Significance of modification of slurry infiltration process for the precursor impregnation and pyrolysis process of SiCf/SiC composites

Abstract Several intermediate steps were applied before the precursor infiltration and pyrolysis process to improve the infiltration of SiC slurry for promoting the infiltration of SiC slurry into fiber voids. These steps include sonication, popping, electrophoretic deposition, vacuum infiltration and cold isostatic pressing (CIP). The intermediate processes, especially popping and CIP, had a beneficial effect on green density enhancement and improving the homogeneous infiltration of the slurry into fiber fabrics. The density of the SiCfiber/SiCfiller green body was 2.20 g/cm3, which corresponded to 68 % of relative density. The SiCf/SiC composite has a high density of 2.65 g/cm3 after seven PIP cycles.