A research based on advance dual-coil electromagnetic forming method on flanging of small-size tubes

Using electromagnetic forming process to flanging small-size tubes has been a challenge of modern forming technology. With existing electromagnetic forming system in practical aspects, it is relatively difficult and complex process for designing and winding smaller but stronger driving coil, because of the high structural strength requirement for sustaining strong Lorentz force and the low geometrical permissibility bottlenecked by the size of tubes. To approach the mentioned complication, a practical dual-coil electromagnetic forming method had been presented thoroughly in the following article. For illustrating the basic structure of the method, the two independent driving coils were located at the end of the tube instead of inside the tube. Afterward, the two coils were respectively discharged by two power supplies. They generated entirely different Lorentz force distribution with precise and analogous time controlling. To determine the effectiveness of this method, a theoretical analysis of the forming force of the electromagnetic flanging had been approached thoroughly. Then, a full coupling model of electromagnet-structure was developed to simulate the deformation of the tube. The results showed that an obvious flanging with the maximum radial displacement of 5.08 mm could be achieved on an AA1060 aluminum tube with a thickness of 1 mm and a radius of 10 mm, on the condition of 5.8 kV and 6 kV. At the closure, the influence of the pulse width of discharge currents was discussed. All these theoretical analysis and simulation results are of great potential for designing electromagnetic forming systems and widening their applications in tube flanging.