Microstructures and mechanical properties of carbon/carbon composites reinforced with carbon nanofibersanotubes produced in situ

摘要

Using ferrocene as catalyst and toluene as the liquid precursor, carbon/carbon (C/C) composites were prepared by chemical liquid-vapor infiltration at 850-1100 deg C. The microstructures and properties of C/C composites obtained with different ferrocene contents were studied. The results show smooth laminar and isotropic pyrocarbon are obtained after adding ferrocene to the precursor. Carbon nano-fibers can be formed as the catalyst content is 0.3-1 wt. percent. When the ferrocene content is 2 wt. percent, multi-walled carbon nanotubes with the diameter about 20-90 nm are obtained together with carbon-encapsulated iron nanoparticles. After adding ferrocene to the precursor, the fracture modes of the composites change from brittle facture to tough fracture. The flexural strength of the composites is a maximum for 0.3 wt. percent ferrocene in the precursor, higher than for ferrocene contents of 0,0.5,1 and 2 wt. percent. The flexural modulus of the composites decreases after adding ferrocene to the precursor.