| 摘要 |
PURPOSE:To obtain a high-efficiency sintered permanent magnet with magnetic anisotropy excellent in temp. coefficient of magnetic properties by incorporating to Fe rare-earth elements consisting of light and heavy rare-earth elements in a specific ratio, B and Co each in a specific percentage. CONSTITUTION:The sintered permanent magnet with magnetic anisotropy which, when the sum of light rare-earth elements R1 and heavy rare-earth elements R2 is R (rare-earth elements), satisfies R2/R1<=2.3 by atomic ratio and consists of, by atomic percentage, 12.0-40% R, 4-20% B, <=18% Co and the balance Fe with inevitable impurities is prepared: where R1 means one element among Dy, Tb and Ho and is regulated to 30-80% based on R; R2 consists of >=80%, in total, of Nd and Pr and the balance constituted of at least one element among the rare earth elements other than R1, including Y. In this way, the high-efficiency magnet combining (BH) max of >= about 10MGOe with satisfactory stability represented by iHc of >= about 10kOe and moreover limiting the absolute value of the temp. coefficient of Br at -30-60 deg.C to <= about 0.05%/ deg.C can be obtained. |
