Electromagnetic forming (EM forming) is a high energy rate metal forming process, that uses ultrastrong pulsed magnetic fields , to reshape metal parts rapidly .
In practice the metal "work piece" to be fabricated is placed in close proximity to a heavily constructed coil of wire (the work coil). A huge pulse of current is forced through the work coil by rapidly discharging a high voltage capacitor bank. This creates an ultrastrong and rapidly changing electromagnetic field.
The field induces a circulating electrical current within the work piece through electromagnetic induction, and this induced current creates another magnetic field around the metal work piece. Because of Lenz's Law, the magnetic field created within the metal work piece repels the field created by the work coil.
If the work coil current is sufficiently high, the magnetic forces can permanently deform the metal work piece. The metal forming process occurs extremely quickly (typically tens of microseconds).