Neodymium iron boron (NdFeB) permanent magnet is a tetragonal crystal formed by Nd (neodymium), Fe (iron) and B (boron). It is the permanent magnet material with practical value and mass production so far. , known as the "Magnetic King".

According to different preparation processes, NdFeB magnets are divided into three categories: sintered, bonded and hot-pressed.

NdFeB sintered magnets are anisotropic dense magnets manufactured by powder metallurgy; NdFeB bonded magnets are non-dense isotropic magnets bonded with NdFeB microcrystalline powder and polymers. Boron hot-pressed magnets are anisotropic dense magnets manufactured by hot-pressing and hot-deformation methods. Among them, sintered NdFeB magnets have the magnetic properties and are used in the amount; NdFeB bonded magnets can be magnetized in any direction, and permanent magnets with complex shapes and high dimensional accuracy can be produced by molding and injection molding; NdFeB hot-pressed magnets The usage amount is the small, currently only Datong Company in Japan is in mass production, and the main application field is the EPS system of automobiles.