Silicon carbide infiltration of porous CC composites for improving oxidation resistance Original Research Article

This paper deals with the attempts made at LCTS to replace part of the carbon matrix of CC composites by silicon carbide in order to improve the oxidation resistance. Oxidation kinetics of CCSiC are presented, as well as the incidence of oxidation on the degradation of the microstructure and the tensile strength of the composites. Modelling of the oxidation kinetics allows prediction of mass losses as a function of temperature, thickness of seal-coating, level of mechanical loading, and reactivity of the components toward oxygen. On the basis of this model, it is possible to determine a mechanism controlling the oxidation kinetics, the degradation mode of the composite, and then the evolution of the tensile properties in oxidizing environments. Finally, further improvement in the oxidation resistance of the CCSiC composites is discussed, based on a change in the thickness and nature of the SiC seal-coating.