Bonded magnets made with atomized permanent magnetic powders
US6555018B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 2001 |
| Grant date | Apr 29, 2003 |
| Priority date | — |
| Expiry date | Feb 28, 2021 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB22F2998/10
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The invention relates to magnets, particularly bonded magnets, of the Re—Fe—B type made from atomized magnetic powders and to methods of producing the powders and the magnet. The magnetic powders comprise, by weight, about 15% to 25% of RE; about 0.8% to 2.0% of B; about 1% to 10% of T; and balanced with Fe, Co, or mixtures thereof; wherein RE is one or more rare earth elements selected from the group consisting of Y, La, Ce, Pr, Nd, Sm, Er, Gd, Tb, Dy, Ho, Tm, Yb and Lu, and T is one or more elements selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W. To produce bonded magnets, the atomized powders are heat treated, combined with a binder, pressed or molded, and cured to produce the bonded magnets. As compared to bonded magnets made from melt-spun powders or from other conventional atomized powders, bonded magnets of the present invention exhibit one or more of the following properties: less loss of intrinsic coercivity under repeated injection molding cycles; less internal magnetic shearing loss; improved flowability of the magnetic powders; improved Br and part integrity; less environmental degradation after exposure to high temperature and le…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.