Oxidation behaviour of carbon short fibre reinforced C/SiC composites

Oxidation kinetics of carbon short fibre reinforced C/SiC composites was measured by a thermobalance. The oxidation along the carbon fibre bundles and their contacts was identified as the dominating mechanism. To improve oxidation resistance, oxidation barriers in the junctions between the fibre bundles have to be established. Therefore, the infiltration of the carbon prepregs by molten silicon, which is essential for the formation of microstructure during the production of the composites, was investigated. The infiltration was monitored in situ using a thermooptical measuring device (TOM). Infiltration kinetics was controlled by SiC formation at a temperature below 1500 °C and by capillary flow at a temperature of 1700 °C.