ABSTRACT
The oxidation behaviour of both unprotected and protected carbon-carbon (C/C) composites has been studied in a temperature range of 500°C to 1100°C. Protective systems investigated have included SiC coatings, either alone, or combined with a crack sealing glass material.
Chemical Vapour Deposition has been used to apply the SiC coatings to the C/C composites. Scanning and transmission electron microscopy have been important in the characterisation of microstructures related to coating parameters and in the investigation of crack patterns due to thermal expansion mismatches between the SiC coating and the C/C substrate. A boric oxide glass sealant has been investigated, important considerations being viscosity, oxygen diffusivity, effects of moisture and volatility of the glass at high temperature.
