JP3294929B2 - Laminated core - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated magnetic core using an Fe-based soft magnetic alloy having excellent magnetic properties.

[0002]

2. Description of the Related Art Conventionally, 50% Ni--Fe permalloy cores and 8%
A 0% Ni-Fe permalloy core is used. However, magnetic cores made of these magnetic materials have a large core loss in a high frequency range, and in a frequency band of several tens of kHz or more, the temperature of the magnetic core rises sharply, making it difficult to use. Accordingly, in recent years, a core made of a Co-based amorphous magnetic material has been used as a core for a switching power supply, etc., taking advantage of a feature of low core loss and high squareness in a high frequency range. However, the Co-based amorphous magnetic core has a high raw material cost and a high price, a saturation magnetic flux density of usually 10 kG or less, and several tens kHz to 100 kHz.
In the frequency range of Hz, there is a problem that the magnetic core is not sufficiently reduced in size because the saturation magnetic flux density is low and thus the operating magnetic flux density is easily restricted.

On the other hand, a magnetic core made of an Fe-based amorphous magnetic material has a high saturation magnetic flux density.
As described in JP-A No. 3 (KOKAI) No. 3 (KOKAI), it is known that a DC BH curve having a high squareness ratio and a high maximum magnetic permeability can be obtained. However, the magnetic core using this Fe-based amorphous alloy has a drawback in that the core loss is large. Therefore, an attempt has been made to improve the core loss by adjusting the added element.
There is a problem that the core loss is still large as compared with the Co-based amorphous alloy.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a laminated magnetic core having a small core loss in a high frequency range and a high saturation magnetic flux density.

[0005]

According to a first aspect of the present invention, there is provided a laminated magnetic core comprising an Fe-based soft magnetic alloy laminated with an alloy thin ribbon. that Do of fine crystal grains at least 50% or more average grain size 30nm following body-centered cubic structure of the organization
Amorphous phase remaining in the grain boundaries together with the Fe-based soft magnetic alloy is to have a composition represented by the following formula, and the saturation magnetic flux
The density is not less than 1.62T and 100 kHz,
Core loss at 0.2T is 79.7W / kg or less
It is. Fe _b B _x M _y where M is, Ti, Zr, Hf, V , Nb, Ta, M
one or more elements selected from the group consisting of o and W, and any one of Zr, Hf, and Nb, b = 85 to 93 at%, x = 0.5 to 9 Atomic% , y = 4
９9 atomic%.

According to a second aspect of the present invention, there is provided a laminated magnetic core comprising a plurality of thin alloy ribbons made of a Fe-based soft magnetic alloy, wherein at least 50% of the structure of the Fe-based soft magnetic alloy is provided. Rutotomoni amorphous phase but such a fine crystal grain of the following body-centered cubic structure an average grain size 30nm
There remains in the grain boundary, the Fe-based soft magnetic alloy is to have a composition represented by the following formula, and the saturation magnetic flux density is 1.62T
As mentioned above, at 100kHz, 0.2T
Aros is 79.7 W / kg or less . _{(Fe 1-a Z a)} b B x M y however Z is Ni, 1 kind or two kinds of Co, M is
One or more elements selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Mo, and W, and any one of Zr, Hf, and Nb, and a ≦ 0 .
2, b = 85 to 93 atomic%, x = 0.5 to 9 atomic% , y = 4
９9 atomic%.

[0007]

[0008]

[0009]

[0010]

[0011]

[0012]

[0013]

According to the present invention, since a magnetic core made of a soft magnetic alloy ribbon having a special composition is laminated and used, high saturation magnetic flux density is exhibited and core loss is reduced. In particular,
Even when compared with a core using an Fe-Si-B-based amorphous alloy known to exhibit excellent soft magnetic properties, the core according to the present invention exhibits the same excellent saturation magnetic flux density. ,
The core loss is lower than the core loss of the Fe—Si—B amorphous alloy. Therefore, according to the present invention, there is provided a small-sized and light-weight magnetic core having a high saturation magnetic flux density with a small loss in a high frequency range.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of a laminated magnetic core according to the present invention. A laminated magnetic core A of this embodiment is provided with a ribbon 1 made of various soft magnetic alloys having a composition described later.
And wound and laminated so as to sandwich the insulating film 2 between the layers. The ribbon 1 has a structure in which at least 50% or more of the structure is composed of fine crystal grains having a body-centered cubic structure with an average crystal grain size of 30 nm or less.

[0015] As a first example of a soft magnetic alloy constituting the ribbon 1, are represented by a composition formula of Fe _{b B x} M _y, M is
One or more elements selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Mo, and W, and any one of Zr, Hf, and Nb, and b = 75
９３93 at%, x = 0.5１８18 at%, y = 4〜9 at% can be used. In addition,
The B content in the above composition formula is preferably 10 atomic% or less in order to obtain a high saturation magnetic flux density of 1.5 T or more. Is increased, and eddy current loss at high frequencies can be reduced.

[0016] As a second example of the soft magnetic alloy constituting the ribbon _{1, (Fe 1-a Z} a) represented by _b the composition formula of B _x M _y, Z is, Ni, 1 kind of Co Or two, M is
One or more elements selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Mo, and W, and any one of Zr, Hf, and Nb, and a ≦ 0 .
2, b = 75 to 93 atomic%, x = 0.5 to 18 atomic%, y =
Those satisfying the relation of 4 to 9 atomic% can be used. In addition, about the B content in the said composition formula,
To obtain a high saturation magnetic flux density of 1.5 T or more, the content is preferably 10 atomic% or less, but when the B content is in the range of 10 to 18 atomic%, the electric resistance of the alloy increases, and eddy current loss at high frequencies Can be reduced, so it may be in the range of 10 to 18 atomic%.

[0017] As a third example of the soft magnetic alloy constituting the ribbon 1, it is represented by a composition formula of _{Fe b B x M y X z} ,
M is one or more elements selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Mo, and W, and includes any of Zr, Hf, and Nb; X
Is one or more of Cr, Ru, Rh and Ir, b = 75 to 93 at%, x = 0.5 to 18 at%, y
= 4 to 9 atomic% and z ≦ 5 atomic%. The B content in the above composition formula is preferably 10 atomic% or less in order to obtain a high saturation magnetic flux density of 1.5 T or more, but when the B content is in the range of 10 to 18 atomic%, Electric resistance increases,
Since eddy current loss at high frequencies can be reduced, the range may be 10 to 18 atomic%.

[0018] As a fourth example of the soft magnetic alloy constituting the ribbon _{1, (Fe 1-a Z} a) is indicated by _b B _x M compositional formula of _y X _Z, Z is Ni, among Co 1 M is one or more elements selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Mo, W, and any one of Zr, Hf, and Nb. And X is C
one or more of r, Ru, Rh, and Ir, a ≦ 0.1, b = 75 to 93 atomic%, x = 0.5 to
A material that satisfies the relationship of 18 at%, y = 4 to 9 at%, and Z ≦ 5 at% can be used. The B content in the above composition formula is preferably 10 atomic% or less in order to obtain a high saturation magnetic flux density of 1.5 T or more, but when the B content is in the range of 10 to 18 atomic%, As the electrical resistance increases and the eddy current loss at high frequencies can be reduced,
The range may be 10 to 18 atomic%.

[0019] As a fifth example of the soft magnetic alloy constituting the ribbon 1, it is represented by a composition formula of _{Fe b B x M y X '} t,
M is one or more elements selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Mo, and W, and contains any of Zr, Hf, and Nb; Is one or more of Si, Al, Ge and Ga, b = 75 to 93 at%, x = 0.5 to 18 at%, y =
Those satisfying the relationship of 4 to 9 atomic% and t ≦ 4 atomic% can be used. The B content in the above composition formula is preferably 10 atomic% or less in order to obtain a high saturation magnetic flux density of 1.5 T or more.
In the range of 0 to 18 atomic%, the electric resistance of the alloy increases, and the eddy current loss at a high frequency can be reduced.

[0020] As a sixth example of the soft magnetic alloy constituting the ribbon 1, are represented by a composition formula _{(Fe 1-a Z a)} b B x M y X 't, Z is, Ni, the Co One or two of them, M
Is one or more elements selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Mo, and W;
And X ′ contains Sr, Hf, or Nb, and X ′ is S
one or more of i, Al, Ge and Ga, a ≦ 0.2, b = 75 to 93 at%, x = 0.5 to 18
Atomic%, y = 4 to 9 atomic% and t ≦ 4 atomic% can be used. The B content in the above composition formula is preferably 10 atomic% or less in order to obtain a high saturation magnetic flux density of 1.5 T or more, but when the B content is in the range of 10 to 18 atomic%, Since the electric resistance increases and the eddy current loss at high frequency can be reduced,
The range may be up to 18 atomic%.

[0021] As a seventh example of the soft magnetic alloy constituting the ribbon _{1, Fe b B x M y} X z X ' is represented by a composition formula of _t, M is, Ti, Zr, Hf, V , Nb , Ta, Mo,
W is one or more elements selected from the group consisting of W, and includes any of Zr, Hf, and Nb, and X is one or more of Cr, Ru, and Ir; Is S
one or more of i, Al, Ge, and Ga, b = 75 to 93 atomic%, x = 0.5 to 18 atomic%, y =
Those satisfying the relationship of 4 to 9 atomic%, z ≦ 5 atomic%, and t ≦ 4 atomic% can be used. The B content in the above composition formula is preferably 10 atomic% or less in order to obtain a high saturation magnetic flux density of 1.5 T or more, but when the B content is in the range of 10 to 18 atomic%, Since electric resistance increases and eddy current loss at high frequency can be reduced,
The range may be 0 to 18 atomic%.

[0022] As an eighth embodiment of the soft magnetic alloy constituting the ribbon 1, it is represented by a composition formula _{(Fe 1-a Z a)} b B x M y X z X 't, Z is, Ni, One or two of Co
The species, M, is Ti, Zr, Hf, V, Nb, Ta, Mo,
W is one or more elements selected from the group consisting of W, and includes any of Zr, Hf, and Nb, and X is one or more of Cr, Ru, and Ir; Is S
one or more of i, Al, Ge and Ga, a ≦ 0.2, b = 75 to 93 at%, x = 0.5 to 18
Atomic%, y = 4 to 9 atomic%, z ≦ 5 atomic%, and t = ≦ 4 atomic% can be used. In addition,
The B content in the above composition formula may be in the range of 10 to 18 atomic%.

In order to manufacture the ribbon 1, alloy raw materials are mixed and melted so as to have the composition described above to obtain a molten alloy.
A liquid quenching method is used in which a molten metal is jetted onto a rotating metal roll made of copper or the like to rapidly cool the roll. By this liquid quenching method, a ribbon-like ribbon in an amorphous state can be obtained. Once you have this ribbon, cut it to the required length or width,
It is stamped into a desired shape and used for a magnetic core.

For the processed ribbon, 500 to 700
It is preferable to perform a heat treatment for cooling after heating at a temperature of ° C. This heat treatment precipitates a fine crystalline phase in the amorphous phase and improves magnetic properties.

The reason why it is preferable to use the above-mentioned composition in the soft magnetic alloys having the above-mentioned compositions. B for alloys of the above composition
Is always added. B is considered to have the effect of increasing the ability of the soft magnetic alloy to form an amorphous phase and the effect of suppressing the formation of a compound phase that adversely affects the magnetic properties in the heat treatment step. Therefore, the addition of B is essential. Originally, α-
Although Zr and Hf hardly form a solid solution with Fe, the entire alloy having the above composition is rapidly cooled to become amorphous, so that Zr and Hf become Zr and Hf.
And Hf to form a solid solution in supersaturation, and heat treatment performed thereafter adjusts the solid solution amount of these elements to partially crystallize and precipitate as a fine crystalline phase, thereby improving the soft magnetic properties of the obtained soft magnetic alloy. The magnetostriction of the ribbon can be reduced. Also,
In order to precipitate a microcrystalline phase and to suppress the coarsening of the crystal grains of the microcrystalline phase, it is considered necessary to leave an amorphous phase which may be an obstacle to crystal grain growth at the grain boundary. Further, this grain boundary amorphous phase becomes α α by increasing the heat treatment temperature.
It is considered that by forming a solid solution of M elements such as Zr, Hf, and Nb discharged from -Fe, formation of an Fe-M-based compound that degrades soft magnetism is suppressed. Therefore, Fe-Zr (H
It is important to add B to the f) type alloy.

If the X content of B is less than 0.5%, the amorphous phase at the grain boundary becomes unstable, so that a sufficient addition effect cannot be obtained. On the other hand, if X exceeds 18%, BM and Fe-B
The tendency of the system to form borides is increased, and as a result, heat treatment conditions for obtaining a fine crystal structure are restricted, and good soft magnetic characteristics cannot be obtained. By adding an appropriate amount of B in this manner, the average crystal grain size of the fine crystal phase precipitated is 30
nm or less.

In the composition formulas of the soft magnetic alloys of the first to eighth examples, in order to easily obtain an amorphous phase, any one of Zr, Hf, and Nb having particularly high amorphous forming ability is contained. There is a need. In addition, Zr, Hf, and Nb can be partially replaced with Ti, V, Ta, Mo, and W among other elements in the 4A to 6A group. In the alloy of the present invention, the M element is a relatively slow diffusion species, and the addition of the M element is considered to have an effect of reducing the growth rate of the fine crystal nuclei, and is indispensable for the refinement of the structure. However, the addition amount of the M element Y
When the content is 4% or more, the effect of reducing the nucleus growth rate is lost, and as a result, the crystal grain size becomes coarse and good soft magnetism cannot be obtained. In the case of an Fe-Hf-B alloy, Hf = 5 atomic%
Is 13 nm, whereas Hf = 3.
At atomic%, it is as coarse as 39 nm. If the Y content exceeds 9 atomic%, the tendency of the formation of MB-based or Fe-M-based compounds increases, and good characteristics cannot be obtained. It becomes difficult to work into a core shape. Therefore, the range of Y is set to 4 to 9 atomic%.

In the composition formulas of the soft magnetic alloys of the second, fourth, sixth and eighth examples, the amount b of Fe, Co and Ni is not more than 93 atomic%. This is because if b exceeds 93 atomic%, it becomes difficult to obtain an amorphous single phase by the liquid quenching method, and as a result, the structure of the alloy obtained after the heat treatment becomes non-uniform, so that a high magnetic permeability is obtained. This is because they cannot be obtained. In order to obtain a saturation magnetic flux density of 10 kG or more, b is more preferably 75 atomic% or more, so b is set to 75 to 93 atomic%.

Among the above-mentioned additional elements, Nb and Mo have a small absolute value of free energy of oxide formation, are thermally stable, and are hardly oxidized during production. Therefore, when these elements are added, the production conditions are easy, the production can be performed at low cost, and the cost is also advantageous. When the soft magnetic alloy is manufactured by adding these elements, specifically, an inert gas is partially supplied to the tip of a nozzle of a crucible used when quenching a molten metal while supplying an inert gas. Or in an atmosphere of the atmosphere.

The reasons for limiting the alloying elements contained in the ribbon 1 according to the present invention have been described above. In order to improve the corrosion resistance other than these elements, Cr, Mo, or Ru, R
It is also possible to add a platinum group element such as h or Ir. When these elements are added in more than 5 atomic%,
Since the saturation magnetic flux density is significantly deteriorated, it is necessary to suppress the addition amount to 5 atomic% or less. Further, if necessary, Y, rare earth element, Zn, Cd, Ga, In, Ge, Sn, P
b, As, Sb, Bi, Se, Te, Li, Be, M
The magnetostriction of the laminated core A can be adjusted by adding elements such as g, Ca, Sr, and Ba. In addition, in the ribbon 1, even if unavoidable impurities such as H, N, O, and S are contained to such an extent that desired characteristics are not deteriorated, the composition may be regarded as the same as the composition of the soft magnetic alloy used in the present invention. Of course you can.

Next, an insulating layer 2 interposed between the layers of the ribbon 1
Is provided for the purpose of preventing dielectric breakdown between layers during high-voltage driving, reducing eddy current loss and suppressing heat generation, and includes resin-based coatings and resin tapes, inorganic-based material coatings and inorganic-material tapes. Alternatively, inorganic particles such as alumina, magnesia, boron nitride, silica sand, and quartz are dispersed in water glass, or these inorganic particles are coated on a resin tape or baked as necessary after coating. Is used as appropriate.
As a resin material constituting the insulating layer 2, a solvent-type varnish tape in which an alkyd resin is dissolved in an organic solvent, a non-solvent-type varnish tape composed of a styrene monomer and an unsaturated polyester resin, an acrylic resin, a polyester resin, and an epoxy ester resin Resin and the like can be exemplified.

In order to coat the insulating layer 2 on the ribbon 1, for example, a method of attaching inorganic particles to the surface of the ribbon 1 by electrophoresis, a method of coating by thermal spraying, or a method of applying inorganic particles by sputtering or vacuum deposition A method of coating a layer or the like can be used as appropriate. Alternatively, the insulating layer 2 can be manufactured by injecting silica sand, quartz, or the like, alone or as a mixture, into a resin.

The magnetic core A constructed as described above is mainly composed of the soft magnetic alloy having the composition described above.
It exhibits an extremely excellent saturation magnetic flux density of about 3 to 1.64 T (tesla), reduces core loss in a high frequency range of about 100 kHz, generates little heat, and does not cause characteristic deterioration. Therefore, it contributes to reducing the size and weight of the magnetic core.

FIG. 2 shows a second embodiment of the laminated magnetic core according to the present invention. In the laminated magnetic core B of this embodiment, a plurality of rings 3 made of a soft magnetic alloy having the above-mentioned various compositions are prepared. Are laminated with an insulating layer 4 interposed therebetween. The soft magnetic alloy forming the ring 3 may be the same as the soft magnetic alloy forming the ribbon 1 of the magnetic core A described above, and the material forming the insulating layer 4 may be the magnetic core described above. A material equivalent to the insulating layer 2 of A can be used. The core 3 having the structure of this example is formed by laminating the rings 3... Exhibiting excellent soft magnetic properties, so that it exhibits excellent soft magnetic properties and a small core loss, and can be used to reduce the size and weight of the core. Contribute.

FIGS. 3 and 4 show a third embodiment of the laminated magnetic core according to the present invention.
The iron cores 5, 5 are arranged opposite to each other and combined, and a coil 7 is provided in the combined portion to constitute a transformer. Each of the iron cores 5 is formed by laminating an E-shaped thin plate 5A stamped and formed from a soft magnetic alloy ribbon, and has an I-shaped base 5a and legs 5b and base 5a formed at both ends thereof. And a projection 5c formed on the center side. The iron cores 5, 5 are formed of legs 5 b and projections 5.
The protrusions 5c are joined together with an adhesive layer 6 interposed therebetween, and a coil 7 is wound around the outer periphery of the overlapping portion of the protrusions 5c. In addition, the thin plates 5A may be laminated in a state where they are individually insulated by an insulating layer or an insulating coating as necessary, and a gap may be provided intermittently in the adhesive layer 6 between the iron cores 5, 5. good.

Even in the magnetic core C having the structure of this example, since the thin plates 5 and 5 made of a soft magnetic alloy exhibiting excellent soft magnetic characteristics are laminated, excellent soft magnetic characteristics and little core loss are obtained. And contributes to reducing the size and weight of the magnetic core. In addition, since the E-shaped iron cores 5 and 5 are coiled by being stacked one above the other, the number of assembling steps is reduced as compared with a magnetic core having a configuration in which E-shaped and I-shaped iron thin plates are alternately combined one by one. In addition, the manufacturing becomes easy, and the insulating layer 6 or the gap portion is provided between the magnetic cores 5, 5, so that the reduction rate of the magnetic permeability of the iron core at the time of DC superposition can be improved.

"Preparation Example" A material was prepared so as to have a composition as shown in Table 1 below, and the material was subjected to high frequency melting in a crucible equipped with a nozzle to obtain a molten alloy, which was then rotated at high speed. A liquid quenching method in which the roll was blown out from a nozzle and quenched was performed to obtain an alloy ribbon having a thickness of 15 to 20 μm. The obtained ribbon was punched into an annular shape having an outer diameter of 10 mm and an inner diameter of 6 mm, and was subjected to a heat treatment of heating at 600 to 650 ° C. for 1 hour, and then an insulating paper was stuck thereon for insulation treatment. Twenty of these insulated disks were stacked to form a magnetic core, wound, and core loss was measured using an AC magnetization tester (MMS0375) manufactured by Ryowa Electronics Co., Ltd. Table 1 shows the results.

[0038]

[Table 1]

As is clear from the results shown in Table 1, the magnetic core according to the present invention has an excellent saturation magnetic flux density in the range of 1.4 to 1.64 Tesla (T), and has very small core loss at 100 kHz and is extremely excellent. Demonstrated characteristics.

[0040]

As described above, the present invention is characterized in that a magnetic core made of a soft magnetic alloy ribbon having a special composition is used and laminated, so that a high saturation magnetic flux density is exhibited and a core loss is small. . In particular, even when compared with a core using an Fe-Si-B-based amorphous alloy known to exhibit excellent soft magnetic properties, the core according to the present invention exhibits the same excellent saturation magnetic flux density. Above, a core loss lower than the core loss of the Fe—Si—B based amorphous alloy is shown. Therefore, according to the present invention, it is possible to provide a small-sized and light-weight magnetic core having a low saturation magnetic flux density and a low loss in a high frequency range.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of a magnetic core according to the present invention.

FIG. 2 is a perspective view showing a second embodiment of the magnetic core according to the present invention.

FIG. 3 is an exploded perspective view showing a third embodiment of the magnetic core according to the present invention.

FIG. 4 is a perspective view of a magnetic core according to the third embodiment.

[Explanation of symbols] 1 ribbon, 2, 4 insulating layer, 3 ring, 5 magnetic core,

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akihiro Makino 1-7 Yukitani Otsukacho, Ota-ku, Tokyo Alps Electric Co., Ltd. (72) Inventor Shoji Yoshida 1-7 Yukitani-Otsukacho, Ota-ku, Tokyo Al Within Ps Electric Co., Ltd. (72) Inventor Takeshi Masumoto 3-8-22 Uesugi, Aoba-ku, Sendai-shi, Miyagi (72) Inventor Akihisa Inoue Kawachi-no-Kawachi, Aoba-ku, Sendai, Miyagi 11-806 References JP-A-4-213804 (JP, A) JP-A-2-258957 (JP, A) JP-A-5-255818 (JP, A) JP-A-5-93249 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) H01F 1/12-1/38 C22C 38/00 303

Claims (2)

(57) [Claims] In a laminated magnetic core in which alloy ribbons made of an Fe-based soft magnetic alloy are laminated, at least 50% or more of the structure of the Fe-based soft magnetic alloy has an average crystal grain size of 30 nm.
The following body-centered cubic structure of fine crystal grains from such Rutotomoni non
Amorphous phase remains in the grain boundaries, the Fe-based soft magnetic alloy is to have a composition represented by the following formula, and the saturation magnetic flux density is 1.
It is more than 62T and 100kHz, 0.2T
A laminated core having a core loss of 79.7 W / kg or less . Fe _b B _x M _y where M is, Ti, Zr, Hf, V , Nb, Ta, M
one or more elements selected from the group consisting of o and W, including any of Zr, Hf, and Nb, b = 85 to 93 at%, x = 0.5 to 9 Atomic% , y = 4-9
Atomic%. 2. In a laminated magnetic core in which thin alloy ribbons made of an Fe-based soft magnetic alloy are stacked, at least 50% or more of the structure of the Fe-based soft magnetic alloy has an average crystal grain size of 30 nm.
The following body-centered cubic structure of fine crystal grains from such Rutotomoni non
Amorphous phase remains in the grain boundaries, the Fe-based soft magnetic alloy is to have a composition represented by the following formula, and the saturation magnetic flux density is 1.
It is more than 62T and 100kHz, 0.2T
A laminated core having a core loss of 79.7 W / kg or less . _{(Fe 1-a Z a)} b B x M y however Z is Ni, 1 kind or two kinds of Co, M is
At least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Mo, and W, and containing any of Zr, Hf, and Nb; .2, b = 85 ~93 atomic%, x = 0.5~ 9 atoms
% , Y = 4 to 9 atomic%.