Packing State and Compaction Equation of Monosize Spherical Powders

Abstract

Changes that occur during compaction are described utilising three equations related to stages in the densification of monosize spherical metal powders, consisting of an equation to describe geometric changes, an equation relating to the effect of pressure which causes flattening of originally spherical particles, and a third equation relating green strength and compacting pressure. Two new concepts are proposed, involving a quantitative description of the change of shape of originally spherical particles by flattening and the increase in interparticle contact area, and a parameter s, a function of particle coordination, packing state, and flattening parameter, is introduced. The continuous development of relative density during compaction is described in terms of the parameter s. PM/0720