静态图像粒度粒形分析方法对氧化铝颗粒的测定研究

Approach of Imaging Particle Analysis on α-Alumina powders

为了准确全面地了解颗粒的形貌和粒度信息,我们运用一种新型的图像粒度粒形分析技术,对5种工艺制备α氧化铝的粒度和粒形进行了定量分析,并与激光粒度仪的粒度分析结果和SEM颗粒形貌分析结果进行了对比研究。结果表明,这种分析技术具有对颗粒形貌进行三维量化的微观表征能力,可同时获得包括颗粒的等效体积直径、等效面积直径、费雷特直径、内径、厚度、最小外接圆直径等粒度参数及分布,以及长宽比、无规度、沃德尔球形度、欧奇奥钝度、欧奇奥粗糙度和分形维数等颗粒形貌分布数据。此外,该方法可与扫描电镜实现很好的对应,并能捕捉到激光粒度分析难以统计到的少于1%的超大颗粒,表现出很高的准确性、客观性和可靠性。因此,这种新型的图像分析技术有望成为包括α氧化铝在内的多种粉体的颗粒分析测试和工艺开发研究的有力工具。

The particle size and crystal morphology of α-alumina prepared by five different processes were quantitatively analyzed by Occhio static particle size and shape analyzer,including particle size parameters such as equivalent volume diameter,equivalent area diameter,Ferret diameter,inner diameter,thickness,minimum circumferential diameter,as well as particle shape distribution including aspect ratio,irregularity,Wadell’s sphericity,Occhio bluntness,Occhio roughness and fractal dimension,which were compared with the particle size results by laser diffraction particle analyzer(LDA)and scanning electron microscopy(SEM)particle morphology.The results show that an advanced static particle size and shape analyzer has powerful high resolution sampling capability and micro-level Characterization capability of three-dimensional quantification against particle morphology.The lower limit of particle size analysis is down to 200 nm.The data required from LDA and SEM can be obtained at the same time by one sampling progress.Compared with LDA,the advanced static image method can capture less than 1%of the super-large particles in the sample system with more accurate,objective,reliable and reasonable results,which were missed by laser diffraction method.The comparative experiments with SEM show that the particle images from the shape analyzer can completely correspond to that of SEM.The sample preparation for the imaging particle sizer is simple,and the morphology of tens of thousands of particles can be quantitatively analyzed.It is extremely rich and more reliable and accurate.Therefore,it is a powerful tool for the development and application of α-alumina process,and an essential analytical means for the upgrading and transformation of basic research characterization technology.