自由电弧法与等离子电弧法制备超细粉末对比研究

Contrast Study on Free Arc Method and Arc Plasma Method for Ultrafine Powder Preparation

摘要:

采用自由电弧法和等离子电弧法分别制备超细SnO2粉末，利用X射线衍射(XRD), 扫描电镜(SEM)及能谱分析(EDAX)测试手段对样品的物相、形貌、粒度等进行表征。结果发现：等离子电弧法制备出的粉末粒度较小，粒子均匀，大部分为球形，且杂质少；而自由电弧法制备的粉末粒度较大，且含有大量的C杂质。通过对粉末的形核长大机制进行分析讨论，发现温度、温度梯度、饱和度是形核长大的重要影响因素。等离子电弧法容易获得较高的温度及温度梯度，有助于粉末的形核长大，获得较高的形核率，易制得超细粉末

Abstract:

Ultrafine SnO2 nanopowder was prepared by a free arc method and an arc plasma method, respectively. Then the phases, morphology and particle size were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectrometry (EDS). The results show that the powder prepared by the arc plasma method has uniform particles with smaller size and fewer impurities, which are mostly spherical; while the powder prepared by the free arc method has bigger particle size and much C impurities. Nucleation and growth mechanism of the powder was analyzed and it is found that the temperature, temperature gradient and saturation are significant influencing factors. Arc plasma method has easily higher temperature and temperature gradient, so it is favorable for nucleation and growth to obtain high nucleation rate