How reliable the light scattering in sizing the deformable particles by milling?

Abstract

Milling a metal powder is a commonly used method for producing metal flakes with a specific aspect ratio. The size measurement of such milling products is troublesome due to the shape and size changes. Thus, many challenges are facing the particle size measurements of deformable particles after milling operation. One of these challenges is the difficulty in getting a clear image from one specific device when the flake size is very small and the difference between the major dimensions to the minimum dimensions is very large. Adjusting the orientation of the flake in front of the size measuring detector is another challenge. In this study, different techniques, such as Occhio optical particle sizer, light scattering, and scanning electron microscope (SEM) was used to follow directly or indirectly the changes in milling product size. The results showed that the size analysis by volume using light scattering is better than using sizing by number. The comparison between the Occhio and light scattering resulted in a close agreement between the two techniques, especially for the particles larger than 10 µm.