A Finite Element Model of Warm Metal Powder Compaction Process

The development of finite element model for the simulation of a complete warm forming process of powder sintered component is presented here. The material constitutive laws were derived based on a continuum mechanics approach. The process of green compact generation was represented by a large displacement based finite element formulation. Three constitutive relations, i.e., Mohr-Coulomb, Elliptical Cap, and combination of these two yield models were used to describe the deformation behaviour of the powder mass during compaction. However, an Elliptical Cap model was shown to be the most appropriate. A plasticity theory of friction was employed in the treatment of the powder-tooling interface. The Roscoe-Burland criterion was used to describe the densification and dimensional change of the compact during the sintering. The staggered-incremental-iterative solution strategy was established to solve the non-linearity in the systems of equations. The numerical simulation results were validated through experimentation where a good agreement was observed.