Hydrogen induced radial anisotropic R-Fe-B magnet (R=Pr,Dy)

Abstract

The effect of alloying concentration of Dy and the absorption amount of hydrogen on the magnetic properties of PrFeB magnets have been studied in this work. Experimental * data show that the easy direction of magnetization (EDM) of the Pr-Fe-B-H system is determined by hydrogen concentration. Radial anisotropic magnets can be obtained from hydrogenated PrlSFe,gB6 powders with hydrogen of 4500 ppm. A slight decrease of hydrogen content down to 4250 ppm leads to a uniaxial anisotropic magnet. Partial replacement of Pr by Dy significantly influences the anisotropy of the Pr-Fe-B-H system with saturated hydrogen. A 0.9 at. % Dy substitution for Pr changes the anisotropy of hydrogen decrepitated powders from planer to cone, thus resulting in an isotropic magnet. As the amount of Dy substitution increases to 1.35 at. %, the EDM of magnets persist in the field direction during alignment compaction.