MAGNET

Magnets are made from magnetically hard ferromagnetic materials. Such materials retain significant residual magnetization after the external magnetic field is turned off. The main properties of the magnet are determined by the parameters of the demagnetizing section of the magnetic hysteresis loop - between the points of residual induction +Br (-Br) and coercive force -Hc (+Hc). Magnets made of neodymium + iron + boron alloy (Nd2Fe14B) have the highest magnetization force and resistance to demagnetization. Such magnets have been used in industry since the 1980s. Most often, they are produced by the method of powder metallurgy - this is pressing and sintering in an atmosphere of inert argon gas. Neodymium magnets most often have an external protective metal coating of zinc, nickel, copper, and even gold.