Electromagnetically Assisted Sheet Metal Stamping and Deep Drawing

Factors such as limited draw in and friction against tool surfaces cause difficulty in forming of sheet metals. Most of the strain tends to localize in the wall of the formed part while the bottom, in contact with the punch surface, and the flange, held down with the blank holder do not undergo much deformation. Augmentation of conventional forming processes with electromagnetic forming has been proposed as a method to attain higher draw depths by distributing strains more uniformly and encouraging draw in. In separate experiments, electromagnetic forming coils were embedded either in the bottom of the punch or in the blank holder. In both cases, multiple electromagnetic pulses in the coils followed by movement of the punch lead to higher draw depth as compared to corresponding stamping or deep drawing processes.