JPH01156452A - Fe-based magnetic alloy - Google Patents

Abstract

PURPOSE:To obtain an Fe-based magnetic alloy having superior magnetic properties and reduced in magnetostriction by rapidly cooling a molten Fe-Ni-Co alloy having a specific composition containing Si and B as essential elements to make the above alloy amorphous and then applying heat treatment to the above to form a part of the structure into fine crystals. CONSTITUTION:A molten Fe-based alloy represented by a general formula (where M' means at least one kind selected from Nb, W, Ta, Mo, and other elements, X means at least one element among, C, Ge, Ga, Al, and Be, Y means at least one kind selected from P, Sb, In, As, and other elements, a=0-0.2, b=0-0.5, a+b=0-0.5, y=4-30, z=2-9, alpha=0-20, gamma=0-20, delta=0-2, and y+z+gamma=10-35) is cooled rapidly so as to be formed into amorphous state, which is subjected to heat treatment at 450-700 deg.C so as to be formed into a structure in which at least 50% of the structure is composed principally of Fe solid solution of bcc structure and is in a state of fine crystals as to have <=1,000Angstrom average grain size measured by the maximum size and the balance remains in the amorphous state.

Description

Detailed Description of the Invention [Field of Application in the Ordinary Industry] The present invention is directed to Fe-based magnetic alloys having excellent magnetic properties and low magnetostriction, particularly Fe-based magnetic alloys having a structure mostly composed of fine crystal grains.
0 Regarding Base Magnetic Alloys Conventionally, ferrite, which has advantages such as low eddy current loss, has been mainly used as a magnetic core material for high frequency transformers, magnetic heads, saturable reactors, check coils, etc. However, since ferrite has a low saturation magnetic flux density and poor temperature characteristics, it has the disadvantage that it is difficult to miniaturize the magnetic core when used in high frequency transformers and gear coils.

In recent years, amorphous magnetic alloys with high saturation magnetic flux densities have been viewed as promising to compete with conventional magnetic core materials, and amorphous alloys with various compositions have been developed mainly using Fe yarns. Fe-based amorphous alloys have the advantage of being cheaper in material cost than Co-based alloys, but on the other hand, they have a higher core loss than Co-based amorphous alloys at high frequencies for boat fishing, and have lower magnetic permeability. The problem is that it is low. On the other hand, the amorphous alloy of Co thread has small core loss at high frequencies and high magnetic permeability, but the core loss and magnetic permeability change over time are large. Furthermore, since expensive Co is used as the main raw material, a cost disadvantage cannot be avoided.

Under these circumstances, various proposals have been made regarding Fe-based amorphous magnetic alloys.

Special Publication No. 17019/1986 discloses Fe with 74 to 84 atoms.
, B of 8 to 24 raw materials, at least one of Sl of 16 atoms or less and C of 6 atoms or less, and at least 85 atoms of the structure are an amorphous metal. It has the shape of a matrix and has precipitates of crystalline particles of alloying components distributed discontinuously throughout the amorphous metal matrix, and the crystalline particles have a size of 0.05 to 1 μm. An iron-based boron-containing magnetic non-magnetic non-magnetic material having an average particle size and an average interparticle distance of 1 to 10 μm, and characterized in that the particle group occupies an average volume fraction of 0.01 to 0.3 of the whole. A crystalline alloy is disclosed. The crystalline grains of this alloy are said to be a discontinuously distributed α-(Fe, St) grains that act as pinning points of the domain wall.

Also, JP-A-60-52557 is FeB CubBe
5t(1 (however, 75≦a≦85, 0≦b≦1.5.1
Disclosed is a low-loss amorphous magnetic alloy having the following relationship: 0≦C≦20°d≦10 and c+d≦60). This amorphous magnetic alloy is heat treated at a temperature below the crystallization temperature and above the Curie temperature.

[Problem that the invention seeks to solve]

Although the core loss is reduced due to the presence of discontinuous crystal grain groups in the Fe-based magnetomagnetic alloy of Japanese Patent Publication No. 60-17019,
It is unsatisfactory as a material for magnetic cores in high-frequency transformers and chisels because of its large change over time.

On the other hand, the Fe-based amorphous alloy of JP-A No. 60-52557 contains Cu, so the core loss is significantly reduced, but it is not as satisfactory as the Fe-based amorphous alloy containing crystalline particles mentioned above. isn't it. Further, there are problems in that changes in core loss over time, magnetic permeability, etc. are not sufficient. In addition, the magnetostriction is large, the variation in magnetic properties is large, and the Curie temperature is
It is lower than -8t-A1 alloy and Fe-5t alloy, and its magnetic properties are also inferior in stability.

Therefore, an object of the present invention is to provide a novel Fe-based magnetomagnetic alloy that has low magnetostriction and excellent stability in core loss, change in core loss over time, magnetic permeability, and other magnetic properties.

[Means for solving problems]

As a result of intensive research in view of the above objectives, the present inventors have determined that the general formula % (atomic ti) (where M is Nb, W, Ta, Zr, Hf, Ti, M
o+V.

Cr, Mn p White metal element Sc, Y, rare earth element +
Au a Zn.

At least one element selected from the group consisting of Sn*Re, X is CrGe*Ga*AL, Be
At least one element selected from the group consisting of, Y is p
+ sb + In rAs + Li + Mg, Ca
+Sr, Ba+Cd, Pb, Bi lNt O+S,
At least one element selected from the group consisting of Se and Te, 0≦a<0-2.0≦b<0.5.0≦a+b<0.5
t4≦y≦60, 2≦2≦9, 0≦α≦20゜0≦γ≦
20, 0≦δ≦2, 10≦y+z+r≦35.

) If at least 50% of the structure of an alloy with the composition represented by They discovered that magnetism can be obtained and came up with the present invention.

In the present invention, St and B are essential elements, and are elements useful for refining the crystal grains of the alloy and improving the magnetostriction adjustment soft magnetic properties.

The alloy of the present invention preferably comprises -dan81. It is obtained by forming an amorphous alloy by adding B and then forming fine crystal grains by heat treatment.

The reason for limiting the St-containing jky is that if y exceeds 30 atoms, the magnetostriction will become large under conditions with good soft magnetic properties, which is undesirable, and if y is less than 4 atoms, the soft magnetic properties will deteriorate significantly, which is undesirable. be. The reason for limiting the B content to 2 is that if 2 is less than 2 atoms, it is difficult to obtain a uniform crystal grain structure and the soft magnetic properties deteriorate, which is undesirable.
This is because if the magnetic field exceeds the maximum magnetostriction, the magnetostriction becomes large under heat treatment conditions that provide good soft magnetic properties, which is undesirable.

X is at least one element selected from the group consisting of C, Ge, Ga*At+Be, and these elements are effective for amorphization, magnetostriction, Chier temperature adjustment, etc. The reason for limiting γ is that if it exceeds 20 atoms, the soft magnetic properties will deteriorate significantly and the saturation magnetic flux density will also decrease.

Regarding the value of the total amount y+z+γ of St, B, and X, y+
If z+γ is less than 10 atoms, it is difficult to make it amorphous and the magnetic properties deteriorate, which is undesirable. On the other hand, if y-I-z+r is 3
If it exceeds 5 atoms, there will be a significant decrease in saturation magnetic flux density and deterioration of soft magnetic properties. A more preferable range of St and B content is 10≦y≦25°4≦2≦7.

Within this range, particularly excellent soft magnetism can be obtained, and magnetostriction can also be easily obtained.

In the alloy according to the present invention, M has the effect of making crystal grains finer and improving corrosion resistance, and can be contained in an amount of 20 atoms or less. The reason for this is that M contains Miiα
This is because when the amount exceeds 20 atoms, the saturation magnetic flux density decreases significantly. A particularly preferable range of α is 1≦α≦1
0, and excellent soft magnetism can be obtained within this range. In particular, Nb, W, Ta, and Mo are preferable as M in terms of soft magnetic properties.

The additive element Y is P*Sb, In*As r L
i* Niat Ca , Sr rBa , Cd
, Ph , Bj, , N r Or S r S
It is at least one element selected from the group consisting of e and Te, and may contain up to two atoms.

The remainder is essentially Fe, excluding impurities, but F
A part of e may be replaced by Ni and/or Co. Ni content Jila is OSa<0.2, but
This is because soft magnetism deteriorates significantly when it exceeds 0.2, and tVfK is preferably in the range 110≦a; S 0.1
It is. Particularly good soft magnetism can be obtained within this range.

The Co content satisfies 0≦b<o, s, and the total sum a+b with the Ni content satisfies 0≦a+b<0.5. Particularly preferable Co content and the sum of Co and Ni contents are 0
≦b≦0.1.0≦a+b≦0.1.

The alloy of the present invention is an alloy mainly composed of a fine ccFe solid solution, in which at least 50% of the structure is composed of fine crystal grains, and the average grain size measured at the maximum dimension of the crystal grains is 1000A.
The alloy has an average grain size of It is made from crystallized K.

Particularly excellent soft magnetic properties can be obtained when the average particle size of the nine particle sizes measured in the maximum dimension is 500A or less.

Although the remainder of the crystal grains are mainly amorphous, the alloy of the present invention can obtain sufficiently excellent soft magnetic properties even if it is substantially 100% crystalline.

Furthermore, the alloy of the present invention is an alloy mainly composed of bccFe solid solution, and the saturation magnetostriction λs is in the range of -5x10 to +5x10-', and the magnetostriction is significantly lower than that of the Fe-based amorphous alloy. Furthermore, alloys with almost zero magnetostriction can also be obtained.

The Fe-based magnetic alloy of the present invention can be produced by the single roll method as described above.
Amorphous thin strips are prepared by the twin roll method, centrifugal quenching method, etc., and then heat treated to form fine crystal grains. Amorphous films are prepared by vapor deposition, sputtering, ion blating, etc. An amorphous wire was obtained by a method of post-heat treatment and crystallization, a method of obtaining amorphous powder by an atomization method or a cavitation blowing method, and then a method of heat-treating and crystallizing it, a spinning method in a rotating liquid, or a glass-covered spinning method. It can be produced by various methods such as a method of post-heat treatment and crystallization. Therefore, the alloy of the present invention can be made into various shapes such as powder, wire, ribbon, and film, and can also be made into a bulk body by pressure welding.

The heat treatment performed before obtaining this alloy is performed for the purpose of reducing internal strain, creating a fine grain structure, improving soft magnetic properties, and reducing magnetostriction.

Heat treatment is usually done in vacuum or with water purple gas or nitrogen gas.

This is carried out in an inert gas atmosphere such as argon gas. However, depending on the case, it may be performed in the atmosphere.

The heat treatment temperature and time vary depending on the shape, size, and composition of the magnetic core made of amorphous alloy ribbon, but generally 450℃~
Preferably, the temperature is 700°C for about 5 minutes to 24 hours.

Conditions for heating and cooling during heat treatment can be arbitrarily changed depending on the situation. The heat treatment can also be performed in a multi-stage heat treatment pattern, in which the heat treatment is performed multiple times at the same temperature or at different temperatures. Furthermore, the present alloy can also be heat treated in a direct current or alternating current magnetic field. Magnetic anisotropy can be produced in the p-based alloy by heat treatment in a magnetic field. When heat-treated by applying a magnetic field in the magnetic path direction of a magnetic core made of this alloy, a product with good B-H curve squareness can be obtained, which can be used for saturable reactors, magnetic switches, cores for pulse compression, and reactors for preventing spike voltages. On the other hand, when heat treatment is performed by applying a magnetic field in the direction perpendicular to the magnetic path, the B-H curve becomes sloped, and excellent characteristics with low squareness ratio and constant velocity magnetic properties are obtained, and the transformer It is suitable for use as noise filters, check coils, etc.

It is not necessary to apply a magnetic field throughout the heat treatment, and it is sufficiently effective if it is applied at a temperature lower than the Chierly temperature Tc of the alloy. The Chielly temperature of the main phase of the alloy of the present invention is higher than that of the amorphous alloy, and heat treatment in a magnetic field can be applied even at a temperature higher than the Chielly temperature of the amorphous alloy. Further, the soft magnetic properties can be further improved by heat treatment in a rotating magnetic field. Alternatively, the alloy can be heat-treated by passing a current through the alloy and applying a high-frequency magnetic field to generate heat in the alloy.

The magnetic properties can also be adjusted by heat treatment under stress. In particular, since the alloy of the present invention has the characteristic of low magnetostriction, it has the characteristic that the magnetic properties do not deteriorate even after forming an insulating layer on the alloy surface, impregnation or coating, and mold cores with excellent characteristics. Cut cores, coated cores, magnetic heads, etc. can be produced.

[Example] The present invention will be explained in more detail with reference to the following example.
The present invention is not limited to these examples. Example 1 Si 17.5 at%, B5 at%, Nb5a
An alloy ribbon was produced by a single roll method from a molten metal having a composition of t% and the balance substantially consisting of Fe. The plate thickness was 18 μm and the width was 311I+.

When this alloy was subjected to X-ray diffraction, a halo pattern unique to amorphous alloys was obtained. No crystalline phase was observed in the results of structure observation using a transmission electron microscope. The crystallization temperature of this alloy was 541° C. Next, this alloy was wound into a toroidal shape having an outer diameter of 19 m and an inner diameter of 155 m to prepare a wound magnetic core. Next, this wound magnetic core was heated to 560°C.
It was charged into a furnace with an Ar atmosphere maintained at
The mixture was cooled to room temperature at a cooling rate of 1.

FIG. 1(a) shows an X-ray diffraction pattern, and FIG. 1(b) shows a schematic diagram of the microstructure observed and observed with a transmission electron microscope.

From the results of structure observation using X-ray diffraction and transmission electron microscopy, it was confirmed that the majority of the structure of the alloy of the present invention is a fine grain size of 50 to 500A and represents a ccFe solid solution.

As for magnetic properties, saturation magnetic flux density Bs is 12.4KG, IKH
Effective magnetic permeability at z is 14300.2KG100KH
Core loss W2/1 at z (IIK is 630 mW/
cc and was confirmed to exhibit excellent soft magnetism. It was also confirmed that the saturation magnetostriction λ was +2.5×10, which was significantly smaller than that of the Fe-based amorphous alloy.

Actual flow example 2 5i17.8at% in atoms, B5. Oat%, Nb3
．． An alloy thin strip having a thickness of 18 μm and 5 m was produced by a single roll method from a molten metal having a composition of 1 atm and the remainder substantially consisting of Fe. This alloy exhibited a halo pattern characteristic of amorphous alloys as a result of X-ray diffraction, and no crystalline phase was observed in the results of structural observation using a transmission electron microscope, indicating that it was an amorphous single phase.

Next, this alloy ribbon was wound into a toroidal shape having an outer diameter of 19 and an inner diameter of 15 m, and was heat-treated in a nitrogen gas atmosphere to form a toroidal magnetic core. The holding time was 1 hour. During the heat treatment, a magnetic field of 50,000 e was applied to the sample and the sample was rotated. Cooling was carried out at a cooling rate of 5'c/H.

The relationship between heat treatment temperature and magnetic properties and the ratio of crystalline phase are determined first.
Shown in the table.

Table 1 It can be seen that when the ratio of crystalline phase exceeds 50%, the saturation magnetostriction constant λB becomes extremely small, and the soft magnetic properties also show good properties. Although the effective magnetic permeability at 1 KHz may be slightly lower than that of an amorphous alloy with a crystalline phase ratio of 0%, it is a value that poses no practical problem, and is characterized by a significantly small λ8, making it suitable for impregnation, etc. Since the deterioration of magnetic properties due to distortion is small, it is advantageous when used for mold cores, etc.

Example 6 An alloy ribbon having the composition shown in Table 2 and having a thickness of 15 μm and a width of 5 mm was produced by a single roll method.

Next, this alloy ribbon was wound to have an outer diameter of 19 fi and an inner diameter of 15 mm to make a toroidal magnetic core, and after heat treatment in an N2 gas atmosphere at a temperature higher than the crystallization temperature, the core loss at 100 KHz, 0.27, and the saturation magnetostriction λ were 8120°C. The rate of increase in core loss after holding for 1000 hours was measured.

Wo: Initial core loss Wtooo: Core loss cylinder after 1000 hours Table 2 Note that as a result of structure observation using a transmission electron microscope, it was confirmed that the microstructure was almost the same as in Example 1.

As can be seen from the table, the alloy of the present invention has a Fe base of 7 mol 7
As alloy, the saturation magnetostriction λ8 is extremely small and the core loss is also small. Furthermore, compared to Fe-based and Co-based amorphous alloys, the rate of change in core loss over time is significantly smaller and more stable. Therefore, a highly reliable magnetic core can be manufactured.

Example 4 An alloy film having the composition shown in Table 3 and having a thickness of 6 μm was prepared on an Otoceram substrate by magnetron sputtering. As a result of X-ray diffraction, it was confirmed that the alloy film obtained was almost an amorphous single phase.

Next, this alloy was heat treated in an N gas atmosphere to a temperature higher than the crystallization temperature. The fiber composition of the obtained alloy film was almost the same as in Example 1. Next, the IMHz effective magnetic permeability μeIM of this alloy film was measured, and then the IMHz effective magnetic permeability μ”IM after holding at 120°C for 100 hours was measured.IMHz
The rate of change in effective magnetic permeability Δμ0Mth0M As can be seen from the above, the alloy film of the present invention is superior in that the change over time is significantly smaller than that of the conventional alpha alpha alloy film.

〔Effect of the invention〕

According to the present invention, it is possible to obtain an Fe-based magnetic alloy having excellent soft magnetic properties, low magnetostriction, and excellent thermal stability, so the effects are remarkable.

[Brief explanation of the drawing]

FIG. 1(a) is a diagram showing an example of the X-ray diffraction pattern of the alloy of the present invention, and FIG. 1(b) is a diagram showing a schematic diagram of the structure of the alloy of the present invention observed by a transmission electron microscope.

Claims (1)

[Claims] 1. General formula (Fe_1_-_a_-_bNi_aCo_b)_1_
0_0_-_y_-_z_-_α_-_β_-_γ_-
_δSi_yB_zM'_αX_γY_δ (atomic %) (However, M' is Nb, W, Ta, Zr, Hf, Ti,
At least one element selected from the group consisting of Mo, V, Cr, Mn, platinum metal element, Sc, Y, rare earth element, Au, Zn, Sn, Re, X is C, Ge, Ga, Al, B
At least one element selected from the group consisting of e, Y is P, Sb, In, As, Li, Mg, Ca, Sr, Ba
, Cd, Pb, Bi, N, O, S, Se, and Te, and 0≦a<0.2, 0≦b≦0.5, 0≦a+b <0.5
, 4≦y≦30, 2≦z≦9, 0≦α≦20, 0≦γ≦
20, 0≦δ≦2, 10≦y+z+γ≦35. ) and at least 50% of the tissue
% of the crystal grains, and the average grain size measured at the maximum dimension of the crystal grains is 1000 Å or less. (2) In the Fe-based magnetic alloy according to claim 1, a, b, y, z, α, and γ are 0≦a≦0.1, 0≦b≦0.1, 0≦a+b ≦0.1
, 10≦y≦25, 4≦z≦7, 1≦α≦10, 0≦γ
An Fe-based magnetic alloy characterized by satisfying the relationship of ≦10. (3) The Fe-based magnetic alloy according to claims 1 and 2, wherein the remainder of the structure is amorphous. (4) The Fe-based magnetic alloy according to claims 1 and 2, characterized in that the structure consists of substantially fine crystal grains. (5) The Fe-based magnetic alloy according to any one of claims 1 to 4, wherein the crystal grains are mainly composed of Fe solid solution having a bcc structure. (6) The average grain size measured at the maximum dimension of the crystal grains is 5
6. The Fe-based magnetic alloy according to claim 1, wherein the Fe-based magnetic alloy has an average grain size of 00 Å or less. (7) The Fe-based magnetic alloy according to any one of claims 1 to 6, wherein M' is at least one element selected from the group consisting of Nb, W, Ta, and Mo. (8) Saturation magnetostriction λ_s is -5×10^-^6 to +5×1
The Fe-based magnetic alloy according to any one of claims 1 to 7, characterized in that the Fe-based magnetic alloy is in the range of 0^-^6.