The presence of defects such as voids, inter-lamellar porosities or cracks, provides a decrease of the effective thermal conductivity of plasma sprayed coatings as well as a decrease of the corresponding mechanical properties such as the Young’s modulus. In general, effective properties of thermal spray coatings are thus strongly different from that of the bulk material and have thus to be quantified to validate their in service performances. A complementary approach allowing understanding the relationships between the microstructure of a coating and its macro-properties is the use of Finite Element Modeling. The case of composite coatings is still more complicated due to the presence of different materials. In the present study, thermo-mechanical properties of a plasma sprayed composite coating were estimated by numerical modeling based on FEM. The applied method uses directly cross-sectional micrographs without simplification using a one-cell per pixel approach. Characteristics such as the thermal conductivity, the Young modulus, the Poisson ratio and the dilatation coefficient were considered. The selected example was an AlSi/polyester coating used as abradable seal in the aerospace industry.