Oxidation Behavior of Silicon Nitride Containing Iron

The oxidation behavior of silicon nitride ceramics containing iron in air at 1 300-1 500℃ was investigated. The results indicate that the presence of iron in the ceramics causes a slight increase in the oxidation rate. The oxidation of Fe-Si₃N₄ obeys the parabolic oxidation law, with an activation energy of 285 kJ/mol. Based on the element mapping analysis, iron diffused to the surface during the oxidation process, causing a decrease in the oxidation resistance. However, the oxidation rate of Fe-Si₃N₄ is still appropriate for applications in air at high temperatures.