Oxidation Behavior of ZrB 2 –SiC Composites at Low Pressures

ZrB 2 ‐60 mol% SiC composite with a eutectic microstructure was oxidized at 1573 to 1873 K with reduced total pressures ( P tot ) 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 SiO 2 / ZrO 2 + SiO 2 / ZrO 2 / ZrB 2 was formed at > 0.13 kPa, whereas only porous ZrO 2 remained at < 0.13 kPa, P tot < 1.33 kPa and higher than 1773 K. With increasing , the parabolic oxidation constant decreased, whereas the linear oxidation constant increased.