JPH06287720A - Permanent magnet alloy - Google Patents

Abstract

PURPOSE:To use a powder of the resulting alloy for a bond magnet and to improve magnetic properties, especially Br and iHC, by incorporating rare earth elements, Fe, B, and C in the percentages represented by formula. CONSTITUTION:This permanent magnet alloy has a composition represented by formula RxFe100-x-y-zByCz (where R means rare earth elements including Y, x=1 to 10, y>0, z>0, and y+z=10 to 30) or RxFe(100-x-y-z) CouByCz (where u=0 to 50) A molten metal of this alloy is formed into ribbon state by means of rapid cooling method, etc., and crushed. Then, the resulting powder is mixed with epoxy resin, etc., and formed into a bond magnet. By this method, the inexpensive magnet excellent in magnetic properties can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet alloy. More specifically, the present invention relates to a rare earth-iron-based permanent magnet having unprecedentedly high magnetic properties, and particularly to an Nd-Fe-B-based permanent magnet alloy useful as a bonded magnet.

[0002]

2. Description of the Related Art Nd-Fe-B system permanent magnet alloys are attracting attention due to their excellent magnetic properties, and their application to various industrial fields is expanding. Above all, this Nd-Fe
It is known that the use of a -B permanent magnet as a bonded magnet is excellent in formability into various shapes and structures and has high magnetic properties.

With respect to the rare earth / iron permanent magnet alloys such as the Nd-Fe-B system, investigations have been made on the relationship between the magnetic properties and the alloy properties and the crystal structure of the alloys, and the alloy crystals. The refinement of grains contributes to the improvement of magnetic characteristics, and the amount of rare earth elements added is reduced,
It has been proposed to realize a permanent magnet alloy having higher corrosion resistance and higher magnetic properties.

However, in the above studies, it is difficult to improve both Br and _i Hc.
It was considered to be almost impossible, and it was thought that there would be a limit to improving the magnetic properties of the permanent magnet alloy. In this situation, the present invention has been made, overcomes the limitations of the prior art, and brings Br and _i H
It is an object of the present invention to provide a new rare earth-iron-boron-based permanent magnet alloy that can improve both c-characteristics and is particularly useful as a bonded magnet.

[0005]

SUMMARY OF THE INVENTION The present invention, as to solve the above problems, an atomic ratio is, the following formula _{R x Fe (100-xyz)} B y C z (R, 1 kind including Y Or 2 or more kinds of rare earth elements, 1 ≦ x ≦ 10, 0 <y, 0 <z, and 10 ≦ y + z ≦
30) is provided.

Further, according to the present invention, in the above alloy composition, a part of Fe (iron) is replaced with Co (cobalt),
Atomic ratio following formula _{R x Fe (100-xyzu)} Co u B y C z (R represents one or more rare earth elements including Y, 1 ≦ x ≦ 10.0 < y, 0 <Z, 10 ≦ y + z ≦
A permanent magnet alloy represented by the formula (3,0 ≦ u ≦ 50).

[0007]

That is, the present invention makes use of the characteristics of a permanent magnet alloy with a low rare earth content, which is known to have excellent corrosion resistance, etc. Has been attracting attention as a contribution to
It is intended to provide an alloy capable of improving both Br and _i Hc characteristics by adding (carbon) more than ever before.

[0008] This alloy, in its composition, is a low-added rare earth element having an atomic ratio of 1 to 10 as expressed by the above formula, and further, B (boron) and C (carbon).
It is mandatory to add and together. The total atomic ratio of the two is 10 to 30. Addition of B and C promotes grain refinement of the alloy composition and improves magnetic properties, and when the atomic ratio is less than 10 and exceeds 30, the improvement of properties cannot be expected. It has very limited requirements.

Further, it has been known that a low-level addition amount of a rare earth element such as Nd causes a two-phase crystal phase to be mixed, whereby the corrosion resistance and the magnetic characteristics are improved. Further, the addition of Co is also for improving the magnetic characteristics. In this case, the atomic ratio needs to be 50 or less.

The alloy of the present invention having the above-mentioned characteristics is obtained by dissolving elements having a required composition by a conventionally known method or the like, obtaining a ribbon-shaped molded body or the like by a super-quenching method, and then crushing this. Thus, a magnet for a bonded magnet or the like can be obtained. Examples will be shown below to describe the permanent magnet alloy of the present invention in more detail.

[0011]

EXAMPLES Examples 1 to 10 have compositions of Nd _4.5 Fe _77.5 B _(18- α ₎ C α (0 <α <1
The alloy represented by 8) was prepared by high-frequency melting and formed into a ribbon by the ultra-quenching method. Roll peripheral speed is 10-40
The range was m / s.

The obtained ribbon was crushed to a particle size of 300 μm or less, and then mixed with an epoxy resin to prepare a bonded magnet. The magnetic properties of the obtained bonded magnet are shown in Table 1 below. It was confirmed that by substituting a part of B (boron) with C (carbon), magnetic properties superior to those of conventional alloys can be obtained, and in particular, both Br and _i Hc are improved.

[0013]

[Table 1]

Examples 11 to 17 have a composition of Nd _(4.5- β ₎ RβFe _77.5 B ₁₀ C ₈ (1 ≦ β <
4.5) (where R is a rare earth element) was prepared by high-frequency melting and formed into a ribbon shape by the ultraquenching method. The roll peripheral speed was in the range of 10 to 40 m / s.
As the peripheral velocity increased, it changed from crystalline to amorphous.

The obtained ribbon is crushed to have a particle size of 300 μm.
The following was mixed with an epoxy resin to obtain a bonded magnet.
The magnetic properties of this magnet were measured, and the results shown in Table 2 below were obtained. It is understood that by replacing a part of Nd with another rare earth element, magnets with various characteristics can be obtained. For example, it was confirmed that the addition of Dy increases _i Hc and (BH) _max , and that the simultaneous addition of Ce and C makes it possible to obtain an inexpensive magnet without deteriorating the characteristics.

[0016]

[Table 2]

Examples 18 to 20 have compositions of Nd _4.5 Fe _(77.5- γ ₎ CoγB ₁₀ C ₈ (1 <γ
The alloy represented by <13) was prepared by high-frequency melting and ribbon-formed by the ultra-quenching method. Roll peripheral speed is 10-40
The range was m / s. Particle size of the obtained ribbon is 300 μm
It was ground into the following and mixed with an epoxy resin to obtain a bonded magnet. The magnetic properties were measured and the results shown in Table 3 were obtained.

It has been confirmed that the addition of a small amount of Co improves the characteristics as compared with the case where no Co is added.

[0019]

[Table 3]

[0020]

As described in detail above, the present invention provides a permanent magnet alloy useful for a bonded magnet, which has a low rare earth content and is excellent in magnetic properties.

Claims (2)

[Claims] 1. A atomic ratio composition, the formula _{R x Fe (100-xyz)} B y C z (R represents one or more rare earth elements including Y, 1 ≦ x ≦ 10, 0 <Y, 0 <z, 10 ≦ y + z ≦
30) is a permanent magnet alloy. Wherein the atomic ratio composition, the formula _{R x Fe (100-xyzu)} Co u B y C z (R represents one or more rare earth elements including Y, 1 ≦ x ≦ 10 , 0 <y, 0 <z, and 10 ≦ y + z ≦
30 and 0 ≦ u ≦ 50).