Preparation And Prospective Application Of Short Carbon Fiber/Sic Multilayer Composites By Tape Casting

Silicon carbide multilayer composites containing short carbon fibers (Csf/SiC) were prepared by tape casting and pressureless sintering. The C fibers were dispersed with dispersants into a solvent mixture firstly and then mixed with SiC slurry to make green Csf/SiC tapes. Triton X100 was found to be the best dispersant for Toho Tenax HTC124 fibers. Fibers resulted homogeneously distributed in the tape and tended to align fairly well along the tape casting direction. The addition of short C fibers hindered the shrinkage in the plane containing the fibers during sintering. The resulting microstructure of the composite materials was investigated. This kind of composite layers could be integrated in a thermal protection system (TPS) structure, since the outer dense SiC layers can provide excellent oxidation resistance and good heat conductivity in the plane, while Csf/SiC layers in the middle of the multilayer architecture could grant low thermal conductivity through the TPS thickness.