Synthesis and Electrophoretic Deposition of an Yttrium Silicate Coating System for Oxidation Protection of C/C-Si-SiC Composites

摘要

Due to favorable chemical and mechanical properties of yttrium silicate coatings (low Young's modulus, low thermal expansion coefficient, low evaporation rate and oxygen permeability, good erosion resistance), this material is a promising complement to SiC coatings for protecting C/C-Si-SiC composites. For the preparation of silicate powders, the Pechini method was used. As a coating method, electrophoretic deposition from stable suspensions based on isopropanol was chosen. Under controlled deposition voltage and duration, coatings of various thicknesses were deposited. The deposited layers were characterized by SEM and EDX analysis. The protectiveness of these coatings was tested by isothermal thermogravimetry.