Radial orientation rare earth-cobalt magnet rings
US4533407A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 1981 |
| Grant date | Aug 6, 1985 |
| Priority date | — |
| Expiry date | Mar 30, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49076
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Apparatus and method for forming radial orientation rare earth-transition metal magnets in continuous arc rings by hot isostatic pressing. A method includes the steps of compacting rare earth-transition metal powders having a particle size up to 40 microns into radially oriented rings in a mold provided with a radially aligning field, stacking a plurality of compacted radially oriented rings within an annular cavity within a sealed, evacuated cannister to form a cylinder of a predetermined height, subjecting the cannister to temperatures in the range of 900.degree. to 1150.degree. C. under a gas pressure of 15 kpsi to densify the compacts, and cooling the cannister and the compacts to room temperature. An apparatus for performing the above-described method, includes a mold for forming green compacts having a central iron core or mandrel, an outer housing forming an annular space between it and the iron mandrel, plungers for compacting into a ring rare earth-transition metal powder within the annular space, and means for forming a radially oriented magnetic field. The magnetic field forming means includes a pair of electromagnetic coils with bucking fields disposed on opposite axial…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.