High Temperature Oxidation Behavior of Silicon Carbide Ceramic

Oxidation thermodynamics of silicon carbide (SiC)ceramic was studied by means of HSC Chemistry code, and the weight change, morphology and phase of oxidation products were analyzed by thermogravimetric analysis(TG), scanning electron microscopy(SEM ) and X-ray diffraction (XRD). The results showed that SiC ceramic could be oxidized to silicon dioxide(SiO2) with release of small molecular gases under oxidizing atmosphere at 800°C, and the formed SiO2 film with appropriate fluidity and low oxygen diffusion coefficient could prevent the spread of oxygen with the oxidation temperature increasing up to 1200°C, which favored the anti-oxidation of SiC ceramic matrix composite.