MoSi 2 –Si–B/SiC double-layer oxidation protective coating for carbon/carbon composites

Abstract

A new MoSi₂–Si–B ceramic coating was prepared on the surface of SiC coated carbon/carbon (C/C) composites by a simple and low-cost slurry method. The microstructures of the double-layer coatings were characterised by X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy analyses. It could effectively protect C/C composites from oxidation for 100 h with a weight loss of 0·2% in air at 1773 K and for 40 h with a weight loss of 4·2% at 1073 K. The oxidation protective coating was principally due to the production of eutectic glass film for decreasing oxygen diffusing through the coating.