Distribution Status of Trace Oxygen in Fe sub(3) Si-Si sub(3) N sub(4)

The distribution status of trace oxygen in the ferro-silicon nitride (Fe sub(3) Si-Si sub(3) N sub(4)) was investigated at the present, which was prepared by flash combustion synthesis method from FeSi75. The results showed that while the grain size of FeSi75 used in preparing Fe sub(3) Si-Si sub(3) N sub(4) was less than0.074 mm, "active oxidation" occurred firstly, silicon was oxidized to form gaseous SiO(g), oxygen partial pressure was reduced in the system, silicon reacted with nitrogen directly to form Si sub(3) N sub(4) while the system oxygen partial pressure approached less than 10 super(-19) MPa (T=1823K). O sub(2)(g) promoted the formation of Si sub(3) N sub(4), Gaseous SiO(g) finally reacted with nitrogen and Si to form Si sub(2) N sub(2) O. The ferro silicon nitride was characterized by X-ray diffractometer and scanning electron microscope, the distribution of Si sub(2) N sub(2) O was uneven in the silicon nitride, and Si sub(2) N sub(2) O mainly distributed around Fe sub(3) Si or near the hole.