DEM As a Tool for Optimizing Powder Metallurgy Processes

Abstract Powder metallurgy processes such as cold and hot isostatic pressing and powder-bed fusion additive manufacturing are being extensively used to produce metallic and ceramic parts due to several significant benefits these techniques provide, including reduction in wasted material, more precise handling of complicated shapes and requirement of fewer steps to achieve the final geometry and tolerance. Often the quality of the products obtained through these processes is greatly affected by the homogeneity of the feedstock powders used. But the presence of particles of different shapes and sizes in the powders may lead to inhomogeneous distribution which give rise to segregation of particles. In this study, discrete element method was used to investigate the degrees of segregation of a binary mixture in a cylindrical die with sharp stepped features. To study the effect of the composition of the binary mixture, three different mass ratios are considered in the study. In addition, vibrations are applied to the cylindrical die to increase the compaction of the particles in the stepped regions of the die. The effects of vibration amplitude and vibration frequency on the size segregation of the particles in the die are studied. At higher amplitude location dependent segregation patterns were observed.