Master alloy for magnet production and a permanent alloy
US5431747A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 18, 1993 |
| Grant date | Jul 11, 1995 |
| Priority date | — |
| Expiry date | Feb 18, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F1/0577
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A master alloy for magnet production, which contains as main ingredients R representing at least one element selected from rare-earth elements including Y, T representing Fe or Fe and Co, and B, and includes columnar crystal grains substantially made up of R.sub.2 T.sub.14 B, and crystal grain boundaries composed primarily of R-enriched phases having an R content higher than that of R.sub.2 T.sub.14 B, said columnar crystal grains having a mean diameter lying in the range of 3 to 50 .mu.m. The master alloy is formed into a sintered magnet through pulverization, compacting and sintering steps. The dispersion of the R-enriched phases in the master alloy is so well-enough that the R-enriched phases can also be well dispersed in the resulting sintered magnet. In addition, the master alloy is so easily pulverized that the incorporation of oxygen at the time of pulverization can be reduced. To add to this, pulverized powders having a sharp grain size distribution can be obtained, so that the sintered magnet can have crystal grains with even diameters. Thus, the sintered magnet achieved can have high magnetic characteristics.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.