Abstract
Thermal Barrier Coatings (TBCs) are the key-technology to improve thermal efficiency for heat engines such as gas turbines in power stations, and it has been applied to both blades and vanes of gas turbines. About TBCs, it is important to ensure thermal barrier property after long-term operation, because of main purpose for addition of TBCs. However, it has been reported that progression of sintering phenomena and consequently degradation of thermal barrier property occur in the porous TBCs ceramic top coat. In this study, three kinds of TBCs specimens that have different distributions of pore area were subjected to various long-term high temperature exposures. Then, both thermal conductivity and porosity (based on cross-sectional SEM image and its image analysis) of top coat were measured. From obtained data, behavior of thermal barrier property change and influence of different distribution of pore area to the above-mentioned behavior were discussed.
