摘要
本文对 Si 粉在高压氮气中自蔓延燃烧合成(SHS)Si_3N_4的反应机理进行了研究.燃烧反应中 Si 以蒸汽形式与N_2在 Si_3N_4晶种表面反应,反应分为两个主要阶段:(1)动力学反应阶段:Si 蒸汽不需经过扩散直接与 N_2进行反应,反应速度快;(2)扩散控制反应阶段:Si 蒸汽经过 N_2气层扩散到 Si_3N_4晶种表面与 N_2反应,反应受扩散控制,速度较慢.
A reaction mechanism for the self-propagating high temperature(combustion)synthesis(SHS)of silicon nitride under pressurized nitrogen has been proposed.The reaction is betweenSi vapor and N_2 on the surfaces of Si_3N_4 microcrystals which act as seeds in the combustionreaction.The reaction can be divided into two stages:(1)Kinetic reaction stage:Si vapor reactswith N_2 directly(without diffusion)on the surfaces of Si_3N_4,the reaction rate is very high;(2)Diffusion-controlled reaction stage:Si vapor diffuses through a layer of N_2 to the surfaces ofSi_3N_4 and reacts with N_2,the reaction is diffusion-controlled and slows down obviously.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
1993年第4期433-440,共8页
Journal of Inorganic Materials
基金
国家自然科学基金
关键词
自蔓延
燃烧合成
硅粉
氮化硅
陶瓷
Reaction mechanism
SHS
Silicon
High pressure nitrogen
Silicon nitride
