Oxidation protective glass coating for SiC coated carbon/carbon composites for application at 1773 K

To prevent carbon/carbon composites from oxidation at 1773 K, an efficient oxidation protective glass coating has been prepared on the surface of SiC coated C/C composites by a simple and low-cost method. The microstructures and phase composition of the as-prepared coating were examined by SEM and XRD. Oxidation testing shows, after oxidation in air at 1773 K for 140 h and thermal cycling between 1773 K and room temperature for 8 times, the weight loss of the coated sample is only 0.98%. The oxidation of the coated C/C composites is attributed to the formation of bubble holes on the coating surface and microcracks in the coating.