Hard ferrite magnets belong to sintered permanent magnetic
material, which made from oxide iron, barium, and strontium
carbonate by ceramic processing technology, just because of the
processing method, it also named as ceramic magnets in America.This
magnetic material has strong ability to resist demagnetization and
the advantage of low cost.
Ferrite permanent magnets classified as isotropic and anisotropic.
Isotropic ferrite magnets have weak magnetic strength, but it can
be magnetized through different directions. Anisotropic ferrite
magnets have stronger magnetic strength than isotropic, but it can
be only magnetized through certain direction.
By magnetic strength, ferrite magnets or ceramic magnets are much
weaker than neodymium permanent magnets and SmCo magnets, but
stronger than AlNiCo magnets. But its advantages of low cost,
excellent corrosion and demagnetization resistance, which makes it
widely used in the area of magnetic separator, speaker magnets,
magnetic toys, office magnets, car magnets. From the aspect of
shape, hard ferrite magnets are usually available as ceramic block
magnets, ferrite ring magnets, ferrite disc magnets and ceramic
block magnets. Ferrite disc magnets often used on office magnets,
ferrite ring magnets often used to make loudspeaker, ferrite block
magnets can be used to make separate magnets.
Ferrite magnets (ceramic magnets ) was developed in the year of
1960, and it is lower in power (B, Br, BHmax) compared to other
formulations, and are very brittle. However, they have very high
Hcj and good Tc, and are quite corrosion-resistant. So ceramic
magnets are a cost-effective choice.
Ferrite magnets produced by powder metallurgy ways, the remanence
is low, The coercive force is high, especially suit for magnetic
structure used in the condition of dynamic operation. The material
is hard and crisp, silicon carbide tools are used for cutting
machine. The main material for ferrite magnets is oxide, not easy
to be rust.