Fe-based PM alloy powder of Fe-2.5Ni-0.5Mo-2Cu-0.4C was pressed by high velocity compaction combined with die wall lubrication, and the effect of die wall lubrication on high velocity compaction behavior and sintering properties of the Fe-based PM alloy were studied. The results indicate that the impact force, green density, sintered density of samples increase with the augment of the impact velocity and die wall lubrication. Compared with that without die wall lubrication, the green density and sintered density of the sample with die wall lubrication are about 0.07-0.12 g/cm3 and 0.08~0.11 g/cm3 higher at the same impact velocity, respectively, while the ejection force of the die wall lubricated sample is much smaller, and reduced about 26%~36%. The green compact with die wall lubrication has much fewer porosity than that without die wall lubrication, and more mechanical bonding and cold welding regions are observed. The sintered samples mainly consists of gray pearlite and white ferrite, and more pearlite is observed in the sintered sample with die wall lubrication.

Multi-particle finite element method (MPFEM) simulation has been proven an efficient approach to study the densification behaviors during powder compaction. However, comprehensive comparisons between 2D and 3D MPFEM models should be made, in order to clarify which dimensional model produces more accurate prediction on the densification behaviors. In this paper, uniaxial high velocity compaction experiments using Ti-6Al-4V powder were performed under different impact energy per unit mass notated as Em. Both 2D and 3D MPFEM simulations on the powder compaction process were implemented under displacement control mode, in order to distinguish the differences. First, the experimental final green density of the compacts increased from 0.839 to 0.951 when Em was increased from 73.5 J/g to 171.5 J/g. Then detailed comparisons between two models were made with respect to the typical densification behaviors, such as the density-strain and density-pressure relations. It was revealed that densification of 2D MPFEM model could be relatively easier than 3D model for our case. Finally, validated by the experimental results, 3D MPFEM model generated more realistic predictions than 2D model, in terms of the final green density’s dependence on both the true strain and Em. The reasons were briefly explained by the discrepancies in both the particles’ degrees of freedom and the initial packing density.