R-T-B based sintered magnet
US10847290B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 11, 2014 |
| Grant date | Nov 24, 2020 |
| Priority date | — |
| Expiry date | Jun 27, 2037 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C2202/02
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
To provide an R-T-B based sintered magnet having high Br and high HcJ while suppressing the content of Dy. Disclosed is an R-T-B based sintered magnet represented by the formula: uRwBxGayCuzAlqM(balance)T, where R is composed of light rare-earth element(s) RL and heavy rare-earth element(s) RH, RL is Nd and/or Pr, RH is Dy and/or Tb, T is Fe, and 10% by mass or less of Fe is capable of being replaced with Co, M is Nb and/or Zr, inevitable impurities being included, and u, w, x, y, z and q are expressed in terms of % by mass; RH accounts for 5% by mass or less of the R-T-B based sintered magnet, 0.4≤x≤1.0, 0.07≤y≤1.0, 0.05≤z≤0.5, 0≤q≤0.1, and 0.100≤y/(x+y)≤0.340; v=u−(6α+10β+8γ), where the amount of oxygen (% by mass) is α, the amount of nitrogen (% by mass) is β, and the amount of carbon (% by mass) is γ; and v and w satisfy the following inequality expressions: v≤32.0, 0.84≤w≤0.93, and −12.5w+38.75≤v≤−62.5w+86.125.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.