JPS6110208A - Manufacture of rare earth and iron permanent magnet - Google Patents

Abstract

PURPOSE:To obtain the permanent magnet with high energy product having high magnetic flux density and high coercive force by uniting through heating after laminating the crystalline thin band of a rare earth and iron permanent magnetic alloy formed by way of a molten metal quenching method. CONSTITUTION:A rare earth and iron permanent magnetic alloy contains at least one chosen from yttrium and such rare earth metals as Ce, Pr, Nd and Sm, and iron as a principal componet, and further contains such a nonmetal as B, C to stabilize. As an axis C orientates at right angles to a thin band surface when the rare earth and iron permanent magnetic alloy is made to change into a thin band with the molten metal quenching method, the rare earth and iron permanent magnetic alloy changes into a thin band with bursting an alloyed molten metal over a rotary cooler. This crystalline thin band gained is united by heating after laminating in order to become a desired form. Heating temperature differs depending on a composition. The temperature to unite needs to be at least 600 deg.C, and it is preferable that the temperature to prevent a liquid phase from crystallizing needs to be at most 1,100 deg.C.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a method for manufacturing rare earth/iron permanent magnets.

[Technical background of the invention and its problems]

Permanent magnets of rare earth 00 series have been known for some time. Since this permanent magnet has a high energy product, it is used in a wide range of fields. Recently, even (high energy product)
For example, rare earth/Fe-based permanent magnets having a magnetic flux of 30 MGOe or more are being researched. This rare-earth/iron-based permanent magnet is a promising material because it has a high energy product and also has the advantage of being inexpensive compared to Co-based magnets because it is mainly composed of Fe.

Although it can be manufactured, it requires processes such as pressing in a magnetic field after crushing, and in addition to the disadvantage that the process is complicated, there is a risk of contamination with impurities during the manufacturing process, especially during the crushing process, making it difficult to obtain stable magnetic properties. There was a drawback.

[Purpose of the invention]

The present invention has been made in consideration of the above points, and is a method for manufacturing rare earth/iron permanent magnets that can easily obtain rare earth/iron permanent magnets that have high magnetic flux density, high coercive force, and a large energy product. The purpose is to provide

[Summary of the invention]

The present invention is based on the discovery that when a rare earth/iron permanent magnet alloy is produced by a molten metal quenching method, the zero axis of the ribbon is oriented perpendicular to the ribbon surface. be.

That is, the present invention involves the first step of obtaining a crystalline ribbon made of a rare earth/iron permanent magnet alloy by a molten metal rapid cooling method.
) A second step of integrating the laminate made of crystalline ribbons obtained in the first step by heating:
This is a method for manufacturing an iron-based permanent magnet alloy.

Rare earth/iron permanent magnet alloys include yttrium and Oe,
At least one selected from rare earth metals such as Pr, Nd, and Sm (or Mitsushi metals (M, M), which are compatible with rare earth elements in multiple degrees) and iron as main components, further containing B, O, etc. for stabilization. Contains non-metals. For example, taking B as an example, R1a p BαFeβ R:Y, rare earth 0.001≦α≦0.5 0.5≦β≦0.95 α+β<1. O where α<0.001. When β<0.5, the coercive force does not improve and it is unsuitable as a permanent magnet alloy, and when α>0.5゜β>0.95, the magnetic flux density decreases and it is unsuitable as a permanent magnet alloy. Appropriate.

Also, as equivalent to B, O, N, 0. P.H.

S, Al, Sr, etc. are mentioned. Part or all of B may be replaced with these elements.

In addition, we focused on improving the corrosion resistance of the obtained crystalline ribbon, and as a result of repeated research on the effects of various elements on corrosion resistance, R
- Based on Fe-B alloy, Or andl
A new finding has been discovered that the addition of AJ or AJ can significantly improve corrosion resistance compared to K. Ri-a-β
-rBαFeβMγ (where R=Y.

One or more types of rare earth 1M84 (Mitsushi Metal),
M=Or, one or two types of Al, α, β, r are 0001≦α≦0.5, 0.5≦β≦0.95, 0.0, respectively
Corrosion resistance is particularly good in the range of 01≦γ; 01; α+β+γ<1).

If the amount of 13 added is less than 0001, the coercive force will not increase, making it unsuitable as a permanent magnet alloy.

If it exceeds 0.5, the magnetic flux density will decrease, which is not preferable.

If Fe is less than 0.5, the magnetic flux density will be insufficient, and if it exceeds 095, the coercive force will decrease. When the value of γ is less than 0.001, no effect of improving corrosion resistance is observed, and when it exceeds 0.01, the magnetic flux density decreases.

When such a rare earth/iron permanent magnet alloy is formed into a thin ribbon by a molten metal quenching method, the C-axis is oriented perpendicularly to the surface of the ribbon under certain cooling conditions. This is a phenomenon not seen in Sm-Co systems. The manufacturing process is similar to that used for amorphous alloys. That is, the molten alloy is spouted onto a rotary cooling body that is cooled with water to form a thin ribbon.

At this time, if the rotational speed of the rotary cooling body is too high, the ribbon becomes amorphous and is not oriented and does not function as a permanent magnet. On the other hand, if the rotation speed is slow, although the material becomes crystalline, the crystal grains become granular and the orientation deteriorates, resulting in poor magnetic properties. Considering this, it is preferable that the surface speed of the rotary cooling body is in the range of 3 to 20 m7 seconds.

The crystalline ribbons thus obtained are stacked in a desired shape and integrated by heating. Although the heating temperature varies depending on the composition, a temperature of 600° C. or higher is required for integration, and is preferably 1100° C. or lower to prevent liquid phase crystallization.

During the treatment, a treatment time of about 0.1 to 5 hours is sufficient.

Furthermore, in order to obtain a larger energy product, it is preferable to apply a pressure of about 0.1 ton/cd during heating and integration.

〔Effect of the invention〕

As explained above, according to the present invention, the steps of conventional methods such as crushing and pressing in a magnetic field can be omitted, thereby achieving a significant simplification of the process and improving the magnetic properties of the resulting permanent magnet. be done.

[Embodiments of the invention]

Examples of the present invention will be described below.

(Example 1) An alloy having a composition of Nd0.17B0.11Fe0.72 was formed into a thin ribbon using a molten metal quenching method. That is about 10jl
The molten alloy is injected and cooled by argon gas pressure through a quartz nozzle onto the surface of a roll that rotates in seconds.
A crystalline ribbon of 00 μm was obtained. The results of measuring the obtained nine ribbons using an X-ray diffractometer are shown in Figure #11, and for comparison, the results of X-ray diffraction of the alloy powder material are shown in Figure 2.

It can be seen that, compared to the alloy powder material, in the case of the molten metal quenched ribbon, the C axis is oriented in the direction perpendicular to the ribbon surface.

The thin strips obtained by the molten metal quenching method were cut into tanzag shapes with a length of 10 liters, 100 strips were stacked, and heat treatment was performed at 1080° C. x IH while press forming at a pressure of 2 tons/d. The obtained magnetic properties are shown in Table 1.

(Example 2) Thin strips of magnetic alloys of Pr0.15, Bo,08, and Fe0.77 were prepared and laminated in the same manner as in Example 1, and 2 to
Heat treatment at 1100° C. x IH was performed while press molding at n/a/(. The magnetic properties obtained are shown in Table 1.

(Example 3) A magnetic alloy ribbon of NdO,2, Bo,2, FeO,6 was produced using the same manufacturing method as in Example 1.
It was molded into a ring shape with an outer diameter of 10 mm and an inner diameter of 5 mm, and this ring was laminated and heat treated in the same manner as in Example 1, and its magnetic properties are shown in Table 1.

For comparison, the characteristics of a permanent magnet having the same composition as Examples 3 to 3 and produced by the powder sintering method are also shown.

As is clear from Table 1, using the method of the present invention K
Compared to the conventional method, the energy product ((BH) may)
It can be seen that the results are improved. This seems to be due to the fact that there is no pulverization process, so there is no risk of contamination with impurities, and the effect of laminated heat treatment. In addition, the conventional powder sintering method can omit steps such as crushing and pressing in a magnetic field, making manufacturing extremely easy.

(Example 3) As alloy raw materials, Nd0.16, Bo, 07 in atomic ratio
4.

Alloy of FeO, 756, Oro, 01 (hereinafter referred to as [alloy IJ
) and Nd O,15, Bo,05, Fe
Two types of alloys of O,77 (hereinafter referred to as "alloy 1") were prepared and formed into thin ribbons using a molten metal quenching method. That is 10
The molten alloy is injected and cooled by argon gas pressure through a quartz nozzle onto the surface of a roll that rotates at jl seconds.
A crystalline ribbon with a thickness of 100 μm was obtained.

The obtained thin strips were cut into long tanzak shapes of 10 periods, laminated, and heated at 1100°C while being press-formed at a pressure of 2 tons/d.
Heat treatment is performed in an xlH argon atmosphere, and a vertical 10-
+ A permanent magnet with a width of 10 m and a thickness of 10 m was produced.

The magnetic properties of the permanent magnet obtained in this way are shown in Table 1. For comparison, Table 1 also lists the magnetic properties of permanent magnets of Alloy (1) and Alloy (I) produced by the conventional powder sintering method.

Next, the two types of permanent magnets produced in the example were heated at 30℃4%.
Table 2 also shows the results of observing the corrosion state of the surface after being left in a NaCl aqueous solution. Figure 1 shows the results of examining the change in magnetic flux density over time.

As is clear from Table 2 and Figure 3, by using the method of the present invention, it is possible to manufacture rare earth iron permanent magnets that have not only high magnetic flux density, coercive force, and large maximum energy product, but also high corrosion resistance. I can do it. Also, conventional dissolution,
Work processes such as crushing, orientation, and molding can be omitted, making manufacturing extremely easy.

[Brief explanation of the drawing]

FIG. 1 shows Md0.17 according to the present invention. Bo, 11. Pe
X-ray diffraction diagram of 0.72 ribbon, Figure 2 shows NdO,17,
Bo, 11, X-ray diffraction diagram of Fe0072 powder, 3rd
The figure shows the temporal characteristics of Br. Agent Patent Attorney Kensuke Chika (and 1 other person) No.
1 figure

Claims (1)

[Scope of Claims] (1) A rare earth/iron permanent magnet characterized by laminating crystalline thin strips made of a rare earth/iron permanent magnet alloy produced by a molten metal quenching method and then heating and integrating the crystalline ribbons. How to manufacture magnets. (2) The method for manufacturing a rare earth/iron permanent magnet according to claim 1, wherein the heating is performed at a temperature range of 600 to 1100°C. (3) The rare earth/iron permanent magnet raw material alloy is R_1_
-_a_-_βB_αFe_β (α and β are atomic ratios) R:
Claim 1, characterized in that it has a composition of at least one of Y and a rare earth element: 0.001≦α≦0.5 0.5≦β≦0.95 α+β<1.0 A method for manufacturing rare earth/iron permanent magnets. (4) The rare earth-iron permanent magnet alloy is R_1_-_α_-_β-_γB_αFe_βM_γ(
α, β, γ are atomic ratios) R: Y and at least one of rare earth elements 0.001≦α≦0.5 0.5≦β≦0.95 0.001≦γ≦0.1 α+β+γ<1 2. A method for producing a rare earth/iron permanent magnet according to claim 1, wherein the rare earth/iron permanent magnet has a composition.