Influence of h-BN as an additive on oxidation behaviour and kinetic characteristics of carbon/carbon composites

Abstract Due to favourable self-healing function of its oxidation product, hexagonal boron nitride is now increasingly used to improve the oxidation resistance of carbon-based composites. In this study, based on a kinetics model and isothermal oxidation tests, the influence of h-BN particle size and content on oxidation behaviour and kinetic characteristics of C/C composite at 600–900 °C was discussed. Finally, oxidation-controlling mechanisms were proposed for these composites. The results show that addition of h-BN increases the activation energy of the carbon/oxygen reaction and hinders internal diffusion. Moreover, compared to h-BN content, h-BN particle size has a greater effect on oxidation resistance.