6～8% Y2O3 partially stabilized ZrO2 (YPSZ) nanostructuredcoatings were fabricated by atmospheric plasma spraying(APS). The fractured cross-section morphologies of thesamples were observed by scanning electron microscopy(SEM). The thermal conductivities of free-standing purenanostructured YPSZ coatings samples were determined usingthe laser flash technique. Specific heat was measured througha differential scanning calorimeter. The results showed thatthere is a great difference between the fractured cross-sectionmicrostructure of nanostructured and conventional zirconiacoatings. The nanostructured one exhibits a bimodaldistribution of microstructure, viz. directional crystal andisometric crystal structure. Plasma spraying parameters have asignificant effect on the microstructure through changing thecontent of isometric crystal structure in the coating. Thethermal conductivity decreased with increased isometriccrystal microstructure content. The thermal conductivity canbe lowered up to 60%.
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