JPH02236219A - Production of ultra-microcrystalline magnetic alloy - Google Patents

Abstract

PURPOSE:To obtain an ultra-microcrystalline magnetic alloy excellent in high-frequency magnetic properties by applying magnetic field to an Fe-Cu alloy foil in a specific direction to carry out primary magnetic heat treatment and then performing secondary magnetic heat treatment by applying magnetic field to the above foil in a direction dissimilar to the above direction. CONSTITUTION:A magnetic field is applied to an alloy foil having a composition containing Fe, Cu, and M (where M means at least one element selected from Mb, W, Ta, Zr, Hf, Ti, and Mo) as essential elements in a specific direction, e.g., a longitudinal direction to carry out primary magnetic heat treatment. Subsequently, a magnetic field is applied to the above foil in a direction dissimilar to the above direction, e.g., a width direction or a thickness direction to carry out secondary magnetic heat treatment. By this method, the magnetic alloy in which fine crystalline grains comprise at least 50% of a structure and which has excellent high-frequency magnetic properties can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing an ultrafine crystalline magnetic alloy with excellent high frequency magnetic properties used in saturable reactors, transformers, choke coils, magnetic heads, etc. be.

[Prior Art] The above-mentioned magnetic core components are generally required to have low magnetostriction, high effective magnetic permeability, and high saturation magnetic flux density, and in addition, these magnetic properties do not change over time and are durable. It is necessary to have excellent sexual characteristics.

In addition to the above characteristics, the core loss is small, especially for saturable reactors used in magnetic amplifier circuits, etc.
Good control magnetization characteristics (low uncontrollable magnetic flux density) are also required.

In addition, reactors for semiconductor circuits are used to prevent current spikes and current linking that occur when the semiconductor circuit is turned on and off, causing current exceeding the standard value to flow through the semiconductor, destroying the semiconductor circuit, and preventing the semiconductor circuit from malfunctioning due to noise. It is inserted into the magnetic field, has particularly high effective magnetic permeability, and is required to have a high squareness ratio in order to suppress only the above-mentioned abnormal current.

In addition, especially in the common mode choke, in order to prevent unipolar noise, it is necessary to increase the effective operating magnetic flux density, and the squareness ratio in the DC BH curve is required to be small.

In addition, in transformers, in particular, similar to common mode chokes, the squareness ratio in the DC B-H curve is low in order to prevent unipolar noise, and with the recent shift to high frequency drive types of switching power supplies, high frequency characteristics (For example, low iron loss when driven at high frequency) is required.

In recent years, Fe-based and Co-based non-quality alloys have attracted attention as phase materials having high saturation magnetic flux density.

Go-based non-quality alloys have the advantages of low magnetostriction and high effective magnetic permeability, and have recently been used as magnetic core materials for saturable reactors as disclosed in Japanese Patent Laid-Open No. 57-210612 or Japanese Patent Laid-open No. 57-210612.
No. 7-21512 discloses the use of a Co-based non-quality alloy. On the other hand, the saturation magnetic flux density of Fe-based non-quality alloys is higher than that of CO-based non-quality alloys.
As described in Japanese Patent No. 183, it is known that heat treatment in a non-oxidizing atmosphere has the advantage of providing DC magnetic properties with a high squareness ratio.

As mentioned above, Fe-based non-quality alloys have the advantage of higher saturation magnetic flux density than CO-based amorphous alloys, but for example, saturable reactors using Fe-based non-quality alloys in magnetic amplifier circuits of switching power supplies Especially when using 20
When driven at a high frequency higher than k tl z, the core loss and control magnetization characteristics are inferior to Go-based non-quality alloys, and the total control magnetization force is large, so the control magnetization current for controlling the output voltage is large. There are problems in that the temperature of the magnetic core increases, the load on the control circuit increases, efficiency decreases, and the durability of surrounding components decreases.

Furthermore, when a reactor for a semiconductor circuit is made of an Fe-based amorphous alloy, the magnetostriction is extremely large and the effective magnetic permeability is low, so that the effect of preventing spike currents etc. is not sufficient.

In addition, conventionally, the transformer of switching power supplies was mainly made of Mn.
-Zn ferrite is used, but an attempt to use a Fe-based non-quality alloy in a transformer of a switching power supply driven at high frequency is described in IEICE Technical Report PE-84-3812. However, this report points out that when Fe-based non-quality alloys are used, their properties tend to deteriorate due to mechanical stress due to their large magnetostriction, and when impregnated cores or cut cores are used, high-frequency magnetic properties deteriorate. It has been pointed out.

Therefore, it has low magnetostriction and high effective magnetic permeability comparable to Co-based non-quality alloys, saturation magnetic flux density equivalent to Fe-based non-quality alloys, and has excellent durability without changing its properties over time. A superior material was desired.

The present inventors have proposed a method that can solve these drawbacks.
In Japanese Patent Application No. 62-367187, an alloy having a new ultrafine grain structure and a method for manufacturing the same were published.

This alloy is mainly composed of Fe, Cu and M (where M is
Nb, W, Ta, Zr, Hf, "I'i and Mo)
At least 50% of the structure has a grain size of 100
It is an alloy consisting of ultrafine crystal grains of 0A or less.

When this alloy is used in the above-mentioned saturable reactor or common mode choke, it is heat treated in a magnetic field to make the B-H curve shape suitable for the application. [Problems to be solved by the invention] However, If a simple heat treatment in a magnetic field is performed, for example, when a high squareness ratio type characteristic is obtained, there is a problem in that the core loss increases significantly depending on the composition. On the other hand, when the characteristics are of a low squareness ratio type, there is a problem that the effective magnetic permeability becomes too low.

As a manufacturing method for solving such problems, the inventors of the present invention have previously applied in Japanese Patent Application No. 77315/1983 for a method of performing heat treatment in a magnetic field after crystallization heat treatment.

However, such a manufacturing method has the problem of relatively large variations in characteristics, and a manufacturing method that obtains similar characteristics by another method has been desired.

An object of the present invention is to provide a method for producing an ultrafine magnetic alloy having excellent high-frequency magnetic properties exhibiting low magnetic core loss with a high squareness ratio or high magnetic permeability with a low squareness ratio.

[Means for Solving the Problems] As a result of intensive studies to achieve the above object, the present invention considers Fe, Cu and M (where M is Nb, W, "I").
An ultrafine-crystalline magnetic alloy containing as an essential element at least one element selected from the group consisting of a, Zr, Hf, Ti, and Mo, and at least 50% of the structure consists of fine crystal grains. In the manufacturing method, a magnetic field is applied in a specific direction and a first magnetic field heat treatment is performed, and then a magnetic field is applied in a direction different from that direction and a second magnetic field heat treatment is performed to improve the magnetic properties. The inventors have discovered that a microcrystalline magnetic alloy can be stably produced and have conceived the present invention.

When the magnetic field heat treatment is performed using a 13-H curve for a high squareness ratio type, the direction of magnetic field application during the first magnetic field heat treatment is set in the longitudinal direction of the ribbon (if the magnetic core shape is used, the magnetic field direction is It is most preferable to apply the magnetic field in the second magnetic field heat treatment in the width direction of the ribbon (in the case of a magnetic core shape, in the direction perpendicular to the magnetic path), and an alloy with a high squareness ratio and low core loss can be obtained. Cheap.

On the other hand, when using a low squareness ratio type B-H curve,
The direction of magnetic field application in the magnetic field heat treatment shown in Table 1 is the width direction of the ribbon (
It is most preferable to apply the magnetic field in the second magnetic field heat treatment in the longitudinal direction of the ribbon (in the case of a magnetic core shape, perpendicular to the magnetic path), and with a low squareness ratio. It is easy to obtain alloys with high magnetic permeability.

In the manufacturing method of the present invention, heat treatment is required so that at least 50% of the structure becomes fine crystal grains,
This heat treatment may be performed during the first heat treatment in a magnetic field while crystallizing it, or may be performed separately before the first heat treatment in a magnetic field.

The atmosphere for the heat treatment is preferably an inert gas atmosphere such as Ar or nitrogen, a vacuum, hydrogen, or the like. The magnitude of the applied magnetic field varies depending on the direction of application and the shape of the alloy, but when applied in the longitudinal direction, the magnitude of the magnetic field is O. lOe or more, looo when applying in the width direction
E or higher is desirable.

Particularly preferably, it is more than toe in the longitudinal direction and lo in the width direction.
000e or more.

Further, the average grain size of the crystal grains of the produced alloy is 1000 grains or less, and particularly excellent properties are easily obtained when the average grain size is 500 grains or less. More preferably 20 to 200 people.

Further, the above characteristics can also be obtained by heat treatment in a magnetic field that combines two or more magnetic fields applied in different directions.

As the alloy according to the present invention, the present inventors have specially developed
There is an Fe-based ultrafine crystal alloy previously filed as No. 367187. This alloy has the composition formula: (Fe, -, Ma), @ I -A - F-, -,
CuSi,B. M'.

(However, M is Co and/or Ni, M゜ is Nb,
At least one element selected from the group consisting of W, Ta, Zr, Hf, Ti and Mo, a+ X+ V
+ Z and α are 0≦a≦0.5, 0.1≦X, respectively
≦3, O, O≦y≦30I O≦Z≦25.5
≦y+z≦30 and 0.1≦α≦30 are satisfied. ), an Fe-based ultrafine crystalline alloy in which at least 50% of the structure consists of fine crystal grains; -+-ICL
lxSlyl3J'aM"BX, (where M is Co and/or Ni, M" is Nb, W, 'ra, Zr,
}At least one element selected from the group consisting of If, 'ri and Mo, M'' is ■, Cr, Mn, A
l, platinum base, Sc, Y, rare earth elements, Au, Zu, S
At least one element selected from the group consisting of n, Re, X is C, Ge, P, Ga, Sb, In, 13e, A
at least one element selected from the group consisting of s, and a, X+ y+ Z+ OL+ β and T are each 0≦a≦0.5, O. l≦X≦3. O;
0≦y≦30, 0≦2≦25, 5≦y1z≦30.0
. l≦α≦30. β≦10, γ≦10 are satisfied. )
It is an Fe-based microcrystalline alloy having a composition represented by the following, and at least 50% of the structure is composed of fine crystal grains.

Here, Fe, Cu and M (where M is Nb,
W, 'l'a, Zr, Hf, 'l'i and Mo
Cu, which is considered to be an element that promotes the formation of crystal nuclei and promotes crystal growth, and M, which is considered to be an element that suppresses crystal growth, are made essential elements. This is because an Fe-based ultrafine-crystalline alloy is obtained through the interaction of This microcrystalline alloy is made into microcrystals by heat treatment after deterioration, and it is preferable that it contains elements that promote deterioration, such as Si and B, in addition to the above-mentioned essential elements.

[Examples] Hereinafter, the present invention will be explained according to Examples, but the present invention is not limited thereto.

Next range ± atomic% Cu l%, Nb2.5%, Si13.5%
A molten alloy consisting of 7.2% B and essentially Fe was rapidly cooled by a single roll method to produce an amorphous alloy ribbon having a width of 5 nnn and a thickness of 18 μm.

Next, this alloy was wound to form a toroidal wound magnetic core with an outer diameter of 19 mu+ and an inner diameter of 15 mm, and then a glass-coated copper wire was wound around it.
A current is passed through the copper wire in the magnetic path direction of the magnetic core and in the longitudinal direction of the ribbon.
A magnetic field of 0e was applied. Next, this magnetic core was placed in a tube furnace in a nitrogen gas atmosphere maintained at 550° C. and held for 1 hour, and then cooled to room temperature at a rate of about 10° C./min to perform a first heat treatment in a magnetic field. Next, the sample was placed in a magnetic field heat treatment furnace maintained at 300°C with a structure in which a magnetic field of about 30,000 e was applied in the direction perpendicular to the magnetic path (in the ribbon width direction), and a magnetic field was applied, and after holding for a certain period of time, it was taken out from the furnace and air-cooled. Heat treatment was performed in a magnetic field. The heat treatment pattern is shown in FIG.

FIG. 2 shows the dependence of the squareness ratio Br/B, and the magnetic core loss Pc on the magnetic field heat treatment time of the second heat treatment at 100 KHz and 2 KG.

By the manufacturing method of the present invention that performs the second heat treatment in a magnetic field, characteristics of high squareness ratio and low core loss can be obtained. Note that most of the thin plate structure of the alloy consisted of ultrafine crystal grains with a grain size of approximately 100 grains.

An amorphous alloy ribbon with a width of 10M and a thickness of 18μm was obtained by rapidly cooling a molten alloy consisting of atomic percent of Cu, 3% of Nb, 3.5% of Sil, 9% of B, and the balance Fe using a single roll method. was created.

Next, the second alloy thin plate was surface coated with AQ20, and this was wound to form a toroidal magnetic core with an outer diameter of 19 mm and an inner diameter of 15 mm. While applying a magnetic field, the temperature was increased to 550°C at a heating rate of 5°C/min and held for 1 hour.
After cooling to 300°C at a cooling rate of °C/min, a magnetic field of l 00e was applied in the magnetic path direction (longitudinal direction of the ribbon).
After holding at 300'C for a certain period of time, return to room temperature at 5"C/IIIi
It was cooled at a cooling rate of n. The heat treatment pattern is shown in FIG. When applying a magnetic field in the direction of the magnetic path, a copper rod was placed in the center of the magnetic core and a direct current was applied thereto.

The microstructure of the alloy ribbon after heat treatment was the same as in Example 1.

FIG. 4 shows the dependence of the effective magnetic permeability μmlK on the magnetic field heat treatment time of the second heat treatment at the squareness ratio B r /B l @ and l K Hz.

By the manufacturing method of the present invention that performs the second heat treatment in a magnetic field, characteristics of high magnetic permeability with a low squareness ratio can be obtained. Such characteristics are ideal for common mode choke cores and the like.

Main atomic %: Cul%, Nb2.5%, Mo0.5%, Si
The melted alloy consisting of 14%, 89%, 001% and the balance substantially Fe was rapidly cooled by a single roll method to produce an amorphous alloy ribbon having a width of 25 mm and a thickness of 20 μ+71.

Next, MgO powder was applied to the surface of this alloy ribbon by electrophoresis, and the ribbon was wound to an outer diameter of 80M and an inner diameter of 65mm.
A toroidal wound magnetic core was fabricated. Next, a glass-coated copper wire was wound around this magnetic core, and the wire was placed in a furnace maintained at 450°C in an Ar gas atmosphere, and an electric current was passed through the copper wire.
A magnetic field of e was applied. On the other hand, a magnetic field of 1×500 e was applied from the outside of the furnace in the width direction of the ribbon, and heat treatment was performed in a synthetic magnetic field. After putting the sample into the furnace, the temperature was increased to 53°C at a heating rate of 2°C/min.
The temperature was raised to 0°C, held for 1 hour, and then cooled to room temperature at a heating rate of 2.5°C/lIIin.

The core loss of the alloy after heat treatment is 4 at 100 KHz and 2 KG.
It was 50o+w/cc. For comparison, heat treatment was performed under the same conditions without applying the magnetic field in the width direction of the ribbon.
00KHz, 2KG core loss is 9 6 0i+w/c
c, and the core loss was reduced by the heat treatment of the present invention.

[5M light effect] According to the present invention, it is possible to provide a method for manufacturing an ultrafine crystal magnetic alloy with excellent high/4 wave magnetic properties suitable for saturable reactors, transformers, choke coils, magnetic heads, etc. There are some notable ones.

[Brief explanation of drawings]

FIGS. 1 and 3 are diagrams showing examples of heat treatment patterns according to the present invention, and FIGS. 2 and 4 are diagrams for explaining the present invention, showing the relationship between magnetic properties and heat treatment time in a magnetic field. It is. Math 1 diagram? lfJ2 map Sabama EJ story fake middle 'a 41 machima (h) Jozu time mourning map puP! 5 Nakaka Akari Interchange (9) Diagram Heat treatment time in magnetic field (h) Procedural amendment (spontaneous) 1998/10-7 Japan Patent Application No. 574 7 1999 Title of Invention: Manufacture of ultrafine-crystalline alloy Relationship with the case of the person making the method amendment

Claims (5)

[Claims] (1) Fe, Cu and M (M is Nb, W, T
In a method for producing an ultrafine crystalline magnetic alloy containing as an essential element at least one element selected from the group consisting of a, Zr, Hf, Ti, and Mo, and at least 50% of the structure is composed of fine crystal grains, is applied in a specific direction and the first
A method for producing an ultrafine-crystalline magnetic alloy, which comprises performing heat treatment in a magnetic field, and then applying a magnetic field in a direction different from that direction to perform heat treatment in a second magnetic field. (2) The magnetic field application direction in the first magnetic field heat treatment is the longitudinal direction of the alloy ribbon, and the magnetic field application direction in the second magnetic field heat treatment is the width direction or thickness direction of the alloy ribbon. The method for producing an ultrafine crystal magnetic alloy according to claim 1. (3) The magnetic field application direction in the first magnetic field heat treatment is the width direction or thickness direction of the alloy ribbon, and the magnetic field application direction in the second magnetic field heat treatment is the longitudinal direction of the alloy ribbon. The method for producing an ultrafine crystal magnetic alloy according to claim 1. (4) The method for producing an ultrafine-crystalline magnetic alloy according to any one of claims 1 to 3, characterized in that the heat treatment step is performed multiple times. (5) A method for producing an ultrafine-crystalline magnetic alloy having the above composition, wherein the heat treatment in a magnetic field is performed in a magnetic field that is a combination of magnetic fields applied in different directions.