Magnetic properties of anisotropic Nd-Fe-B HDDR powders prepared from strip cast alloys
K. Morimoto, K. Kato, K. Igarashi and R. Nakayama

ABSTRACT
Anisotropic hydrogenation-decomposition-desorption-recombination (HDDR)- treated powders were prepared from strip cast (SC) Nd10.1Pr2.9Fe74.6Co5.8B6.2Zr0.1 Ga0.3 alloy flakes. The alloy flakes were annealed at various temperatures before the HDDR treatment. Br and (BH)max of the powder are increased as the annealing temperature increases from 1000 to 1160#, which can be ascribed to growth of the original Nd2 Fe14B grains. The powder obtained from the optimally annealed alloy flakes, exhibits Br of 1.46T,HcJ of 1210kA/m, and (BH)max of 388kJ/m3, which are superior to those of the powder prepared using the conventional book-mold cast (BMC) ingots. They would be related to the complete elimination of a-Fe phase in the strip cast flakes.

© 2003 Elsevier B.V. All rights reserved.