Densification kinetics and mechanical properties of carbon/carbon composites reinforced with carbon nanotubes produced in situ

Carbon nanotube reinforced carbon/carbon composites were fabricated via in situ growth of carbon nanotubes directly on needle-punched felts following direct resistive heating thermal gradient chemical vapor infiltration. The infiltration kinetics, mechanical properties and microstructure of carbon nanotube reinforced carbon/carbon composites were studied. The results show that rough laminar pyrocarbon is obtained owing to CNTs favoring the formation of high-textured pyrocarbon. When nickel nitrate content is 0.10 ml/L, carbon nanotubes with the diameter about 30 nm are obtained together with continuous network on the carbon fibers. The flexural strength and interlaminar shear strength of the composites obtained with 0.1 mol/L nickel nitrate contents are increased by nearly 44.2% and 40.7%, respectively, compared to that of the composite containing no carbon nanotubes.