Study the densification behavior and cold compaction mechanisms of solid particles-based powder and spongy particles-based powder using a multi-particle finite element method

Powders could be based on solid particles or spongy particles depending on the powder manufacturing procedures. In this article, the numerical study of the cold compaction process for copper solid particles-based powder (i.e. Cu solid powder) and spongy particles-based powder (i.e. Cu sponge powder) has been carried out by using a two-dimensional multi-particle finite element method (2D-MPFEM) based on single action die compaction. The effects of internal pores content, external pressure, initial packing structure on the packing densification were systematically presented. Relative density, stress distribution, internal pore deformations, and force chain movements, particle rearrangement, and interfacial behavior within spongy particles were characterized and analyzed. The results reveal that the densification behavior of the sponge powder depends basically on the internal pore's content. Moreover, at low and medium relative density (rho < 0.95), the densification behavior of the sponge powder is faster than solid particles-based powder. However, at higher relative density near unity, the force required to cause further compaction is significantly larger in the sponge powder. In addition, from the microscopic analysis, the deformation behavior of the particles and the internal pores and the force chain development rely mostly on the structure configuration, internal pore content and its position.