟，μ 和 Laves 相均被确定为含有 Co、Cr、W 和 Mo 的四元化合物。与 Co7W6 型 μ 相相比，W1 和 W3 位是 Mo 原子取代的优选位点， Co1位是四元μ相中Cr原子的优选取代位点，导致原子位移和晶格参数的改变。与 Co2W 型 Laves 相相比，