Evaluation of microhardness and elastic modulus of thermally sprayed nanostructured zirconia coatings

Results concerning microhardness and roughness (Ra) of plasma sprayed coatings fabricated from nanostructured partially stabilized zirconia (PSZ) feedstock are presented. Nanostructured zirconia particles were plasma sprayed (Ar/H2) at three power levels, with two argon flow rates at two spray distances. The results indicate that the microhardness, elastic modulus and roughness of the nanostructured zirconia coatings exhibit the following trends: the smoother the roughness, the higher the microhardness and elastic modulus. It was found that roughness is an indicator of the coating state that reflects the intrinsic microstructure of the coatings. It was ascertained that a surface profilometer could be used to determine the level of microhardness and elastic modulus as a non-destructive and in situ test by simple comparison with standard samples.