Influence of discharge energy on electromagnetic compaction characteristics of copper powders with same compression amount

[Display omitted] •The copper powders with controlled the compression amount were compacted.•The electromagnetic compaction characteristics of powders was investigated.•The densification behavior and flow pattern of powder particles were analyzed.•The mechanical properties of compacts and compaction relationship were studied. Electromagnetic powder compaction technology is an effective method for producing high density and strength parts. In this work, the influence of discharge energy on the electromagnetic compaction characteristics of copper powders with same compression amount was studied through experiment investigation and numerical simulation. The finite element simulation, micro morphology observation, and compressive strength testing were conducted. Results showed that the propagation direction of stress was 45° from top to bottom of compacts. At 7–9 kJ, there was a turning phenomenon in the direction of stress propagation at the upper edge position due to the restriction of shim. As the discharge energy increased, the pores on the upper end face shifted towards reduction and concentration, ultimately forming local defects with large pores. This method could be used to improve the compaction quality of the local position of compacts. The compressive strength of compacts also increased gradually and then almost linearly, and the maximum value was 164.07 MPa. The relationships between volume strain and compaction time were obtained, R-square exceeded 0.9997 under different discharge energies, indicating high reliability.