Ceramic Fibre Composite Sintering and Densification
topic
Ceramic matrix composite densification by chemical vapour infiltration deposits SiC or carbon matrix within the fibre preform from methyltrichlorosilane or methane precursor gas at 900 to 1100 degrees Celsius over hundreds of hours, while polymer infiltration and pyrolysis uses multiple impregnation and pyrolysis cycles of polycarbosilane or phenolic resin to progressively fill preform porosity to final density above 2.5 grams per cubic centimetre.
Role
Controls the matrix microstructure, density, and porosity of ceramic matrix composites that determine thermomechanical performance, thermal conductivity, and oxidation resistance, with each densification route creating a distinct matrix microstructure whose crack deflection capability at the fibre-matrix interface determines whether the composite exhibits brittle monolithic ceramic or graceful notch-insensitive composite fracture behaviour.