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February 19, 2010

EMPs (Electromagnetic pulses) that create rather than destroy


Long story short: Many view EMPs as the most potentially devastating aspect of nuclear weapons. Now comes a team of German researchers who have succeeded in using controlled EMPs as metalworking instruments, creating a machine capable of punching clean holes 3cm in diameter through 1mm-thick sheet steel of the type used to build car bodies.

From a January 14, 2010 Economist story: "Now a group of researchers at the Fraunhofer Institute for Machine Tools and Forming Technology in Chemnitz, Germany, has found a way to use an EMP device to shape and punch holes through industry’s metallic heavyweight—steel. This could transform manufacturing by doing away with the need to use large, heavy presses to make goods ranging from cars to washing machines.

"Verena Kräusel and her colleagues performed their trick by beefing up an existing electromagnetic-forming machine. Such machines use a bank of capacitors to discharge a current rapidly through a coil. The coil converts the current into a powerful magnetic field. When the component to be worked is placed next to such a machine, the coil induces in it a corresponding field. Like poles repel, and the repulsion between the two fields is strong enough to make the metal distort.

"Dr Kräusel and her colleagues boosted the power of their machine by strengthening its coil and speeding up the rate at which the capacitors dump their charge. The result is an extremely strong field—one that delivers enough pressure when it hits the steel to punch out the material next to it, leaving a hole behind. The impact pressure on the steel is about 3,500 atmospheres. That is the weight of three small cars pressing on an area only a centimetre or so square.

"Although using a heavy press to bend metal and cut holes in it is fast, the tearing action at the edges of the holes leaves ragged, sharp tailings, known as burrs. This means that parts stamped out this way have to be cleaned up, usually by hand, which increases production costs. The need to keep replacing the stamps and dies used by the press, as they become blunt, also adds to the expense.

"Lasers are one alternative. They can cut cleaner holes in steel, but they are slower than stamping because they need to burn their way around the part. They are also expensive to operate. An electromagnetic punch, however, stamps its hole without tearing the metal, which means no burrs are left behind, and it never gets blunt. In fact, says Dr Kräusel, her machine can punch a hole clean through a sheet of steel in a fifth of second—compared with the 1.4 seconds needed by a laser."

February 19, 2010 at 02:01 PM | Permalink


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Yeah that's incredible, I've seen this being used in automobile factories on TLC. It's amazing this technology!

Posted by: Brandon T | Feb 19, 2010 11:00:35 PM

LOL...how scientific...

"the weight of three small cars"!

Great idea though.

Posted by: Joe Peach | Feb 19, 2010 5:04:59 PM

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