Electromagnetic flanging using a field shaper with multiple seams

Electromagnetic forming is a high-speed forming method based on pulsed magnetic force, which can greatly improve the forming limit of materials. Flat helical coils are often used in conventional electromagnetic flanging. It is difficult to set multi-turn coils in the flanged area if the size of the hole is small. The field shaper is used to concentrate the magnetic field into the specific area to be deformed. Compared with the tapered field shaper, the single-step field shaper is more efficient because it can generate greater electromagnetic force in the forming area. However, the magnetic field distribution on the workpiece will not be uniform due to one seam existence. Thus, the electromagnetic flanging using a field shaper with multiple seams was proposed. The distribution of the electromagnetic force on the sheet can be adjusted by adding short seam on the field shaper. Finally, the deformation uniformity of the sheet is improved due to the uniform distribution of electromagnetic force on sheet. The sheet-deformed profile obtained by experiment and simulations was compared, and the correctness of simulation results was verified.