C/SiC composites prepared by inner siliconizing process

C/SiC composites were prepared by inner siliconizing process. The strength, matrix composition and microstructure of the composites were investigated by three-piont-bending method, XRD and SEM. The results show that CVD-SiC coating can protect the carbon fibers from attack by melting silicon. The SiC matrix without silicon is made when the molar ratio of C to Si is 10 : 9 by controlling the ratio of phenolic resin and silicon powder. The flexural strength and shear strength of the C/SiC composites are 247 MPa and 13. 6 MPa respectively. The failure module of the C/SiC composites exhibit typical toughness fracture module with many pulled-out fibers in the cross-section of the composite fracture specimens, the fracture toughness (K_IC) of the composite is 12.1 MPa·m^1/2.