A NEW PROCESS FOR PRODUCING SiC COATING ON CARBON FIBRES AND THE MECHANICAL PROPERTIES OF SiC COATED FIBRES

SiC coated fibres were obtained by a new method using SiO and CO to form SiC and deposit on to the carbon fibres. Columnar β-SiC grains grew radially out from the carbon fibre surface and formed a SiC coating with corncob-like surface morphology. When the thickness of the SiC coating increases to≥0.2pm, the tensile strength of the SiC coated fibre decreases with the increasing of thickness of SiC coating and this result is coincident with Ochiai' s theoretical model. For the fibres with l}cm SiC coating, their mechanical behavior in tensile is similar to a 1 D brittle fibre-brittle matrix composite with weak fibre-matrix bonding and multiple fracture of SiC coating is shown. The degradation of the carbon fibre core caused by the coating process is discussed.