Rare earth-iron-boron magnet powder and process of producing same
US4981532A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 19, 1988 |
| Grant date | Jan 1, 1991 |
| Priority date | — |
| Expiry date | Aug 19, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F1/0573
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a rare earth-iron-boron alloy magnet powder, each individual particle includes a recrystallized grain structure containing a R.sub.2 Fe.sub.14 B intermetallic compound phase as a principal phase thereof, wherein R represents a rare earth element. The intermetallic compound phase are formed of recrystallized grains of a tetragonal crystal structure having an average crystal grain size of 0.05 .mu.m to 50 .mu.m. For producing the above magnet powder, a rear earth-iron-boron alloy material is first prepared. Then, hydrogen is occluded into the alloy material by holding the material at a temperature of 500.degree. C. to 1,000.degree. C. either in an atmosphere of hydrogen gas or in an atmosphere of hydrogen and inert gases. Subsequently, the alloy material is subjected to dehydrogenation at a temperature of 500.degree. C. to 1,000.degree. C. until the pressure of hydrogen in the atmosphere is decreased to no greater than 1.times.10.sup.-1 torr, and is subjected to cooling.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.