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Delamination Mechanisms of Thermal and Environmental Barrier Coatings on SiC/SiC Ceramic Matrix CompositesAdvanced ceramic thermal harrier coatings will play an increasingly important role In future gas turbine engines because of their ability to effectively protect the engine components and further raise engine temperatures. However, the coating durability issue remains a major concern with the ever-increasing temperature requirements. In this paper, thermal cyclic response and delamination failure modes of a ZrO2-8wt%Y2O3 and mullite/BSAS thermaVenvironmenta1 barrier coating system on SiC/SiC ceramic matrix composites were investigated using a laser high-heat-flux technique. The coating degradation and delamination processes were monitored in real time by measuring coating apparent conductivity changes during the cyclic tests under realistic engine temperature and stress gradients, utilizing the fact that delamination cracking causes an apparent decrease in the measured thermal conductivity. The ceramic coating crack initiation and propagation driving forces under the cyclic thermal loads, in conjunction with the mechanical testing results, will be discussed.
Document ID
20050207422
Document Type
Conference Paper
Authors
Zhu, Dongming (NASA Glenn Research Center Cleveland, OH, United States)
Choi, Sung R. (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 1, 2003
Subject Category
Metals and Metallic Materials
Meeting Information
Symposium on Advances in Thermal and Environmental Barrier Coatings International Thermal Spray Conference and Exposition (ITSC 2003)(Orlando, FL)
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.