Investigation of Hard Magnetic Behaviors for Nd-Fe-B Based Magnets Prepared by Hydrogen Decrepitation Technique

In the present work, we investigated the hard magnetic properties of Nd-Fe-B magnets prepared by the decrepitation technique. The microstructure of (Nd0.935Dy0.065)14.5Fe79.4B6.1 HD - magnet was observed and the average grain size is about 6-15 µm. The HD alignment degree f is about 93%. Most rich-Nd phase can be found at grain boundaries of main phase, but a few rich – Nd phase occurs within main phase grains. The magnetizing field dependence of the hardmagnetic properties for the (Nd0.935Dy0.065)14.5Fe79.4B6.1 were investigated. The value of magnetizing field for the saturation coercivity is smaller than the value of the saturation coercivity, showing that the coercivity for the (Nd0.935Dy0.065)14.5Fe79.4B6.1 HD-magnet is controlled by the nucleation mechanism. Meanwhile, the temperature dependence of coercivity for HD magnet Nd14.5Fe79.4B6.1 was analyzed.