Rare-Earth Magnets Could Be Used in High-Temperature Applications

Originally Published MDDI June 2004

R&D DIGEST

Erin Bradford

Engineers at Electron Energy Corp. (Wyomissing, PA) have been granted a research contract to study the effects of radiation and high temperature on the properties of samarium-cobalt (SmCo) permanent magnets. The program will also study the improvement of thermal stability in a vacuum at temperatures up to 550°C.

Such magnets could be a major boon to those who make medical devices that may be autoclaved or otherwise subjected to elevated temperatures, according to Peter Dent, Electron Energy's director of marketing. In fact, some such devices already exist. “[These] include surgical tools such as motors and fluid-handling equipment, magnetic separation devices, and blood pumps,” he added.

The SmCo magnets are made from a material that is a few times higher in energy density than other high- temperature magnet materials. This higher energy density allows designers to create smaller, less costly, more powerful assemblies and systems that can operate in a wider thermal range. Moreover, system components containing magnetic materials can be designed to perform physically closer to the extreme environments in proximity to heat sources. Moving the magnetic materials closer to the heat source reduces total system mass.

Such magnets could be useful in applications such as implants or diagnostic devices in the body that are subjected to high temperatures during preparations for use. “The samarium-cobalt magnets, unlike neodymium magnets, do not lose their magnetic field strength,” Dent explained. They are highly stable at elevated temperatures and when subjected to high radiation doses, which could be helpful for devices that endure a rigorous sterilization process.

Samarium-cobalt magnets designed and manufactured by the company have already been used successfully in NASA's Deep Space 1 ion engine.

The University of Dayton Research Institute (Dayton, OH) and The Ohio State University (Columbus, OH) will partner with Electron Energy in the research study.

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