Fabrication of Dense Carbon Fiber Reinforced SiC Composites by Controlling the Rheology of Polycarbosilane Solution

摘要

Dense carbon fiber reinforced silicon carbide composites were prepared by polymer impregnation and pyrolysis with rheological properties of polycarbosilane such as different molecular weight and solution concentrations. During polymer impregnation and pyrolysis process, the densification mechanism of inter-/intra-bundle pores in the carbon fiber preform was also studied by using Hg-porosimeter. Almost of the pores in the carbon preform were filled within 3rd polymer impregnation and pyrolysis cycles when 60 wt % of highly viscous polycarbosilane solution. Inter-bundle pores ranging from 20 to 400 urn were previously filled and the small pores less than 1 urn were newly formed after pyrolysis.