Explanation Electromagnetic forming

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when switch closed, electrical energy stored in capacitor bank (left) discharged through forming coil (orange) producing rapidly changing magnetic field induces current flow in metallic workpiece (pink). current flowing workpiece produces corresponding opposite magnetic field rapidly repels workpiece forming coil, reshaping workpiece - in case, compressing diameter of cylindrical tube. reciprocal forces acting against forming coil resisted supportive coil casing (green).


in practice metal workpiece fabricated placed in proximity heavily constructed coil of wire (called work coil). huge pulse of current forced through work coil rapidly discharging high voltage capacitor bank using ignitron or spark gap switch. creates rapidly oscillating, ultrastrong electromagnetic field around work coil.


the high work coil current (typically tens or hundreds of thousands of amperes) creates ultrastrong magnetic forces overcome yield strength of metal work piece, causing permanent deformation. metal forming process occurs extremely (typically tens of microseconds) and, because of large forces, portions of workpiece undergo high acceleration reaching velocities of 300 m/s.







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