High-temperature oxidation of silicon nitride powder under noisothermal conditions

The authors used differential thermal analysis to try to determine the reactions that occur and the temperatures at which they occur when silicon nitride is heated at a constant rate in air up to 1500 degrees C. They found that the oxidation of the silicon nitride proceeds in two stages. At the first stage (1000-1100 degrees C) a fine layer of silicon oxynitride is formed on the surface of the nitride particles. At the second stage (above 1200 degrees C) the nitride and oxynitride are oxidized to silicon dioxide.