Method for producing rare earth alloy
First Claim
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1. A method for producing a rare earth alloy which comprises:
- preparing a mixed raw material powder comprising at least one of the oxides of rare earth elements R.sub. 1, an iron powder and a boron containing powder selected from the group consisting of boron, ferroboron and boron oxide in a manner such that the resultant alloy product consists essentially of;
15-65 atomic % R1,35-83 atomic % Fe, and0-15 atomic % B, in which R1 represents at least one of heavy rare earth elements selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm and Yb;
said mixed raw material powder further comprising metallic Ca and/or Ca hydride in an amount of 1.2-3.5 times by weight of the amount stoichiometrically required for reducing oxygen in said raw material powder and at least one of the oxides of said rare earth elements R1, and 1-15 % by weight of calcium chloride based on the oxides of said rare earth elements R1 ;
compacting the resultant mixture;
subjecting the resultant compacted mixture to reduction-diffusion treatment under a nonoxidizing atmosphere at a temperature of 950°
-1200°
C.;
bringing the reduced mass to a particle size of 8 mesh to 35 mesh;
contacting the resultant reduced mass with water to form a slurry-like substance; and
treating said slurry-like substance with water by stirring the slurry and removing water to recover the resultant alloy powder;
whereby said alloy powder has an oxygen content of at most 7000 ppm, and a carbon content of at most 1000 ppm.
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Abstract
A rare earth alloy for producing permanent magnet comprised of: 15-65 atomic % R1, 35-83 atomic % Fe, and 0-15 atomic % B, where R1 represents at least one of heavy rare earth elements Gd, Tb, Dy, Ho, Er, Tm and Yb. This alloy is produced by reducing a mixture of correspoding rare earth oxides, Fe, and a boron containing material by Ca, contacting the reduced mass with water, and treating the resultant slurry with water. Using this alloy, Fe-B-R base magnets wherein R1 is substituted for part of R (R representing lanthanide and/or Y) having a high performance are produced with a reduced cost.
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5 Claims
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1. A method for producing a rare earth alloy which comprises:
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preparing a mixed raw material powder comprising at least one of the oxides of rare earth elements R.sub. 1, an iron powder and a boron containing powder selected from the group consisting of boron, ferroboron and boron oxide in a manner such that the resultant alloy product consists essentially of; 15-65 atomic % R1, 35-83 atomic % Fe, and 0-15 atomic % B, in which R1 represents at least one of heavy rare earth elements selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm and Yb;
said mixed raw material powder further comprising metallic Ca and/or Ca hydride in an amount of 1.2-3.5 times by weight of the amount stoichiometrically required for reducing oxygen in said raw material powder and at least one of the oxides of said rare earth elements R1, and 1-15 % by weight of calcium chloride based on the oxides of said rare earth elements R1 ;compacting the resultant mixture; subjecting the resultant compacted mixture to reduction-diffusion treatment under a nonoxidizing atmosphere at a temperature of 950°
-1200°
C.;bringing the reduced mass to a particle size of 8 mesh to 35 mesh; contacting the resultant reduced mass with water to form a slurry-like substance; and treating said slurry-like substance with water by stirring the slurry and removing water to recover the resultant alloy powder; whereby said alloy powder has an oxygen content of at most 7000 ppm, and a carbon content of at most 1000 ppm. - View Dependent Claims (2, 3, 4, 5)
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Specification