Mechanics of Powder Compaction

Abstract

In this work mechanics of metal powder compaction are investigated using a micromechanics based approach. Close packed arrangements under plane strain condition with two different starting relative densities are considered. These unit cells are studied for basic densification response in the relative density range 0.78 – 0.98. The material parameters are computed from the plane strain form of Shima and Oyane yield function[1] and are found to be in good agreement with the experimental results reported for Copper powder. This method allows us explain the yield function parameters from the mechanics of particle deformation. Initial pore shape, loading path, and material hardening are found to influence the yield function parameters and hence the yield surface at a given relative density. These studies show that the initial and evolving pore structure during densification is responsible for the path dependency of the macroscopic yield behavior.