Thermally Sprayed CaZrO3 Coatings

A comparative study of CaZrO3 coatings prepared by air plasma and flame spray processes is presented. The microstructural characteristics and phases were analyzed and discussed as a function of the spraying temperature achieved with each technique. Vickers hardness tests performed on polished cross sections of the different coatings were used to estimate their porosity. Thermal diffusivity values measured on freestanding thick coatings (500 mu m) using the laser flash technique were very low and depended strongly on the pore shape. Crystallization was promoted by treating the coatings at 1200 degrees C, and the results are explained with aid of the ZrO2-CaO equilibrium phase diagram.