平面冲击波作用下TiO2晶粒的相变纳米化

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

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。

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.