JPH0353048A - Fe-base magnetic alloy - Google Patents

Abstract

PURPOSE:To produce a magnetic alloy having superior soft magnetism by preparing an Fe-base magnetic alloy which consists of specific percentages of Fe, Ni, Co, Si, B, Nb, C, Sb, etc., and in which the content and average grain size of fine crystalline grains are specified, respectively. CONSTITUTION:An Fe-base magnetic alloy having a composition represented by a general formula (Fe1-a-bNiaCob)100-y-z-alpha-beta-gamma-deltaSiyBzM'alphaXgammaYdelta (where M' means at least one element selected from Nb, W, Ta, Zr, Hf, etc., X means at least one element selected from C, Ge, Ga, Al, Be, etc., Y means at least one element selected from Sb, In, As, Li, Mg, etc., and the symbols (a), (b), (y), (z), (alpha), (gamma), and (delta) stand for, by atomic%, 0-<0.2, 0-0.5, 0-30, 9-15, 0-20, 0.20, and 0-2, respectively, and further, 0<a+b<0.5 and 10<=y+z+alpha+gamma<=35 are satisfied) and also having a structure in which fine crystalline grains comprise at least 50% and the average of the grain sizes measured by respective maximum sizes of the above crystalline grains is regulated to <=1000Angstrom is prepared. By this method, the magnetic alloy having superior soft magnetism and reduced in magnetostriction can be obtained.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is directed to Fe having excellent soft magnetic properties and low magnetostriction.
Base magnetic alloys, especially F whose structure is mostly composed of fine crystal grains
This invention relates to an e-based magnetic alloy.

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, and choke coils. However, since ferrite has a low saturation magnetic flux density and poor temperature characteristics, it has the disadvantage that it is difficult to downsize the magnetic core when used in high frequency transformers and choke coils.

In recent years, non-quality magnetic alloys with high saturation magnetic flux densities have shown promise as competitors to conventional magnetic core materials, and various compositions have been developed.

Amorphous alloys are mainly divided into Fe-based and Co-based.
Non-quality Co-based alloys have the advantage of being cheaper in material cost than Go-based alloys, but on the other hand, they generally have the problem of higher core loss and lower magnetic permeability than Co-based amorphous alloys at high frequencies. On the other hand, Go-based amorphous alloys have low 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 magnetic alloys.

Japanese Patent Publication No. 17019/1987 discloses Fe of 74 to 84 atomic%.
and at least one of 8 to 24 atomic % B, 16 atomic % or less Si, and 3 atomic % or less C, and at least 85% of the structure is an amorphous metal. It has the shape of a matrix and has precipitates of crystalline grains of alloy components discontinuously distributed throughout the amorphous metal matrix, and the crystalline grains have an average size of 0.05 to 1 tm. An iron-based boron-containing magnetic amorphous material having a particle size and an average interparticle distance of 1 to 1O-, and the particle group occupying an average volume fraction of 0.01 to 0.3 of the whole. Discloses quality alloys. The crystalline particles of this alloy are said to be discontinuously distributed α (Fe, Si) particles that act as binning points of the domain wall.

Also, JP-A-60-52557 is Fea Cub
Bc Sid (75≦a≦85, 0≦b≦1.
5,10≦C≦20, d≦10 and c10d≦30). This non-quality magnetic alloy is heat treated below the crystallization temperature and above the Curie temperature.

[Problems to be Solved by the Invention] The Fe-based soft magnetic alloy disclosed in Japanese Patent Publication No. 17019/1987 has a reduced core loss due to the presence of discontinuous crystal grain groups;
It is not satisfactory as a material for magnetic cores in high-frequency transformers and chokes because it changes significantly over time.

On the other hand, the Fe-based non-quality alloy of JP-A No. 60-52557 contains Cu, so the core loss is significantly reduced, but like the crystalline particle-containing Fe-based non-quality alloy mentioned above, it is not satisfactory. . 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 the Si-AQ alloy and the Fe-Si alloy, and the stability of the magnetic properties is also inferior.

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

[Means for Solving the Problems] As a result of intensive research in view of the above objectives, the present inventors have developed the general formula (F e, -s-bN 1 acOb) toe-y-
t-a-g-+-s S L y B1 M'. x,
y. (atomic %) (However, M' is Nb, W, Ta, Zr, Hf, Ti,
Mo, V, Cr, Mn, white metal element, Sc, Y
, rare earth elements, Au, Zn, Sn, Re, X is C, Ge, Ga,
At least l elements selected from the group consisting of AQ, Be, P, Y is Sb, In, As, Lit Mg+ Ca
+ Sr, Ba, Cd, Pb, Bi, N, O, S, Ss
and at least one element selected from the group consisting of Te, and O≦a<0. 2, O≦b≦0. 5, O
≦a+b<0. 5, 0≦a+b<0.9 (z≦15
, O≦α≦20, O≦γ≦20.0≦δ≦2, 10≦y
10z1α10γ≦35 is satisfied. ) If at least 50% of the structure of the alloy is composed of fine crystal grains and the grain size measured at the maximum dimension of the crystal grains has an average grain size of 1000 or less, excellent soft magnetism can be obtained. The inventors have discovered that the present invention is possible.

In the present invention, B is an essential element, and is an element useful for refining the crystal grains of the alloy, adjusting magnetostriction, and improving the soft magnetic properties. The alloy of the present invention is preferably obtained by once forming a non-quality alloy and then heat treating it to form fine grains.

The reason for limiting the Si content y is that if y exceeds 30 atom %, magnetostriction becomes large under conditions of good soft magnetic properties, which is not preferable. The reason for limiting the B content to 2 is
This is because if 2 is less than 9 atomic %, it is undesirable from the viewpoint of strength, and if 2 is more than 15 atomic %, the soft magnetic properties deteriorate, which is undesirable.

X is at least one element selected from the group consisting of C, Ge, Ga, AQ, Be, and P, and these elements are effective for amorphization, magnetostriction, Curie temperature adjustment, and the like.

The reason why the X content γ is limited is that if it exceeds 20 atomic %, the soft magnetic properties will deteriorate significantly and the saturation magnetic flux density will also decrease.

Regarding the value of the total amount of Si, B, M, and If it exceeds 35 m%, there is a significant decrease in saturation magnetic flux density and deterioration of soft magnetic properties.

In the alloy according to the present invention, M' has the effect of refining crystal grains and improving corrosion resistance, and can be contained in an amount of 20 atomic % or less. The reason for this is that when the M' content α exceeds 20 atomic %, the saturation magnetic flux density significantly decreases.

A particularly preferable range of α is 1≦α≦10, 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 Sb, In, As, Li, M
g, Ca, Sr, Ba, Cod, Ph, Bi, N, O,
At least l selected from the group consisting of S, 3e and Te
It is a seed element and may contain 2yK% or less.

The remainder is essentially Fe, excluding impurities, but F
A part of e may be replaced by Ni and/or Co. The Ni content a is O≦a 0.2, but
This is because soft magnetism deteriorates significantly when it exceeds 0.2, and a particularly preferable range is 0≦a (0.1. Particularly good soft magnetism can be obtained within this range.

The Go content b satisfies O≦b<0.5, and the total sum a+b with the Ni content satisfies O≦a+b<0.5. A particularly preferable Co content and the sum of Co and Ni contents are O
≦b≦0.1, O≦a10b o. It is 1. The alloy of the present invention is an alloy mainly composed of a fine bccFe 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 1000 or less. It is an alloy.

Usually, an amorphous alloy is produced by a liquid quenching method such as a single roll method or a twin roll method, or a vapor phase quenching method such as a sputtering method or a vapor deposition method, and then heated and crystallized.

Particularly excellent soft magnetic properties can be obtained when the average particle size measured at the maximum dimension is 500 or less.

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

The alloy of the present invention is an alloy mainly composed of bccFe solid solution, and has a saturation magnetostriction λS of −5×10−“~15XIO−”
The magnetostriction is significantly lower than that of Fe-based amorphous alloys. 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.
A method in which a non-quality ribbon is prepared by twin roll method, centrifugal quenching method, etc., and then heat treated to form fine crystal grains.Amorphous film is prepared by vapor deposition method, spatter method, ion plating, etc., and then heat treated and crystallized. method, method of obtaining amorphous powder by atomization method or cavitation method and then heat treatment to crystallize it, spinning method in rotating liquid or glass coating method.
It can be produced by various methods, such as obtaining a non-quality line and then heat-treating it to crystallize it. 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 or the like.

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

The heat treatment is usually performed in a vacuum or in an atmosphere of an inert gas such as hydrogen gas, nitrogen gas, or 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 non-quality alloy ribbon, but are 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. Further, the heat treatment can be performed in multiple times at the same temperature or different temperatures, or the heat treatment can be performed in a multi-stage heat treatment pattern. Furthermore, the present alloy can also be heat treated in a direct current or alternating current magnetic field. Magnetic anisotropy can be produced in this 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 a direction perpendicular to the magnetic path, the B-H curve becomes sloped, and characteristics suitable for a transformer with a low squareness ratio and excellent constant magnetic permeability are obtained. Suitable for use as noise filters, choke 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 Curie temperature Tc of the alloy. The Curie 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 temperatures higher than the Curie temperature of non-quality alloys. Further, the soft magnetic properties can be further improved by heat treatment in a rotating magnetic field. It is also possible to heat treat the alloy by generating heat in the alloy during heat treatment. 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, M! It is characterized by little deterioration of magnetic properties even when three edge layers are formed, impregnated or coated, and it is possible to produce molded cores, cut cores, coated cores, magnetic heads, etc. with excellent properties.

[Examples] The present invention will be explained in more detail by the following examples.
The present invention is not limited thereto Example 1 Sil4at%, Bloat%, Nb3at% in atomic%
, Aulat% and the remainder was substantially Fe, an alloy ribbon was produced by a single roll method. The plate thickness was 18 mm and the width was 3 mm.

This alloy X! When diffraction was performed, 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.

Next, a toroidally wound magnetic core having an outer diameter of 19 mm and an inner diameter of 15 mm was prepared from this alloy. Next, the 20-wound magnetic core was placed in a furnace in an Ar atmosphere maintained at 550°C, and after being held for 1 hour, it was taken out of the furnace and cooled to room temperature.

FIG. 1(a) shows an X-ray diffraction pattern, and FIG. 1(b) shows a schematic diagram of the microstructure 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 structure of the present alloy, which is a heat-treated amorphous alloy, consists mostly of fine bccFe solid solution grains with a grain size of 50 to 200 grains.

As for the magnetic properties, the saturation magnetic flux density Bs is 12, IKG, IK
Effective magnetic permeability at Hz Ic is 26000.2KG
Core loss W,/IOOK at IOOKHz is 450
mW/cc, and it was confirmed that it exhibited excellent soft magnetism. Further, the saturation magnetostriction λS was +2.2×10 −1 , which was confirmed to be significantly smaller than that of the Fe-based amorphous base metal.

Example 2 An alloy ribbon having the composition shown in Table 1 and having a thickness of 15 tm and a width of 5 mm was produced by a single roll method.

Next, this alloy ribbon was wound to an outer diameter of 19M and an inner diameter of 15mm to create a toroidal magnetic core, and after heat treatment at a temperature higher than the crystallization temperature in an N2 gas atmosphere, the core loss at 100KHz and 0.2T and the saturation magnetostriction λs were 120℃. The rate of increase in core loss after holding for 1000 hours was measured. The results obtained are shown in Table 2.

Here, W −W ΔW=W. XIOO (W,: initial core loss, W,...,: core loss after 1000 hours) Furthermore, as a result of observation using a transmission electron microscope, it was confirmed that the microstructure was the same as in Example ■. It was done.

As can be seen from the table, the alloy of the present invention has a significantly smaller saturation magnetostriction λS and a smaller core loss than the conventional Fe-based amorphous alloy. Furthermore, compared to Fe-based and Go-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.

Table 1 Example 3 An alloy film having a composition shown in Table 3 and having a thickness of 3 was fabricated on a photoceram 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, add this alloy to N! Heat treatment was carried out by heating above the crystallization temperature in a gas atmosphere. The structure of the obtained alloy film was almost the same as that of Example 1. Next, the effective magnetic permeability μ1 at I MHz of this alloy film was measured, and then the effective magnetic permeability μalM at I MHz after being held at 120° C. for 1000 hours was measured. Table 2 shows the rate of change Δμ1M of the effective magnetic permeability at 1 MHz.

μi+IM Table 2 As can be seen from Table 2, the alloy film of the present invention exhibits significantly less change over time than the conventional amorphous alloy film.

[Effects of the Invention] According to the present invention, an Fe-based magnetic alloy having excellent soft magnetic properties, low magnetostriction, and excellent thermal stability can be obtained, so the effects are remarkable.

[Brief explanation of drawings]

FIG. 1(a) is a diagram showing an example of the xNA 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 (8)

[Claims] (1) General formula (Fe_1_-_a_-_bNi_aCo_b)_1_
0_0_-_y_-_z_-_α_-_β_-_γ_-
＿δSi_yB_zM'_αX_yY_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, P,
Y is 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
, 0≦y≦30, 9<z≦15, 0≦α≦20, 0≦γ
≦20, 0≦δ≦2, 10≦y+z+α+γ≦35. ), at least 50% of the structure consists of fine crystal grains, and the average grain size measured at the maximum dimension of the crystal grains is 1000 Å or less. Base magnetic alloy. (2) In the Fe-based magnetic alloy according to claim 1, a,
b, y, z, α, γ are 0≦a≦0.1, 0≦b≦0.1, 0≦a+b≦0.1
, 1≦α≦10, 0≦γ≦10. (3) The Fe-based magnetic alloy according to claim 1 or 2, wherein the remainder of the structure is amorphous.
Base magnetic alloy. (4) The Fe-based magnetic alloy according to claim 1 or 2, wherein 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 made entirely 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, having 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 λs is -5×10^-^6+5×10^
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 -^6.