Alloying effect on the magnetic properties of RFeB-type bulk magnets

作者：Chang H W^*; Hsieh C C; Gan J Y; Cheng Y T; Shih M F; Chang W C

来源：Journal of Physics D: Applied Physics , 2011, 44(6): 064002.

DOI：10.1088/0022-3727/44/6/064002

Composition dependence on the magnetic properties of directly casted cylindrical RFeBM-type magnets with diameters from 0.7 mm to 1.5 mm has been studied. In order to refine the microstructure for improving the magnetic properties of bulk magnets with various sizes, the following ways were adopted in the alloys: (1) changing the boron concentration, (2) substituting different kinds of refractory elements for Fe, (3) adding a slight carbon and finally, (4) adopting multi-component refractory elements. The experimental results showed that the Nd(9.5)Fe(72.5)Ti(3)B(15) bulk magnets with a diameter of 0.7 mm demonstrated the optimal magnetic properties of B(r) = 6.5 kG, (i)H(c) = 10.3 kOe and (BH)(max) = 8.7 MG Oe, while the highest (i)H(c) of 16.2 kOe was achieved for the Pr(9.5)Fe(71.5)Nb(4)B(15) magnet. Meanwhile, the diameter of the magnets could be increased to 0.9 mm preserving the attractive magnetic properties by the substitution of 0.5 at% Zr for Ti in the Nd9.5Fe72.5Ti3B15 magnet. Finally, the directly casted Nd(9.5)Fe(72.5-y)Ti(2.5)Zr(0.5)Cr(y)B(15-x)C(x) (x = 0.25-1; y = 0-3) magnets with a larger diameter of 1.3 mm exhibited attractive magnetic properties of B(r) = 5.3-6.

• 出版日期2011-2-16