The influence of aluminum oxide on the heat resistance of the coatings based on the zirconium boride–silicon composite

The process of the formation of coatings based on zirconium boride, silicon, and aluminum oxide on graphite by the thermal treatment of the mixtures of the initial components in air has been studied. During the chemical reactions, a vitreous melt encapsulating the particles of zirconium boride and silicon is formed, which provides high heat resistance of the material. The effect of the composition, temperature, and mode of heating on the kinetics of oxidation of graphite samples with the coatings during their thermal treatment at 1400°C has been studied via the methods of thermogravimetric, thermal, and X-ray phase (XPA) analyses. The compositions of the coatings that effectively protect graphite from oxidation in air at temperatures of up to 1400°C have been proposed based on the results of the study.