Thermal barrier coatings (TBCs) are being extensively used for improving the performance and extending the life of combustor and gas turbine components. TBC thermal properties, thermal conductivity and heat capacity (the product of density and specific heat), are important parameters in those applications. These TBC properties are usually measured by destructive methods, involving separating the ceramic coating layer from the substrate and performing density, specific heat, and thermal diffusivity measurements. Nondestructive evaluation (NDE) methods, on the other hand, allow for direct TBC property measurement on natural TBC samples. Therefore, they can be used for inspecting the quality of as-processed components and monitoring TBC degradation during service. This paper presents a multilayer thermal-modeling NDE method, which analyzes data obtained from pulsed thermal imaging, to determine thermal conductivity and heat capacity distributions over the entire surface of a TBC specimen. The measurement accuracy was investigated and compared with standard destructive measurement data. Experimental results are presented and discussed.
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