Method for production of rare-earth element/cobalt type magnetic powder for resin magnet
US4689073A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 1986 |
| Grant date | Aug 25, 1987 |
| Priority date | — |
| Expiry date | Feb 28, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F1/0553
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A rare earth-element/cobalt type magnetic powder which possesses outstanding magnetic properties and which is useful for making a resin magnet is produced by a method which comprises thermally reducing a mixture consisting of oxide of samarium, oxide of praseodymium, optionally oxide of neodymium, and cobalt powder, thereby causing diffusion of consequently produced samarium, praseodymium, and/or neodymium in the cobalt powder, subjecting the resultant reaction product to a heat-treatment involving standing at 600.degree. to 900.degree. C. for 30 minutes to 5 hours and subsequent quenching from this temperature at a rate of not less than 10.degree. C./minute, adding the product of the heat-treatment to water, thereby converting the product into a slurry, treating the slurry with water and an aqueous acid solution, and comminuting the resulting powder into particles of an average diameter of 3 to 10 .mu.m thereby obtaining a magnetic powder having a composition represented by Sm.sub.1-x Pr.sub.x Co.sub.z or Sm.sub.1-x Pr.sub.x-y Nd.sub.y Co.sub.z (wherein x, y, and z satisfy the relations 0.05.ltoreq.x.ltoreq.0.40, 0.01.ltoreq.y.ltoreq.0.39, 0.01.ltoreq.x-y.ltoreq.0.39 and 4.7.ltore…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.