| 摘要 |
PURPOSE: An R-T-B sintered permanent magnet is provided to have high performance enough to be used for the purpose needing high Br and high(BH)max. CONSTITUTION: An R-T-B sintered permanent magnet is composed of main composition containing 28-33wt% of R and 0.5-2wt% of B and inevitable impurities. 0.01-0.06wt% of M1(at least one sort of elements selected from the group composed of Nb, Mo, W, V, Ta, Cr, Ti, Zr, and Hf) and/or 0.01-0.3wt% of M2(at least one sort of elements selected from the group composed of Al, Ga, and Cu) are contained as main compositions. A brand method for mixing two sorts of R-T-B alloy powder of different content is used to prepare the permanent magnet. Then, the total amount of R elements in the composition of the R-T-B alloy powder is the same as the respective alloy powder. The crystal structure of the R-T-B sintered permanent magnet has an R2T14B typed columnar crystal particle(1) and a crystal grain phase(2). Then, the R-T-B sintered permanent magnet has a particular distribution of density of Dy on the columnar crystal particle and the crystal grain phase. |
