High‐Temperature Active Oxidation of Chemically Vapor‐Deposited Silicon Carbide in an Ar─O2 Atmosphere

摘要: Active oxidation behavior of chemically vapor-deposited silicon carbide in an Ar─O2 atmosphere at 0.1 MPa was examined the temperature range between 1840 and 1923 K. The transition from active (mass loss) to passive gain) observed certain distinct oxygen partial pressures (PO2t). values PO2t increased with increasing decreasing total gas flow rates. This well explained by Wagner's model thermodynamic calculations. rates (ka) O2 rate-controlling step concluded be diffusion through gaseous boundary layer.