Thermo-physical and thermal insulation properties of multi-scale nanostructured thermal barrier coatings using as-prepared t′-8YSZ feedstocks

Abstract

The thermal conductivity and thermal expansion coefficient are important thermo-physical properties for thermal barrier coatings (TBCs). In this work, multi-scale nanostructured 8YSZ coatings were fabricated using as-prepared nanostructured t′-8YSZ feedstocks by atmospheric plasma spraying (APS) onto NiCoCrAlYCe coated K417G superalloys. Meanwhile, conventional t-8YSZ feedstocks were also selected for comparison. The thermo-physical properties of both coatings have been studied. Results indicate that nanostructured 8YSZ coatings have a lower thermal conductivity than conventional counterparts especially when the temperature is above 1000 °C. Nanostructured 8YSZ coatings have better thermal insulation capability compared with conventional 8YSZ coatings. Therefore, the nanostructured coatings using t′-8YSZ feedstocks have a broad prospect for service at elevated temperature.