Patent ID: 9548148
Date: 2017-01-17
CPC Classifications: C22C,H01F

Claim:
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 wherein, LR contains Nd, and optionally at least one light rare earth element selected from the group consisting of Y, La, Ce, Pr and Sm, HR contains Dy or/and Tb, and optionally at least one heavy rare earth element selected from the group consisting of Gd, Ho, Er, Tm, Yb and Lu, T contains Fe or/and Co, and optionally at least one element selected from the group consisting of Mn and Ni, B represents boron with part of it replaced by C (carbon), the R-T-B based sintered magnet containing 0.15 to 0.65 mass % of HR, and the concentration of HR in the core portion is lower than that in the shell portion.