Microstructure and Thermal Properties of Nanostructured 8 wt.% CeO2 Doped YSZ Coatings Prepared by Atmospheric Plasma Spraying

Nanostructured 8 wt.% CeO2-5.4 wt.% Y2O3-ZrO2 (CeYSZ) coatings were prepared by atmospheric plasma spraying technology. The microstructure, thermal diffusivity, and thermal cycle behavior of CeYSZ were investigated. The results show that the as-sprayed nano-CeYSZ coatings consist of tetragonal ZrO2 and Ce element is in solid solution with ZrO2. The CeYSZ coatings are characterized by nano-zones (unmelted nanoparticles), melted dense areas, splats, and pores. The thermal diffusivity of nano-CeYSZ coatings is 0.548 × 10−6 m2/s at room temperature. The addition of CeO2 decreases the thermal diffusivity of nano-YSZ coatings, which is mainly caused by the point defect scattering and grain-boundary scattering. The thermal cycle life of nano-CeYSZ coatings is about 860 cycles at 1050 °C. The spallation of the coatings occurs at the interface of CeYSZ/TGO.