Rare-earth magnet and method for producing the same
US10199145B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 2012 |
| Grant date | Feb 5, 2019 |
| Priority date | — |
| Expiry date | Jun 8, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F41/0293
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Provided is a rare-earth magnet containing no heavy rare-earth metals such as Dy or Tb in a grain boundary phase, has a modifying alloy for increasing coercivity (in particular, coercivity under a high-temperature atmosphere) infiltrated thereinto at lower temperature than in the conventional rare-earth magnets, has high coercivity, and has relatively high magnetizability, and a production method therefor. The rare-earth magnet RM includes a RE-Fe—B-based main phase MP with a nanocrystalline structure (where RE is at least one of Nd or Pr) and a grain boundary phase BP around the main phase, the grain boundary phase containing a RE-X alloy (where X is a metallic element other than heavy rare-earth elements). Crystal grains of the main phase MP are oriented along the anisotropy axis, and each crystal grain of the main phase, when viewed from a direction perpendicular to the anisotropy axis, has a plane that is quadrilateral in shape or has a close shape thereto.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.