Ultrasonic evaluation of iron powder during compaction

Prior studies have shown that the cyclic application of pressure can be far more effective in consolidating composite compacts than monotonic compaction. To study a simple system, pure aluminum and hardened steel rods were assembled in arrays and consolidated under cyclic pressure at room temperature. Idealized experiments and finite element simulations showed similar results for enhanced densification under cyclic pressure. Both inter-particle friction and pressure amplitude were shown to have important and predictable effects. Inter-particle friction hinders monotonic consolidation but assists cyclic compaction. Consolidation is enhanced with increasing numbers of pressure cycles and pressure-cycle amplitude, while the maximum pressure is fixed.