FE-B magnets containing Nd-Pr-Ce rare earth elements
AssigneeYamaha Corporation
InventorsKenzaburou Iijima, Takeo Sata
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Abstract
A rare earth magnet article of the Fe-B type is provided herein characterized by consisting essentially of the three rare earth elements Nd-Pr-Ce in combination within defined atom ratios of each in the formula: (Nd.sub.1-(p+q) Pr.sub.p Ce.sub.q).sub.x B.sub.y Fe.sub.1-(x+y) wherein 0.1.ltoreq.x.ltoreq.0.3, 0.02.ltoreq.y.ltoreq.0.09, 0.1.ltoreq.p.ltoreq.0.3 and 0.02.ltoreq.q.ltoreq.0.15. The magnet is prepared by a process which assures that the resultant magnet has a coercive force, Hc, of at least about 5kOe, and a residual magnetic flux density, Br, of at least about 10kG, which magnetic properties are substantially the same within the range of the sintering temperatures of the process.
Claims4
A rare earth magnet article consisting essentially of the three rare earth elements Nd-Pr-Ce within defined atom ratios of each in the formula:
- (Nd.sub.1-(p+q) Pr.sub.p Ce.sub.q).sub.x B.sub.y Fe.sub.1-(x+y)
- wherein 0.1.ltoreq.x.ltoreq.0.3, 0.02.ltoreq.y.ltoreq.0.09, 0.1.ltoreq.p.ltoreq.0.3 and 0.02.ltoreq.q.ltoreq.0.15;
- said magnet having been prepared by melting said constituents into an alloy thereof, casting said molten alloy, comminuting said cast alloy into powders having an average diameter of 2.0 to 50 .mu.m, compacting said powders within a magnetic field, and sintering said compacted powders at 950 degrees to 1200 degrees C. for at least 1 hour to 4 hours, the resultant magnet having a coercive force Hc of at least about 5kOe, and a residual magnetic flux density Br of at least about 10kG, which magnetic properties are substantially the same within the range of said sintering temperatures.
Dependencies are inferred from the claim text.