▎ 摘　　要

In this study, the carbon fiber surface is spray coated with polysilazane preceramic precursor and pyrolyzed at different pyrolytic temperatures to form the ceramic-carbon fiber composite (SiCN-CCFC) with dense layer of amorphous SiCN ceramic film. The specific strength and modulus of SiCN-CCFC are enhanced 44.26% and 15.37% with spraying 40 wt.% polysilazane preceramic precursor diluted in acetone and then pyrolyzing at 450 ? compared with those of the pure carbon fiber. The carbon fiber spray coated with 20 wt% polysilazane preceramic precursor with 0.5 wt.% graphene in acetone is pyrolyzed at 450 C to form the graphene-reinforced ceramic-carbon fiber composite (SiCN-GRCFC) whose specific strength and modulus are enhanced 73.15% and 41.15%, respectively, compared with those of the pure carbon fiber. The results of potentiodynamic polarization reveal the electrochemical properties between the pure carbon fiber and SiCN-CCFC that the corrosion potential increases from -0.0971 V to 0.5862 V, the corrosion current density decreases from 1.72 x 10(-2 )to 1.32 x 10(-7) mA.cm(-2), and the corrosion rate extremely decreases from 9.98 x 10(-2) to 9.54 x 10(-7) mm.year(-1). The electrochemical properties between the pure carbon fiber and SiCN-GRCFC show that the corrosion potential increases from -0.0971 V to 0.5873 V, the corrosion current density decreases from 1.72 x 10(-2) to 3.61 x 10(-6) mA.cm(-2), and the corrosion rate extremely decreases from 9.98x10- 2 to 2.88 x 10(-5) mm.year(-1). Therefore, it can be concluded that the SiCN coating incorporated with additional graphene content can significantly enhance the mechanical properties and corrosion resistance of the commercial carbon fiber.