Protection mechanism of enamel-alumina composite coatings on a Cr-rich nickel-based superalloy against high-temperature oxidation

IMR OpenIR

	Protection mechanism of enamel-alumina composite coatings on a Cr-rich nickel-based superalloy against high-temperature oxidation
	Wu, Mingyu; Chen, Minghui; Zhu, Shenglong; Wang, Fuhui; mhchen@imr.ac.cn
	2016
发表期刊	SURFACE & COATINGS TECHNOLOGY
ISSN	0257-8972
卷号	285 页码:57-67
摘要	As the service environment has become increasingly harsh, high-temperature protective coatings were widely researched and applied in industrial fields. K444 is a typical Cr-rich Ni-based superalloy used in power system. Its protection at high temperatures relies on the formation of chromia which is not alone but accompanied by the growth of other oxides or compounds thereby decreasing the oxidation resistance of chromia. In this paper, an enamel-alumina composite coating was prepared on the K444 alloy. Its oxidation behavior at 900 degrees C was investigated and the oxidation mechanisms were carefully elucidated. Results indicate that oxidation resistance of the K444 superalloy has been increased for more than six times by the enamel-alumina composite coatings. As the traditional theory suggested, the enamel composite coatings retard oxygen diffusion to the superalloy surface, leading to the decrease of oxidation rate. However, it is found that the protection mechanism is more associated with the change of oxidation mode of the alloy substrate, i.e. preventing Cr oxidation while promoting Al and Ti oxidation by the enamel coatings. Furthermore, this protection depends strongly on the alumina content of the enamel composite coating. With higher alumina content, the enamel composite coating retards oxygen diffusion more effectively, and the oxidation mode with respect to the selective oxidation of Al keeps unchanged for longer times. (C) 2015 Elsevier B.V. All rights reserved.
部门归属	[wu, mingyu ; chen, minghui ; zhu, shenglong ; wang, fuhui] chinese acad sci, inst met res, lab corros & protect, shenyang 110016, peoples r china
关键词	Oxidation Diffusion Modeling High-temperature Protective Coating
资助者	National Natural Science Foundation of China [51471177]; National High Technology Research and Development Program of China (863 Program) [2012AA03A512]; National Key Basic Research Program of China (973 Program) [2012CB625100]
收录类别	sci
语种	英语
WOS记录号	WOS:000369200600007
引用统计	被引频次：22[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/75082
专题	中国科学院金属研究所
通讯作者	mhchen@imr.ac.cn
推荐引用方式 GB/T 7714	Wu, Mingyu,Chen, Minghui,Zhu, Shenglong,et al. Protection mechanism of enamel-alumina composite coatings on a Cr-rich nickel-based superalloy against high-temperature oxidation[J]. SURFACE & COATINGS TECHNOLOGY,2016,285:57-67.
APA	Wu, Mingyu,Chen, Minghui,Zhu, Shenglong,Wang, Fuhui,&mhchen@imr.ac.cn.(2016).Protection mechanism of enamel-alumina composite coatings on a Cr-rich nickel-based superalloy against high-temperature oxidation.SURFACE & COATINGS TECHNOLOGY,285,57-67.
MLA	Wu, Mingyu,et al."Protection mechanism of enamel-alumina composite coatings on a Cr-rich nickel-based superalloy against high-temperature oxidation".SURFACE & COATINGS TECHNOLOGY 285(2016):57-67.