Methods of quantification of the internal structures of spray granules

Granules for die pressing applications prepared by means of spray drying need to possess specific properties defined by the end-application. The internal structure of the granules is therefore an important quality-determining property because it influences both the processing properties of the loose granules and the defect distribution in the sintered ceramic part. In this paper, an optimized, artifact-free, gentle and reproducible preparation method based on ion beam technology for exposing the internal granule structures is presented. Model Al2O3 granules are used to demonstrate the possibilities for imaging via high-resolution scanning electron microscopy and quantification of the granules in terms of porosity as well as particle and additive distribution.