JPH07258728A - Production of iron-base fine crystal soft magnetic alloy - Google Patents

Abstract

PURPOSE:To produce the iron-base fine crystal soft magnetic alloy having high magnetic permeability and low magnetic core loss by heat treating iron-base amorphous alloy under the prescribed condition. CONSTITUTION:An iron-base amorphous alloy of about <=30% crystal phase content which is obtained by a melt quenching method of single roll method, etc., is heat treated. The alloy preferably contains 0.1-3 atomic % Cu, 1-10% at least one kind among Nb, Mo, W, Ta, Ti, Zr, Hf, 0-25% Si, 0-20% B, in particular, the general equation, Fe100-x-y-z-aCuxSiyBzMa (in the equation M is Nb, Mo, W, Ta, 0.5<=x<=2%, 5<=y<=20%, 5<=z<=11%, 14<=y+z<=25%, 0.5<=y/z<=3, 2<=a<=5%) is preferably satisfied. Further, the heat treatment conditions are as follows: 0.5<=GAMMAH<=300 deg.C/min (GAMMAH: temp. rising rate); 450 deg.C<=TAUA<=700 deg.C (TA: heat treatment temp.); 5min<=tA<=24hr (tA: heat treatment time); 0.5(-)GAMMAC(-)300 deg.C/min (GAMMAC: temp. lowering rate) and C02<=4% (C02: residual oxygen concentration in the atmosphere).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to various transformers,
Fe, which has excellent magnetic properties and is suitable for use in choke coils, saturable reactors, magnetic heads, etc.
The present invention relates to a method for producing a base fine crystal soft magnetic alloy.

[0002]

BACKGROUND OF THE INVENTION In recent years, various Fe-based soft magnetic alloys having low core loss and low magnetostriction have been developed as magnetic core materials for various transformers, choke coils, saturable reactors, magnetic heads, and the like.

As such a soft magnetic alloy, for example, Japanese Patent Publication No. 4-4393 discloses a general formula: (Fe _1-w M _w ) _100-XYZa Cu _X Si _Y B
_Z M ^′ _a (where M is Co and / or Ni, M ^′ is at least one element selected from the group consisting of Nb, W, Ta, Zr, Hf, Ti and Mo, w, x, y,
z and a are 0 ≦ w ≦ 0.5 and 0.1 ≦ x, respectively.
≦ 3, 0 ≦ y ≦ 30, 0 ≦ z ≦ 25, 5 ≦ y + z ≦ 3
0, 0.1 ≦ a ≦ 30 is satisfied. ), A composition in which at least 50% of the structure is composed of fine crystal grains having an average grain size of 1000Å or less, and the balance is substantially amorphous, has a low core loss and It has been shown to be a soft magnetic alloy with low magnetostriction.

[0004] Among the microcrystalline soft magnetic alloy having the above composition, at least one element M ^'is selected Nb, W, Ta, from the group consisting of Mo, w,
x, y, z and a are w = 0, 0.5 ≦ x ≦ 2, 5 ≦
y ≦ 20, 5 ≦ z ≦ 11, 14 ≦ y + z ≦ 25, 2 ≦ a
The fine crystalline soft magnetic alloy satisfying ≦ 5 is a soft magnetic alloy having a particularly high saturation magnetic flux density, low core loss and low magnetostriction, which is disclosed in Japanese Patent Publication No. 4-4393, “Yoshizawa, Yamauchi: Japanese application. The Magnetics Society of Japan, 13 , 231 (1989) "," Yoshizawa, Yamauchi: The Japan Institute of Metals, 53 , 241 (1989) "and" Y. Yoshizawa an
d K. Yamauchi: Matterial Science and Engineering , A13
3, 176 (1991) ”.

On the other hand, the basic manufacturing method of the fine crystalline soft magnetic alloy having the above composition is disclosed in Japanese Patent Laid-Open No. 3190/1990.
The method for producing a fine crystalline soft magnetic alloy is disclosed in Japanese Patent Publication No. 09-09, in which a molten alloy having the above-described composition is rapidly cooled to form an amorphous alloy, and the obtained amorphous alloy is heat-treated. The process comprises forming fine crystal grains having an average grain size of 1000Å or less.

In order to facilitate industrial mass production of the amorphous alloy in the step of rapidly cooling the molten metal into the amorphous alloy in the method for producing the fine crystalline soft magnetic alloy, the general formula Fe _{100-xyza is used.} during _{Cu x Si y B z M a} ( wherein, M is Nb, Mo, W, represents at least one element selected from the group consisting of Ta, x, y, z and a are, respectively 0.5 ≦ x ≦ 2 (atomic%), 5 ≦ y ≦ 2
0 (atomic%), 5 ≦ z ≦ 11 (atomic%), 14 ≦ y + z
It satisfies ≦ 25 (atomic%) and 2 ≦ a ≦ 5 (atomic%). )
The present applicant proposes to use an alloy having a composition represented by the following formula and having a ratio of y and z (y / z) in the above composition in the range of 0.5 ≦ y / z ≦ 3. Proposed in No. 5-207677.

Further, in the above-mentioned Japanese Patent Application Laid-Open No. 3-219090.
Is the heat treatment temperature in the process of forming fine crystal grains.
(T_A) And heat treatment time (t_A) Are 45
0 ≦ T _A≤700 (° C), 5 minutes ≤t_A<24 hours satisfied
It shows that you must do it.

Regarding the changes in the magnetic permeability and the core loss with respect to the heat treatment temperature and the heat treatment time when the fine crystalline soft magnetic alloy is produced from the amorphous alloy having the composition represented by Fe _73.5 Cu ₁ Nb ₃ Si _13.5 B ₉ , , "Yoshizawa, Yamauchi:
In the Journal of the Japan Institute of Metals, 55 , 588 (1991) ”, an amorphous alloy having a composition represented by Fe _73.5 Cu ₁ Nb ₃ Si _13.5 B ₉ is heat-treated to obtain fine crystal grains. After the formation of heat treatment, heat treatment in a magnetic field at a temperature higher than 250 ° C gives induced anisotropy as the heat treatment time increases, and the magnetic permeability decreases. "Yoshizawa, Yamauchi: Japan Society for Applied Magnetics. Journal, 14 , 193 (1990) ”. The above experimental results show that induced anisotropy is imparted and magnetic permeability is reduced even in the temperature lowering process of the heat treatment process for crystallizing an amorphous alloy. However, the temperature decrease rate in the heat treatment step,
It does not disclose the relationship with the magnetic permeability of the obtained fine crystalline magnetic alloy.

Further, regarding the relationship between the residual oxygen concentration in the heat treatment atmosphere and the magnetic permeability of the obtained fine crystal soft magnetic alloy in the step of forming fine crystals, JP-A-2-
It is disclosed in Japanese Patent No. 38520. In this publication,

[0010]

[Chemical 1]

(However, M is Co and / or Ni, and M'is Nb, W, Ta, Zr, Hf, Ti and Mo.
At least one element selected from the group consisting of
M ″ is at least one element selected from the group consisting of V, Cr, Mn, Al, Pt group, Se, Y, rare earth elements, Au, Zn, Sn, Re, and X is C, Ge. , P, G
It is at least one element selected from the group consisting of a, Sb, In, Be and As, and a, x, y, z, α, β and γ are 0 ≦ a <0.5 and 0.1, respectively. ≦ x <3, 0 ≦
y <30, 0 ≦ z <24, 0 ≦ y + z ≦ 35, 0.1 ≦
α ≦ 30, 0 ≦ β ≦ 10 and 0 ≦ γ ≦ 10 are satisfied. )
It has been shown that the magnetic permeability of the fine crystal soft magnetic alloy having the composition represented by the following formula decreases with an increase in the residual oxygen concentration in the heat treatment atmosphere. Further, in the heat treatment step, if the residual oxygen concentration in the atmosphere exceeds 0.05%,
It has been shown that the surface of a wound magnetic core produced using a ribbon of this alloy is oxidized. However, there is no disclosure about the influence of residual oxygen in the heat treatment atmosphere on the magnetic core loss, and there are many unclear points about the relationship between the residual oxygen concentration in the heat treatment atmosphere and the magnetic core loss of the obtained fine crystalline magnetic alloy.

[0012] It should be noted that the above-mentioned known documents do not disclose the relationship between the temperature rising rate in the heat treatment step and the magnetic characteristics such as magnetic permeability and magnetic core loss of the obtained fine crystalline soft magnetic alloy.

The present invention has been made in view of the above prior art.
As a result of diligent study, Fe-based amorphous alloy was heat treated to produce Fe.
When producing a base fine crystal soft magnetic alloy, if the heat treatment temperature, heat treatment time, temperature rising rate, temperature lowering rate and residual oxygen concentration are controlled within a specific range, the magnetic permeability is high,
Further, they have found that an Fe-based fine crystalline soft magnetic alloy having a low magnetic core loss can be obtained, and completed the present invention.

[0014]

It is an object of the present invention to provide a method for producing an Fe-based fine crystalline soft magnetic alloy which has a high magnetic permeability and is capable of industrially mass-producing an Fe-based fine crystalline soft magnetic alloy with a small magnetic core loss. It is an object.

[0015]

SUMMARY OF THE INVENTION In the method for producing an Fe-based fine crystalline soft magnetic alloy according to the present invention, when an Fe-based amorphous alloy is heat-treated to produce an Fe-based fine crystalline soft-magnetic alloy, heat treatment is performed under the following conditions. it is characterized in that; heating rate _{(Γ H): 0.5 ≦ Γ} H ≦ 300 ℃ / min annealing temperature _{(T a): 450 ≦ T} a ≦ 700 ℃ heat treatment time (t _a): 5 min ≦ t _A ≤ 24 hours Cooling rate (Γ _C ): 0.5 ≤ Γ _C ≤ 300 ° C / min Residual oxygen concentration in atmosphere ( _CO2 ): _CO2 ≤ 4% In the present invention, the Fe-based amorphous alloy is , Cu, Nb, M
It is desirable that the Fe-based amorphous alloy contains at least one element selected from the group consisting of o, W, Ta, Ti, Zr, and Hf. Among them, Cu is 0.1 to 3
Atomic%, Nb, Mo, W, Ta, Ti, Zr and Hf
It is preferable that the Fe-based amorphous alloy contains at least one element selected from the group consisting of 1 to 10 at%, Si at 0 to 25 at%, and B at 0 to 20 at%. general formula: _{Fe 100-xyza Cu x Si y} B z M a ( wherein, M represents, Nb, Mo, W, represents at least one element selected from the group consisting of Ta, x, y, z and a is 0.5 ≦ x ≦ 2 (atomic%), 5 ≦ y ≦
20 (atomic%), 5 ≦ z ≦ 11 (atomic%), 14 ≦ y +
z ≦ 25 (atomic%), 0.5 ≦ y / z ≦ 3 (atomic ratio),
It is particularly preferable that the Fe-based amorphous alloy has a composition represented by 2 ≦ a ≦ 5 (atomic%).

In the present invention, it is preferable to perform the heat treatment under the following conditions: Temperature rising rate (Γ _H ): 1 ≦ Γ _H ≦ 200 ° C./min Heat treatment temperature (T _A ): 500 ≦ T _A ≦ 650 ° C. Time (t _A ): 5 minutes ≦ t _A ≦ 6 hours Cooling rate (Γ _C ): 1 ≦ Γ _C ≦ 200 ° C./min Residual oxygen concentration in atmosphere (C _O2 ): C _O2 ≦ 4% Furthermore, the present invention So it is particularly preferable to perform the heat treatment under the following conditions: heating rate _{(Γ H): 1 ≦ Γ} H ≦ 100 ℃ / min annealing temperature _{(T a): 500 ≦ T} a ≦ 650 ℃ heat treatment time (t _a ): 5 minutes ≤ t _A ≤ 6 hours Cooling rate (Γ _C ): 3 ≤ Γ _C ≤ 100 ° C / minute Residual oxygen concentration in atmosphere ( _CO2 ): _CO2 ≤ 0.5%

[0017]

DETAILED DESCRIPTION OF THE INVENTION The method for producing the Fe-based fine crystalline soft magnetic alloy according to the present invention will be specifically described below.

In the present invention, an amorphous alloy having a specific composition is heat-treated under the conditions described below to produce a Fe-based fine crystal soft magnetic alloy. The amorphous alloy used in the present invention is a Fe-based amorphous alloy, specifically, C
It is an alloy containing at least one element selected from the group consisting of u, Nb, Mo, W, Ta, Ti, Zr and Hf. Among them, from the viewpoint of the obtained magnetic characteristics (high magnetic permeability and low core loss), Cu is 0.1 to 3 atomic%, Nb, M
1 to 10 atomic% of at least one element selected from the group consisting of o, W, Ta, Ti, Zr and Hf, S
A Fe-based amorphous alloy containing i in an amount of 0 to 25 atomic% and B in an amount of 0 to 20 atomic% is preferable.

In the present invention, the general formula: Fe _100-xyza C
_{u x Si y B z M a} ( where in the general formula, M is, N
represents at least one element selected from the group consisting of b, Mo, W and Ta, and x is 0.5 ≦ x ≦ 2 (atomic%)
And y satisfies 5 ≦ y ≦ 20 (atomic%), and z
Satisfies 5 ≦ z ≦ 11 (atomic%), and a is 2 ≦ a ≦
It satisfies 5 (atomic%). Also, x and y are 14 ≦ y + z
≦ 25 (atomic%) is satisfied, and the ratio y of y and z is y
/ Z (atomic ratio) satisfies 0.5 ≦ y / z ≦ 3. It is particularly preferable that the Fe-based amorphous alloy having the composition represented by the formula (1) is obtained in order to obtain a fine crystal alloy having excellent magnetic properties (high magnetic permeability and low magnetic core loss).

The Fe-based amorphous alloy used in the present invention may have V, C if necessary, in addition to the composition of the above general formula.
r, Mn, Co, Ni, Ti, Zr, Hf, C, Ge,
Elements such as P, Ga, platinum group elements, and Au may be contained in a range of 5 atomic% or less. Further, unavoidable impurities such as O, N and S may be contained as long as the characteristics of the obtained Fe-based fine crystal soft magnetic alloy are not deteriorated.

Examples of the method for producing the Fe-based amorphous alloy having the above composition include the following methods. First, from the molten metal of the above composition, single roll method,
By a known liquid quenching method such as the twin roll method, a ribbon shape,
A linear or powdery Fe-based amorphous alloy is formed. The plate thickness of the Fe-based amorphous alloy ribbon manufactured by the single roll method or the like is usually about 5 to 100 μm, but the plate thickness is 25 μm.
The Fe-based fine crystalline soft magnetic alloy obtained by heating the following Fe-based amorphous alloy ribbon is particularly suitable as a magnetic core material used at high frequencies.

F used for the heat treatment used in the present invention
The e-based amorphous alloy may contain a crystalline phase, but Fe
If the crystal content (x _C ) in the base amorphous alloy is 30% or less, the fine structure of the fine crystalline alloy obtained by the heat treatment becomes uniform and excellent magnetic properties are exhibited.
The crystal content (x _C ) of the base amorphous alloy is preferably 30% or less. Here, in the present invention, the crystal content (x _C ) is the area of the diffraction peak from the crystalline phase (S _C ) and the amorphous content as shown in FIG. 2 in the X-ray diffraction pattern of the Fe-based amorphous alloy. It is defined as x _C (%) = S _C / (S _C + S _A ) × 100 using the area (S _A ) of the broad diffraction pattern due to the phase. However, Fe manufactured by the single roll method
In the case of the base amorphous alloy ribbon, the X-ray diffraction shall be measured from the free surface side of the ribbon.

Fe-based amorphous compound produced by a single roll method or the like
In the case of a gold ribbon, the crystal content (x _C) Is over 30%
Then, the mechanical strength of the ribbon will deteriorate, so
Difficult to dynamically wind or slit the ribbon
It becomes difficult and suitable for various transformers and choke coils.
Pretreatment of heat treatment such as processing Fe-based amorphous alloy into shape
It causes some trouble.

In particular, in order to mass-produce industrially stable Fe-based fine crystalline soft magnetic alloys, the crystal content (x _C ) of the Fe-based amorphous alloy ribbons should be 5% or less. It is preferably 0%, and most preferably 0%. When the Fe-based fine crystalline soft magnetic alloy is produced by the method of the present invention using the Fe-based amorphous alloy having the above composition, the Fe-based fine crystalline soft magnetic material having high saturation magnetic flux density, low magnetic core loss and low magnetostriction is obtained. It enables mass production of alloys. Further, the alloy having the above composition is easy to industrially mass produce the Fe-based amorphous alloy.

Among the Fe-based amorphous alloys, Cu is 0.1%.
1 to 3 atomic%, Nb, Mo, W, Ta, Ti, Zr
And at least one element selected from the group consisting of Hf
1 to 10 atomic% of element, 0 to 25 atomic% of Si,
And a Fe group containing B in an amount of 0 to 20 atomic%
Amorphous alloy, especially the general formula: Fe_100-xyzaCu_xSi _y
B_zM_aA Fe-based amorphous alloy having a composition represented by
By using the method of the present invention and heat treatment,
And excellent high permeability, low core loss Fe-based fine crystalline soft magnetism
Since an alloy can be obtained, Cu is added to 0.5 to 2 layers.
Fe-based amorphous alloys containing 0.5% by weight, especially the general formula: Fe
_100-xyzaCu_xSi_yB_zM_a(However, the above general formula
Medium M is selected from the group consisting of Nb, Mo, W and Ta.
Represents at least one element, and x is 0.5 ≦ x ≦
2 (atomic%) is satisfied, and y is 5 ≦ y ≦ 20 (atomic%)
And z satisfies 5 ≦ z ≦ 11 (atomic%), and a
Satisfies 2 ≦ a ≦ 5 (atomic%). Also, x and y are
14 ≦ y + z ≦ 25 (atomic%) is satisfied, and
The ratio y / z (atomic ratio) of y and z is 0.5 ≦ y / z ≦ 3.
Meet ) Fe-based amorphous having a composition represented by
It is preferable to use a quality alloy.

In the present invention, F having the above composition is used.
For an e-based amorphous alloy, the following temperature rising rate (Γ _H ), heat treatment temperature (T _A ), heat treatment time (t _A ), temperature decrease rate (Γ
_C ) and the heat treatment atmosphere under the condition of residual oxygen concentration (C _O2 ) to produce a Fe-based fine crystalline soft magnetic alloy.
The heat treatment of the Fe-based amorphous alloy is usually performed in a heating furnace.

The heating rate (Γ _H ) is the average heating rate from the crystallization start temperature of the Fe-based amorphous alloy to the target heat treatment temperature. the temperature difference between base amorphous alloy crystallization starting temperature (T _C) and a target (set) the heat treatment temperature (T _a ^C), the target from the crystallization starting temperature (T _C) (setting been) divided by the heat treatment temperature (T _a ^C) the amount of time spent in the temperature is raised to (min). Here the target (the set) heat treatment temperature (T _A ^C) is actually Fe in the range of 450-700 ° C.
This is the temperature at which the base amorphous alloy is heat-treated. For example, when the temperature is raised and held for a certain period of time, it is the holding temperature, and when it is changed over time after the temperature is raised, the average heat treatment temperature (average holding temperature). Is.

The heat treatment temperature (T _A ) means F to obtain (manufacture) an Fe-based microcrystalline alloy from an Fe-based amorphous alloy.
This is the temperature at which the e-based amorphous alloy is heat-treated. The heat treatment time (t _A ) is the time (minutes) when the temperature is within the range of the heat treatment temperature (T _A ).

The temperature decrease rate (Γ _C ) means the average cooling rate when the Fe-based fine crystalline soft magnetic alloy is cooled from the heat treatment temperature (T _A ) to 250 ° C., and is specifically a target (setting). has been) a temperature difference between 250 ° C. and the heat treatment temperature (T _a ^C), divided by the target (set) the heat treatment temperature (T _a ^C) from required lowered to 250 ° C. time (min) value Is.

The heating rate (Γ _H ) is 0.5 to 300 ° C. /
Min, preferably 1 to 200 ° C./min, more preferably 1
It is desirable to be in the range of -100 ° C / min, most preferably 1-9 ° C / min. When the temperature rising rate (Γ _H ) is in the above range, it is possible to obtain an Fe-based fine crystal soft magnetic alloy having high magnetic permeability and small magnetic core loss. In addition, the heating rate (Γ
_{When H 2} ) is in the above range, temperature control during temperature increase becomes easy and a large-scale heat treatment apparatus is not required.

In order to obtain a Fe-based fine crystal soft magnetic alloy having a high magnetic permeability and a low magnetic core loss, the temperature rising rate (Γ _H ) is set to 0.
It is necessary to set it to 5 ° C./minute or more, and more preferably 1 ° C./minute or more. Moreover, in order to obtain a temperature rising rate (Γ _H ) exceeding 300 ° C./min, a large-scale special heat treatment furnace must be used. Therefore, from the viewpoint of reducing the manufacturing cost, it is desirable that the temperature rising rate (Γ _H ) be 300 ° C./minute or less.

The method for heating the Fe-based amorphous crystal alloy to raise the temperature is not particularly limited, but specifically, (1)
_A method of inserting an Fe-based amorphous alloy into a heat treatment furnace kept at a desired heat treatment temperature (T _A ) and heating the alloy to raise the temperature, (2) pre-heating the Fe-based amorphous alloy A method may be mentioned in which the Fe-based amorphous alloy is placed in a heat treatment furnace and heated together with the heat treatment furnace to raise the temperature.

The heat treatment temperature (T _A ) is usually 450 to 70.
It is in the range of 0 ° C, preferably 500 to 650 ° C. When the heat treatment temperature (T _A ) is within the above range, fine crystals can be formed in a short time. Further, it is possible to obtain an Fe-based fine crystal soft magnetic alloy having high magnetic permeability and low magnetic core loss.

The heat treatment time (t _A ) is usually 5 minutes to 2 minutes.
It is desirable to be in the range of 4 hours, preferably 5 minutes to 6 hours. When the heat treatment time (t _A ) is within the above range, the entire alloy can be heated to a uniform temperature, and the magnetic properties of the obtained Fe-based fine crystal soft magnetic alloy have less variation. Further, it is possible to obtain a Fe-based fine crystalline soft magnetic alloy having a high magnetic permeability and a low magnetic core loss, and it is also excellent in productivity.

In the present invention, considering the manufacturing cost and the ease of temperature control during heat treatment, the heat treatment temperature (T _A ) is
It is preferable that the temperature is in the range of 500 to 650 ° C. and the heat treatment time (t _A ) is in the range of 5 minutes to 6 hours.

The temperature lowering rate (Γ _C ) is 0.5 to 300 ° C. /
Min, preferably 1 to 200 ° C./min, more preferably 3
It is desirable to be in the range of up to 150 ° C / min. When the temperature lowering rate (Γ _C ) is in the above range, it is possible to obtain a Fe-based fine crystal soft magnetic alloy having high magnetic permeability and small core loss. Further, when the temperature lowering rate (Γ _C ) is within the above range, the temperature adjustment during the temperature lowering becomes easier, and a large-scale heat treatment apparatus is not required.

Fe-based fine grains having high magnetic permeability and low core loss
In order to obtain a crystalline soft magnetic alloy, the cooling rate (Γ_C) Faster
It is better to do it, but the rate of temperature drop is over 300 ℃ / min.
(Γ _C), A large-scale forced cooling machine is used in the heat treatment furnace.
You have to set up a structure. This reduces manufacturing costs
From the aspect of_C) Is less than 300 ℃ / min
It is desirable that it is below.

The method for cooling the Fe-based fine crystal soft magnetic alloy is not particularly limited, but methods such as furnace cooling and air cooling can be adopted. Specifically, (1) a method of taking out the Fe-based fine crystalline soft magnetic alloy from the heat treatment furnace and naturally cooling the Fe-based fine crystalline soft magnetic alloy outside the heat treatment furnace,
(2) A method of taking out the Fe-based fine crystalline soft magnetic alloy from the heat treatment furnace and cooling it by blowing an inert gas for cooling to the Fe-based fine crystalline soft magnetic alloy, (3) Fe-based fine crystal soft magnetic alloy in the heat treatment furnace Natural cooling, (4) a method of cooling the Fe-based fine crystal soft magnetic alloy in the heat treatment furnace by increasing the flow rate of the atmosphere gas in the heat treatment furnace, (5) a Fe-based fine crystal soft magnet in the heat treatment furnace A method of directly blowing an inert gas onto the magnetic alloy to cool it, (6) a method of forcibly cooling the furnace wall from the outside by air cooling or water cooling, and cooling the Fe-based microcrystalline soft magnetic alloy in a heat treatment furnace You can

Residual oxygen concentration (C _O2 ) in heat treatment atmosphere
Is 4% or less, preferably 0.5% or less. When the residual oxygen concentration (C _O2 ) in the heat treatment atmosphere is within the above range, it is possible to obtain a Fe-based fine crystal soft magnetic alloy having high permeability and low core loss.

The heat treatment can be performed in vacuum,
It is preferably carried out in an inert atmosphere such as nitrogen or argon. When the heat treatment is performed in an oxidizing atmosphere having a residual oxygen concentration of more than 4%, such as the air, the magnetic permeability of the obtained Fe-based fine crystalline soft magnetic alloy is remarkably reduced and the core loss is also increased.

FIG. 1 shows a preferable heat treatment pattern in the heat treatment method for the Fe-based fine crystal soft magnetic alloy according to the present invention. The heat treatment pattern shown in FIG. 1 has an initial temperature (T _i ).
A step of raising the temperature to the heat treatment temperature (T _A) from step holds a predetermined time at the heat treatment temperature (T _A) and the heat treatment temperature (T
_A ) to a temperature near the initial temperature (T _i ). In the heat treatment pattern shown in FIG. 1, the temperature increase rate (Γ _H ) is the slope of the thick line (H), and the temperature decrease rate (Γ _C ) is (−1) times the slope of the thick line (C). In the heat treatment pattern shown in FIG. 1, the (set) heat treatment temperature (T _A ^C ) is a holding temperature for holding at a certain constant temperature within the heat treatment temperature (T _A ).

In particular, in the heat treatment according to the heat treatment pattern shown in FIG. 1, the temperature rising rate (Γ _H ), the heat treatment temperature (T _A ), the heat treatment time (t _A ) and the temperature lowering rate (Γ _C ).
It is desirable that the heat treatment temperature (T _A ) and the heat treatment time (t _A ) satisfy the following formula.

[0043]

[Equation 1]

The unit of t _A in log ₁₀ (t _A ) in the above formula is time. (For example, when t _A is 1 hour, log ₁₀ (t _A ) is 0.) In the present invention, the heat treatment temperature (T _A ) and the heat treatment time (t _A ) are within the above ranges. Most preferably, (T _A ) is held constant.

In the present invention, the temperature rising rate (Γ _H ), heat treatment temperature (T _A ), heat treatment time (t _A ),
The Fe-based amorphous alloy is heat-treated under the conditions of the temperature lowering rate (Γ _C ) and the residual oxygen concentration (C _O2 ) of the heat treatment atmosphere to produce a Fe-based fine crystalline soft magnetic alloy. It is particularly desirable to heat treat the amorphous alloy.

The heating rate _{(Γ H): 0.5 ≦ Γ} H ≦ 300 ℃ / min annealing temperature _{(T A): 450 ≦ T} A ≦ 700 (℃) heat treatment time (t _A): 5 min ≦ t _A ≦ 24 h cooling rate _{(Γ C): 0.5 ≦ Γ} C ≦ 300 residual oxygen concentration (° C. / min) atmosphere _{(C O2): C O2 ≦} 4 (%) rate of temperature increase (gamma _H): 1 ≦ Γ _H ≦ 200 ℃ / min annealing temperature _{(T A): 450 ≦ T} A ≦ 700 (℃) heat treatment time (t _A): 5 min ≦ t _A ≦ 24 h cooling rate _{(Γ C): 1 ≦ Γ} C ≦ 200 (° C. / min) residual oxygen concentration in the atmosphere _{(C O2): C O2 ≦} 4 (%) rate of temperature increase _{(Γ H): 1 ≦ Γ} H ≦ 200 ℃ / min annealing temperature (T _a): 500 ≦ T _A ≦ 650 (° C.) Heat treatment time (t _A ): 5 min ≦ t _A ≦ 6 h Temperature decrease rate (Γ _C ): 1 ≦ Γ _C ≦ 200 (° C./min) Residual oxygen concentration in atmosphere (C _{O2 ): C O2 ≦ 4 (%} ) rate of temperature increase _{(Γ H): 1 ≦ Γ} H ≦ 200 ℃ / min annealing temperature _{(T A): 500 ≦ T} A ≦ 650 (℃) heat treatment time (t _A): 5 Min ≤ t _A ≤ 6 hours Temperature decrease rate (Γ _C ): 1 ≤ Γ _C ≤ 200 (° C / min) Residual oxygen concentration in atmosphere ( _CO2 ): _CO2 ≤ 0.5 (%) Temperature increase rate (Γ _{H): 1 ≦ Γ H ≦} 100 ℃ / min annealing temperature _{(T A): 500 ≦ T} A ≦ 650 (℃) heat treatment time (t _A): 5 min ≦ t _A ≦ 6 h cooling rate (gamma _C): 3 ≦ Γ _C ≦ 150 (° C./min) Residual oxygen concentration in atmosphere (C _O2 ): C _O2 ≦ 4 (%) Temperature rising rate (Γ _H ): 1 ≦ Γ _H ≦ 9 ° C./min Heat treatment temperature (T _A ): 500 ≤ T _A ≤ 650 (° C) Heat treatment time (t _A ): 5 minutes ≤ t _A ≤ 6 hours Temperature decrease rate (Γ _C ): 3 ≤ Γ _C ≤ 150 (° C / min) Residual oxygen in the atmosphere concentration (C _O2 : C _O2 ≦ 4 (%) rate of temperature increase _{(Γ H): 1 ≦ Γ} H ≦ 100 ℃ / min annealing temperature _{(T A): 500 ≦ T} A ≦ 650 (℃) heat treatment time (t _A): 5 minutes ≤ t _A ≤ 6 hours Temperature decrease rate (Γ _C ): 3 ≤ Γ _C ≤ 150 (° C / min) Residual oxygen concentration in atmosphere ( _CO2 ): _CO2 ≤ 0.5 (%) Temperature increase rate (Γ _{H ): 1 ≦ Γ H ≦ 100} ℃ / min annealing temperature _{(T A): -25log 10 (} t A) + 500 ≦ T A ≦ -25log 10 (t A) +630 (℃) heat treatment time (t _A): 5 minutes ≤t _A ≤24 hours Temperature decrease rate (Γ _C ): 3 ≤ Γ _C ≤150 (° C / min) Residual oxygen concentration in atmosphere ( _{CO 2} ): _{CO 2} ≤0.5 (%) Temperature increase rate (Γ _{H ): 1 ≦ Γ H ≦ 100} ℃ / min annealing temperature _{(T A): -25log 10 (} t A) + 500 ≦ T A ≦ -25log 10 (t A) +630 (℃) heat treatment time (t _A): 5 ≦ t _A ≦ 6 h cooling rate _{(Γ C): 3 ≦ Γ} C ≦ 150 (℃ / min) residual oxygen concentration in the atmosphere _{(C O2): C O2 ≦} 0.5 (%) In the present invention, The heat treatment can be performed either in a magnetic field or in a non-magnetic field, but it is preferable to use the above conditions in a non-magnetic field.

The method for producing the Fe-based fine crystal soft magnetic alloy according to the present invention may be of either batch type or continuous type as long as the above conditions are satisfied. Considering mass productivity, the continuous type heat treatment apparatus is superior, and the above conditions are relatively more easily satisfied than the batch type heat treatment apparatus.

The Fe-based fine crystalline soft magnetic alloy obtained by the method of the present invention preferably contains Cu in an amount of 0.5 to 2 atomic%, and Fe _100-xyza Cu _x Si _y B _z M
_a (In the formula, M represents at least one element selected from the group consisting of Nb, Mo, W, and Ta, and x, y, z, and a are each 0.5 ≦ x ≦ 2 (atomic% ) 5 ≦ y
≦ 20 (atomic%), 5 ≦ z ≦ 11 (atomic%), 14 ≦ y
It is particularly preferable to have a composition represented by + z ≦ 25 (atomic%), 0.5 ≦ y / z ≦ 3 (atomic ratio), and 2 ≦ a ≦ 5 (atomic%).

In such an Fe-based fine crystal soft magnetic alloy obtained in the present invention, the structure of fine crystal grains of an Fe solid solution having a bcc structure accounts for 50% or more of the whole. Crystal content of magnetic alloy (x _C )
Is x _C ≧ 50%.

The average grain size (D) of the fine crystal grains in the Fe-based fine crystal soft magnetic alloy is preferably 500 Å or less, more preferably 50 to 300 Å. For the average grain size (D) of fine crystal grains, the Bcc peak reflection (110) of the X-ray diffraction pattern is used, and the Scherrer equation (D = 0.9λ) is used.
/ Β cos θ) (Elementary X-ray Diffraction by Karity, New Edition of X-ray Diffraction)
(Second Edition), BDCulity), pp. 91-94). The Fe-based fine crystalline soft magnetic alloy having the above composition obtained in the present invention has particularly high magnetic permeability and low core loss.

[0051]

According to the present invention, it is possible to industrially mass-produce an Fe-based fine crystal soft magnetic alloy having high magnetic permeability and low core loss.

[0052]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited to these examples. In each of the following examples and comparative examples, the heat treatment was performed without a magnetic field.

[0053]

Examples 1 to _{3 An} amorphous alloy having a composition of Fe ₇₆ Cu ₁ Nb ₃ Si ₁₁ B ₉ (atomic%) and having a composition of about 17 μm was obtained by a single roll method. An alloy ribbon (X _c = 0%) is formed, and the obtained amorphous alloy ribbon is wound in a toroidal shape to have an outer diameter of 25 mm and an inner diameter of 15 m.
A toroidal magnetic core having a width of m and a width of 10 mm was produced. This magnetic core was heat-treated under the following conditions, the obtained magnetic core made of Fe-based fine crystal soft magnetic alloy was wound, and the magnetic permeability (μ) and magnetic core loss (P _C ) of the magnetic core were measured. The results are shown in Table 1.
Shown in.

The heat treatment temperature (T _A ^C ) [target (set) heat treatment temperature] shown in Table 1 is
As a result of various experiments conducted by changing the heat treatment temperature (T _A ), the temperature showed the highest magnetic permeability (μ).

In the present invention, the magnetic permeability (μ) is the frequency (f) = 1 kHz, the maximum applied magnetic field (H _m ) is 5 mOe, and the magnetic core loss (P _C ) is the frequency (f) = 100 k.
The measurement was performed under the conditions of Hz and maximum magnetic flux density (B _m ) = 0.1T.

[0056] heating rate _{(Γ H): 5,10,60 (℃} / min) Heat treatment temperature (T _A ^C): 560,570,570
(℃) Heat treatment time (t _A ): 1 hour Cooling rate (Γ _C ): 100 (℃ / min) Heat treatment atmosphere ： Residual oxygen concentration in nitrogen atmosphere (C _O2 ): 0.15 (%) Fe-based fine crystal The magnetic core made of soft magnetic alloy has a heating rate (Γ _H ).
There in a range of 5 to 60 ° C. / min, higher by selecting appropriate heat treatment temperature (T _A ^C) of about 47,000 to 51,000 permeability (mu) is obtained. High permeability (mu) annealing temperature capable of obtaining a (T _A ^C), together with a decrease in Atsushi Nobori rate (gamma _H), it can be seen that slightly shifted to the low temperature side.

[0057] As for the core loss (P _C), in the range of heating rate (gamma _H) is 5 to 60 ° C. / min, of about 15 mW / kg by choosing appropriate annealing temperature (T _A ^C) A low price is obtained.

[0058]

[Table 1]

[0059]

[Examples 4 to 6] The magnetic cores prepared in the same manner as in Examples 1 to 3 were heat-treated under the following conditions, and the magnetic cores made of the obtained Fe-based fine crystalline soft magnetic alloy were wound to form magnetic cores. The magnetic susceptibility (μ) and the magnetic core loss (P _C ) were measured. The results are shown in Table 2.
Shown in.

Here, the heat treatment temperature (T _A ^C ) [target (set) heat treatment temperature] shown in Table 2 is
As a result of various experiments conducted by changing the heat treatment temperature (T _A ), the temperature showed the highest magnetic permeability (μ).

[0061] heating rate _{(Γ H): 60 (℃} / min) Heat treatment temperature (T _A ^C): 560,570,570
(℃) heat treatment time (t _A): 1 hour cooling rate _{(Γ C): 3,10,100 (℃} / min) heat treatment atmosphere: the residual oxygen concentration in the nitrogen atmosphere _{(C O2): 0.15 (%} ) The core made of Fe-based fine crystal soft magnetic alloy has a cooling rate (Γ _C )
There in a range of 3 to 100 ° C. / min, higher by selecting appropriate heat treatment temperature (T _A ^C) of about 46000 to 49000 permeability (mu) is obtained. High permeability (mu) annealing temperature capable of obtaining a (T _A ^C), together with a decrease in cooling rate (gamma _C), it can be seen that slightly shifted to the low temperature side.

[0062] As for the core loss (P _C), in lowering rate (gamma _C) of 3 to 100 ° C. / min range, 15 mW / kg by choosing appropriate annealing temperature (T _A ^C)
A low price is obtained.

[0063]

[Table 2]

[0064]

[Examples 7 to 10] The magnetic cores produced in the same manner as in Examples 1 to 3 were heat-treated under the following conditions, and the obtained magnetic cores made of Fe-based fine crystal soft magnetic alloys were wound, and the magnetic cores were permeable. The magnetic susceptibility (μ) and the magnetic core loss (P _C ) were measured. The results are shown in Table 3.
Shown in.

[0065] heating rate _{(Γ H): 60 (℃} / min) Heat treatment temperature ^{_{(T A C): 570 (}} ℃) heat treatment time (t _A): 1 hour cooling rate _{(Γ C): 100 (℃} / min ) heat treatment atmosphere: the residual oxygen concentration in the nitrogen atmosphere (C _O2): 0.1, 0.1
5, 0.3, 4 (%)

[0066]

[Comparative Examples 1 and 2] Magnetic cores prepared in the same manner as in Examples 1 to 3 were heat-treated under the following conditions, and the obtained magnetic cores made of Fe-based fine crystal soft magnetic alloys were wound to form magnetic cores. The magnetic susceptibility (μ) and the magnetic core loss (P _C ) were measured. The results are shown in Table 3.
Shown in.

[0067] heating rate _{(Γ H): 60 (℃} / min) Heat treatment temperature ^{_{(T A C): 570 (}} ℃) heat treatment time (t _A): 1 hour cooling rate _{(Γ C): 100 (℃} / min ) Heat treatment atmosphere: Nitrogen Residual oxygen concentration ( _CO2 ) in the atmosphere: 16, 20 (%) From Examples 7 to 10 and Comparative Examples 1 and 2, the residual oxygen concentration ( _CO2 ) in the atmosphere was 0.1 to 0.1%. Almost l in the range of 4%
It decreases in proportion to og ₁₀ (C _O2 ). It can be seen that the magnetic permeability (μ) decreases by about 20% as the residual oxygen concentration (C _O2 ) in the atmosphere increases by one digit. This agrees with the tendency of the experimental results disclosed in Japanese Patent Laid-Open No. 2-38520. However, when the residual oxygen concentration (C _O2 ) in the atmosphere is 4% or more, the permeability (μ) is significantly deteriorated.

Further, it can be seen that the magnetic core loss (P _C ) is almost constant when the residual oxygen concentration (C _O2 ) in the atmosphere is 4% or less.

[0069]

[Table 3]

[0070]

Examples 11 to 14 The magnetic cores prepared in the same manner as in Examples 1 to 3 are heat-treated under the following conditions, and the magnetic cores made of the obtained Fe-based fine crystalline soft magnetic alloy are wound to form magnetic cores. The magnetic susceptibility (μ) and the magnetic core loss (P _C ) were measured. The results are shown in Table 4.

Here, the heat treatment temperature (T _A ^C ) [target (set) heat treatment temperature] shown in Table 4 is
As a result of various experiments conducted by changing the heat treatment temperature (T _A ), the temperature showed the highest magnetic permeability (μ).

[0072] heating rate _{(Γ H): 60 (℃} / min) Heat treatment temperature ^{_{(T A C): 500~600 (}} ℃) heat treatment time (t _A): 1,3,5,8 h cooling rate (gamma _C): 100 (° C. / min) heat treatment atmosphere: residual oxygen concentration (C _O2 in nitrogen atmosphere): 0.15 (%) Fe based microcrystalline soft magnetic alloy core, the heat treatment time (t _a ^C) is 1 In the range of up to 8 hours, the magnetic permeability (μ) and the core loss (P _C ) show similar values. The heat treatment temperature (T _A ^C) is not increased. Suitable heat treatment temperature (T _A ^C) is slightly shifted to the low temperature side. The rate of change is, the heat treatment time (t _A ^C) is 25 ° C. In one digit increase
It is a degree.

[0073]

[Table 4]

[Brief description of drawings]

FIG. 1 shows a preferable heat treatment pattern in a heat treatment method for an Fe-based fine crystal soft magnetic alloy according to the present invention.

FIG. 2 is a schematic diagram showing an X-ray diffraction pattern of a Fe-based fine crystal soft magnetic alloy.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location H01F 1/14

Claims (5)

[Claims] 1. A method for producing an Fe-based fine crystalline soft magnetic alloy, characterized in that, when the Fe-based amorphous alloy is heat-treated to produce an Fe-based fine crystalline soft-magnetic alloy, the heat treatment is performed under the following conditions: heating rate _{(Γ H): 0.5 ≦ Γ} H ≦ 300 ℃ / min annealing temperature _{(T A): 450 ≦ T} A ≦ 700 ℃ heat treatment time (t _A): 5 min ≦ t _A ≦ 24 hours cooling rate (Γ _C ): 0.5 ≦ Γ _C ≦ 300 ° C./min Residual oxygen concentration in atmosphere (C _O2 ): C _O2 ≦ 4% 2. The Fe-based amorphous alloy contains 0.1 to 3 atomic% of Cu, and 1 or more of at least one element selected from the group consisting of Nb, Mo, W, Ta, Ti, Zr and Hf. 2. The method for producing an Fe-based fine crystalline soft magnetic alloy according to claim 1, wherein the Fe-based amorphous alloy is an Fe-based amorphous alloy containing 1 to 10 atomic%, 0 to 25 atomic% Si, and 0 to 20 atomic% B. . Wherein the Fe-based amorphous alloy has the general formula: _{Fe 100-xyza Cu x Si y} B z M a ( where at least M has, Nb, Mo, W, is selected from the group consisting of Ta Indicates one element, x, y, z and a
Are 0.5 ≦ x ≦ 2 (atomic%) and 5 ≦ y ≦ 2, respectively.
0 (atomic%), 5 ≦ z ≦ 11 (atomic%), 14 ≦ y + z
≦ 25 (atomic%), 0.5 ≦ y / z ≦ 3 (atomic ratio), 2
The method for producing an Fe-based fine crystalline soft magnetic alloy according to claim 1, wherein the Fe-based amorphous alloy has a composition represented by ≦ a ≦ 5 (atom%). 4. The method for producing a Fe-based fine crystalline soft magnetic alloy according to claim 1, wherein the heat treatment is performed under the following conditions: Temperature rising rate (Γ _H ): 1 ≦ Γ _H ≦ 200 ° C. / Minute Heat treatment temperature (T _A ): 500 ≦ T _A ≦ 650 (° C.) Heat treatment time (t _A ): 5 min ≦ t _A ≦ 6 hours Temperature decrease rate (Γ _C ): 1 ≦ Γ _C ≦ 200 (° C./minute) Residual oxygen concentration in atmosphere (C _O2 ): C _O2 ≦ 4 (%) 5. The method for producing an Fe-based fine crystalline soft magnetic alloy according to claim 4, wherein the heat treatment is performed under the following conditions: Temperature rising rate (Γ _H ): 1 ≦ Γ _H ≦ 100 ° C./min Heat treatment temperature (T _A ): 500 ≤ T _A ≤ 650 (° C) Heat treatment time (t _A ): 5 minutes ≤ t _A ≤ 6 hours Temperature decrease rate (Γ _C ): 3 ≤ Γ _C ≤ 100 (° C / min) Residual oxygen in the atmosphere Concentration (C _O2 ): C _O2 ≦ 0.5 (%)