The service life of neodymium iron boron-the long-term stability of permanent magnets

The stability of the performance of permanent magnetic materials is an important indicator of permanent magnetic materials. Stability mainly refers to the process of changing the magnetic properties of the magnet under the influence of internal and external factors after magnetization. It is usually expressed by the rate of change of performance indicators. Common causes of changes in magnetic properties include temperature, time, electromagnetic field, radiation, mechanical vibration and shock, etc. We have introduced the temperature stability of permanent magnet materials (temperature coefficient of remanence, temperature coefficient of coercive force, reversible temperature). Coefficient, you can check other news information on our website), let’s understand the time stability of permanent magnet materials.

If the magnet is working for a long time or placed for a long time, the surrounding environment (such as temperature, humidity, corrosive liquid, etc.) may cause the physical and chemical properties of the magnet to change. After the permanent magnet is magnetized, most of the area is magnetized to a specific direction, but the magnetization direction of some small magnetic domains is chaotic (called reversal magnetization nucleus). Under the action of various environmental factors, the original reversal magnetization nucleus As it grows up, new magnetization reversal nuclei will be produced, which will attenuate the magnetic properties of the permanent magnet. This change is generally a slow and irreversible change from the surface to the inside, which directly affects the main performance parameters of the magnet, remanence, intrinsic coercivity, coercivity or maximum magnetic energy product, and even leads to complete failure of the magnet. This loss of magnetic properties is irrecoverable, even if the magnet is re-magnetized, it cannot be restored to the level before being placed for a long time. In recent years, as NdFeB permanent magnet materials have been widely used in aerospace, electric vehicles, high-power wind power and other fields with long service life requirements, application designers have become more aware of the time stability of NdFeB permanent magnets. Pay more attention to it.