Finite Element Method in Powdered Metal Compaction Processes

Abstract

A finite element method for the compaction process of metallic powder is introduced in the present work. Basic equations for the finite element formulation are summarized. A yield criterion, which is modified by describing asymmetric behavior of powder metal compacts, is introduced and applied to various classes of powdered metal compaction processes. Three material parameters are involved in the yield function and determined from the behavior of sintered powder compacts as a function of relative density. The FEM simulation includes single-action and double-action pressings of solid cylinders as well as cylindrical rings of relatively long parts (Class II parts). The compaction process for multi-level flanged components (Class III and Class IV parts) is also analyzed. The predicted results from simulations are summarized in terms of density distributions within the compacts and pressure distributions exerted on the die-wall interfaces, and also in terms of effectiveness with increased relative motions with in the compacts and the effect of various compaction schemes of combination of punch motions. Results obtained in the multi-level compaction process are discussed in terms of average relative density distributions at each height.