CARBON CARBON COMPOSITES PREPARED BY A RAPID DENSIFICATION PROCESS CHEMICAL LIQUID VAPOR INFILTRATION

Carbon carbon comosites with density as high as 1.74 g/cm 3 were obtained within 3 hours by a novel method called chemical liquid vapor infiltration densification (CLVD).The preforms adapted were carbon felt disks (160 mm od×80 mm id×10 mm thick of each),which have been densified in a liquid carbon source.The liquid precursor used in the present work was composed of CYH and KEE.The disks were heated by radiation which could create an inside out thermal gradient and immersed in liquid precursor in a water cooled chamber.Rough laminar and smooth laminar deposited carbon microstructure was observed under crossed polarizers.The highest deposition rate obtained in this study was 64 μm/h which was over two order of magnitude faster than the typical value of 0.1 μm/h~0.25 μm/h for the ICVI process in the temperature range from 900℃~1 100℃.Also the reasons for rapid densification by this method were discussed considering a large thermal gradient within the preforms and chemical reaction occurred in liquid vapor medium.