Magnetic properties and microstructures of Nd-Dy-Fe-Co-B-Ga hot-deformed magnets

Die-upset, fully-dense nanocrystalline magnets were prepared from Nd-Dy-Fe-Co-B, Pr-Dy-Fe-Co-B, and Nd-Dy-Fe-Co-B-Ga alloys. The substitution of Nd with Pr was observed to dramatically increase the H/sub ci/ of a hot deformed magnet, while a Ga addition significantly increased the B/sub r/ and H/sub ci/ of an equivalent magnet. High-resolution transmission electron microscope (HRTEM) techniques have identified a discreet Ga-rich grain-boundary phase, which is associated with grain-boundary smoothing and enhanced hot workability, and hence improved magnetic performance.