Abstract No.:	5294
Scheduled at:	Friday, June 09, 2017, Hall 12 3:00 PM Aviation & Power Generation Industry VI
Title:	Influence of the interface healing between the splashed particles and underlying bond coating on the cyclic oxidation behavior of LPPS MCrAlY bond coats
Authors:	Bang-Yan Zhang* / Xi'an Jiaotong University, P.R. China Guan-Jun Yang/ Xi'an Jiaotong University, P.R. China Cheng-Xin Li/ Xi'an Jiaotong University, P.R. China Chang-Jiu Li/ Xi'an Jiaotong University, P.R. China
Abstract:	The growth behavior of thermally grown oxide (TGO) on the bond coats of thermal barrier coatings (TBCs) has a significant impact on the TBCs life time. The splashed particles on the thermally sprayed MCrAlY bond coat surface have weak bonding with the underlying bulk coating, which will lead to the formation of mixed oxides and promote the failure of TBCs. In this study, the interface between the splashed particles and underlying bond coating was healed by vacuum pre-treatment (pre-diffusion). The bond coats were divided into three groups by the ways of pre-treatments. Two groups of bond coats were respectively subjected to two different pre-treatments (pre-diffusion-oxidation and pre-oxidation) prior to cyclic oxidation tests. The third bond coats were directly subjected to the same cyclic oxidation tests. Results show that the different bond coats present different cyclic oxidation behavior. The bond coat with pre-diffusion-oxidation exhibited the best cyclic oxidation resistance, and the ones without pre-treatment had the worst cyclic oxidation resistance. Meanwhile, the mixed oxides on the surface of bond coating with pre-diffusion-oxidation appeared latest, and mixed oxides on the bond coating without pre-treatment came into being at the earliest time. It is revealed that the healing of interface between the splashed particles and underlying bulk coating can effectively improve the cyclic oxidation resistance. This research will benefit the development of long-life and highly reliable TBCs.

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