Celsian/yttrium silicate protective coating prepared by microwave sintering for C/SiC composites against oxidation

A novel celsian/yttrium silicate coating was prepared by microwave sintering on the surface of C/SiC composites. During sintering process, celsian crystallized from BaO–Al2O3–SiO2 (BAS) glass in the coating and yttrium silicate was formed through the reaction of yttrium oxide and molten BAS glass. The composition and microstructure of the coatings were investigated and the efficiency of the composite coating against oxidation was characterized. The result showed the coating was dense and pore-free. The celsian/yttrium silicate coating can protect C/SiC composites for no less than 90 min at 1773 K in air.