Q. Wang, Y. Liu, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, China; F. Wang, Z. Ma, Beijing Institute of Technology, Beijing, China
YPSZ nano-structured coatings were fabricated by APS. The fractured cross-section morphology were observed by SEM. The thermal diffusivity measurements of free standing pure nano-structured YPSZ coatings were made using the laser flash technique. Specific heat was measured through a differential scanning calorimeter.
The studied results shown that there is a great difference between the fractured cross-section microstructure of nanometer and micrometer powdered coatings, there is a bimodal distribution of microstructure, viz. directional crystal and isometric crystal structure, plasma spraying parameters has significant effect on microstructure, and this is due to the different content of isometric crystal structure in the coating, and the thermal conductivity decreased with increased content, when it’s got to 50%, the thermal conductivity can decrease probably 60%.
Key word: nano-structured zirconia coatings, thermal conductivity, coating microstructure, fractured morphology
Summary: Plasma spraying parameters has significant effect on content of isometric crystal structure at bimodal distribution. The microstructure of YPSZ nano-structured coatings can be analyzed by SEM of the fractured cross-section microstructure. The thermal conductivity of nano-structured zirconia coatings decreased with increased content of isometric crystal structure, when it got to 50%, the thermal conductivity can decrease probably 60%.
