Title:
PROCESS FOR PRODUCING PERMANENT MAGNETS
Document Type and Number:
WIPO Patent Application WO/1988/000387
Kind Code:
A1
Abstract:
A process for heat-treating of rare earth permanent magnets chiefly of the Nd-Fe-B system. In the permanent magnet easily oxidized in the open air, an alloy thereof is pulverized, orientated compression-molded in a magnetic field or compression-molded in a non-magnetic field, and sintered at 900� to 1200�C, then ground and polished into a practical shape, subjected to solution heat treatment at 900� to 1200�C in an atmosphere of oxygen and/or nitrogen, or aged at 300� to 900�C, so that an oxide and/or a nitride film of 0.001 to 10 mum in thickness is formed on the surface of the magnet in order to prevent the oxidation and to remove work strain.
Inventors:
IMAIZUMI NOBUO (JP)
Application Number:
PCT/JP1986/000327
Publication Date:
January 14, 1988
Filing Date:
June 27, 1986
Export Citation:
Assignee:
NAMIKI PRECISION JEWEL CO LTD (JP)
International Classes:
B22F3/24; C22C1/04; H01F1/057; H01F41/02; (IPC1-7): H01F1/08; H01F41/02
Foreign References:
| JPH05964739A | ||||
| JPS59217304A | 1984-12-07 | |||
| JPH0615904A | 1994-01-25 | |||
| JPH0634005A | 1994-02-08 | |||
| JPH0654406A | 1994-02-25 | |||
| JPH0663902A | 1994-03-08 |
Other References:
See also references of EP 0289599A4
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