The brief introduction of the material of permanent magnets

　　Though the magnetization of external magnetic field, even in fairly large reverse magnetic field, permanent magnets material can still maintain the magnetic in a small part of or a large part of the original magnetization direction.

　　Requirements on this kind of permanent magnets' material is that residual magnetic induction Br should be high, and the coercive force BHC (i.e., resistance to demagnetization ability ) is strong, and magnetic energy product ( BH ) (i.e., to provide space for large magnetic energy ) is large. Relative to the soft magnetic materials, it is also known as the hard magnetic material.

　　Permanent magnets' material has alloy, ferrite and intermetallic compounds.

　　Alloy includes casting, sintering and machinable alloy. The main varietiy of casting alloy has: AlNi ( Co ), FeCr ( Co ), FeCrMo, FeAlC, FeCo ( V ) ( W ), Sintering alloy: ReCo (Re represents a rare earth elements ReFe ), and AlNi ( Co ), FeCrCo; Machinable alloy are: FeCrCo, PtCo, MnAlC, CuNiFe and AlMnAg, between the two, the one with lower BHC is also called semi permanent magnetic material.