Axially Movable Electromagnetic Forming System for Large-Scale Metallic Sheet

Abstract

How to generate strong enough electromagnetic forces in the electromagnetic forming process is an important issue for sheet forming. For this purpose, an axially movable electromagnetic forming system was designed, fabricated, and tested. To validate the effectiveness of the system, a series of experiments on the forming of AA1060 with a diameter of 440 mm and a thickness of 3 mm has been carried out. A pulsed magnet with an inner diameter of 100 mm and an outer diameter of 200 mm was used to drive the sheet. A capacitor bank power supply (200 kJ/25 kV/640 μF) has been used to energize the coil. The experimental results have shown that the maximum deformation depth of the workpiece is only about 90 mm when the forming coil was fixed after three discharges. This value can be greatly increased to 130 mm by the use of the proposed forming method in which the distance between the coil and the deformed workpiece was decreased in each discharge process. Meanwhile, the geometric accuracy between the final deformed workpiece and die is less than 3 mm according to the three-dimensional scanning analysis.