The coating of continuous carbon fiber bundles with sic by chemical vapor deposition: A mathematical model for the CVD-process

A mathematical model is presented for the description of the chemical vapor deposition of SiC on continuous fibers bundlesconsisting of several hundreds or even several thousands of individual filaments. Based on chemical engineeringkinetics, the model predicts the mean layer thickness and the layer thickness distribution on the monofilaments of the bundle. The model presupposes that the kinetics of the deposition on the outer surface, the effective diffusion coefficientand the geometry of the fiber bundleare known. The results of the calculations are presented in terms of the change of the diameter of the fibers as a function of the distance from the axis of the bundlefor different positions in the reactor and as the relative concentration of the precursor as a function of the distance from the axis of the bundlefor different positions in the reactor and for different deposition conditions. Using the model presented the mean layer thickness was calculated for different reaction conditions and a comparison between calculated and measured values is given.