ABSTRACT Coating application to superalloys provides oxidation and corrosion resistance. One of the key elements in gas turbine coatings is aluminium (Al) which forms a thin, dense alumina layer upon exposure to oxygen and impedes further oxygen diffusion into the alloy. However, Al in the coating depletes due to inward diffusion and oxide formation. The rate of Al depletion is a function of the coating composition/structure, substrate alloy composition/structure and service conditions. In this study, a PtAl diffusion coating, was applied onto polycrystalline IN738LC and single crystal CMSX-4. The coated systems were exposed to 1080°C for 1000 h. Both SEM and XRD analyses were carried out on the as-coated and tested samples. It was found that despite the much higher Al content in CMSX-4, Al depletion was greater. With the higher Cr in IN738LC, a diffusion barrier enriched in Cr/Mo was able to form and reduce the Al depletion.

中文翻译：

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高温暴露后 PtAl 涂层 CMSX-4 和 IN738LC 中的铝消耗和元素重新分布

摘要 高温合金的涂层应用提供了抗氧化和抗腐蚀性能。燃气轮机涂层中的关键元素之一是铝 (Al)，它在暴露于氧气时会形成薄而致密的氧化铝层，并阻止氧气进一步扩散到合金中。然而，由于向内扩散和氧化物形成，涂层中的铝耗尽。铝消耗率是涂层成分/结构、基材合金成分/结构和使用条件的函数。在这项研究中，将 PtAl 扩散涂层应用于多晶 IN738LC 和单晶 CMSX-4。涂层系统暴露于 1080°C 下 1000 小时。SEM 和 XRD 分析都是在涂层和测试样品上进行的。发现尽管 CMSX-4 中的铝含量高得多，但铝的消耗量更大。由于 IN738LC 的 Cr 较高，