Investigation of the Interaction of Y2O3–Al2O3–SiO2 Coatings with Water Vapor and Na2SO4 at Temperatures to 1450°C

Coatings based on the system Y2O3–Al2O3–SiO2 are promising for protecting silicon carbide based materials from the effects of an oxidizing atmosphere, water vapor, and salt vapors. The interaction of Y2O3–Al2O3–SiO2 coatings, obtained by the sol-gel method, with water vapor and Na2SO4 salt was investigated. Coatings based on the yttrium aluminosilicate system were found to have good oxidative and chemical resistance to water vapor and Na2SO4 salt at temperatures 1300 – 1450°C. The weight gain for the coated samples tested in Na2SO4 salt vapor did not exceed 1%. The initial SiC substrates are characterized by active oxidation processes with weight reduction from 8 to 11%.