PhysOrg.com -- The bodywork on motor vehicles must be sufficiently stable, but processing the high-strength steels involved -- for example punching holes in them -- can prove something of a challenge. A new steel-cutting process will save time, energy and money in the future.
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Squealing tires and the crunch of impact - when an accident occurs, the steel sheets that form a motor vehicle’s bodywork must provide adequate impact protection and shield its passengers to the greatest extent possible. But the strength of the steels that are used throw up their own challenges, for example when automobile manufacturers have to punch holes in them for cable routing. Struggling to pierce the hard steel, mechanical cutting tools rapidly wear out.
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“The new method is based on electromagnetic pulse technology (EMPT), which was previously used primarily to expand or neck aluminum tubes. We've modified it to cut even hard steels. Whereas a laser takes around 1.4 seconds to cut a hole, EMPT can do the job in approximately 200 milliseconds - our method is up to seven times faster.”
To be able to use this process to cut steel, the researchers simply had to modify the coil to ensure the resulting electromagnetic field is strong enough: the pressure with which the field hits the steel must be so high that it forcibly expels the material from the sheet.
“The impact pressure on the steel is approximately 3,500 bar, which equates to the weight of three small cars on a single fingernail,” says Kräusel.
http://www.physorg.com/news178914974.htmlInteresting method. I didn't even realize electromagnetic pulses were used this way. Learn something everyday.