JPH0530285B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a multilayer magnetic alloy ribbon suitable for magnetic materials used for controlling current and voltage such as power conversion, modulation, and amplification, and a method using the same. It concerns the magnetic core.

[Prior Art] A soft magnetic core is used to convert, modulate, and amplify electric power using electromagnetic induction. For example, typical soft magnetic materials are silicon steel for power applications, and permalloy and soft ferrite for light electrical applications, but amorphous alloys have also come into practical use in recent years.

These materials are typically used in the form of a toroidal wound core or a laminated core punched into a predetermined shape. In the case of a toroidal magnetic core, winding strain is added and the magnetic properties are deteriorated, so strain-removal annealing is performed to remove the strain and restore the magnetism. However, magnetism may not be fully recovered by strain relief annealing, which poses a practical problem.

There are many cases where the magnetism is not sufficiently improved by strain relief annealing in materials with large magnetostriction. This is particularly noticeable in Fe-based amorphous alloys.
The reason is as follows.

That is, in the case of a toroidal magnetic core, the stress applied to the material is tension on the outer circumferential side and compressive force on the inner circumferential side. In the case of a material with positive magnetostriction, the compressive force applied to the inner circumferential side deteriorates the magnetism. On the other hand, when the magnetostriction is negative, the tension applied to the outer circumferential side causes magnetic deterioration.

Although these strains that cause magnetic deterioration may be removed by sufficient annealing, they often remain and the magnetic properties are not fully recovered. Especially in the case of amorphous alloys, their magnetism deteriorates due to crystallization, so
It often happens that it is not possible to perform sufficient sintering to remove distortion. This is the main reason why the wound core properties of Fe-based amorphous alloys are inferior to those of single sheets, where heat treatment conditions can be easily controlled.

Furthermore, even for materials with small magnetostriction, it is difficult to stably produce a material with completely zero magnetostriction, so strain relief annealing cannot be omitted.

[Problems to be solved by the invention] The present invention solves the following problems when using a conventional soft magnetic material for a magnetic core:
The object of the present invention is to provide a soft magnetic material that does not require strain relief sintering, which is indispensable, or strict control of sintering conditions.

[Means and effects for solving the problem] The present invention provides a multilayer magnetic alloy consisting of a rapidly solidified layer of a melt formed by a single roll, in which at least one ferromagnetic alloy layer has positive magnetostriction and at least one layer has positive magnetostriction. The present invention relates to a multilayer magnetic alloy ribbon characterized by integrally forming a negative ferromagnetic alloy layer.

Figure 1 shows an example of a two-layer alloy ribbon. Here, if layer A is an alloy layer with positive magnetostriction, layer B must be an alloy layer with negative magnetostriction. When the multilayer magnetic alloy ribbon of the present invention having ferromagnetic alloy layers with positive and negative magnetostrictions is used as a toroidal magnetic core, the following practically beneficial effects appear.

As shown in Figure 2, a thin ribbon wound in a toroidal shape is subjected to tension on the outside and compression on the inside across the neutral line. It is known that magnetic anisotropy occurs in a material with positive magnetostriction in the direction parallel to the tension force, and magnetic anisotropy occurs in the direction perpendicular to the compressive force. On the other hand, stress has the opposite effect on materials with negative magnetostriction.

Therefore, if the multilayer magnetic alloy ribbon of the present invention is wound with the alloy layer with positive magnetostriction on the outside and the alloy layer with negative magnetostriction on the inside, the longitudinal direction (circumferential direction) of the entire material will be It becomes an axis of easy magnetization, which brings about a very favorable effect in practice. For example, it exhibits excellent soft magnetism even without or with insufficient strain relief annealing. Another advantage is that a large squareness ratio can be easily obtained.

If the negative magnetostriction alloy layer is wound on the outside and the positive alloy layer is wound on the inside, the axis of easy magnetization will be perpendicular to the longitudinal direction, and the magnetic core will exhibit constant magnetic permeability characteristics.

In this way, by using the alloy ribbon of the present invention multilayered with a plurality of alloy layers with different signs of magnetostriction as a magnetic core, strain relief annealing and magnetic field annealing can be omitted, or the annealing conditions can be relaxed. I can do it. In addition, by simply changing the winding method, it can be used for applications that require different characteristics.

Next, a method for manufacturing the multilayer magnetic alloy ribbon of the present invention will be explained below.

The multilayer magnetic alloy ribbon of the present invention is produced using a single roll quenching method. The single roll quenching method is a method in which a metal roll is used as a cooling substrate, and a molten alloy is jetted onto the rotating outer peripheral surface of the roll to rapidly solidify it. A specific example of the apparatus for producing the multilayer alloy ribbon of the present invention is shown in FIG.

This device is basically the same as that shown in the well-known Japanese Patent Application Laid-Open No. 57-177860. That is, using the outer peripheral surface of a rotating roll, a composite material made of a plurality of alloys having different compositions is directly produced by rapidly cooling the melt.

In FIG. 3, 1a is a crucible for melting alloy A, and 1b is a crucible for melting alloy B.

Here, alloy A is an alloy with positive magnetostriction, and alloy B is an alloy with negative magnetostriction, or vice versa. The crucibles are integrated via a partition plate 3. 2a and 2b are nozzles that spout molten metal, and alloys A and B, respectively.
It corresponds to

The melted alloys A and B are ejected onto the outer peripheral surface of the cooling body 4, which rotates almost simultaneously, and are rapidly solidified. In the case of FIG. 3, a two-layer composite quenched ribbon is formed, with alloy A on the roll side and alloy B on the free side.

In this method, an important factor for forming a composite material with good interlayer adhesion and compositionally separated two layers is the distance between the nozzles 2a and 2b.

If the distance between the two is too large, the adhesion will be poor,
If they are too close together, the alloys will mix. However, the problem of the nozzles being too close together rarely occurs in practice.

Alloys A and B may mix if the nozzle spacing is 1 mm or less, but if the nozzle spacing is 1 mm or less,
This is because it is difficult to approach a diameter close to mm or less due to problems with the strength of the partition plate and constraints on crucible processing.

On the other hand, sufficient consideration must be given to the upper limit of the nozzle spacing. If the nozzle spacing is too large, the A alloy on the upstream side will completely solidify, and when the molten alloy B is layered on top of it and solidified, unless the wetting of the A and B alloys is particularly good,
The two may separate or have extremely poor adhesion.

Appropriate nozzle spacing depends on the combination of alloys and which side is on the roll surface side, but in the case of amorphous alloys, a range of 1 to 6 mm is desirable.

Further, when a crystalline alloy is used as the roll surface side, the nozzle spacing on the free surface side is preferably large, and is preferably in the range of 3 to 15 mm, regardless of whether it is an amorphous alloy or a crystalline alloy.

What is important is that the multilayer body includes at least one ferromagnetic alloy layer each having positive magnetostriction and one ferromagnetic alloy layer having negative magnetostriction. In this case, it is preferable that at least one layer is an amorphous alloy layer. This is mainly to improve bondability and mechanical strength.

In the multilayer magnetic alloy ribbon of the present invention, ferromagnetic alloys that can constitute positive magnetostriction include amorphous alloys (numbers after component elements indicate atomic percent);
Fe ₇₉ B ₁₃ Si ₈ , Fe ₇₂ Co ₁₀ Mo ₂ B ₁₂ C ₄ , Fe _80.5 B ₁₂ Si _6.5
In crystalline metals such as _C1 , Fe, Fe−3wt%Si, Fe
-13wt%Al, Fe-Co ₅₀ , etc.

In addition, ferromagnetic alloys with negative magnetostriction include amorphous alloys such as Co ₇₈ Si ₈ B ₁₄ ′Co ₄₀ Ni ₄₀ B ₂₀ , and crystalline metals such as Ni and Ni−18.5wt%Co. They may be combined as appropriate depending on the purpose, characteristics, etc.

[Examples] Example 1 A two-layer amorphous alloy ribbon consisting of two types of alloys having different signs of magnetostriction was produced using the apparatus shown in FIG. 3a. However, the numbers for the A alloy are Fe ₇₉ Si ₈ B ₁₃ (at%), and the numbers for the B alloy are Co ₇₈ Si ₈ B ₁₄ (at%).

The nozzle used in the production was a double slit nozzle with two 0.4 x 5 mm ² slit openings spaced 2 mm apart.

Further, as shown in FIG. 3b, the crucible is partitioned at the center of the two nozzle openings to prevent alloy A and alloy B from mixing.

After heating the crucible with high-frequency heating and melting both alloys together, both molten metals were simultaneously jetted from each nozzle, and an alloy ribbon with a thickness of approximately 40 μm was formed from the two layers of alloys A and B. Obtained.

It was confirmed by X-ray diffraction that both layers A and B of the ribbon were amorphous. Also, the cross section is EPMA
Elemental analysis revealed that the two alloys were not intermixed, except for a thin layer (<2 μm) at the boundary near the center of the plate thickness.

The inner diameter of this ribbon is 15mm so that the A alloy becomes the outer surface.
When magnetically measured by winding it around a toroidal core with an outer diameter of 20 mm, excellent soft magnetic properties with a DC coercive force of 0.03 Oe were obtained even without sintering.

When this core was annealed at 350°C for 60 minutes without a magnetic field, it exhibited soft magnetic properties equivalent to those of a single-layer ribbon of A alloy that was annealed in a magnetic field under the same heating conditions.

In addition, when we measured the magnetic properties by winding it around a toroidal core with the same dimensions and shape as above, with the A alloy on the inside, we found that the change in magnetic permeability was small (change rate <5%) up to high magnetic flux density. Indicated.

As described above, the multilayer magnetic alloy ribbon of the present invention with different magnetostriction signs has features not found in conventional materials, such as omitting or simplifying sintering and being able to obtain different properties depending on the winding method. It can be seen that this shows that

Example 2 A three-layer amorphous alloy ribbon was manufactured using a three-layer nozzle as shown in FIG. The dimensions of the slit-shaped openings are 0.4 x 5 mm ² , and the mutual spacing is 2.
mm.

Further, alloys A and C are Fe ₆₂ Co ₁₀ Mo ₂ B ₂₂ C ₄ (positive magnetostriction), and B is Ni (negative magnetostriction).

As in Example 1, the crucible is partitioned to prevent different types of alloys from mixing with each other.

After the entire crucible was heated with high frequency to melt all of the A, B, and C alloys, all the molten metals were jetted out from each nozzle almost simultaneously, resulting in A-B-C.
A ribbon with a thickness of about 60 μm consisting of three alloy layers was obtained. It was confirmed by X-ray diffraction of the cross section of the plate that A and C were amorphous and B was crystalline.

Using chemical etching method, this three-layer ribbon is
A ring-shaped core with an outer diameter of 25 mm and an inner diameter of 15 mm was punched out, and 20 sheets were laminated to produce a ring-shaped stacked iron core.

After annealing this iron core at 350℃ for 60 minutes in a magnetic field at 10Oe, the characteristics at a frequency of 400Hz were evaluated.

The iron loss at Bm=0.5T was 0.6W/Kg.
A distinctive feature of this core was that it emitted almost no vibration noise even when the measured magnetic flux density was high.

[Effects of the Invention] As described above, the multilayer magnetic alloy of the present invention consisting of two or more alloys with different magnetostriction signs has the following effects:
Omit strain relief annealing after the winding process or relax conditions (e.g. omit magnetic field, relax heating condition control standards)
This has great practical merits as it is possible to reduce noise and noise.

In addition, one material can be rolled (inside and outside the ribbon surface)
It also has new functions that could not be achieved with conventional materials, such as the ability to exhibit completely different magnetic properties just by changing the material, so new applications can be expected.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example (in the case of two layers) of the multilayer magnetic alloy ribbon of the present invention, and FIG. 2 is a schematic diagram of the type and magnitude of stress applied to the cross section of the ribbon wound in a toroidal shape. Figure 3 is a conceptual explanatory diagram of the melt quenching apparatus for manufacturing the multilayer magnetic alloy ribbon of the present invention, a general illustration, b nozzle illustration, and Figure 4 an explanatory diagram for manufacturing the three-layer magnetic alloy ribbon. A is a shape diagram of a nozzle, and B is a structural explanatory diagram of a crucible. 1a, 1b...crucible, 3...partition plate, 4...
...Cooling body, 5...Alloy ribbon.

Claims (1)

[Claims] 1. A multilayer magnetic alloy consisting of a rapidly solidified layer of a melt formed by a single roll, in which at least one ferromagnetic alloy layer with positive magnetostriction and at least one ferromagnetic alloy layer with negative magnetostriction are integrated. A multilayer magnetic alloy ribbon characterized by being formed into. 2. The multilayer magnetic alloy ribbon according to claim 1, wherein at least one layer is an amorphous magnetic alloy layer. 3. Laminating multilayer magnetic alloy ribbons in which at least one ferromagnetic alloy layer with positive magnetostriction and at least one ferromagnetic alloy layer with negative magnetostriction are integrally formed as a rapidly solidified layer of a melt by a single roll. mosquito,
A magnetic core formed by winding.