机械力作用下锐钛矿型TiO_2的相变  

Phase transformations of anatase TiO_2 induced by mechanical force

作　　者：欧阳全胜[1] 

机构地区：[1]中南大学冶金科学与工程学院,长沙410083

出　　处：《粉末冶金材料科学与工程》2012年第3期333-338,共6页Materials Science and Engineering of Powder Metallurgy

基　　金：国家自然科学基金重点资助项目(50434010)

摘　　要：采用振动磨样机和行星球磨机研磨锐钛矿型TiO2粉体,利用XRD技术对比分析锐钛矿相在2种研磨设备中的相变特点,利用SEM观察振动磨样机中粉体的形貌变化,并对振动磨样机中生成金红石相的机械化学相变宏观动力学及相变过程物质的微观结构变化进行研究。结果表明:锐钛矿相在振动磨样机和行星球磨机中的相变现象不同,在行星球磨机中表现为锐钛矿相→TiO2-Ⅱ相→金红石相的分步相变;而在振动磨样机中除了发生分步相变外,推测还可能发生了锐钛矿相→金红石相的直接相变,并进一步推测剪切力是促进这一直接相变的重要因素。在振动磨样机中形成金红石相的机械化学相变宏观动力学满足Avrami-Erofe’ev模型。Anatase TiO2 powder was milled to study the phase transformations in ring-roller milling and planetary ball mill respectively by XRD technique, and observe the morphologies of the powder in the ring-roller by SEM technique. The mechanochemical macrokinetics for forming ruffle phase and the changes of microstructure of the powder milled with different time in the ring-roller were investigated in detail. Results show that anatase TiO2 powder is demonstrated to induce different phase transformation phenomena with mechanical processing： a step-by-step transformation from anatase to TiO2- Ⅱ and then to ruffle in both two mills; a supposed direct transformation from anatase to futile in the ring-roller mill. The author further guesses that shear force might be one of the key factors to promote the direct transformation. The mechanochemical macrokinetics for forming rutile phase in the ring-roller mill meets the kinetic Avrami-Erofe＇ev kinetics model.

关 键 词：锐钛矿 TiO2-Ⅱ 金红石 二氧化钛 机械化学 相变 剪切力 

分 类 号：TQ03[化学工程] TQ174