Magnetic Properties of TbCu_7-Type Sm-Fe-N Melt-Spun Ribbons

摘要

Effects of the preparation condition on magnetic properties were investigated in isotropic TbCu_7-type Sm-Zr-Fe-Co-N materials made by the melt-spinning process. All the Sm-Zr-Fe-Co powders melt-spun with wheel speeds of 30-40 m/s showed a single-phase structure with crystalline TbCu_7. The grain size of the powder decreased monotonically with the increase of the wheel speed. The H_(CJ) B_r and (BH)_(max) of the powder increased with decreasing grain size. In this study, maximum hard magnetic property was achieved in Sm_(8.7)Zr_(1.0)Fe_(85.8)Co_(4.5)N_x powder melt-spun at 40 m/s. A compression-molded bonded magnet using powder melt-spun with at a wheel speed of 40 m/s showed excellent hard magnetic properties: B_r = 0.83 T, H_(CJ) = 720.5 kA/m, (BH)_(MAX) = 113.9 kJ/m~3. These results show that the TbCu7-type Sm-Fe-N material has high performance and practicality for isotropic bonded magnets.