Microstructure and mechanical properties of short carbon fibre/SiC multilayer composites prepared by tape casting

Silicon carbide multilayer composites containing short carbon fibres (Csf/SiC) were prepared by tape casting and pressureless sintering. The C fibres were dispersed in solvents with dispersant (Triton X-100) firstly and then mixed with the SiC slurry to make green Csf/SiC tapes. Fibres were homogeneously distributed in the tape and tended to align fairly well along the tape casting direction. The addition of short C fibre hindered the shrinkage in the plane containing the fibres as well as the grain growth of SiC during sintering. The weight loss occurring during oxidation tests of Csf/SiC multilayer composites increased with fibre amount and material porosity. Elastic modulus of Csf/SiC multilayer composites decreased linearly with fibre amount. Bending strength presented clear relationship with the relative density, that is with the total porosity.