Theoretical Investigation for the Active-to-Passive Transition in the Oxidation of Silicon Carbide

Gerard L. Vignoles (1) , Junjie Wang (2) , Litong Zhang (2) , Qingfeng Zeng (2) , Alain Guette (1)

1 LCTS - Laboratoire des Composites Thermostructuraux
2 TSCM - National Key State Laboratory for ThermoStructural Composites

The oxidation of silicon carbide at high temperatures from 673.15 to 2173.15 K is investigated by using thermodynamic equilibrium calculations and a mass transfer model. The dominant reaction of the active-to-passive transition and five other dominant reactions, which are in six different temperature regions, have been determined according to the main equilibrium products. Then, a modified Wagner's model has been developed to determine the active-to-passive transition boundary by combining mass transport and thermodynamic calculations. The present theoretical calculations satisfactorily explained the reported experimental and theoretical data. The influence of flow rate on the active-to-passive transition boundary has been explained using our model. The rate controlling mechanism of the oxidation at the active-to-passive transition point is proposed.

Domaines: Matériaux

Gerard L. Vignoles, Junjie Wang, Litong Zhang, Qingfeng Zeng, Alain Guette. Theoretical Investigation for the Active-to-Passive Transition in the Oxidation of Silicon Carbide. Journal of the American Ceramic Society, 2007, 91 (5), pp.1665 - 1673. ⟨10.1111/j.1551-2916.2008.02353.x⟩. ⟨hal-00410187⟩