Microstructure and magnetic properties of sintered Nd-Fe-C magnets

Sintered magnets of nominal composition Nd/sub 15/Fe/sub 77/C/sub 8/ (magnet A) and of a Nd- and C- rich composition Nd/sub 28/Fe/sub 63/C/sub 9/ (magnet B) have been prepared by the conventional powder metallurgy. The magnets show a nearly isotropic behaviour, the magnetic polarization at an applied magnetic field of 1350 kA/m was about J(1350 kA/m)=1.1 T, the coercivity of the polarization, H/sub cJ/, was rather small, the highest values in the annealed magnets were only about 250 kA/m. From these results we can make the conclusion, that the preparation of sintered Nd-Fe-C composition by the conventional powder metallurgy is not promising for the production of permanent magnets.<
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