Analysis of shear band instabilities in compaction of powders

A model for metal powder compaction is proposed as an interpolation between well-known models corresponding to a high level of porosity with low inter-particle cohesive strength or a low level of porosity with high cohesion. A simple model for analysis of shear band development in uniformly strained solids is used to study the possibility of flow localization during metal powder compaction. It is found that the material model predicts localization when the porosity is high and the cohesion is low, and localization is also predicted at intermediate levels of porosity, but not at low porosity levels where full cohesion applies.