2020-05-07 11:15:57

Why do NdFeB magnets demagnetize at high temperature?

In the process of our use, demagnetization is also very normal, because some external factors and some self factors are likely to cause demagnetization, so let's understand why the demagnetization of NdFeB magnet occurs in high temperature environment? 

The demagnetization of NdFeB magnet in high temperature environment is determined by its physical structure. The reason why a general magnet can generate a magnetic field is that the electrons carried by the substance itself rotate around the atom in a certain direction, and then a certain magnetic force will occur, which will affect the surrounding affairs. However, the rotation of electrons around atoms in a given direction is also limited by certain temperature conditions. Different magnetic materials can experience different temperatures. In the case of too high temperature, the electrons will go against their original orbit and form a chaos phenomenon. At this time, the local magnetic field of the demagnetizing material will be disrupted and demagnetized.

 

And the temperature resistance of NdFeB magnet is about 2 Baidu, which means that it will be demagnetized if it exceeds 2 Baidu. If the temperature is higher, the demagnetization will be more serious. Is magnet degaussing permanent or temporary at high temperature?

 

The Curie temperature of NdFeB magnet is 320 ℃ - 380 ℃, but in fact, the molecular structure of NdFeB has changed when it is heated. If the Curie temperature can not reach the theoretical value, the magnetic force will go out. The temperature resistance of NdFeB tested by me is 100 degrees. When the temperature is heated to about 100 degrees, the magnetic force starts to decrease, but the speed cannot be opened. After 150 degrees, the magnetic force drops significantly and rapidly. The magnetic force basically goes out after holding on to 150 degrees for 20 minutes. The demagnetized NdFeB can only reach about 50% of the original value. And the surface appears black oxidation.

 

The most effective solutions for demagnetization of NdFeB magnet at high temperature

 

1、 Do not put neodymium iron boron magnet products in too high temperature, especially pay attention to its critical temperature, i.e. Er Baidu. Adjust its working environment temperature in time to reduce demagnetization as much as possible.

 

2、 Starting from technology, we should improve the functions of products using NdFeB magnets, so that they can have a more temperature structure and are not easily affected by the environment.

 

3、 You can also select the high coercive force data of the same magnetic energy product. If you can't find the higher coercive force data of the lower magnetic energy product at the expense of a little magnetic energy product, then you can choose to use SmCo. As for the reversible demagnetization, you can only choose SmCo.