Passive‐Oxidation Kinetics of SiC Microparticles

We investigated the oxidation kinetics of SiC materials in the form of powders (average dimension 4 μm) in the temperature range 1100°–1500°C in dry air. The oxidation process was monitored through the relative mass gain in a thermobalance. As the specific surface area of the particles was measured, the recorded mass gain could be converted into the corresponding oxide thickness. The oxidation isotherms were fitted to a linear‐parabolic equation, and the parabolic rate constant was evaluated. Up to 1400°C, temperature dependence can be described by a single activation energy of 179 kJ/mol, which increases in the 1400°–1500°C temperature range. These results are compared with the oxidation behavior of sintered polycrystalline and monocrystalline SiC materials.