Characteristics of metal flow in cold extrusion under electric-hydraulic chattering

An experimental setup for cold extrusion process with electric-hydraulic chattering was developed and its working principle was introduced. The finite element (FE) model for a kind of cup part (material: 20Cr) was built by using the software Deform-3D. FE simulation experiments with and without electric-hydraulic chattering were carried out to analyze the velocity fields and the metal grid flow lines. The extrusion experiments of the cup part were also performed under different conditions. The difference of metal flow lines with and without electric-hydraulic chattering was discussed via a scanning electron microscope (SEM) and the Keyence super-depth three-dimensional microscopic system. The results showed that with the electric-hydraulic chattering, the velocity of material flow increases, whereas deformation resistance decreases. Electric-hydraulic chattering results in easy metal flow, small bending degree of metal flow lines, slender and dense metal grains, and thereby an improved quality of the deformed parts.