Magnetic alloy powder for permanent magnet and mfg. method thereof

A technology of permanent magnets and magnetic alloys, applied in the direction of magnetic materials, magnetic objects, inorganic materials, etc., can solve the problems of flattening the shape of magnetic powder, reducing the molding efficiency, and deteriorating the fluidity of magnetic powder, achieving excellent atmospheric corrosion resistance, high temperature The effect of small change and excellent fluidity

Inactive Publication Date: 2002-07-24
SUMITOMO SPECIAL METAL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in this method, there is a problem that the shape of the magnetic powder is flattened because molten metal particles that are not completely cooled are violently sprayed onto the cooling plate.
The flattening of the magnetic powder deteriorates the fluidity of the magnetic powder and lowers the molding efficiency, which causes a decrease in the yield in the pressing process or the spraying process

Method used

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  • Magnetic alloy powder for permanent magnet and mfg. method thereof
  • Magnetic alloy powder for permanent magnet and mfg. method thereof
  • Magnetic alloy powder for permanent magnet and mfg. method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0059] In this example, using master alloys having various compositions shown in Table 1 below, alloy melts were sprayed in an argon atmosphere to produce powders composed of spherical particles. The temperature of the alloy melt during spraying is about 1400-1500°C, and the temperature of the argon atmosphere is about 30°C.

[0060] Next, the thus-produced powder was classified with a sieve to obtain a powder with a particle diameter of 38 μm to 63 μm, and then the magnetic properties of the powder (residual magnetic flux density B r and coercive force H cJ ). Table 1 shows the evaluation results for sample Nos. 1 to 20. The values ​​shown in Table 1 are values ​​measured with a vibrating sample type magnetometer.

[0061] No.

Composition (mass%)

magnetic properties

Br(T)

h cJ (MA / m)

1

30.0Nd-69.0Fe-0.5B-0.5C

0.778

0.850

2

28.0Nd-69.0Fe-2.0Co-0.5B-0.5C

0.804

0.814

3

22.0Nd-8.0Pr-69.0Fe-...

Embodiment 2

[0078] In this embodiment, B is essential, and in addition to B, C, S, P, or Si is added. In this example, the melt of an alloy containing Q (Q is an element including B, C, S, P and / or Si) in an amount of 0.5% by mass to 2.0% by mass is rapidly cooled by a spraying method, thereby forming a powder change. The content ratio of B to the total content of Q is 0.10 or more and less than 0.95.

[0079] As can be seen from Table 3, excellent magnetic properties can be obtained according to this embodiment.

Embodiment 3

[0081] Powder particles with a particle size of 63 μm or less

[0082] As can be seen from Table 4, the recoveries of samples Nos. 1, 3, 21, 22 and 24 were 70% or more, which was much higher than the recoveries of samples Nos. 17 and 18 of the comparative example. This means that the addition of C, S, P and / or Si helps to make the particle size of the spray powder smaller. The main reason for the particle size reduction is that the viscosity of the alloy melt during spraying is reduced by adding an appropriate amount of elements.

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Abstract

To mass-produce alloyed rare-earth magnetic powder having high coercive force by using the gas atomization method. Spherical powder is formed by spraying molten alloyed pig iron containing R (R is at least one kind of rare-earth elements including Y.) of >=20 wt.% and <=40 wt.%, T (T is a transition metal including Fe as the main component.) of >=60 wt.% and <=79 wt.%, and Q (Q is an element including B (boron) and C (carbon)) of >=0.5 wt.% and <=2.0 wt.%, in the non-oxidative atmosphere, and the shape of particles of the powder is substantially spherical. After that, the spherical powder is heat-treated at a temperature of >=500 deg.C and <=800 deg.C.

Description

technical field [0001] The present invention relates to rare earth magnetic alloy powders used in rare earth bonded magnets and sintered magnets that can be used in various motors and actuators, and to permanent magnets produced using the magnetic alloy powders. Background technique [0002] The melt of the raw material alloy is cooled and solidified by the metal ingot method or the strip casting method, thereby using the Nd-containing 2 Fe 14 The technology in which the B-type tetragonal crystal phase is the main phase has enabled the mass production of Nd-Fe-B-based rare earth magnetic alloys. [0003] Different from the above-mentioned mass production technology, the use of the gas spraying method is disclosed in Japanese Patent Publication No. 5-18242, Japanese Patent Publication No. 5-53853, Japanese Patent Publication No. 5-59165, and Japanese Patent Publication No. 7-110966. Technology for manufacturing Nd-Fe-B series rare earth magnetic alloy powder. [0004] The ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F1/057H01F1/058
CPCH01F1/058H01F1/0574
Inventor 富泽浩之金子裕治
Owner SUMITOMO SPECIAL METAL CO LTD
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