Oxidation resistant yttrium silicates coating for carbon/carbon composites prepared by a novel in-situ formation method

Yttrium silicates interlayer coatings of the SiC/yttrium silicates/borosilicate glass multi-layer coating system were prepared by a novel in-situ formation method using Si and Y2O3 as starting materials in an oxidation atmosphere. The surface and cross-section microstructures of the coatings were characterized by XRD and SEM analyses. Oxidation resistance of the coated samples was tested. Results showed that dense yttrium silicate interlayer coatings with good bond to SiC and borosilicate glass were prepared and the as-prepared multi-layer coating could protect C/C composites from oxidation at 1873 K in air for 202 h with a weight loss of 2.87 × 10−3g/cm2.