Oxidation behavior of dense SiOC monolithics: The oxide scale development

Forming stable and continuous oxide scale is the key to resist oxidation by acting as a surface-diffusion barrier to reduce further oxygen attack. Oxidation behavior of dense SiOC monolithics was studied from 900 °C to 1200 °C for up to 18 h. The oxide scale formed at 1000 °C and 1200 °C was ∼106 μm and ∼81 μm in thickness, respectively. High thermal misfit strain induced by the large thickness and volume shrinkage originated from crystallization of silica resulted in the scale cracking with oxidation time. However, the scale formed at 1100 °C remained dense and thin (∼43 μm) without any visible defects, protecting the SiOC base effectively.