| 초록 |
Annulus carcon fiver preforms were infiltrated with TG-CVI of propane, ethanol and mixture of these two gases. Amounts of deposition in the preform were estimated with mathmatical modeling and compared with experimental data. The overall deposition rate constant of carcon with propane precursor obtained in these processes was 2.2 times bigger than that reported by Vaidyaraman. That with ethanol precursor was obtained by multiplying 0.018 to the gas phase decomposition reaction rate constant reported by Li et al. When a mixture gas of propane and ethanol was used, the amounts of deposition in each part of the preform were more uniform in our system becuase of the different temperature dependencies of the deposition rate constants of propane and ethanol. It could be shown in this research that a more uniform deposition throughout the preform can be obtained with a mixture precursor gas and a proper temperature gradient in the preform. |
