75％TiO_2-25％SiO_2氧化物的机械合金化

Mechanical alloying of 75%TiO_2-25%SiO_2 oxide

金红石TiO_2是常用的钛阳极耐蚀载体材料。鉴于SiO_2具有更高的耐蚀性、耐磨性和稳定性,而且价格低廉。因此,本文尝试以锐钛矿TiO_2和石英SiO_2颗粒原料,采用机械合金化(MA)方法制备ZiO_2-SiO_2二元氧化物。本文通过30小时机械合金化作用,制备了摩尔浓度为75%TiO_2-25%SiO_2二元氧化物载体材料。通过XRD、DTA和TEM分析并观测了所获材料的组织结构和晶粒形貌。结果发现在MA作用下,该载体材料中的锐钛矿TiO_2显著细化,有部分纳米晶粒出现,SiO_2晶粒细化效果相对较弱;透射电镜下,粉末颗粒呈理想的等轴形态;产生了锐钛矿TiO_2向金红石TiO_2的相变,其相变温度比采用常规方法下的相变温度明显降低了约350℃;获得SiO_2、TiO_2互溶的固溶体组织,特别是生成了采用常规方法难以获得的TiO_2-SiO_2非平衡间隙固溶体。

Rutile TiO2 is often used as an anti-corrosive carrier material for titanium anodes. Because SiO2 has higher corrosion resistance, better wearresistance and lower cost, an attempt has been made in this paper to prepare a TiO2- SiO2 binary carrier material from anatase TiO2 and quartz SiO2 through mechanical alloying （MA） method. In this paper, a binary oxide whose molar concentration was 75%TiO2-SiO225% was obtained by 30h mechanical alloying. The phase structure and particle morphology of the prepared material were examined by means of XRD, DTA and TEM. It is indicated that after MA： （1） the particle sizes of anatase TiO2 has been fined, nanometer crystals have appeared. However, the reduce effect on SiO2 crystal size has not been so obvious. （2） The morphology of the obtained oxide particles has been typically equiaxal. （3） The phase transformation from anatase TiO2 to rutile TiO2 has taken place and its starting temperature has been decreased by about 350℃, compared with the result of the conventional method. （4） A kind of solid solution of SiO2-TiO2 has formed in the obtained oxides. The non-equilibrium solid solution of TiO2-SiO2 is difficult to be achieved from the conventional method.