Numerical simulation of powder metal forming process using the SPH Method

The method of Smoothed Particle Hydrodynamics (SPH) is used for the numerical simulation of compaction of iron powder. The character of SPH allows for accurately tracking relevant material properties within a Lagrangian coordinate system without the problems due to limited mesh deformation allowed by the fixed connectivity of the Finite Element Method (FEM). Compaction is imposed by contact between the particles and a rigid FEM model for the tools. Volumetric compaction tests are performed to derive material characteristics to be used by the SPH simulations and the results are used to validate the SPH compaction simulation. Simulation of the thermal deformation during the subsequent sintering process is best simulated by the FEM. A unique methodology for mapping SPH onto a FE mesh has been developed and validated. To evaluate proposed simulation results, experiments for a pebble share part of an MP3 player have been performed. Density distributions and reaction force from the die after the compaction process are compared with simulation results. The distortions and stresses due to the thermo-mechanics of the sintering process on the finite element model obtained after mapping of the final SPH state have been evaluated as well.