Coating and Impregnation of Carbon-Carbon Composites with Ceramics by Electrophoretic Deposition

Abstract : Electrophoretic deposition of ceramic coatings on porous graphite and on a 2D C-C composite was studied using colloidal and fused SiO2, SiC and SiN. It was shown that all these ceramic materials acquire an electric charge and hence deposit under the electric field. In addition to the formation of a surface deposit, the induction of particles into the pores of porous graphite was demonstrated. The effects of deposition voltage, solvent properties and particle concentration on penetration were studied by examination of cross- sections in the SEM and by quantitative analysis of induced SiO2. Ceramic deposits of CeO2, ZrO2 and Al2O3 were formed on graphite and 2D C-C by an electrochemical reduction of aqueous solutions containing inorganic salts of the appropriate metals.