The influence of temperature on the texture of carbon/carbon composites infiltrated by ethylene pyrolysis

Two-dimensional carbon fiber felts with the density of 0.4 g/cm ³ were infiltrated under negative pressure, at the temperatures of 950~1200°C, using ethylene as the precursor, to prepare carbon/carbon (C/C) composites samples. The effect of infiltration temperature on density profile of the infiltrated samples and the texture of deposited pyrolytic carbon were studied. The results show that pure high-textured carbon matrix forms at the temperature of 1150~1200°C; medium and high textured carbon forms at 1050~1100°C. As mentioned in particle-filler model, the intermediates produced in thermal decomposing of hydrocarbon include small linear hydrocarbons, aromatic hydrocarbons and polycyclic aromatic hydrocarbons, which are influenced by the reaction temperatures. The texture of deposited pyrolytic carbon are the results of the mole ratio of the aromatic to linear hydrocarbons, which is improved with the increase of reaction temperature, leading to the production of high textured pyrolytic carbon.