NdFeB Magnet Corrosion Technology: Alloying. Adding to the alloy of some alloying elements can be increased to a certain extent, the corrosion resistance of NdFeB magnets.

NdFeB magnets are divided into two types of alloying elements added: M1 (Al, Cu, Zn, Ga, Ge, Sn), and M2 (V, Mo, W, Nb, Ti, Zr); first the formation of Nd-M1 or Nd -Fe-M1 intergranular phase; second form Nd-B or Fe-M2-B intergranular phase.And when you do not have to add alloying elements compared to those in the grain boundary to form a new phase has a higher corrosion potential, can delay and prevent the grain boundary Germany decomposition, delay the production of the grain boundary corrosion. Although the addition of alloying elements can improve the corrosion resistance of magnets, but sometimes will reduce the magnetic properties of magnets. For example: Co magnet to join can increase the Curie temperature and corrosion resistance.However, the coercivity has declined; Al, Nd, Sn, Ga and other elements to join can increase the coercivity, but the non-magnetic elements, and adding Br can greatly reduce the amount of excess, and thus makes the (BH) max decrease . On the other hand, alloying material costs will also increase, so that the complexity of manufacturing processes, thereby limiting the corrosion of this method in the application of magnets.