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Surface Cracking and Interface Reaction Associated Delamination Failure of Thermal and Environmental BarrierIn this paper, surface cracking and interface reactions of a ZrO2-8wt%Y2O3 and mullite/BSAS/Si thermal and environmental barrier coating system on SiC/SiC ceramic matrix composites were characterized after long-term combined laser thermal gradient and furnace cyclic tests in a water vapor containing environment. The surface cracking was analyzed based on the coating thermal gradient sintering behavior and thermal expansion mismatch stress characteristics under the thermal cyclic conditions. The interface reactions that were largely enhanced by the coating surface cracking in the water vapor environment were investigated in detail, and the reaction phases were identified for the coating system after the long-term exposure. The accelerated coating delamination failure was attributed to the increased delamination driving force under the thermal gradient cyclic loading and the reduced interface adhesion due to the detrimental interface reactions. The coating design issues will also be discussed based on the observed failure mechanisms under the high-heat-flux test conditions.
Document ID
Document Type
Conference Paper
Zhu, Dongming
(NASA Glenn Research Center Cleveland, OH, United States)
Choi, Sung R.
(NASA Glenn Research Center Cleveland, OH, United States)
Eldridge, Jeffrey I.
(NASA Glenn Research Center Cleveland, OH, United States)
Lee, Kang N.
(NASA Glenn Research Center Cleveland, OH, United States)
Miller, Robert A.
(NASA Glenn Research Center Cleveland, OH, United States)
Date Acquired
August 23, 2013
Publication Date
January 8, 1990
Subject Category
Composite Materials
Meeting Information
Symposium on Advanced Ceramic Coatings for Structural, Environmental and Functional Applications 27th Annual International Conference on Advanced Ceramics and Composites(Cocoa Beach, FL)
Distribution Limits
Work of the US Gov. Public Use Permitted.

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