NUMERICAL-MODELS FOR PREDICTING TRACER PROFILES IN SILICON DOUBLE-OXIDATION EXPERIMENTS

Standard numerical techniques are used to model the development of tra cer profiles in ''double-oxidation'' experiments involving silicon or silicon-based ceramics. These models are more generally applicable tha n previously developed analytical models. In particular, the numerical model allows the relative contribution to oxidation by network and in terstitial oxygen diffusion through the silica scale to be varied, and can accommodate a position-dependent diffusion coefficient. The resul ts of calculations are compared to previously published profiles.