| (19) |
 |
|
(11) |
EP 0 157 329 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
16.06.1987 Bulletin 1987/25 |
| (43) |
Date of publication A2: |
|
09.10.1985 Bulletin 1985/41 |
| (22) |
Date of filing: 25.03.1985 |
|
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| (84) |
Designated Contracting States: |
|
AT BE CH DE FR GB IT LI LU NL SE |
| (30) |
Priority: |
30.03.1984 US 595277
30.03.1984 US 595290
|
| (71) |
Applicant: UNION OIL COMPANY OF CALIFORNIA |
|
() |
|
| (72) |
Inventor: |
|
- Ghandehari, Mohammad H.
()
|
|
| |
|
| (54) |
Rare earth-containing magnets |
(57) Compositions for the production of rare earth-ferromagnetic-metal permanent magnets
comprise mixtures of rare earth-ferromagnetic-metal alloy powder and a lesser amount
of a powdered second-phase sintering aid, wherein there is added up to about 2 percent
by weight of a particulate refractory oxide, carbide, or nitride additive. Permanent
magnets are prepared by mixing the components, aligning the mixture in a magnetic
fieid, pressing and sintering. The refractory material inhibits grain growth in the
second phase during sintering, improving the magnetic properties of the major phase.