Permanent magnet material and bonded magnet
US5968290A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 27, 1998 |
| Grant date | Oct 19, 1999 |
| Priority date | — |
| Expiry date | Mar 27, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12431
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A permanent magnet material has a principal phase of TbCu7 type crystal structure and improved magnetic properties. This permanent magnet material is represented by the general formula: R1.sub.x R2.sub.y B.sub.z N.sub.u M.sub.100-x-y-z-u, wherein R1 is at least one rare earth element including Y, R2 is at least one element selected from the group consisting of Zr, Hf and Sc, M is at least one element selected from Fe and Co, x, y, z and u are atomic percents individually defined as x.gtoreq.2, y.gtoreq.0.01, 4.ltoreq.x+y.ltoreq.20, 0.ltoreq.z.ltoreq.10, and 0<u.ltoreq.20. The permanent magnet material has a principal phase of a TbCu.sub.7 type crystal structure. The permanent magnet material satisfies the relation of t.ltoreq.60 and .sigma./t.ltoreq.0.7, wherein t(nm) is an average crystal grain size of the principal phase and .sigma.(nm) is a standard deviation of the crystal grain size.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.