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本文以硅溶胶、尿素和炭黑为原料，采用溶胶-凝胶碳热氮化法在1500℃、2h条件下制得粒径为50～80nm的Si3N4纳米粉末．比较了由硅溶胶与尿素经氨解合成的前驱体和硅溶胶二种不同起始物料的反应活性，研究了氮化条件对合成反应的影响．结果表明：氨解前驱体使硅溶胶中的结构水排除，有助于加快反应速率，提高产物氮含量．本文同时以Y（NO3）3为添加剂，在溶液状态与硅源混合，合成了Si3N4－Y2O3纳米复合粉末.
In this paper, silica sol, urea and carbon black as raw materials, the use of sol-gel carbonitriding at 1500 ℃, 2h conditions of the particle size of 50 ~ 80nm Si3N4 nano-powder. The reactivity of two different starting materials, which are precursors of silica sol and urea by ammonolysis and the silica sol, was compared. The effect of nitriding conditions on the synthesis reaction was also studied. The results show that the ammoniated solution can eliminate the structural water in silica sol, accelerate the reaction rate and increase the nitrogen content of the product. In the meantime, Y (NO3) 3 was used as additive to synthesize Si3N4-Y2O3 nanocomposite powder in the state of solution mixed with silicon source.