Wet Oxidation Behavior of Near-Stoichiometric SiC Fibres in the Simulated Aeroengine Circumstance

The precursor-derived and near-stoichiometric SiC fibres (KD-S) were exposed at 1000–1500°C for 1 h in the simulated aeroengine circumstance of PH2O:O2:Ar = 14:8:78 KPa with the gas rate of 200 ml/min. The results indicated that the oxidized KD-S fibres were covered by silica layer. The oxygen content, grain size of silica, and oxide layer thickness increased, whereas the tensile strength decreased with rising annealing temperature. KD-S fibres treated under simulated aeroengine circumstances showed larger SiO2 grain size, thicker silica layer, and better residual strength than those annealed in dry air. The steam could accelerate the oxidation on KD-S fibres by reducing the active energy. The influence of water vapour on the oxidation behavior of KD-S SiC fibres was investigated and discussed as well.