Highly dense anisotropic Sm-Fe-N-based bonded magnets including unsaturated polyester prepared by powder compacting press

Methods of preparing Sm-Fe-N-based bonded magnets, including unsaturated polyester by the powder compacting press, and of improving the motor efficiency of the small brushless motor were studied. The developed method enabled the preparation of Sm-Fe-N-based bonded magnets under a low pressure, which suggests that the developed method has an advantage in the preparation process. The application of these developed magnets improved the motor efficiency by 5% compared with that using isotropic Nd-Fe-B bonded magnet with the (BH)_max value of 80 kJ/m³.