Reasons and solutions for demagnetization of neodymium iron boron magnets at high temperature
Among the commonly used magnetic materials, NdFeB permanent magnet materials have poor temperature characteristics, and the maximum operating temperature of the N range is 80°C.
Some magnet users find that the magnetic performance of the magnet starts to be abnormal when the temperature of the magnet is 80℃. What caused this?
The reason for the demagnetization of NdFeB magnets at high temperature is that the magnetic domain molecules in the NdFeB magnets are arranged regularly after magnetization, and the high temperature causes these molecules to be disordered, resulting in unstable magnetic properties. It can also be explained in this way: most of the electrons in the magnet rotate around the atom in the same direction, so that each electron generates a magnetic field, which is the magnetic field generated by the magnet in a macroscopic view. So now that the temperature rises, the irregular movement of the molecules is accelerated, so as the temperature rises, the regular form of movement inside is destroyed, so the magnetism weakens or disappears.
The solution to the demagnetization of neodymium iron boron magnets at high temperature: the coercive force is a major indicator of resistance to the external environment. The higher the coercive force, the better the high temperature resistance coefficient. Different grades of magnet grades should be selected at a certain working temperature.
- N range: within 80℃, the NdFeB magnet can be guaranteed not to demagnetize.
- M level: within 100℃, the NdFeB magnet can be guaranteed not to demagnetize.
- H file: within 120℃, the NdFeB magnet can be guaranteed not to demagnetize.
- SH file: within 150℃, the NdFeB magnet will not demagnetize.
- UH file: within 180℃, the NdFeB magnet can be guaranteed not to demagnetize.
- EH file: within 200℃, the neodymium iron boron magnet can be guaranteed not to demagnetize.