Suppression of non-oriented grains in Nd-Fe-B hot-deformed magnets by Nb doping

0.2 at.%Nb doping to a Nd12.83Fe76.7Co4.50Ga0.53B5.44 alloy suppress the surface crystallization in melt-spun ribbon, thereby suppressing the formation of non-oriented grains during the hot-deformation process to form bulk anisotropic magnet, which leads to the enhancement of remanence. High resolution transmission electron microscopy and three-dimension atom probe tomography revealed that the segregation of Nb at the grain boundaries hinders the grain growth during the hot-deformation process, thereby reducing the size and the aspect ratio of Nd2Fe14B grains and increasing coercivity.