溶胶－凝胶工艺合成ZrO_2超微粉末的研究

Preparation of Ultrafine ZrO_2 Powders by Sol-Gel Method

以自制Ｚｒ（ＯＣ_３Ｈ_７）_４和Ｙ（ＣＨ_３ＣＯＯ）_３为原料，应用溶胶、凝胶法制备了组份为ＺｒＯ_２－９ｍｏｌ％Ｙ_２Ｏ_３超微粉末．实验表明：温度、湿度、溶液的浓度．介质和催化剂等是影响形成溶胶、凝胶的主要因素．通过ＴＧ－ＤＴＡ、ＸＲＤ、ＢＥＴ比表面积测量以及ＴＥＭ等分析手段研究了粉末的结构与性能．结果表明：钇稳定立方相二氧化锆（ＹＳＺ）超微粉末的合成温度在４７０℃左右．粉末经５００℃以上热处理后变为纯立方相结构．５００℃煅烧２ｈ后的超微粉末颗粒呈球形或近似球形，比表面积为６４．０４ｍ￣２／ｇ，粒径为１５．７ｎｍ．随着烧结温度的升高，ＹＳＺ超微粉末的比表面积减小，粒径增大，预示着颗粒间发生团聚，一次颗粒间的团聚引起了表面积的明显损失和界面的形成．

Zro_2+9mol%Y_2O_3 ultrafine powders, with Zr(OC_3H_7)_4 and Y(CH_3COO)_3 as percursors, were prepared by sol-gel method. The experiment showed that the major factors of the effect on the formation of sol to gel were temperature, humidity, concentration of solution and catalyst. The structure and performance of YSZ powders were characterized by TG-DTA, XRD, BET specific areas measurement and TEM. The results showed that the synthesis temperature of YSZ powders was 470℃ and the powders can convert into Y_2O_3-stabilized ZrO_2 with a pure cubic structure after calcined at above 500℃. The powders calcined at 500℃ for 2h were composed of spherical or approximate spherical particles, the specific surfaces were 64.04 m2/g, the particle sizes were 15.7nm. The specific surface areas of YSZ powders became lower and the particle sizes became bigger when the firing temperature was increasing. This indicated the aggregates occurred among particles. It caused obviously the loss of surface areas and the formation of interface.