Factors that Affect Magnet Stability

If the magnet is being used for a long time or stored 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 random (called reversal magnetization nucleus). Under the action of various environmental factors, as the original reversal magnetization nucleus increases, a new magnetization nucleus will be produced, which will attentuate 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 and maximum magnetic energy product, and even leads to complete failure of the magnet. This loss of magnetic properties is irreversible, 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 and pay more attention to it.