R-T-B based permanent magnet
US11830646B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 2021 |
| Grant date | Nov 28, 2023 |
| Priority date | — |
| Expiry date | May 24, 2042 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C2202/02
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An R-T-B based permanent magnet includes a rare earth element R, a transition metal element T, and B. The permanent magnet includes at least Nd as R. The permanent magnet includes at least Fe as T. The permanent magnet contains main phase grains and R-rich phases. The main phase grains include at least R, T, and B. The R-rich phases include at least R. The main phase grains observed in a cross section of the permanent magnet are flat. The cross section is parallel to an easy magnetization axis direction of the permanent magnet. Each of the R-rich phases is located between the main phase grains. An average value of intervals between the R-rich phases in the easy magnetization axis direction is from 5 μm to a width of the permanent magnet in the easy magnetization axis direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.