Finite element analysis of compressible viscoplasticity using a three-field formulation: Application to metal powder hot compaction Original Research Article

In the present study, a finite element model has been formulated to simulate the hot forging stage in powder metallurgy manufacturing route. The compacted material is assumed to obey a purely viscoplastic compressible flow rule. A three-field formulation (velocity, volumetric strain rate and pressure) has been developed. The associated three-dimensional finite element discretization is detailed. In order to take advantage of an automatic remeshing procedure for linear tetrahedra, the compatible P1+/P1/P1 element is used (4-node element plus additional degrees of freedom and bubble interpolation for velocity). The complete model includes thermomechanical coupling and friction. The formulation is validated versus an analytic solution of uniaxial free compaction and applied to the hot forging of an automotive connecting rod preform.