R-T-B TYPE SINTERED MAGNET, AND MOTOR

文件类型：PDF文档
文件大小：1716K
[Problem] To provide an R-T-B type sintered magnet with a suppressed demagnetization rate at high temperatures that enables the non-use or a significant reduction of the amount used of heavy rare earth elements, such as Dy and Tb, compared with the prior art. [Solution] The R-T-B type sintered magnet contains R2T14B crystal grains and two-grain grain boundaries between R2T14B crystal grains, said R-T-B type sintered magnet being characterized by the presence of the two-grain grain boundary formed with a phase that contains the following ratios of R, Cu, Co, Ga, and Fe : 40 ≤ R ≤ 70, 1 ≤ Co ≤ 10, 5 ≤ Cu ≤ 50, 1 ≤ Ga ≤ 15, 1 ≤ Fe ≤ 40 (wherein, R + Cu + Co + Ga + Fe = 100. R is at least one element selected from among rare earth elements).