Rare earth based sintered magnet
US8961712B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 2, 2012 |
| Grant date | Feb 24, 2015 |
| Priority date | — |
| Expiry date | Aug 2, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F41/0293
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The present invention provides a rare earth based sintered magnet. The magnet is a rare earth based permanent magnet with a R-T-B (R represents one or more elements selected from Y and rare earth elements, T represents one or more metal elements including Fe or the combination of Fe and Co, and B represents B or the combination of B and C) based composition. When a R-rich phase (R represents rare earth element(s)) with atomic ratio of (Fe+Co)/(LR+HR+Fe+Co)≦0.2 (LR represents Y and light rare earth element(s) selected from 57La to 63Eu, and HR represents heavy rare earth element(s) selected from 64Gd to 71Lu) is present in the grain boundary triple point, a region with HR/(LR+HR)≧0.01 (atomic ratio) is present in the R-rich phase, and the region with HR/(LR+HR)≧0.01 accounts for 10% to 90% of the area of the grain boundary triple point.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.