Experimental and numerical investigation of idealized consolidation: Part 1: Static compaction Original Research Article

In order to investigate the compaction of homogeneous and composite powders under carefully controlled conditions, idealized two-dimensional compacts were constructed using rods of aluminum and hardened steel. Special attention was paid to the material behavior of the rods, the die boundary conditions, the periodic packing arrangement, and the shape change during ejection from the dies (springback). Corresponding finite element simulations of uniaxial compaction were carried out. Pressure–density relationships, over a wide range of pressures and densities, were achieved by matching initial packing density and accounting for springback. Springback consists of two significant contributions: particle compressibility and void re-opening. Deformed particle shapes were predicted well and the role of inter-particle friction was found to be minor for the idealized arrangements studied. The ratio of contact pressure over current yield stress is close to 3 for homogeneous compaction, and much higher values are seen for heterogeneous compaction. As expected, the presence of hard particles greatly inhibits the densification process.