Combustion Synthesis of Si3N4 from Si/NH4Cl at Low Nitrogen Pressure
Combustion synthesis (CS) of Si3N4 was accomplished by using as-milled Si/NH4Cl as reactants at low nitrogen pressure.The additive of NH4Cl decreased the combustion temperature and promoted the Si nitridation.Full nitridation of Si was achieved by burning Si in pressurized nitrogen with 10 ~ 25 wt.% NH-4Cl as additives while no Si3N4 diluent added.The maximum combustion temperature (To),the combustion velocity (u) together with the α-Si3N4 content and mean particle size (d50) of the powder products were found to be great dependent on the NH4Cl content added in the reactants.Fine Si3N4 powder products with α-phase content up to 85 wt.% were obtained via steady combustion mode.A mathematical approach named combustion wave velocity methods for the analysis of temperature profiles in CS was proposed and the reaction kinetics was discussed.The apparent activation energy calculated according to the temperature profile analysis method is 29.7 kJ/mol,which agrees well with the corresponding low temperature nitriding combustion of Si.
NH4Cl low nitrogen pressure Si3N4 combustion synthesis
Yixiang Chen Jiangtao Li Zhiming Lin Guanghua Liu Shuliang Yang Jisheng Du
Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,Beijing 100080,China;Gradua Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,Beijing 100080,China Liaoning Jiayi Metals &Minerals Co.Ltd,Dalian 116001,China
国际会议
The Fifth China International Conference on High-Performance Ceramics (第五届先进陶瓷国际研讨会(CICC-5))
长沙
英文
1767-1770
2007-05-10（万方平台首次上网日期，不代表论文的发表时间）