Coating materials for diffusing into magnet of NdFeB and a method of making it
US11848152B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 1, 2020 |
| Grant date | Dec 19, 2023 |
| Priority date | — |
| Expiry date | Aug 1, 2041 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F41/0246
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The application discloses a coating material for fabricating rare earth magnets and a method using the coating material to prepare neodymium-iron-boron (NdFeB) magnets having high coercive force. The coating material includes: alloy powder A and low-melting-point metal powder B. The alloy powder A is heavy rare earth element R powder, or rare earth-metal alloy (RM) powder, or rare earth-metal-hydrogen alloy (RMH) powder. The heavy rare earth elements are Dy and/or Tb, metal is Fe or Co, or an alloy of Fe and Co, and H is hydrogen element. The low-melting-point metal powder B is one or two of Zn, Al, and Ga. The preparation method includes the following steps: the coating material is mixed into a slurry, and the slurry is coated on the surface of NdFeB magnet, and then apply a two-stage diffusion heat treatment to the magnet, followed by an annealing process to obtain a high-coercivity NdFeB magnet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.