A new method for determining the thermal conductivity of metallic bond coats (BCs) and ceramic top coats (TCs) composing thermal barrier coatings (TBCs) in a direction normal to the coating surface at room temperature was developed, and was proposed to the International Organization for Standardization (ISO)/Technical Committee (TC) 107. Thermal conductivities of the substrate, BC, and TC are determined according to calculation using the respective thermal diffusivities, specific heat capacities, and bulk densities. In the present study, the thermal conductivities of three types of TBCs with different TC microstructure were investigated according to the new method. The thermal conductivity of TC was found to depend strongly on its microstructure and to decrease with increasing its porosity.
展开▼
