R-T-B based sintered magnet
US9548148B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 4, 2012 |
| Grant date | Jan 17, 2017 |
| Priority date | — |
| Expiry date | Jul 16, 2033 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C2202/02
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
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).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.