NdFeB permanent magnet with high coercivity and high resistivity and method for preparing the same
US12293868B2 · kind B2 · utility
Inventors
Key dates
| Filing date | Dec 7, 2021 |
| Grant date | May 6, 2025 |
| Priority date | — |
| Expiry date | Nov 25, 2043 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F41/0293
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention discloses an NdFeB permanent magnet with high coercivity and high resistivity and a method for preparing the same. The method comprises the steps of: spraying powdery slurry containing heavy rare earth compounds, oxides and/or carbides on a flaky NdFeB permanent magnets blank after it is subjected to surface cleaning process; then stacking magnets on top of each other, and performing three-stage heat treatment on the stacked magnets to obtain the NdFeB permanent magnet with high coercivity and high resistivity. Heavy rare earth penetrates into interior of the flaky magnets at a high temperature, so that coercivity of the flaky magnets is improved. However, part of the heavy rare earth elements or alloy elements and carbide powder or oxide powder, which are not penetrated into the flaky magnets, form an interlayer bonding two of flaky magnets together.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.