Magnetic field enhancement in electromagnetic forming systems using anisotropic materials

Electromagnetic Forming (EMF) is a type of high rate forming which exploits pulsed power techniques to create high intensive pulsed magnetic fields to rapidly reshape metal parts. This technique is sometimes called magnetic pulse forming. In this technique, a metal work-piece is pushed to a die and formed by a pressure created using an intensive, transient magnetic field. This magnetic field is produced by passing a pulse of electric current through a forming coil in a pulsed power circuit. Application of field shapers has been proposed to enhance the magnetic fields and consequently to increase the applied magnetic pressure at some desired regions. In this paper, 3D Finite element simulations have been applied to study the magnetic field distribution during an electromagnetic forming process with anisotropic material. Anisotropic magnetic material is described using a permeability tensor. Elements of this tensor are obtained from different magnetization curves dependent on the direction of the magnetic field. It has been shown that application of anisotropic materials with appropriate lamination directions can result in an enhancement of the magnetic field at desired points as well as in better overall efficiencies.