R-Fe-B sintered magnet and making method
US11315710B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 8, 2017 |
| Grant date | Apr 26, 2022 |
| Priority date | — |
| Expiry date | Oct 31, 2038 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2201/03
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
An R—Fe—B base sintered magnet is provided consisting essentially of R (which is at least two rare earth elements and essentially contains Nd and Pr), M1 which is at least two of Si, Al, Mn, Ni, Cu, Zn, Ga, Ge, Pd, Ag, Cd, In, Sn, Sb, Pt, Au, Hg, Pb, and Bi, M2 which is at least one of Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, and W, boron, and the balance of Fe, and containing an intermetallic compound R2(Fe,(Co))14B as a main phase. The magnet contains an R—Fe(Co)-M1 phase as a grain boundary phase, the R—Fe(Co)-M1 phase contains A phase which is crystalline with crystallites of at least 10 nm formed at grain boundary triple junctions, and B phase which is amorphous and/or nanocrystalline with crystallites of less than 10 nm formed at intergranular grain boundaries and optionally grain boundary triple junctions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.