An elastic–plastic finite element method for the analysis of powder metal forging

Forging of sintered porous powder metal is studied both theoretically and experimentally. An incremental and piecewise linear elastic–plastic finite element method of solution for the analysis of strain hardening porous material under cold forging is presented. The method is based on Hill’s variational principle for incremental deformations. The overall deformation has been split into a number of stages. The variation of material parameters with relative density has also been accounted for in the model presented. The composite solution yields the deformation load required, deformed geometry of the work material and densification achieved. The model has been applied to study the finite quasi-static axisymmetric compression of sintered cylindrical porous iron compacts under free upsetting. An experiment is also conducted to validate the numerical results obtained from the proposed model with the experimental values observed for deformation load required and bulge developed on the specimen. The results obtained from the proposed model are in good agreement with the experimental observations.