Preparation and properties of carbon fiber-reinforced carbon and ceramic composites through a combination of chemical vapor infiltration and polymer impregnation pyrolysis

Abstract

Carbon fiber-reinforced carbon composites (C/C), carbon fiber reinforced-carbon and silicon carbide binary matrix composites (C/C–SiC) and carbon fiber reinforced carbon–silicon–zirconium–oxygen matrix composites (C/C–Si–Zr–O) were prepared through a combination of chemical vapor infiltration (CVI) and polymer impregnation pyrolysis. The microscopic morphology, phase structure, mechanical properties and thermal conductivity of the C/C, C/C–SiC and C/C–Si–Zr–O composites were investigated by SEM, XRD, EDA and laser flash thermal conductive measurements. Results showed that the flexural strength of the C/C–Si–Zr–O composites was higher than that of the C/C and the C/C–SiC composites, which can be ascribed to their energy absorption mechanisms, such as fiber debonding and pull-out from the matrix. The C/C composites possessed the highest thermal conductivity (69.09 W/(m K) in the parallel direction and 25.28 W/(m K) in the vertical direction), which can be accounted for by the high thermal conductivity of the pyrocarbon matrix, a low porosity of the composites, a long phonon mean free path and fewer structural defects. [New Carbon Materials 2014, 29(6): 467–472]