Explanation
A rapidly changing magnetic field induces a circulating electrical current within a nearby conductor through electromagnetic induction. The induced current creates a corresponding magnetic field around the conductor (see Pinch (plasma physics)). Because of Lenz's Law, the magnetic fields created within the conductor and work coil strongly repel each other.
In practice the metal workpiece to be fabricated is placed in proximity to a heavily constructed coil of wire (called the work coil). A huge pulse of current is forced through the work coil by rapidly discharging a high voltage capacitor bank using an ignitron or a spark gap (copper vapour thyratron) as a switch. This creates a rapidly oscillating, ultrastrong electromagnetic field around the work coil.
The high work coil current (typically tens or hundreds of thousands of amperes) creates ultrastrong magnetic forces that easily overcome the yield strength of the metal work piece, causing permanent deformation. The metal forming process occurs extremely quickly (typically tens of microseconds) and, because of the large forces, portions of the workpiece undergo high acceleration reaching velocities of up to 300 m/s.
Read more about this topic: Electromagnetic Forming
Famous quotes containing the word explanation:
“How strange a scene is this in which we are such shifting figures, pictures, shadows. The mystery of our existence—I have no faith in any attempted explanation of it. It is all a dark, unfathomed profound.”
—Rutherford Birchard Hayes (1822–1893)
“The explanation of the propensity of the English people to portrait painting is to be found in their relish for a Fact. Let a man do the grandest things, fight the greatest battles, or be distinguished by the most brilliant personal heroism, yet the English people would prefer his portrait to a painting of the great deed. The likeness they can judge of; his existence is a Fact. But the truth of the picture of his deeds they cannot judge of, for they have no imagination.”
—Benjamin Haydon (1786–1846)
“There is no explanation for evil. It must be looked upon as a necessary part of the order of the universe. To ignore it is childish, to bewail it senseless.”
—W. Somerset Maugham (1874–1965)