What is the Curie temperature of permanent ferrite magnet?
What is Curie temperature?
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Curie temperature refers to the temperature that a material can change between ferromagnet and paramagnetic. When the temperature is lower than Curie temperature, the material becomes ferromagnet, and the magnetic field related to the material is difficult to change. When the temperature is higher than Curie temperature, the material becomes paramagnetic, and the magnetic field of the magnet is easy to change with the change of the surrounding magnetic field.
What is the Curie temperature of permanent ferrite?
It is reported that the Curie temperature of ferrite is about 450 ℃, usually greater than or equal to 450 ℃. The hardness is about 480-580. The Curie temperature of NdFeB magnets is 350-370 ℃. However, the service temperature of NdFeB magnets can not reach Curie temperature. When the temperature exceeds 180-200 degrees, the magnetic properties of NdFeB magnets have declined a lot, and the magnetic loss is also very large, which has lost the use value.
How to demagnetize ferrite?
The demagnetization of ferrite is more troublesome, because the required temperature is very high. If it needs to be demagnetized cleanly, it needs to be heated to 900 ℃ for re burning. Only a little above the Curie point can not be demagnetized cleanly. If it is possible to demagnetize by AC attenuation.
Attachment: demagnetization curve of ferrite related properties