| abstract |
In the conventional method, Dy metal or the like is selectively present in the grain boundary of the sintered magnet to improve the coercive force, but the physical film forming method using a vacuum bath such as sputtering is used, so that a large amount of magnet treatment is performed. There was a difficulty in mass production. In addition, there is a problem in the cost of the magnet in that it is necessary to use expensive and high-purity Dy metal or the like as the film forming raw material.n n n Nd rich that surrounds the Nd 2 Fe 14 B main crystal by reducing the fluoride, oxide, or chloride of M metal element (where M is Pr, Dy, Tb, or Ho) (rich) A grain boundary modification method for Nd-Fe-B magnets, characterized by diffusing and penetrating M metal component from the surface of the Nd-Fe-B-based sintered magnet body having a grain boundary phase. |