平面冲击波作用下TiO_2晶粒的相变纳米化

利用平面冲击波技术,对溶胶-凝胶法制备的锐钛矿型TiO2粉体和干凝胶进行冲击实验,采用X射线衍射(XRD)、透射电镜(SEM)和激光粒度分析仪(LPSA)等手段对冲击前后的TiO2粉体和干凝胶进行表征。结果表明:冲击波的高温作用能够实现亚稳态的锐钛矿型TiO2向稳定态的金红石型TiO2转变,并且冲击波直接作用于干凝胶时更容易获得稳定态的金红石型TiO2;冲击波的瞬时性可以抑制TiO2晶粒的长大,实现晶粒纳米化;冲击波的高压作用可以有效控制由于溶胶-凝胶法导致的粉体团聚现象。

Study on Nanometerization of Titania Grain during Transformation under Planar Shock Wave

The anatase powders and TiO₂ xerogel powders prepared by the sol-gel method were impacted under planar shock wave. The powders after impact wave loading were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and laser particle size analyzer (LPSA). The results showed that the metastable anatase form of TiO₂ can be transformed into stable rutile under the high temperature effect of the shock wave, and the phase change of the TiO₂ xerogel powders to the rutile phase is more accessible than that of the anatase powders. The short duration of shock wave can inhibit the growth of grain and achieve nano-grains. The high pressure process can effectively control agglomeration as the result of the sol-gel method.