Thermal conductivity of a silicon carbide/pitch-based carbon fiber-epoxy composite

Silicon carbide (SiC) coating on pitch-based carbon fiber (SiC/pitch-CF) was prepared by the carbonization of a SiO2 coating layer onto pitch-CF. SiO2 sol and pitch-CF were mixed together and carbonized in a furnace under argon. The effect of the SiC coating on the thermal properties of pitch-CF was investigated. The thermal conductivity of the SiC/pitch-CF-epoxy composite was measured using the laser flash method. Because of the increase in the contact point of pitch-CF owing to the formation of particulate SiC, the thermal conductivity of SiC/pitch-CF was 38% higher than that of uncoated pitch-based CF when compared with epoxy composites comprising 60 wt% filler loading. However, the thermal conductivity of an epoxy composite comprising SiC/microwave-treated pitch-CF (SiC/M.pitch-CF) was lower than that of the pitch-CF-epoxy composite because of the defects resulting from acid treatment, even though the coating layer was fully covered and uniform compared microwave untreated pitch-CF.