The deformation mechanism of circular hole flanging by magnetic pulse forming

[Display omitted] In this work, numerical simulation and experiments were used to study deformation behavior during a circular hole flanging of QCr0.8 copper alloy sheet by magnetic pulse forming and quasi-static circular hole-flanging with a steel punch. The deformation law, the bending effect, and the stress-strain field evolution of the annular deformation zone were compared for these two processes. The results showed that the inertia derived from high speed forming supposed over the remarkable effect of the radial tensile stress during the magnetic pulse hole-flanging, resulting in the “stretch–bending” effect at the die fillet and expanding the bidirectional elongated strain zone. Under the same experimental conditions, the height of the vertical wall of the hole-flanged part by magnetic pulse forming was remarkably higher than that resulting from hole-flanging with steel punch. At a constant hole-flanging coefficient of 0.56, the vertical wall of the hole-flanged part by magnetic pulse forming was increased 28.83% compared with the one produced with steel punch.