Researchers are working on composites that would make strong magnets that need less of the hard-to-get ingredients.
Stronger, lighter magnets could enter the market in the next few years, making more efficient car engines and wind turbines possible. Researchers need the new materials because today's best magnets use rare-earth metals, whose supply is becoming unreliable even as demand grows.
So researchers are now working on new types of nanostructured magnets that would use smaller amounts of rare-earth metals than standard magnets. Many hurdles remain, but GE Global Research hopes to demonstrate new magnet materials within the next two years.
The strongest magnets rely on an alloy of the rare-earth metal neodymium that also includes iron and boron. Magnet makers sometimes add other rare-earth metals, including dysprosium and terbium, to these magnets to improve their properties. Supplies of all three of these rare earths are at risk because of increasing demand and the possibility that China, which produces most of them, will restrict exports.
However, it's not clear if the new magnets will get to market before the demand for rare-earth metals exceeds the supply. The U.S. Department of Energy projects that worldwide production of neodymium oxide, a key ingredient in magnets, will total 30,657 tons in 2015. In one of the DOE's projected scenarios, demand for that metal will be a bit higher than that number in 2015. The DOE's scenarios involve some guesswork, but the most conservative estimate has demand for neodymium exceeding supply by about 2020.
Link : technologyreview.com
Tidak ada komentar:
Posting Komentar