MECHANICALLY ALLOYED 1/12 NITRIDES AND CARBIDES

Nd10Fe90-yMoyNx (y=8,12,15) nitrides and Nd10Fe75Mo15Cx carbides have been prepared by mechanical alloying. The experimental results show that both T(c) and M(s) increase from 310 to 355-degrees-C and from 84.5 to 108.8 emu/g, respectively, when the Mo content is reduced from 15 to 8 at. %. However, the coercivity of the lower Mo content Nd10Fe90-yMoyNx compounds is decreased with a value of H(c) = 4.0-4.5 kOe for y = 8. An increase in coercivity by 2-3 kOe was obtained after an addition of 1.5 at. % Dy in the Nd8.5Dy1.5Fe82Mo8Nx compound. Al-bonded magnets were made with mechanically alloyed powders using Al contents from 5 to 40 wt % and bonding temperatures in the range of 600-680-degrees-C. The coercivity of the bonded magnets was found to increase by about 1-2 kOe. The best results are obtained on a 10 wt % Al sample, bonded at 660-degrees-C with H(c) = 9.5 kOe. Both the nitrides and carbides had very high coercivities (H(c) > 22 kOe) at low temperatures.