Study on preparation and properties of continuous carbon fiber-reinforced silicon carbide composites

3-D continuous fiber-reinforced silicon carbide composites were manufactured by LPCVI ( low pressure chemical vapor immersion). Effects of the densification of the composites, the pyrolitic carbon interphase thickness and the type of fiber on the properties of the composites were studied. The properties of the composites are improved as the densification increases due to the improvement of the degree of load transfer. The effect of interphase thickness on the properties of the composites can be interpreted from the effects of the interphases thickness on interfacial bonding strength, the slide stress on debonding face, the degradation of fiber during the manufacture of pyrolitic carbon interphase and the protective role of interphase to fiber. The composites with higher bending strength and fracture toughness can be achieved when the interphase thickness is 0.1 μm. The type of fiber affects the properties of composites apparently due to the effects of the properties of fiber on residual thermal stress and stress redistribution.