Microstructure formation and high temperature oxidation behavior of Ti-Al-Cr-Y-Si coatings on TiAl
Microstructure formation and high temperature oxidation behavior of Ti-Al-Cr-Y-Si coatings on TiAl
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DOI：
10.1016/j.apsusc.2021.150191
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发表时间：
2021-10
影响因子：
6.7
通讯作者：
R. Swadźba;P. Bauer
中科院分区：
文献类型：
--
作者：
R. Swadźba;P. Bauer
采用封闭式空心阴极物理气相沉积（CHC-PVD）方法在γ-TiAl 48-2-2合金表面制备了Ti-Al-Cr-Y-Si涂层，用于高温氧化防护。该研究涉及的涂层的生长机制，初始微观结构的分析，以及使用高分辨率扫描透射电子显微镜（STEM）和高温X射线衍射（HT-XRD）的相变研究。在850 °C下对涂覆的合金进行高温氧化测试，其中观察到与裸48-2-2合金相比低五倍的质量增加。详细的微观结构调查允许表征的热生长的氧化物规模，这被发现是由纳米层的二氧化钛，等轴（Al，Cr）2 O3和柱状氧化铝。这些调查提供了微观结构的证据，Cr对形成的Al 2 O3，这是假设以前的效果。高温氧化过程中，钇在氧化铝膜的晶界上发生偏聚，表明存在活性元素效应。
The paper presents the application of Closed Hollow Cathode Physical Vapor Deposition (CHC-PVD) method for the depostion of Ti-Al-Cr-Y-Si coatings on γ-TiAl 48-2-2 alloy for high temperature oxidation protection. The study concerned the analysis of the coating’s growth mechanism, initial microstructure as well as phase transformations investigations using high resolution Scanning Transmission Electron Microscopy (STEM) and high temperature X-ray diffraction (HT-XRD). The coated alloy was subjected to high temperature oxidation test at 850 °C where a fivefold lower mass gain compared to bare 48-2-2 alloy was observed. Detailed microstructural investigations allowed to characterize the thermally grown oxide scale, which was found to be composed of nanometric layers of titania, equiaxed (Al,Cr)2O3and columnar alumina. These investigations provided microstructural evidence for the Cr effect on the formation of Al2O3, which was postulated previously. Yttrium was found to segregate to the grain boundaries of alumina oxide scale during high temperature oxidation, indicating the occurence of the reactive element effect.