Recoma™

Samarium Cobalt Magnets

Sintered samarium cobalt (SmCo) magnets, available since the early 1970's, offer the designer a tremendous combination of extremely high magnetic properties, outstanding thermal stability and excellent corrosion resistance. These characteristics make SmCo the ideal material in applications such as servo-motors, pump couplings, and sensors, particularly where the magnet is required to operate at high temperatures, across a broad temperature range or in a corrosive environment. The first alloy composition was SmCo5 with maximum energy products of about 18 MGOe (140 kJ/m3). Shortly after this development, an additional alloy composition, Sm2Co17 was developed by Karl Strnat. This was developed over time to provide over 30 MGOe (240 kJ/m3). Although processing of the 2-17 composition is more difficult, it also has the advantage of generally containing less Cobalt than the 1-5 composition. 2-17 is also corrosion resistant and more stable at very high temperatures. Both types are manufactured by Arnold Magnetic Technologies AG to satisfy specific customer needs. Arnold's brand name of samarium cobalt is Recoma™. MAXIMUM USE TEMPERATURE Although the Curie temperature for SmCo materials is between 750 and 850 degrees, current alloy compositions can only be used up to maximum temperatures of 350 to 550°C, depending upon grade. Compare this with neodymium-iron-boron's (NdFeB) maximum use temperatures of 150 to 220°C. Other advantages of SmCo over NdFeB include better corrosion resistance and greater magnetic output at temperatures above about 150°C. Sensor applications requiring a stable magnetic field benefit from SmCo's low reversible temperature coefficient of induction: -0.030%/°C for Sm2Co17. The best NdFeB varies twice as much. The only common material with a lower coefficient than this is alnico, but with significantly lower magnetic output and resistance to de-magnetization. MANUFACTURING Arnold Magnetic Technologies AG samarium cobalt factory is one of the world's more modern rare earth magnet manufacturing facilities and is equipped with state-of-the-art equipment throughout. A full range of Recoma™ material grades is available and the Company's continuous improvement philosophy ensures that enhanced materials will continue to be developed and introduced. Arnold is one of only a few companies that custom manufactures both fully dense AND polymer bonded samarium cobalt. For information on polymer bonded Sm2Co17, please visit the Bonded Magnet section. RoHS COMPLIANCE Recoma™ Samarium Cobalt Magnets are RoHS compliant.