Investigation of current-assisted electromagnetic tensile forming for sheet metal

Electromagnetic forming (EMF) can greatly improve the materials forming limit, but how to improve the energy utilization of EMF is an urgent problem to be solved. In this paper, the method of current assisted electromagnetic forming (CA-EMF) was proposed and compared the deformation process with traditional EMF. Three forming schemes were carried out to analyze the effects of steel die and bridge structure on current distribution and deformation result of sheet metal. The results show that steel die which is commonly used in traditional EMF was not suitable for CA-EMF. Then, the epoxy plate die with good insulation is used to replace steel die, and a bridge structure is used to form a current loop with the sheet during CA-EMF process. Thus, the current density and electromagnetic force in the deformation area of the sheet were significantly increased. Therefore, CA-EMF is an effective means of improving the plastic deformation effect of metals. The sheet-deformed profile and forming height obtained from experiment and simulation were compared, and the correctness of simulation was proved.