Effect of the type of flame on the microstructure of CaZrO3 combustion flame sprayed coatings

The effect of the flame temperature on the microstructure of CaZrO3 flame sprayed coatings was investigated. Morphological aspects of the ceramic coatings were analysed in terms of splat characteristics, number of cracks/pores and texturing degree. Microhardness measurements were used to estimate the porosity in the coatings. The coating quality was correlated with the texturing degree by using the intensities ratio between selected XRD peaks (I-(101)/I-(121)) of the orthorhombic CaZrO3 phase. A thermal conductivity of 0.6 W m(-1) K-1 was measured at 25 degrees C for a freestanding specimen with 12% of porosity, which confirms the potentiality of CaZrO3 coatings in thermal barrier applications. (c) 2006 Elsevier B.V. All rights reserved.