Reaction behavior of trace oxygen during combustion of falling FeSi75 powder in a nitrogen flow
Reaction behavior of trace oxygen during combustion of falling FeSi75 powder in a nitrogen flow作者机构:School of Materials Science and Engineering University of Science and Technology Beijing
出 版 物:《International Journal of Minerals,Metallurgy and Materials》 (矿物冶金与材料学报(英文版))
年 卷 期:2016年第23卷第8期
页 面:959-965页
核心收录:
学科分类:08[工学] 0817[工学-化学工程与技术] 081701[工学-化学工程]
基 金:financially supported by the National Nature Science Foundation of China (No.51572019)
主 题:silicon nitride combustion synthesis oxygen atmosphere
摘 要:To explore the reaction behavior of trace oxygen during the flash combustion process of falling FeSi75 powder in a nitrogen flow, a flash-combustion-synthesized Fe-Si;N;sample was heat-treated to remove SiO;. The samples before and after the treatment were investigated by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, and the formation mechanism of SiO;was investigated. The results show that SiO;in the Fe-Si;N;is mainly located on the surface or around the Si;N;particles in dense areas, existing in both crystalline and amorphous states; when the FeSi75 particles, which are less than 0.074 mm in size, fell in up-flowing hot N;stream, trace oxygen in the N;stream did not significantly hinder the nitridation of FeSi75 particles as it was consumed by the surface oxidation of the generated Si;N;particles to form SiO;. At the reaction zone, the oxidation of Si;N;particles decreased the oxygen partial pressure in the N;stream and greatly reduced the opportunity for FeSi75 particles to be oxidized into SiO;; by virtue of the SiO;film developed on the surface, the Si;N;particles adhered to each other and formed dense areas in the material.