High-temperature oxidation behavior of SiC-coated carbon fiber-reinforced carbon matrix composites

The high-temperature oxidation behavior of bare and SiC-coated carbon fiber-reinforced carbon matrix (C/C) composites was examined in the temperature range 900-3000 K. In the course of the measurements, the main focus was placed upon the effect of oxygen partial pressure on the oxidation behavior and the transition temperature between the passive and active oxidation regimes. To understand the oxidation behavior of SiC-coated C/C composites quantitatively, a morphological characterization of coating cracks was carried out, and then, in the oxygen diffusion controlling temperature range, an analytical model was developed for the prediction of weight loss due to oxidation of SiC-coated C/C composites. The oxidation rates derived from this model were in fairly good agreement with the experiment results. (C) 1999 Elsevier Science Limited. All rights reserved.