Oxidation Kinetics of Coated Silicon Carbide Fiber-Reinforced Silicon Carbide (SiC/SiC)

摘要

Silicon carbide fiber-reinforced silicon carbide (SiC/SiC) was exposed for 100 hours to dry, flowing oxygen. Oxidation kinetics were determined via thermogravimetric analysis at 981, 1204 and 1316 C (1800, 2200 and 2400 F). The effectiveness of three external coating systems applied for oxidation protection is discussed. In all cases, weight gains were observed, and the pyrolytic carbon interface layer remained intact. A CVD (Chemical Vapor Deposition) SiC external coating is the most promising due to low oxidation kinetics resulting from solid silica formation. A borosilicate glass was observed on the surface of two of the materials that have boron-containing coatings.