Ultra-High Temperature Samarium Cobalt Magnets and Magnet Assemblies

Since 1970, SmCo5 and Sm2Co17 magnets have been satisfying needs for magnets that reach operating temperatures up to 330°C. But when the operating temperature of these conventional magnets exceeds 330°C, their extrinsic demagnetization curves become nonlinear, characterized by a “knee” in the curve.

In 1995, the U.S. Air Force and other branches within the U.S. Department of Defense described requirements for magnets capable of operating at temperatures greater than 400°C. In response to those needs, Electron Energy Corporation (EEC) has developed a new class of Sm2Co17 magnets for use at temperatures up to 550°C. These magnets have high-to-moderate energy product (BH)max, high intrinsic coercivity, Hci, and straight-line extrinsic demagnetization curves up to 550°C.

Our objective during the development of this new class of materials was to maintain a substantially linear extrinsic demagnetization curve at higher temperatures while maintaining the maximum possible energy product.

Accordingly, a new symbol (Tm) was introduced, which is defined as the maximum temperature at which the extrinsic demagnetization curve of a magnet is a straight line.

A straight-line extrinsic demagnetization curve is of value to designers of minimum volume and minimum weight devices. The straight-line curve is even more important for dynamic or highly loaded applications where high demagnetization forces are encountered. For optimum performance, a discrete magnet composition is required for each specific temperature, (Tm).

There is one area in which these ultra-high temperature magnets have already been successfully applied – space travel. In October 1998, NASA launched Deep Space 1, the first in a series of deep-space and Earth-orbiting missions conducted under the New Millennium Program designed to demonstrate new technologies in the environment of space.

During its highly successful primary mission, the satellite tested 12 advanced, high-risk technologies in space, including an ion-propulsion engine manufactured by Hughes Electron Dynamics using EEC’s high temperature magnets. In an extremely successful extended mission, Deep Space 1 encountered the comet Borrelly and returned the best images and other scientific data ever from a comet.

More Information

Brochure: Samarium Cobalt Magnets

Presentation: Sm-Co Magnets and Applications

News Release: Electron Energy Corporation Awarded Air Force STTR Contract to Develop Multiphase Nanocomposite Magnets Capable of Withstanding Ultra-High Temperature Applications

News Release: Electron Energy Corporation Receives NASA SBIR Contract to Continue Development of Ultra-High Temperature Magnetic Bearings for Space Vehicle Systems

News Release: EEC Awarded U.S. Patent for Ultra-High Temperature Magnets

Magnetic Properties of Ultra-High Temperature Samarium Cobalt Magnets

This chart show magnetic properties of commonly used materials. If you would like to see magnetic properties of customized magnet materials, please contact us.

* Depends on the temperature range of the applications. Please contact EEC for additional information.
† Contact EEC to discuss the environmental conditions.

Demagnetization Curves of Ultra-High Temperature Samarium Cobalt Magnets

EEC 24-T400 | EEC 20-T500 | EEC 16-T550