Investigative study on high strain rate powder compaction

Abstract

The field of powder metallurgy (PM) is crucial for producing engineering components with unique properties. Powder compaction, a fundamental step in PM, influences the final product's mechanical and structural characteristics. This research investigates the high strain rate of powder compaction process compared to conventional mechanical pressing. The study involves compacting aluminium powder using electromagnetic compaction and mechanical pressing setups. Three sample sets, each with varying energy levels, were prepared for both methods. The effects of compaction technique on diameter change, hardness, microstructure, and grain characteristics were examined. In the high strain rate process, radial compaction occurred due to the impulsive axial magnetic field, leading to Lorenz forces causing radial pressure. SEM images revealed diffused powder grain boundaries, indicating enhanced densification. Increasing energy levels led to decreased grain junctions, suggesting improved compaction. Hardness values showed slight increases from center to periphery. Optical microscopy illustrated finer, more randomized grain structures in the high strain rate process compared to directional grains in mechanical pressing. The results underscore the benefits of high strain rate compaction in achieving enhanced densification, improved hardness, and finer microstructures. The findings contribute to advancing powder metallurgy techniques and offer valuable insights into the potential applications of high strain rate compaction in engineering components.