| 摘要 |
An R-T-B based sintered magnet maintains high magnetic properties and decreases usage of heavy rare earth elements. The magnet includes main phase grains and grain boundary phases, the main phase grain containing a core portion and a shell portion. X in the main phase LR(2-x)HRxT14B of the core portion ranges from 0.00 to 0.07; x in the main phase LR(2-x)HRxT14B of the shell portion ranges from 0.02 to 0.40; and the maximum thickness of the shell portion ranges from 7 nm to 100 nm. LR contains Nd and one or more light rare earth elements consisting of Y, La, Ce, Pr and Sm; HR contains Dy or/and Tb and one or more heavy rare earth elements consisting of Gd, Ho, Er, Tm, Yb and Lu; T contains Fe or/and Co and one or two kinds of Mn and Ni; and B represents boron partly replaced by C (carbon). |
| 主权项 |
1. A R-T-B based sintered magnet, comprising:
main phase grains and grain boundary phases, said main phase grain contains a core portion and a shell portion, x in the main phase LR(2-x)HRxT14B of said core portion ranges from 0.00 to 0.07, x in the main phase LR(2-x)HRxT14B of said shell portion ranges from 0.02 to 0.04, and the maximum thickness of said shell portion is 7 nm to 100 nm, wherein, LR contains Nd as the essential and one or two or more light rare earth elements selected from the group consisting of Y, La, Ce, Pr and Sm, HR contains Dy or/and Tb as the essential and one or two or more heavy rare earth elements selected from the group consisting of Gd, Ho, Er, Tm, Yb and Lu, T contains Fe or/and Co as the essential and one or two elements selected from the group consisting of Mn and Ni, and B represents boron with part of it replaced by C (carbon). |
