|
Earth MagnetsThe Attraction of Affordable Rare-Earth Magnets
Rare earth permanent magnets are very strong but fairly expensive to produce. They play an important role in electric motors that drive CD ROMS, other computer components, and some electrical systems in automobiles. Cheaper production methods would permit wider applications for these magnets, lowering product prices and leading to significant energy savings. A team of researchers has discovered a method of controlling the solidification process of rare-earth magnets, making them easier and less expensive to produce commercially. The team was led by Charlie Sellers, of the Idaho National Engineering and Environmental Laboratory, and Bill McCallum, of Ames National Laboratory. After investigating a rare-earth permanent magnet phase -- pure neodymium-iron-boron (Nd2Fe14B) -- researchers found that if they added titanium carbide (TiC), the metal does not have to cool as rapidly in order to achieve optimum grain size and magnetic properties. If it doesn't have to cool as rapidly, it can be produced using the simpler, cheaper method of gas atomization. Already, General Motors has replaced its starter motors with a magnet driven motor which is much more energy-efficient. Because this starter motor provides more torque and power, the battery can be smaller and one gear box can be eliminated. The overall weight of the car is thus reduced, making it more fuel efficient.
Sellers, Dan Branagan, and Timothy Hyde of INEEL and McCallum, Matthew Kramer and Kevin Dennis of Ames Laboratory received the 1996 Materials Sciences Award for "Significant Implication for Department of Energy Related Technologies" in metallurgy and ceramics. The two Basic Energy Sciences programs were able to collaborate through ER's Center of Excellence for Synthesis and Processing of Advanced Materials. The Center, established in 1994, promotes and coordinates cooperative research partnerships related to the synthesis and processing of advanced materials. Working with DOE laboratories, universities and industry, the Center helps researchers develop methodologies to control the structure and thereby the properties and behavior of materials; discover and develop high-payoff, advanced materials; and reduce the time and cost of materials commercialization. The permanent magnet project is a work-in-progress with the two labs continuing to develop "model" rare-earth permanent magnet systems, to understand the basic property, structure and processing relationships in order to develop better magnets, easier, and at lower processing costs.
|
