METHOD FOR GRAIN BOUNDARY DIFFUSION OF R-FE-B RARE EARTH SINTERED MAGNETS, HRE DIFFUSION SOURCE AND

Disclosed in the present invention are a method for grain boundary diffusion of R-Fe-B rare earth sintered magnets, an HRE diffusion source and a preparation method therefor, comprising the following steps : a project A forming a dry layer on a high temperature-resistant carrier, wherein an HRE compound powder being attached to the dry layer, and the HRE being at least one selected from Dy, Tb, Gd or Ho; and a project B performing, in a vacuum or an inert atmosphere, thermal treatment on the R-Fe-B rare earth sintered magnets and the high temperature-resistant carrier treated by the project A, and supplying HRE to a surface of the R-Fe-B rare earth sintered magnets. The method may reduce the consumption of rare earth elements, and control the loss of magnet remanence Br while increasing the coercive force.