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R-T-B based rare earth element permanent magnet and magnet composition

一种永久磁铁、组合物的技术，应用在磁性物体、电感/变压器/磁铁制造、磁性材料等方向，能够解决不能得到高特性、剩余磁通密度降低等问题

Inactive Publication Date: 2004-12-22
TDK CORPARATION
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, as the amount of added Zr increases, the residual magnetic flux density decreases, and the original high characteristics cannot be obtained.

Method used

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  • R-T-B based rare earth element permanent magnet and magnet composition
  • R-T-B based rare earth element permanent magnet and magnet composition
  • R-T-B based rare earth element permanent magnet and magnet composition

Examples

Experimental program
Comparison scheme
Effect test

no. 1 Embodiment

[0090] The alloy shown in Fig. 1 was blended according to the final composition shown in Fig. 2 and Fig. 3, then subjected to hydrogen pulverization treatment, and then finely pulverized by a jet mill to an average particle diameter of 5.0 μm. In addition, the types of alloy raw materials used are also described in FIGS. 2 and 3 . After forming in a magnetic field, it is sintered at 1050 and 1070°C, and the resulting sintered body is subjected to two-stage aging treatment.

[0091] For the obtained R-T-B rare earth permanent magnets, the residual magnetic flux density (Br), coercive force (HcJ) and squareness ratio (Hk / HcJ) were measured with a B-H tracer. Also, Hk is the external magnetic field intensity at which the magnetic flux density becomes 90% of the residual magnetic flux density in the second quadrant of the hysteresis loop. The results are also shown in Fig. 2 and Fig. 3 . 4 is a graph showing the relationship between the amount of Zr added and the magnetic proper...

no. 2 Embodiment

[0112] After the alloy a1, alloy a2, alloy a3 and alloy b1 in Fig. 1 are used to form the final composition shown in Fig. 9, they are subjected to hydrogen pulverization treatment, and then finely pulverized by a jet mill to an average particle diameter of 4.0 μm. Then it is formed in a magnetic field, sintered at each temperature of 1010-1100°C, and the obtained sintered body is subjected to two-stage aging treatment.

[0113] The remanence (Br), coercive force (HcJ) and squareness ratio (Hk / HcJ) of the obtained R-T-B system rare earth permanent magnets were measured with a B-H tracer. Also, the value of Br+0.1×HcJ was obtained. The results are also shown in Fig. 9 . Also, FIG. 10 shows the relationship between the sintering temperature and each magnetic property.

[0114] In the second embodiment, in order to obtain high magnetic properties, the oxygen content of the sintered body was reduced to 600-900 ppm by an oxygen-free process, and the average particle diameter of th...

no. 3 Embodiment

[0128] R-T-B series rare earth permanent magnets were obtained in the same process as in the second embodiment except that alloys a1 to a4 and alloy b1 in FIG. 1 were used and blended according to the final composition shown in FIG. 17 . The oxygen content of the permanent magnet was below 1000 ppm, and no coarse crystal grains of 100 μm or more were observed in the sintered structure. For this permanent magnet, the residual magnetic flux density (Br), the coercive force (HcJ), and the squareness ratio (Hk / HcJ) were measured with a B-H tracer in the same manner as in the first example. Also, the value of Br+0.1×HcJ was obtained, and the results are also shown in FIG. 17 .

[0129] The third embodiment was carried out for one of the purposes of confirming the variation of the magnetic properties with the amount of Dy. It can be seen from FIG. 17 that the coercive force (HcJ) increases with the increase in the amount of Dy. On the other hand, all permanent magnets obtained a B...

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Abstract

A sintered body with a composition consisting of 25% to 35% by weight of R (wherein R represents one or more rare earth elements, providing that the rare earth elements include Y), 0.5% to 4.5% by weight of B, 0.02% to 0.6% by weight of Al and / or Cu, 0. 03% to 0.25% by weight of Zr, 4% or less by weight (excluding 0) of Co, and the balance substantially being Fe, wherein a coefficient of variation (CV) showing the dispersion of Zr is 130 or lower. This sintered body enables to inhibit the grain growth, while keeping the decrease of magnetic properties to a minimum, and to improve the suitable sintering temperature range.

Description

technical field [0001] The present invention relates to R (R is one or more than two kinds of rare earth elements, but the concept of rare earth elements containing Y), T (it is Fe or at least one or more transition metal elements with Fe and Co as essential elements) And R-T-B series rare earth permanent magnets with B (boron) as the main component. The present invention also relates to a magnet composition used in the manufacture of R-T-B series rare earth permanent magnets. Background technique [0002] Among the rare-earth permanent magnets, the R-T-B series rare-earth permanent magnets have excellent magnetic properties, and the main component Nd is abundant and relatively cheap, so the demand is increasing year by year. [0003] Research and development to improve the magnetic properties of R-T-B series rare earth permanent magnets is being vigorously carried out. For example, Japanese Unexamined Patent Publication No. 1-219143 reports that adding 0.02 to 0.5 atomic ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F1/055H01F1/057H01F41/02
CPCH01F1/0557H01F41/0253H01F1/0577
Inventor 西泽刚一石坂力日高徹也福野亮
Owner TDK CORPARATION