Effect of Al–Y gradient coating on hot corrosion resistance of γ-TiAl alloy at different temperatures
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所属单位：材料科学与技术学院
发表刊物：Appl Surf Sci
摘要：It is generally accepted that the crack is appeared when the thermal stress is accumulated which caused by the mismatch of coefficient of thermal expansion, through which oxygen will severely destroy the substrate at high temperature environments. Therefore, the coatings with gradient structure to reduce thermal expansion mismatch should greatly improve their service stability. Here Al–Y gradient coating is prepared on γ-TiAl alloy by magnetron sputtering. The results show that the hot corrosion resistance of γ-TiAl alloy could be greatly improved, and the activation energy at (750 °C–950 °C) can be calculated to be 126.88 KJ/mol for the coating. The Al2O3 and Y3Al5O12 (YAG) are the primary phases after hot corrosion, thus providing efficient protection at 750, 850 °C. At 950 °C, the consumption of oxide layers is accelerated due to the increased temperature so that some corrosive elements (such as S and Na) unavoidably invade into the scale. The improvement of hot corrosion resistance primarily owes to the existence of Y preferentially oxidizes Al to form α-Al2O3, and the effect of grain refinement of YAG phases. © 2019
ISSN号：0169-4332
是否译文：否
发表时间：2019-01-01
合写作者：Lin, Hao,Jia, Yanlin,Hu, Rongyao,Yu, Lijia
通讯作者：梁文萍