Oxidation of beta-SiC at high temperature in Ar/O-2, Ar/CO2, Ar/H2O gas mixtures: Active/passive transition

摘要

An experimental study of the active/passive transition in the oxidation of beta-SiC was carried out between 1650 degrees C and 1800 degrees C in Ar/O-2, Ar/H-O and Ar/CO2 gas mixtures or mixtures including two among these oxidant species. For that purpose an experimental device based on a Joule-heated SCS-6 fiber permitted determination of the oxidation regime from changes in electric current. The observed transitions were compared to results from other authors. Two predictive models of the active/passive transition were studied by means of a 3-D simulation of the experimental device in order to have an estimation of the volatilization rate of SiO2. These models were compared against experimental results.