Study of the densification mechanisms of Al-Fe-Cr-Ti alloys during high-velocity compaction based on 3D MPFEM

Aluminum alloy materials are widely used in aerospace and related fields, among which Al-Fe-Cr-Ti alloys have attracted increasing attention owing to their low density and excellent comprehensive properties. However, the densification mechanisms of alloy powders during high-velocity compaction (HVC) remain insufficiently understood. In this study, a three-dimensional multi-particle finite element method (3D MPFEM) model was developed to simulate the HVC process of Al-Fe-Cr-Ti alloy powders and to evaluate the effects of friction coefficient μ, impact energy per unit mass E_m, hammer mass M, and compaction velocity v on powder densification. The results show that increasing μ from 0.25 to 0.65 reduced kinetic-energy transfer and stress transmission, decreasing the relative density ρ of the green from 0.7076 to 0.6797. In contrast, increasing E_m from 55.58 to 144.67 J/g markedly improved densification, with the maximum relative density reaching 0.8881. Displacement-field analysis further revealed that appropriate combinations of M and v promote particle rearrangement and plastic deformation. Experimental validation confirmed that the simulated density evolution agreed well with the measured trend, although the predicted values were slightly lower. These findings indicate that 3D MPFEM can reasonably describe the macroscopic densification trend and provide qualitative particle-scale insights into deformation and energy-transfer behavior during HVC.