Effects of air oxidation on mesophase pitch-based carbon/carbon composites

Mesophase pitch-based carbon-carbon (C/C) composites were fabricated by cycles of impregnation/carbonization using two different preforms. Air oxidation was used as a stabilization process prior to carbonization. In order to study the effects of air oxidation, composites without air oxidation were also fabricated for comparison. The results showed that the effect of air oxidation was different for different preforms. For 2-dimensional (2D) punched carbon cloth preforms, air oxidation could greatly shorten the fabrication period, and had significant effects on the matrix microstructures. Without air oxidation, the carbon matrix of the composites consisted of small domains with a mosaic texture. With air oxidation, the matrix consisted of domains mingled with flow domains. However, air oxidation had little effect on composites prepared from 2D carbon felts preforms, and the corresponding carbon matrix in the composites consisted of mainly small domains with a mosaic texture irrespective of air oxidation.