Study on mechanical characteristics, microstructure and equation of copper powder compaction based on electromagnetic compaction

Electromagnetic powder compaction technology had the advantages of high efficiency and strong impact during the powder forming. The mechanical characteristics of copper powder compaction were investigated through digital image correlation technology under different discharge energies. The microstructure was analyzed by the metallography and electron microscopy. The results showed that the force-displacement curves had a bimodal tendency during the compaction of copper powders. The compaction force and velocity of copper powders gradually increased with the increase of discharge energy. The microstructure distribution of copper compacts was more and more dense as the discharge energy increased. However, the microstructure distribution of the axial direction of compact center was not much different overall at the same discharge energy. There was a tendency that the microhardness values at the center of the upper end faces were gradually larger than that of the lower end faces. The electromagnetic compaction equation of copper powders was established by Gaussian fitting. It had been verified that the error between the predicted and actual values of equation was only 0.47%.