Oxidation Behavior of ZrB2–SiC Composites at Low Pressures

Abstract

ZrB2‐60 mol%SiC composite with a eutectic microstructure was oxidized at 1573 to 1873 K with reduced total pressures (Ptot) and low oxygen partial pressures (). The mass change was continuously measured by a thermobalance, and then fit with a multiple paralinear model. Oxidation scale of SiO2/ZrO2+SiO2/ZrO2/ZrB2 was formed at > 0.13 kPa, whereas only porous ZrO2 remained at < 0.13 kPa, Ptot < 1.33 kPa and higher than 1773 K. With increasing , the parabolic oxidation constant decreased, whereas the linear oxidation constant increased.