Improvement of the magnetic properties of nanocomposite permanent magnetic alloys with Dy and Ga substitutions

The Dy and Ga substituted NdFeB nanocomposite permanent magnetic alloys with high magnetic properties have been prepared by appropriate wheel speed of melt-spinning and post-annealing treatment, Under optimal conditions, compared with the best magnetic properties of ternary NdFeB alloy of J(r) = 1.18T, H-ci = 379.5 kA/m and (BH)(max) = 119.5 kJ/m(3), the best magnetic properties of the alloy with Dy and Ga substitutions are J(r) = 1. 16 T, H-ci = 580.5 kA/m, and (BH)(max) = 162.7 kJ/m(3). The XRD and TEM results showed that each of two alloys consists of hard magnetic 2:14:1 phase and soft magnetic alpha-Fe phase. The grain size of the 2:14:1 phase is about equal in the two alloys. The grain size and content of alpha-Fe phase in Dy and Ga substituted alloy are finer and lower, respectively. (C) 2002 Elsevier Science BX All rights reserved.