SmCo sintered permanent magnet material was developed in the seventies based on the rare earth compositon and the 3D-transition metals.
They can be divided into:
Intermetallic material on SmCo5 base alloy. Suitable for temperatures up to 250° C and characterized by excellent corrosion and temperature stability. Magnetic fields of up to 2500 kA/m are needed to achieve the max. potential (Remanences between 0.8 and 1.0 T).
Permanent magnetic material on Sm2Co17 base alloy. Through targeted use of the additives Fe, Cu and Zr the coercivity can be set to appr. 1500–3000 kA/m.
Compared to SmCo5 the Sm2Co17 can be characterized by even lower temperature coefficients of the remanence and coercivity.
As a result application temperatures of up to 350°C can be achieved.
Disadvantageous, especially for the magnetization of magnet systems, are the very high essential magnetic fields, which can reach values of up to 600 kA/m.
Additionally the high brittleness can result in problems during machining.