ANALYTICAL STUDY OF FIELD SHAper in electromagnetic welding

Electromagnetic Welding (EMW) is a promising and relatively new manufacturing technology which is advantageous over conventional welding in many ways. EMW is a type of impact joining process which makes use of rapid energy source to accelerate and cause collision between two different metals at very high velocities by removing the layer of oxidation. The important characteristic of this process is non-contact Electromagnetic forces causes welding or joining process. The technique can be implemented for different applications, especially those in automotive industry. EMW is more efficient to produce complex components in high strength or low ductility materials. Also due to the plastic deformation in the process, welding between different materials is possible. It is necessary to concentrate the magnetic field in the desired region. The capacitor banks stores the high electrical energy in it. The changing magnetic field will induce eddy currents in the conductive outer work piece, also named the flyer tube. So considering the Lorentz force, the magnetic field outside the flyer tube will exert a force on the flyer tube due to the eddy currents, thrusting the tube inward in radial direction. If correctly executed the high velocity of the inward motion and thus the high-energy impact between outer and inner work piece will result in bonding/joining. It is necessary to concentrate the magnetic field in the desired region. To concentrate the magnetic flux and produce the magnetic pressure over the desired area of workpiece, field shaper can be used inside the working coil. This paper carries out a numerical simulation of different geometries of field shaper and effect of field shaper in EMW.