Densification of carbon/carbon composites by pulse chemical vapor infiltration

Two-dimensional carbon/carbon composites were densified with carbon by pyrolysis of propane using the pulse chemical vapor infiltration (CVI) process which repeats the cycle of evacuation and introduction of gas. The experimental parameters were deposition temperature, reactant gas concentration, flow rate, gas introduction time, evacuation time, and pulse number. The most effective parameters of pulse CVI to densify carbon/carbon composites are deposition temperature and gas introduction time. There was a deposition temperature at which the deposition rate was maximum. At higher deposition temperatures, soot was formed. When the gas introduction time was long, bulk density was higher and infiltration uniformity was better. Through these experiments, the optimum experimental condition for densification was found.