| Scientists invented for cars and wind turbines cheaper magnetic materials |
| Date：2013-01-23 Views：2318 |
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Cerium is a kind of rare earth metal with low price. Scientists at Ames lab have used it to create a high-performance magnetic material similar to the traditional dysprosium magnet, making wind turbines cheaper to manufacture. Kar a. gshneidner of Ames Laboratory of the U.S. Department of energy and his colleagues have developed a new magnetic alloy that can replace the permanent magnet of traditional system. This alloy is a potential substitute for high-performance permanent magnets used in automobile engines and wind turbines. Instead of dysprosium, which is one of the rarest and most expensive rare earth elements, it uses the most abundant rare earth element cerium. As a result, cerium and cobalt alloys Co doped with neodymium, iron and boron have properties comparable to those of traditional sintered magnets containing dysprosium, and are cheaper. Experiments conducted by arjunpathak and Mahmud Khan (now at the University of Miami), postdoctoral researchers at Ames lab, have shown that the intrinsic coercive force of cerium containing alloys - the ability of magnetic materials to resist demagnetization - far exceeds that of dysprosium containing magnets at high temperatures. This material is at least 20% to 40% cheaper than magnets containing dysprosium. "It's a very exciting result, and we found that the performance of this material at 150 ℃ is better than any existing material," said gschneidner. "This material is an important consideration for high temperature applications." The reason for the failure of using cerium in rare earth magnets in the early stage is that cerium reduces the Curie temperature of the material. Above Curie temperature, the alloy will lose its permanent magnetism. However, the team found that CO doping with cobalt allowed them to replace dysprosium with cerium without losing the desired magnetic properties. Looking for a relatively suitable material is the key to reduce the dependence on dysprosium in production. At present, the demand for dysprosium far exceeds its mineral reserves and recovery. "Cerium: an unlikely alternative to dysprosium in high-performance NdFeB Magnets" was published in advanced materials by Arjun K. pathak, Mahmud Khan, Karl. A. gschneidner, Ralph W. McCallum, Lin Zhou, Kewei sun, Kevin W. Dennis of Ames laboratory, Matthew J. Kramer and vitalij pecharsky, Chen Zhou of MEDA engineering services and Frederik E. Pinkerton of GM R & D center. The research work is supported by the ARPA-E project of the U.S. Department of energy (Advanced Research Projects Agency - Key Technology of rare earth substitutes), which develops cheap substitutes for rare earth, a natural material with unique magnetic properties, used in electric vehicle motors and wind turbines. Reach projects look for cheap, rich alternatives to rare earths, while encouraging existing technologies to use them more efficiently |