The influence of pyrolysis temperature on the oxidation resistance of carbon-rich SiCN ceramics derived from reaction of silazanes with acrylonitrile

The influence of pyrolysis temperature on the oxidation resistance of carbon-rich SiCN ceramics derived from reaction of acrylonitrile with a commercially available oligosilazane (HTT1800) and its subsequent pyrolysis in nitrogen atmosphere was evaluated. The investigation of the oxidation behavior reveals that the final pyrolysis temperature plays an important role in the oxidation resistance of the developed SiCN/C nanocomposites. Increasing the pyrolysis temperature promotes an ordering of the free-carbon phase and consequently, an improvement of the oxidation resistance is noticed. However, starting phase separation during annealing at 1500 °C reduces slightly the protection effect provided by the oxidation resistant Si3N4 phase.