Influencing Factors on the Determination of Corundum Particle Parameters by SEM and Image Analysis

Determination of particle size and shape factors of the corundum powders by SEM image analysis has been reported in our preceding work. However, the effect of sample preparation and image processing has not been investigated. In order to obtain appropriate images, samples was well-dispersed by vibrating particles manually up and down, and then thicker Pt coating was well sputter coated on the surface of samples; compared with the magnifications of 100 and 32, magnification of 50 was more reasonable; for distinguishing particles from image background properly, the gray threshold value of 70 was set to transform gray image to binary image; to decrease image noises, three image filters, i.e. Erosion Filter, Dilation Filter and Median Filter were investigated and the last one was the most effective. This method of sample preparation and image processing can be used in regular and irregular particles determination.