Silicon nitride fibers and silicon oxynitride fibers obtained by the nitridation of polycarbosilane

Abstract The nitridation of polycarbosilane began to occur at about 500°C and was completed at 800–1000°C. Beyond the temperature of 1000°C, the structure of the nitrides changed from the amorphous to the crystalline state and at 1400°C, it was αSi3N4. On the basis of the nitridation of polycarbosilane, silicon nitride fibers and silicon oxynitride fibers were obtained from polycarbosilane fibers cured by the electron irradiation and by the oxidation, respectively. They were transparent in visible light. The relationship between tensile strength of silicon oxynitride fibers and oxygen introduced in curing was examined.