Effective solutions for high temperature demagnetization of NdFeB magnets
Iron boron, also known as neodymium iron boron magnet (NdFeB magnet), is a tetragonal crystal formed by neodymium, iron, and boron (Nd2Fe14B). Neodymium magnets were discovered in 1982 by Masato Sagawa of Sumitomo Special Metals in Japan. The magnetic energy product (BHmax) of this magnet is greater than that of the samarium cobalt magnet, and it was the material with the largest magnetic energy product in the world at that time.
Later, Sumitomo Special Metals developed a successful powder metallurgy process (powdermetallurgyprocess). General Motors successfully developed the melt-spinning process, which can prepare NdFeB magnets. This magnet is the strongest permanent magnet available today and the most commonly used rare earth magnet.
NdFeB can last for a long time at room temperature, but it is well known that it will demagnetize at high temperature. The combination of cost and performance of NdFeB magnets makes them a popular choice for the use of traditional magnets and the creation of new product applications. , in the case of a dramatic increase in the existing strength, allows the use of a smaller magnet, advantageous to most designs.
The handling procedures of NdFeB magnets at high temperature need to be careful, because NdFeB magnets are easy to demagnetize at high temperatures. Below we will work with you to understand the problem of high temperature demagnetization of NdFeB magnets. Due to the high content of NdFeB magnets in NdFeB magnets, they are also easily oxidized, so various coatings that meet these conditions depend on the operating environment of NdFeB magnets.
The reason why NdFeB will demagnetize in a high temperature environment is determined by its own 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 atoms in the same direction, thereby generating a magnetic field force, which in turn affects the surrounding related affairs.
However, the rotation of electrons around atoms in a given direction is also limited by temperature conditions. Different magnetic materials can withstand different temperatures. In the case of too high temperature, the electrons will deviate from the original orbit, causing confusion. At this time, the magnetic The local magnetic field of the material will be disrupted, resulting in demagnetization.
The temperature resistance of strong NdFeB magnets is about two hundred degrees, that is, if it exceeds two hundred degrees, demagnetization will occur. If the temperature is higher, the demagnetization will be more serious.
Several effective solutions for high temperature demagnetization of NdFeB magnets
- Do not put NdFeB magnet products in excessively high temperature, especially pay attention to its critical temperature, that is, 200 degrees Celsius, and adjust its working environment temperature in time to minimize the occurrence of demagnetization.
- The second is to start with technology to improve the performance of products using iron boron magnets, so that it can have a higher temperature structure and is not easily affected by the environment.
- You can also choose a high coercivity material with the same magnetic energy product. If it still doesn’t work, you can only sacrifice a little magnetic energy product and find a higher coercivity material with a lower magnetic energy product. If it doesn’t work, you can choose to use samarium cobalt. For reversible demagnetization, only samarium cobalt is selected.