Investigation of Gas-Phase Processes of Obtaining Fiber-Reinforced Organomorphic Ceramic Composites with SiC-Matrix

The isothermal process of chemical vapor deposition for the densification with a SiC-matrix of organomorphic carbon-fiber preforms obtained by carbonization of compressed fibers of oxidized polyacrylonitrile is investigated. Such preforms are characterized by a high (up to 70%) porosity and uniform pore size (the reduced pore diameter ranges from several micrometers to tens of micrometers). Technological parameters of the process of obtaining ceramic-matrix composites (CMC) were optimized by a combination of experimental studies and numerical simulations. Experimental samples of CMC were obtained using a non-halogen precursor, methylsilane CH 3 SiH 3 , and their residual porosity was determined. For the numerical study of the gas-phase process of densification of preforms, a 1D model was used. The simulation results were compared with experimental observations.