CERAMIC MATRIX COMPOSITES MANUFACTURED BY MULTISTEP DENSIFICATION OF Si-O-C FIBRE PREFORM

摘要

Ceramic matrix composites have been manufactured at temperatures below 1100°C by a multistep process which consists in (ⅰ) a polymer impregnation of Si-C-O fibre preform and pyrolysis (PIP) in order to consolidate the preform ; (ⅱ) an impregnation with a slurry of submicronic TiSi_2 powder, (ⅲ) a heat treatment under nitrogen (N_2) in order to reduce the porosity thanks to the volume expansion associated with the nitridation of the active filler ; and (ⅳ) a final densification by PIP. Various liquid polymeric precursors were investigated to perform this final densification. The morphology, the chemical composition and the mechanical properties of the composites were characterized. Based on these characterizations, a preceramic polymer precursor was chosen in order to produce a ceramic matrix composite.