What is the Curie temperature of a permanent ferrite flexible magnet?

- Mar 12, 2019-

What is the Curie temperature of a permanent ferrite flexible magnet? What is the demagnetization temperature? Before we answer this question let's look at the Curie temperature first.


Curie temperature


Curie temperature is the temperature at which a material can change between a ferromagnet and a paramagnet. Below the Curie temperature the material becomes a ferromagnet, and the magnetic field associated with the material is difficult to change. When the temperature is higher than Curie, the material becomes paramagnetic, and the magnetic field of the magnet is easily changed with the change of the surrounding magnetic field.


What is the Curie temperature of a permanent ferrite flexible magnet?


Ferrite magnet Curie temperature at about 450 ℃, is generally higher than 450 degrees. The hardness is around 480-580. NdFeB magnet Curie temperature is generally between 350 and 370 degrees. But the NdFeB magnet use temperature is below the Curie temperature, the temperature of more than 180-200 degrees NdFeB magnetic properties have been attenuated a lot, at this time the NdFeB has lost its use value.


How do you demagnetize the ferrite?


Ferrite demagnetization is complicated because the required temperature is very high. Burning completely demagnetization words need to be heated to 900 ℃. It's not enough that the temperature is just a little bit above Curie. If only the majority of demagnetization is required, the method of ac attenuation can be used to demagnetize.


Attached figure: demagnetization curve of ferrite flexible magnets

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