Carbothermal synthesis of Si3N4 powders using a combustion synthesis precursor
来源期刊：International Journal of Minerals Metallurgy and Materials2013年第1期
论文作者：Ai-min Chu Ming-li Qin Bao-rui Jia Hui-feng Lu Xuan-hui Qu
文章页码：76 - 81
摘 要：Si3N4 powders were synthesized by a carbothermal reduction method using a SiO2 + C combustion synthesis precur- sor derived from a mixed solution consisting of silicic acid （Si source）, polyacrylamide （additive）, nitric acid （oxidizer）, urea （fuel）, and glucose （C source）. Scanning electron microscopy （SEM） micrographs showed that the obtained precursor exhibited a uniform mixture of SiO2 + C composed of porous blocky particles up to ～20 μm. The precursor was subsequently calcined under nitrogen at 1200-1550°C for 2 h. X-ray diffraction （XRD） analysis revealed that the initial reduction reaction started at about 1300°C, and the complete transition of SiO2 into Si3N4 was found at 1550°C. The Si3N4 powders, synthesized at 1550°C, exhibit a mixture phase of α- and β-Si3N4 and consist of mainly agglomerates of fine particles of 100-300 nm, needle-like crystals and whiskers with a diameter of about 100 nm and a length up to several micrometers, and a minor amount of irregular-shaped growths.
Ai-min Chu1,2，Ming-li Qin1，Bao-rui Jia1，Hui-feng Lu1，Xuan-hui Qu1
1. Beijing Key Laboratory for Advanced Powder Metallurgy and Particulate Materials, School of Materials Science and Engineering, University of Science and Technology Beijing2. School of Electro-mechanism Engineering, Hunan University of Science and Technology
摘 要：Si3N4 powders were synthesized by a carbothermal reduction method using a SiO2 + C combustion synthesis precur- sor derived from a mixed solution consisting of silicic acid （Si source）, polyacrylamide （additive）, nitric acid （oxidizer）, urea （fuel）, and glucose （C source）. Scanning electron microscopy （SEM） micrographs showed that the obtained precursor exhibited a uniform mixture of SiO2 + C composed of porous blocky particles up to ～20 μm. The precursor was subsequently calcined under nitrogen at 1200-1550°C for 2 h. X-ray diffraction （XRD） analysis revealed that the initial reduction reaction started at about 1300°C, and the complete transition of SiO2 into Si3N4 was found at 1550°C. The Si3N4 powders, synthesized at 1550°C, exhibit a mixture phase of α- and β-Si3N4 and consist of mainly agglomerates of fine particles of 100-300 nm, needle-like crystals and whiskers with a diameter of about 100 nm and a length up to several micrometers, and a minor amount of irregular-shaped growths.
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