Curie temperature and working temperature of NdFeB magnets
How much temperature can rare earth NdFeB magnets withstand? This is a problem that many customers are concerned about. In fact, it also has a Curie temperature. Many people don't know the difference between the Curie temperature of magnets and the working temperature, and what is the Curie temperature?
What does Curie temperature mean?
Curie temperature is the temperature at which the magnetic material changes between ferromagnet and paramagnetic. When Curie 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 the 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.The Curie temperature of neodymium magnet is 320 ℃ - 380 ℃ ° C. The Curie point is related to the crystal structure of the sintered magnet.
What would be the Curie temperature over NdFeB?
If the temperature reaches Curie temperature, the molecules in the magnet will move violently and demagnetize, which is irreversible.
Working temperature of NdFeB
The surface means the temperature at which the magnet is used. Generally, the working temperature of NdFeB magnet is 80 ℃ - 220 ℃, the upper limit of common material is 80 ℃, and the upper limit of high temperature resistant material is 200 ℃. Within the working temperature range, the corresponding magnetic force will weaken when the temperature rises by 1 ℃, and the magnet will demagnetize rapidly when the temperature exceeds the upper limit, Therefore, when choosing NdFeB magnets, we must know what kind of materials we buy and what the working temperature is.
The relationship between working temperature and Curie temperature of NdFeB
The higher the Curie temperature, the higher the working temperature of the magnetic material, and the better the temperature stability. The Curie temperature of sintered NdFeB can be increased by adding cobalt, terbium and dysprosium.
The maximum operating temperature of sintered NdFeB depends on its magnetic properties and the selection of working point. For the same sintered NdFeB magnet, the more closed the magnetic circuit is, the higher the maximum operating temperature of the magnet is, and the more stable the performance of the magnet is. Therefore, the maximum temperature of the magnet is not a certain value, but changes with the degree of closure of the magnetic circuit.