Patent · US Expired

Rare earth-containing permanent magnets

US3982971A · kind A · utility

21Cited by
3References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 20, 1975
Grant dateSep 28, 1976
Priority date
Expiry dateFeb 20, 1995

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01F1/0557
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

Permanent magnets are disclosed having a very high coercive force and a very great maximum energy product, and consisting essentially of a rare earth-cobalt based alloy. The alloy is expressed by the formula Sm.sub.1.sub.-u Ce.sub.u (Co.sub.1.sub.-v.sub.-w.sub.-x Cu.sub.v Fe.sub.w Mn.sub.x).sub.z where 0.ltoreq.u.ltoreq.0.20, 0.08.ltoreq.v.ltoreq.0.20, 0.ltoreq.w.ltoreq.0.08, 0.01.ltoreq.x.ltoreq.0.15 and 6.0.ltoreq.z.ltoreq.7.8, preferably 7.2.ltoreq.z.ltoreq.7.8. By using these alloys, the magnetic properties of the resultant permanent magnets are superiorly affected, and the magnet-preparing process is rendered much simplified. This is also because the conventional heat aging step may be eliminated, particularly when the z value is within the preferred range.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.