Improvement of the thermal stability of sintered Nd-Fe-B magnets by intergranular addition of Dy82.3Co17.7

In this study, microstructure and magnetic properties of sintered Nd-Fe-B magnets with addition of Dy82.3Co17.7 (wt. %) were investigated. By adding a small amount of Dy82.3Co17.7, the coercivity is improved greatly, and the irreversible loss is decreased sharply. The increase of Curie temperature suggests that Co atoms have entered into the 2:14:1 main phase. Microstructural analysis indicates that a well-developed core-shell structure was formed in the magnets with the addition of Dy82.3Co17.7. The improvement of magnetic properties can be attributed to the microstructural modification and the intrinsic properties' improvement. (C) 2014 AIP Publishing LLC.