CHEMICAL-VAPOR INFILTRATION OF PYROCARBON .1. SOME KINETIC CONSIDERATIONS

Chemical vapour infiltration of pyrocarbon is analysed with respect to (i) the nature of the hydrocarbon (carbon source), (ii) the pyrolysis chemistry and kinetics of homogeneous gas phase reactions, (iii) the kinetics of heterogeneous pyrocarbon deposition reactions, (iv) pore d iffusion in the Fick and Knudsen regime, (v) total pressure, (vi) init ial partial pressure of the hydrocarbon, (vii) inert diluent gases and (viii) hydrogen, both as reaction product and non-inert diluent gas. The analysis shows aspects for the optimization of chemical vapour inf iltration, and it clearly shows methane to be the ideal hydrocarbon fo r various reasons. Copyright (C) 1996 Elsevier Science Ltd