Effects of friction models on the compaction behavior of copper powder

A comparative numerical and experimental analysis of metal powder compaction processes was presented. Closed-die compaction of spherical copper particles with a nominal diameter of 200 μm was analyzed using Multi Particle Finite Element Method (MPFEM). The von Mises material model associated with contact sensing algorithms was employed to investigate variation of coefficient of friction, and contact interactions between powder particles as well as particles with the die walls. Three different friction models (Amonton-Coulomb, Wanheim-Bay, and Levanov) were used to provide a better insight and the latter two were integrated into the commercial finite element package via user-subroutines. To verify the established model, some compaction experiments were carried out. Optical, and scanning electron microscopy analyses were performed, and images obtained were compared with the numerical results. The values of the coefficient of friction obtained using Wanheim-Bay and Levanov friction models fall into the range of 0.04-0.07. From the stress distribution perspective, it was observed that the results obtained with Wanheim-Bay friction model were more conforming to experimental cases where high relative density compaction takes place while Levanov friction model was found to be preferable at low relative density compaction process.