Process for producing permanent magnets and products thereof
US4826546A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 13, 1987 |
| Grant date | May 2, 1989 |
| Priority date | — |
| Expiry date | Aug 13, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C1/0441
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for producing permanent magnet materials, which comprises the steps of: PA1 forming an alloy powder having a mean particle size of 0.3-80 microns and composed of, in atomic percentage, 8-30% R (provided that R is at least one of rare earth elements including Y), 2-28% B, and the balance being Fe and inevitable impurities, PA1 sintering the formed body at a temperature of 900.degree.-1200.degree. C., PA1 subjecting the sintered body to a primary heat treatment at a temperature of 750.degree.-1000.degree. C., PA1 then cooling the resultant body to a temperature of no higher than 680.degree. C. at a cooling rate of 3.degree.-2000.degree. C./min, and PA1 further subjecting the thus cooled body to a secondary heat treatment at a temperature of 480.degree.-700.degree. C. 35 MGOe, 40 MGOe or higher energy product can be obtained with specific compositions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.