溶胶-凝胶法制备纳米Si3N4(Y2O3)粉末的研究

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

Preparatio of Nanosized Si3N4-Y2O3 Powders by Sol-Gel Processing

Nanosized silicon nitride powders were synthesized by using silica sol, urea, and carbon black with the process of sol-gel and carbothermal reduction. Ammonolysis of the aqueous solution of silica sol and urea resulted in the formation of an ammono precursor. The effect of ammono precursor and silica sol on the synthesis of Si₃N₄ powders was investigated. The results showed that using ammono precursor dehydrated can accelerate the reaction rate and increase the nitrogen content of Si₃N₄ powders. Synthesis of nanosized Si₃N₄-Y₂O₃ composite powders from the homogeneous mixture of Y(NO₃)₃ and silica sol in the liquid state was also studied.