Washington, Jan 10 : Researchers at the U.S. Department of Energy's (DOE) Ames Laboratory have designed a high-performance magnet alloy, which would help to make electric drive motors more efficient and cost-effective.
The new magnet alloy operates with a good magnetic strength at 200 degrees Celsius, and is expected to play a major role in advancing electric drive motor technology to meet the enormous swell in consumer demand expected over the next five years.
The work is part of the DOE's Vehicle Technologies Program to develop more energy-efficient and environmentally friendly highway transportation technologies that will enable America to use less petroleum.
According to Iver Anderson, senior metallurgist at the Ames lab, because future ultragreen vehicles like electric cars, fuel-cell automobiles and plug-in hybrids all have electric motors, it's important that those motors be made economically with an operating envelope that fits how they will be driven. or this, the automotive companies in the US have set out a series of parameters that they would like electric motors to meet.
One of those constraints being addressed is the need for permanent-magnet electric motors to operate well at temperatures up to 200 degrees Celsius.
"Most of those types of magnets tend to lose a lot of their magnetic energy at fairly modest temperatures and are operating at much less than half of their power by the time they reach 100 C to 125 C," said Anderson.
"So our challenge was to design a high-performance 2-14-1 permanent magnet alloy that would operate with good magnetic strength at 200 C," he explained.
Meeting that challenge, Anderson and his colleagues - Bill McCallum and Matthew Kramer, designed an alloy that uses a combination of neodymium, yttrium and dysprosium, which have a lower temperature coefficient.
Once they had tweaked the new alloy to perfection, the next thing the researchers did was process it in a fine, spherical powder form using gas atomization, a technique in which kinetic energy from supersonic jets of gas is transferred to a stream of liquid metal, causing it to break up into droplets.
"This method best fits the needs of the automobile industry because they want to make their motors by a very high-volume manufacturing process, and that method is injection molding," explained Anderson.
According to the researchers, they now have what they think is a really good alloy, and also have switched from helium gas to argon gas in the atomization process, which makes the powder-making process a lot cheaper.
"That's a move in the right direction for the purposes of commercialization," said Anderson.