Preparation and Anti-Oxidation Behavior of Mullite Coating on Carbon/Silicon Carbide Composite

Ethyl orthosilicate (TEOS) and aluminum nitrate were used as raw materials for preparation of mullite sol. The mullite coating (MC) on carbon/silicon carbide (Cf/SiC, f refers to fiber, the same below) was prepared by the dip coating method. Isothermal oxidation tests were performed on Cf/SiC and Cf/SiC MC and their oxidation behaviors were studied. The results show that the oxidation of Cf/SiC and Cf/SiC MC can be divided into three main stages: θ\u3c700°C, 700°C\u3cθ\u3c1000°C, 1000°C\u3cθ\u3c1200°C. The oxidation rate-determining steps for each stage are different; the mass loss percentage of the Cf/SiC MC was fifty percent lower than that of the Cf/SiC. The Cf/SiC MC has good oxidation resistance