Abstract No.:	6341
Title:	Microstructure development of an electroplating coated nickel based SC superalloy in oxidation processes: experimental results
Authors:	Kang Yuan / BGRIMM Technology Group, P.R. China Jianming Liu* / BGRIMM Technology Group, P.R. China Linfeng Huang/ BGRIMM Technology Group, China
Abstract:	Electroplating is a coating technology which can make MCrAlY overlays on complex surfaces for gas turbine components. In this study, a nickel based single crystal (SC) superalloy was electroplating-coated by a MCrAlY alloy. After high-temperature oxidation testing, the microstructure of the MCrAlY-superalloy system was investigated. The results showed that some void-like imperfections existed in the electroplating coatings. During the oxidation processes, an alumina-maily TGO was formed at the coating surface. Internal oxidation also occurred in those voids but with a slow oxidation rate. When the Al content decreased to a certain level with ²phase totally depleted, the internal oxidation became much heavier. The microstructure in the SC superalloy also changed due to elemental interdiffusion. In the secondary reaction zone, some heavy element-rich topological closed packed (TCP) phases were formed. It was found that the amount of the TCP phases was much less than in the case when coatings were made by plasma spray technology.

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