JPWO2019031463A1 - Fe-based alloy, crystalline Fe-based alloy atomized powder, and magnetic core - Google Patents

Abstract

An Fe-based alloy having an alloy composition represented by the composition formula (1), which is used for producing a crystalline Fe-based alloy atomized powder. In the composition formula (1), a, b, c, d, e, and α are 0.1 ≦ a ≦ 1.5, 13.0 ≦ b ≦ 15.0, 8.0 <c <12.0. 0.5 ≦ d <4.0, 0 ≦ e ≦ 2.0, 10.0 <c + d <13.5, 0 ≦ α ≦ 0.9, and 71.0 ≦ 100−abc -D-e ≦ 74.0 is satisfied. Fe100-a-bc-d-eCuaSibBc (Mo1- [alpha] Nb [alpha]) dCre ... Composition formula (1)

Description

  The present disclosure relates to Fe-based alloys, crystalline Fe-based alloy atomized powders, and magnetic cores.

Conventionally, an Fe-based alloy powder that is an Fe-based alloy in the form of a powder is known.
For example, Patent Document 1 discloses a general formula (Fe _1-a M _a ) ₁₀₀ as a low-magnetostrictive Fe-based soft magnetic alloy having excellent soft magnetic characteristics (particularly high-frequency magnetic characteristics) and small characteristic deterioration due to impregnation or deformation. _{-x-y-z-α Cu} x Si y B z M 'α ( although, M is Co and / or Ni, M' is Nb, W, Ta, Zr, Hf, from the group consisting of Ti and Mo At least one element selected, a, x, y, z and α are 0 ≦ a ≦ 0.5, 0.1 ≦ x ≦ 3, 0 ≦ y ≦ 30, 0 ≦ z ≦ 25, 5 ≦ y + z ≦ 30 and 0.1 ≦ α ≦ 30), and an Fe-based soft magnetic alloy characterized in that at least 50% of the structure is composed of fine crystal grains. Has been. On page 9 of this Patent Document 1, a powdered one is disclosed as this Fe-based soft magnetic alloy.

Further, Patent Document 2 discloses Fe _{100-abc-c-dfef} Cu _a Si _b B _c M as a soft magnetic powder that can ensure high insulation between particles when compacted. _d M ′ _e X _f (atomic%) [wherein M is at least one element selected from the group consisting of Nb, W, Ta, Zr, Hf, Ti, and Mo, and M ′ is V, Cr, Mn, Al, platinum group element, Sc, Y, Au, Zn, Sn, and at least one element selected from the group consisting of Re and X is C, P, Ge, Ga, Sb, In , Be and As, at least one element selected from the group consisting of a, b, c, d, e and f is 0.1 ≦ a ≦ 3, 0 <b ≦ 30, 0 <c ≦ 25, 5 ≦ b + c ≦ 30, 0.1 ≦ d ≦ 30, 0 ≦ e ≦ 10 and 0 ≦ f ≦ 10. . And a JIS standard sieve having an opening of 45 μm, a JIS standard sieve having an opening of 38 μm, and a JIS standard having an opening of 25 μm. When the sieves are subjected to a classification process in this order, particles that pass through a JIS standard sieve with an opening of 45 μm, do not pass through a JIS standard sieve with an opening of 38 μm are the first particles, and a JIS standard sieve with an opening of 38 μm is used. The particles that pass through and do not pass through the JIS standard sieve having an opening of 25 μm are defined as second particles, and the particles that pass through the JIS standard sieve having an opening of 25 μm are defined as third particles, the coercive force Hc1 of the first particles, The coercive force Hc2 and the coercive force Hc3 of the third particles are such that Hc2 / Hc1 is 0.85 or more and 1.4 or less, and Hc3 / Hc1 is 0.5 or more and 1.5 or less. A soft magnetic powder characterized by satisfying the following relationship is disclosed.

Japanese Patent Application Laid-Open No. 64-073422 JP 2017-110256 A

  As a method for obtaining an Fe-based alloy powder, first, it is also referred to as an Fe-based alloy powder consisting essentially of an amorphous phase (hereinafter referred to as an amorphous Fe-based alloy atomized powder) by an atomization method. Then, the amorphous Fe-based alloy atomized powder is heat-treated, whereby an Fe-based alloy atomized powder (hereinafter referred to as crystalline Fe-based alloy atomized powder (Crystalline) in which a part of the amorphous phase is crystallized is obtained. In some cases, a method of obtaining Fe-based alloy atomized powder) is applied (for example, see the example of Patent Document 2 above).

However, in the conventional crystalline Fe-based alloy atomized powder, the coercive force may be too large.
Even when the crystalline Fe-based alloy atomized powder exhibits a small coercive force, the range of the median diameter d50 exhibiting a small coercive force may be narrow. Such a crystalline Fe-based alloy atomized powder has a problem that the degree of freedom in selecting the median diameter d50 is low.

The present disclosure has been made in view of the above circumstances.
An object of one embodiment of the present disclosure is to provide an Fe-based alloy that can produce a crystalline Fe-based alloy atomized powder having a wide median diameter d50 that exhibits a small coercive force.
The subject of another one aspect | mode of this indication is providing the crystalline Fe base alloy atomized powder with the wide range of the median diameter d50 which shows a small coercive force.
The subject of another one aspect | mode of this indication is providing the magnetic core containing the said crystalline Fe base alloy atomized powder.

Means for solving the above problems include the following aspects.
<1> Used for the production of crystalline Fe-based alloy atomized powder,
An Fe-based alloy having an alloy composition represented by the following composition formula (1).
_{Fe 100-a-b-c} -d-e Cu a Si b B c (Mo 1-α Nb α) d Cr e ... formula (1)
[In the composition formula (1), a, b, c, d, e, and α are 0.1 ≦ a ≦ 1.5, 13.0 ≦ b ≦ 15.0, 8.0 <c <12. 0, 0.5 ≦ d <4.0, 0 ≦ e ≦ 2.0, 10.0 <c + d <13.5, 0 ≦ α ≦ 0.9, and 71.0 ≦ 100−ab− c-d-e ≦ 74.0 is satisfied. ]
<2> The Fe-based alloy according to <1>, wherein d satisfies 0.5 ≦ d ≦ 3.5 in the composition formula (1).
<3> The Fe-based alloy according to <1> or <2>, wherein e satisfies 0.5 <e ≦ 2.0 in the composition formula (1).
<4> The Fe-based alloy according to any one of <1> to <3>, wherein α satisfies 0 <α ≦ 0.9 in the composition formula (1).
<5> The Fe-based alloy according to any one of <1> to <4>, wherein c satisfies 10.0 ≦ c <12.0 in the composition formula (1).
<6> It has an alloy composition represented by the following composition formula (1),
A crystalline Fe-based alloy atomized powder having an alloy structure containing nanocrystal grains having an average grain size of 40 nm or less.
_{Fe 100-a-b-c} -d-e Cu a Si b B c (Mo 1-α Nb α) d Cr e ... formula (1)
[In the composition formula (1), a, b, c, d, e, and α are 0.1 ≦ a ≦ 1.5, 13.0 ≦ b ≦ 15.0, 8.0 <c <12. 0, 0.5 ≦ d <4.0, 0 ≦ e ≦ 2.0, 10.0 <c + d <13.5, 0 ≦ α ≦ 0.9, and 71.0 ≦ 100−ab− c-d-e ≦ 74.0 is satisfied. ]
<7> The crystalline Fe-based alloy atomized powder according to <6>, wherein the coercive force at an applied magnetic field of 40 kA / m is 190 A / m or less.
<8> The crystalline Fe-based alloy atomized powder according to <6> or <7>, wherein d satisfies 0.5 ≦ d ≦ 3.5 in the composition formula (1).
<9> The crystalline Fe-based alloy atomized powder according to any one of <6> to <8>, wherein e satisfies 0.5 <e ≦ 2.0 in the composition formula (1).
<10> The crystalline Fe-based alloy atomized powder according to any one of <6> to <9>, wherein α satisfies 0 <α ≦ 0.9 in the composition formula (1).
<11> The crystalline Fe-based alloy atomized powder according to any one of <6> to <10>, wherein c satisfies 10.0 ≦ c <12.0 in the composition formula (1).
<12> The crystalline Fe-based alloy atomized powder according to any one of <6> to <11>,
A binder for binding the crystalline Fe-based alloy atomized powder;
Including
A magnetic core in which the binder is at least one selected from the group consisting of epoxy resins, unsaturated polyester resins, phenol resins, xylene resins, diallyl phthalate resins, silicone resins, polyamideimides, polyimides, and water glass.

According to one aspect of the present disclosure, an Fe-based alloy that can produce an Fe-based alloy atomized powder with a wide median diameter d50 exhibiting a small coercive force is provided.
According to another aspect of the present disclosure, an Fe-based alloy atomized powder having a wide median diameter d50 that exhibits a small coercive force is provided.
According to still another aspect of the present disclosure, a magnetic core including the Fe-based alloy atomized powder is provided.

In a crystalline Fe base alloy atomized powder, it is a graph which showed relation between d50 and coercive force for every alloy composition (AG). It is.

In the present specification, a numerical range indicated using “to” means a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively.
In this specification, the term “process” is not limited to an independent process, and is included in this term if the intended purpose of the process is achieved even when it cannot be clearly distinguished from other processes. It is.

[Fe-based alloy]
The Fe-based alloy of the present disclosure is an Fe-based alloy used for manufacturing a crystalline Fe-based alloy atomized powder, and is an Fe-based alloy having an alloy composition represented by a composition formula (1) described later.

As described above, the crystalline Fe-based alloy atomized powder is produced by heat-treating the amorphous Fe-based alloy atomized powder. By heat treatment, a part of the amorphous phase of the amorphous Fe-based alloy atomized powder is converted into a crystalline phase, thereby obtaining a crystalline Fe-based alloy atomized powder.
Amorphous Fe-based alloy atomized powder, which is a raw material for crystalline Fe-based alloy atomized powder, is manufactured by an atomizing method using a molten alloy having an Fe-based alloy alloy composition as a raw material. Specifically, the amorphous Fe-based alloy atomized powder is produced by pulverizing the above molten alloy into particles and quenching the obtained molten alloy (hereinafter also referred to as “alloy molten particles”). Is done.
The molten alloy having the alloy composition of the Fe-based alloy is manufactured by dissolving the ingot having the alloy composition of the Fe-based alloy, or directly by dissolving and mixing each component (each element). Manufactured.

The Fe-based alloy of the present disclosure is a raw material for crystalline Fe-based alloy atomized powder.
The concept of the Fe-based alloy of the present disclosure (that is, the raw material of the crystalline Fe-based alloy atomized powder) includes the amorphous Fe-based alloy atomized powder and the raw material of the amorphous Fe-based alloy atomized powder (eg, ingot). Both are included.
In the present disclosure, the particles in the crystalline Fe-based alloy atomized powder may be referred to as crystalline Fe-based alloy atomized particles, and the particles in the amorphous Fe-based alloy atomized powder may be referred to as amorphous Fe-based alloy atomized particles. May be called.

By using the Fe-based alloy of the present disclosure as a raw material, a crystalline Fe-based alloy atomized powder with a wide median diameter d50 showing a small coercive force (for example, a value at an applied magnetic field of 40 kA / m is 190 A / m or less) is produced. it can. Therefore, a crystalline Fe-based alloy atomized powder with a high degree of freedom in selecting the median diameter d50 can be obtained.
The reason why such an effect is obtained is considered that the Fe-based alloy of the present disclosure has an alloy composition represented by the composition formula (1). Details will be described below.

Of the crystalline Fe-based alloy atomized particles, particles having a large particle size may have a larger coercive force than particles having a small particle size. The following reasons can be considered as the reason.
As described above, amorphous Fe-based alloy atomized particles that are raw materials for crystalline Fe-based alloy atomized particles are produced by rapidly cooling molten alloy particles. At this time, the molten alloy particles having a small particle diameter have a large specific surface area, so that the whole is rapidly quenched. For this reason, from the molten alloy particles having a small particle diameter, amorphous Fe-based alloy atomized particles that are homogeneous and highly amorphous (that is, crystal grains are not present in the alloy structure or are extremely reduced) are obtained. Easy to obtain.
However, the molten alloy particles having a large particle diameter have a large specific surface area, so that the cooling rate tends to be relatively slow, and the cooling rate inside the particles tends to be slower than the cooling rate of the particle surface. As a result, from the molten alloy particle having a large particle diameter, an amorphous Fe-based alloy atomized particle having a heterogeneous amorphous phase or an amorphous phase in which crystal grains are partially precipitated can be obtained. There is a case. When such amorphous Fe-based alloy atomized particles are heat-treated, coarse crystals are generated in the alloy structure, and as a result, the coercive force of the obtained crystalline Fe-based alloy atomized particles may increase. .
Regarding the above-described problem, since the Fe-based alloy of the present disclosure has an alloy composition represented by the composition formula (1), it is amorphous in the stage of rapidly cooling the molten alloy particles mainly by the action of Si, B, and Mo. It is considered that the quality improvement effect (hereinafter also referred to as “quick cooling effect”) is excellent. For this reason, when the Fe-based alloy of the present disclosure is used, it is considered that amorphous Fe-based alloy atomized particles that are homogeneous and highly amorphous are easily obtained from molten alloy particles having a relatively large particle size. It is done. As a result, in the crystalline Fe-based alloy atomized powder obtained by heat-treating the amorphous Fe-based alloy atomized powder, it is considered that the coercive force of the particles having a large particle diameter is suppressed from becoming too large.

Furthermore, by using the Fe-based alloy of the present disclosure as a raw material, the coercive force of particles having a small particle diameter in the crystalline Fe-based alloy atomized powder can be reduced. The reason is considered as follows.
The crystalline Fe-based alloy atomized powder has a predetermined particle size distribution. In such crystalline Fe-based alloy atomized powder, it is considered that particles having a small particle size are more susceptible to heat treatment than particles having a large particle size.
In this regard, the alloy composition represented by the composition formula (1) is excellent in the effect of amorphization at the stage of rapidly cooling the molten alloy particles. For this reason, the alloy composition represented by the composition formula (1) varies in the range from a small particle diameter to a large particle diameter in the amorphous Fe-based alloy atomized powder in the stage of heat-treating the amorphous Fe-based alloy atomized powder. Excellent in uniformly crystallizing an amorphous structure of particles of various sizes.
Therefore, it is considered that the coercive force of particles having a small particle diameter in the crystalline Fe-based alloy atomized powder can be reduced by using the Fe-based alloy of the present disclosure as a raw material.

  For the reasons described above, by using the Fe-based alloy of the present disclosure as a raw material, a crystalline Fe base having a wide median diameter d50 range showing a small coercive force (for example, a value at an applied magnetic field of 40 kA / m is 190 A / m or less). It is believed that alloy atomized powder can be produced.

<Alloy composition represented by composition formula (1)>
The Fe-based alloy of the present disclosure has an alloy composition represented by the following composition formula (1).
In addition, the alloy composition does not change in the process from obtaining the Fe-based alloy customized powder from the Fe-based alloy of the present disclosure. Accordingly, the crystalline Fe-based alloy admitted powder obtained from the Fe-based alloy of the present disclosure also has an alloy composition represented by the following composition formula (1).

_{Fe 100-a-b-c} -d-e Cu a Si b B c (Mo 1-α Nb α) d Cr e ... formula (1)
[In the composition formula (1), a, b, c, d, e, and α are 0.1 ≦ a ≦ 1.5, 13.0 ≦ b ≦ 15.0, 8.0 <c <12. 0, 0.5 ≦ d <4.0, 0 ≦ e ≦ 2.0, 10.0 <c + d <13.5, 0 ≦ α ≦ 0.9, and 71.0 ≦ 100−ab− c-d-e ≦ 74.0 is satisfied. ]

(Fe)
In the alloy composition represented by the composition formula (1), Fe is a main element constituting the Fe-based alloy and is an element affecting the saturation magnetization of the crystalline Fe-based alloy ized powder.
“100-abcde” in the composition formula (1) represents the Fe content (atomic%) in the alloy composition, and 71.0 ≦ 100-abcd- e ≦ 74.0 is satisfied.
When “100-ab-c-d-e” is 71.0 or more, the saturation magnetization of the crystalline Fe-based alloy atomized powder is improved.
When “100-ab-c-d-e” is 74.0 or less, a crystalline Fe-based alloy atomized powder having a wide median diameter d50 showing a small coercive force can be obtained.

(Cu)
In the alloy composition represented by the composition formula (1), Cu forms nanocrystal grains (i.e., bccFe-) at the stage of obtaining a crystalline Fe-based alloy atomized powder by heat-treating an amorphous Fe-based alloy atomized powder. It is an element that contributes to the formation of the Si phase.
“A” in the composition formula (1) represents the Cu content (atomic%) in the alloy composition, and satisfies 0.1 ≦ a ≦ 1.5. Thereby, the addition effect of Cu mentioned above is exhibited, and the coercive force of the crystalline Fe-based alloy customized powder is reduced.
When 0.1 ≦ a is not satisfied (that is, when the Cu content is less than 0.1 atomic%), the above-described effect of adding Cu cannot be obtained.
When a ≦ 1.5 is not satisfied (that is, when the Cu content is more than 1.5 atomic%), the saturation magnetization of the crystalline Fe-based alloy admitted powder may be lowered.
In addition, when a ≦ 1.5 is not satisfied, nanocrystalline nuclei are easily generated in the amorphous Fe-based alloy atomized powder, and these nuclei grow into coarse crystals by heat treatment. As a result, crystalline Fe The coercive force of the base alloy ized powder may be too large. From these viewpoints, “a” satisfies a ≦ 1.5. “A” preferably satisfies a ≦ 1.1, and more preferably satisfies a ≦ 1.0.

(Si)
In the alloy composition represented by the composition formula (1), Si contributes to a quenching effect (that is, an effect of amorphization) in the stage of quenching the molten alloy particles, and in the crystalline Fe-based alloy atomized particles. The solid solution in Fe, which is the main component of the nanocrystal grains, contributes to the reduction of magnetostriction or magnetic anisotropy.
“B” in the composition formula (1) represents the Si content (atomic%) in the alloy composition and satisfies 13.0 ≦ b ≦ 15.0. Thereby, the coercive force of the crystalline Fe-based alloy customized powder is reduced.
When 13.0 ≦ b is not satisfied (that is, when the Si content is less than 13.0 atomic%), and when b ≦ 15.0 is not satisfied (that is, the Si content is 15.0). In any case of exceeding (at%), the rapid cooling effect is reduced at the stage of obtaining the amorphous Fe-based alloy atomized powder, and coarse crystal grains on the order of micrometers may be easily precipitated. As a result, the coercive force of the crystalline Fe-based alloy atomized powder may become too large.

(B)
In the alloy composition represented by the composition formula (1), B contributes to the quenching effect in the stage of quenching the molten alloy particles, and in the crystalline Fe-based alloy atomized particles, Fe is the main component of nanocrystal grains. It contributes to the reduction of magnetostriction or magnetic anisotropy.
“C” in the composition formula (1) represents the B content (atomic%) in the alloy composition, and satisfies 8.0 <c <12.0. Thereby, the coercive force of the crystalline Fe-based alloy atomized powder is reduced, and the saturation magnetization of the crystalline Fe-based alloy atomized powder is improved.
When 8.0 <c is not satisfied (that is, when the B content is 8.0 atomic% or less), the quenching effect in the stage of quenching the molten alloy particles is reduced, and coarse crystal grains are likely to precipitate. There is a case. As a result, the coercive force of the crystalline Fe-based alloy atomized powder may become too large.
When c <12.0 is not satisfied (that is, when the content of B is 12.0 atomic% or more), since the ratio of B which is a nonmagnetic element is increased, the saturation of the crystalline Fe-based alloy atomized powder This leads to a decrease in magnetization.

  “C” in the composition formula (1) satisfies 9.0 ≦ c <12.0 from the viewpoint of widening the range of the median diameter exhibiting a small coercive force and increasing the saturation magnetization. Is more preferable and 10.0 ≦ c <12.0 is more preferable.

(Mo, Nb)
In the alloy composition represented by the composition formula (1), Mo is an essential element, contributes to the quenching effect in the stage of quenching the molten alloy particles, and the nanocrystalline grains in the crystalline Fe-based alloy atomized particles. Contributes to uniform particle size. Therefore, Mo contributes to the effect of widening the range of the median diameter d50 showing a small coercive force in the crystalline Fe-based alloy atomized particles.
In the alloy composition represented by the composition formula (1), Nb is an arbitrary element. Although Nb has an effect similar to Mo, it is inferior to the effect of widening the median diameter d50 range showing a small coercive force in crystalline Fe-based alloy atomized particles, compared with Mo. The reason for this is not clear, but it is thought that Nb has a tendency to promote concentration near the surface of the particles as compared to Mo.
“Α” in the composition formula (1) means the ratio of the content of Nb to the total content of Mo and Nb. “Α” satisfies 0 ≦ α ≦ 0.9.
0 ≦ α ≦ 0.9 means that Nb is not contained or, when Nb is contained, the ratio of the content of Nb to the total content of Mo and Nb is 0.9 or less. To do.
As described above, Nb is inferior to Mo in the effect of widening the range of the median diameter d50 showing a small coercive force in the crystalline Fe-based alloy atomized particles. Therefore, when “α” in the composition formula (1) is greater than 0.9 (for example, when α = 1.0, that is, when Mo is not contained and Nb is contained). In the crystalline Fe-based alloy ized powder, the range of the median diameter d50 showing a small holding force may be narrowed.

“Α” in the composition formula (1) preferably satisfies 0 <α (that is, the alloy composition includes both Mo and Nb). When 0 <α is satisfied, the range of the median diameter d50 showing a small holding force becomes wider in the crystalline Fe-based alloy customized powder.
α is more preferably 0.1 or more, and further preferably 0.2 or more.
The upper limit of α is more preferably 0.8, still more preferably 0.6, and still more preferably 0.5.

“D” in the composition formula (1) represents the total content (atomic%) of Mo and Nb in the alloy composition, and satisfies 0.5 ≦ d <4.0. Thereby, in the crystalline Fe-based alloy atomized particles, the range of the median diameter d50 showing a small coercive force is widened, and the saturation magnetization of the crystalline Fe-based alloy atomized powder is improved.
When 0.5 ≦ d is not satisfied (that is, when the total content of Mo and Nb is less than 0.5 atomic%), the above-described effect of adding Mo alone or the effect of adding Mo and Nb is I can't get it.
On the other hand, when d <4.0 is not satisfied (that is, when the total content of Mo and Nb is 4.0 atomic% or more), the content of Fe is relatively reduced, and as a result, the crystal The saturation magnetization of the high-quality Fe-based alloy ized powder tends to decrease. Specifically, since Mo and Nb have a larger atomic weight than other constituent elements (for example, Si, B, etc.), the saturation magnetization when the content exceeds the upper limit compared to other constituent elements. It is thought that the impact on

  As described above, “d” in the composition formula (1) satisfies 0.5 ≦ d <4.0. However, from the viewpoint of further improving the saturation magnetization of the crystalline Fe-based alloy ized powder, the composition formula ( “D” in 1) preferably satisfies 0.5 ≦ d ≦ 3.5.

In the composition formula (1), “c” (that is, the B content (atomic%)) and “d” (that is, the total content of Mo and Nb (atomic%)) is 10.0 <c + d. <13.5 is satisfied. Thereby, in the crystalline Fe-based alloy atomized particles, the range of the median diameter d50 showing a small coercive force is widened, and the saturation magnetization of the crystalline Fe-based alloy atomized powder is improved.
When 10.0 <c + d is not satisfied, the range of the median diameter d50 showing a small holding force may be narrowed in the crystalline Fe-based alloy customized powder.
When c + d <13.5 is not satisfied, the Fe content is relatively reduced, and as a result, the saturation magnetization of the crystalline Fe-based alloy admitted powder may be reduced.

(Cr)
In the alloy composition represented by the composition formula (1), Cr is an arbitrary element.
“E” in the composition formula (1) represents the Cr content (atomic%) in the alloy composition and satisfies 0 ≦ e ≦ 2.0. This improves the saturation magnetization of the crystalline Fe-based alloy atomized powder.
If e ≦ 2.0 is not satisfied, the saturation magnetization of the crystalline Fe-based alloy atomized powder may deteriorate.
e may be 0, but may be greater than 0 (that is, 0 <e).
When 0 <e, the corrosion resistance of the crystalline Fe-based alloy atomized powder is further improved.
When 0 <e, Cr functions as a deoxidizer for removing O as an impurity, and as a result, the coercive force of the crystalline Fe-based alloy atomized powder is further reduced.

In the composition formula (1), e preferably satisfies 0.5 <e ≦ 2.0.
Thereby, the corrosion resistance of the crystalline Fe-based alloy atomized powder is further improved, and the coercive force of the crystalline Fe-based alloy atomized powder is further reduced.

The Fe-based alloy may contain impurities in addition to the alloy composition represented by the composition formula (1).
Examples of the impurities include S (sulfur), O (oxygen), N (nitrogen), C (carbon), P (phosphorus), and the like.
The S content is preferably 200 ppm by mass or less.
The content of O is preferably 5000 ppm by mass or less.
The N content is preferably 1000 ppm by mass or less.
The content of C is preferably 1000 ppm by mass or less.
The content of P is preferably 1000 ppm by mass or less.

[Fe-based alloy ingot]
Next, an Fe-based alloy ingot that is an aspect of the Fe-based alloy of the present disclosure will be described.
The alloy composition of the Fe-based alloy ingot according to one embodiment is an alloy composition represented by the composition formula (1) as described above.
In the Fe-based alloy ingot according to one aspect, for example, the raw materials of each element in the alloy composition represented by the composition formula (1) are dissolved and mixed by a general method, and then cooled by a general method. Can be manufactured.

[Amorphous Fe-based alloy atomized powder]
Next, an amorphous Fe-based alloy atomized powder, which is another aspect of the Fe-based alloy of the present disclosure, will be described.
The alloy composition of the amorphous Fe-based alloy atomized powder according to one embodiment is an alloy composition represented by the composition formula (1) as described above.
The alloy structure of the amorphous Fe-based alloy atomized powder according to one embodiment is substantially composed of an amorphous phase. However, the alloy structure of the amorphous Fe-based alloy atomized powder according to one embodiment may contain a minute amount of crystal phase.

<Content of crystal phase in alloy structure>
In the amorphous Fe-based alloy atomized powder, the content of the crystal phase in the alloy structure is preferably 2% by volume, more preferably 1% by volume or less, particularly preferably based on the entire alloy structure. It is substantially 0% by volume.
When the content of the crystal phase in the alloy structure in the amorphous Fe-based alloy atomized powder is 2% by volume or less, the crystalline Fe-based alloy atomized powder obtained by heat-treating the amorphous Fe-based alloy atomized powder A lower coercivity can be obtained.

In the amorphous Fe-based alloy atomized powder, the content (CP) of the crystal phase in the alloy structure is the area of the broad diffraction pattern derived from the amorphous phase (AA) in the X-ray diffraction spectrum by powder X-ray diffraction. ) And the area (AC) of the main peak, which is the maximum diffraction intensity derived from the crystal phase, can be calculated by the following formula.
Content (CP) (volume%) = AC / (AC + AA) × 100

In the present disclosure, powder X-ray diffraction is performed as follows.
First, a powder to be measured (specifically, an amorphous Fe-based alloy atomized powder or a crystalline Fe-based alloy atomized powder) is compacted to produce an X-ray diffraction sample having a flat surface. Powder X-ray diffraction is performed on the flat surface of the prepared sample for X-ray diffraction to obtain an X-ray diffraction spectrum.
Powder X-ray diffraction is performed using a Cu-Kα radiation source X-ray diffractometer (for example, RINT2000 manufactured by Rigaku Corporation) under the conditions of 0.02 deg / step and 2step / sec in the range of 2θ of 20 to 60 ° C. .

<Median diameter d50>
As described above, by using the Fe-based alloy of the present disclosure (for example, amorphous Fe-based alloy atomized powder) as a raw material, a small coercive force (for example, a coercive force at an applied magnetic field of 40 kA / m is 190 A / m or less). A crystalline Fe-based alloy atomized powder having a wide median diameter d50 indicating magnetic force) can be produced.
It is considered that the heat treatment for obtaining a crystalline Fe-based alloy atomized powder does not affect the particle size distribution of the powder. Therefore, it is considered that the median diameter d50 of the amorphous Fe-based alloy atomized powder is maintained as it is in the crystalline Fe-based alloy atomized powder obtained by heat-treating the amorphous Fe-based alloy atomized powder.
There is no particular limitation on the median diameter d50 (hereinafter also simply referred to as “d50”) of the amorphous Fe-based alloy atomized powder.
The d50 of the amorphous Fe-based alloy atomized powder can be, for example, 3.0 μm or more and 35.0 μm or less.

When the d50 of the amorphous Fe-based alloy atomized powder is 3.0 μm or more, in a magnetic core (for example, a dust core, a metal composite core, etc.) manufactured using the crystalline Fe-based alloy atomized powder, the Fe-based alloy The space factor of the particles can be improved, whereby the saturation magnetic flux density and magnetic permeability of the magnetic core can be improved. The d50 of the amorphous Fe-based alloy atomized powder is preferably 3.5 μm or more, more preferably 5.0 μm or more, and even more preferably 8.5 μm or more.
When the d50 of the amorphous Fe-based alloy atomized powder is 35.0 μm or less, eddy current loss can be reduced in a magnetic core manufactured using the crystalline Fe-based alloy atomized powder. Thereby, for example, the magnetic core loss can be reduced when the magnetic core is used under a high frequency condition of 500 kHz or more. The d50 of the amorphous Fe-based alloy atomized powder is preferably 28.0 μm or less, more preferably 20.0 μm or less.

In the present disclosure, the median diameter d50 means a volume-based median diameter obtained by a laser diffraction method.
Hereinafter, an example of a method for measuring the median diameter d50 of the amorphous Fe-based alloy atomized powder by laser diffraction will be described.
For the entire amorphous Fe-based alloy atomized powder, using a laser diffraction / scattering particle size distribution analyzer (for example, LA-920 manufactured by HORIBA, Ltd.), the particle diameter (μm) and the cumulative frequency (volume) from the small particle diameter side %) And a cumulative distribution curve (that is, a volume-based cumulative distribution curve).
From the obtained cumulative distribution curve, the particle diameter corresponding to the cumulative frequency of 50% by volume is read, and this particle diameter is defined as the median diameter d50 of the amorphous Fe-based alloy atomized powder.

<(D90-d10) / d50>
The amorphous Fe-based alloy atomized powder preferably has (d90-d10) / d50 of 1.00 or more and 4.00 or less.
(D90-d10) / d50 means that the smaller the numerical value, the smaller the variation in particle diameter.
d50 is as described above.
d10 means a particle diameter corresponding to an integrated frequency of 10 volume% in the integrated distribution curve, and d90 means a particle diameter corresponding to an integrated frequency of 90 volume% in the integrated distribution curve.

<Oxide coating>
The amorphous Fe-based alloy atomized powder may include an oxide film in the surface layer portion of each particle.
When the amorphous Fe-based alloy atomized powder having an oxide film in the surface layer portion of each particle is heat-treated, a crystalline Fe-based alloy atomized powder having an oxide film in the surface layer portion of each particle is obtained.

When the amorphous Fe-based alloy atomized powder includes an oxide film, the amorphous Fe-based alloy atomized powder and the crystalline Fe-based alloy atomized powder obtained by heat-treating the amorphous Fe-based alloy atomized powder In this case, an antirust effect can be obtained and unnecessary oxidation can be prevented. Thereby, the storage property of the amorphous Fe-based alloy atomized powder and the crystalline Fe-based alloy atomized powder is improved.
In addition, when the amorphous Fe-based alloy atomized powder includes an oxide film, the insulating property between the particles is improved in the crystalline Fe-based alloy atomized powder, and as a result, the vortex, which is one of the causes of magnetic core loss. Current loss is reduced.
From the viewpoint of obtaining the above-described effect of the oxide film more effectively, the thickness of the oxide film is preferably 2 nm or more.

  In addition, from the viewpoint of making it difficult to hinder the effect of improving magnetic properties by nanocrystallization, and from the viewpoint of formability when producing a magnetic core using a crystalline Fe-based alloy atomized powder, the upper limit of the thickness of the oxide film is 50 nm is preferred.

<Example of Method for Producing Amorphous Fe-Based Alloy Atomized Powder (Production Method A)>
Hereinafter, an example of a production method for producing amorphous Fe-based alloy atomized powder (hereinafter referred to as “Production Method A”) will be shown.
The manufacturing method A includes a step of obtaining an amorphous Fe-based alloy atomized powder by an atomizing method.
As described above, the atomizing method is a method for producing molten alloy powder by pulverizing molten alloy into particles and quenching the obtained molten alloy particles.
According to the atomizing method, an amorphous Fe-based alloy atomized powder including an oxide film in the surface layer portion is easily formed.

In addition, according to the atomization method, amorphous Fe-based alloy atomized particles having a shape surrounded by a curved surface (for example, a spherical shape, a shape approximating a spherical shape, a teardrop shape, a gourd shape, etc.) can be obtained. .
The crystalline Fe-based alloy atomized particles obtained by heat-treating the amorphous Fe-based alloy atomized particles are also formed in a shape surrounded by a curved surface (for example, a spherical shape, a shape approximating a spherical shape, a teardrop shape, a gourd Mold shape, etc.).

The atomizing method is not particularly limited, and known methods such as a gas atomizing method, a water atomizing method, a disk atomizing method, a high-speed rotating water atomizing method, and a high-speed combustion flame atomizing method can be applied.
As an atomization method, it is easy to obtain an amorphous Fe-based alloy, it is excellent in the pulverization performance of the raw material molten metal, and can be cooled at a rate of 10 ³ ° C / second or more (more preferably 10 ⁵ ° C / second or more). The atomizing method is preferable.

In the water atomization method, the raw material molten metal flowing down is sprayed with high-pressure water sprayed from a nozzle to form a powder, and the high-pressure water is used to cool the powdered raw material molten metal. This is a method for obtaining atomized powder (hereinafter also simply referred to as “powder”).
The gas atomization method is a method of obtaining a powder by making a raw material melt into powder by an inert gas sprayed from a nozzle and cooling the powdered raw material melt. Examples of the cooling in the gas atomizing method include cooling with high-pressure water, cooling with a water tank provided in the lower part of the atomizing device, and cooling by dropping in flowing water.
The high-speed rotating water flow atomization method uses a cooling vessel whose inner peripheral surface is a cylindrical surface, and forms a cooling liquid layer in a laminar manner by causing the cooling liquid to flow while swirling along the inner peripheral surface. Is powdered by dropping, and cooled to obtain a powder.
In the high-speed combustion flame atomizing method, a raw material molten metal is powdered by injecting a flame as a flame jet at a supersonic speed or a speed close to the speed of sound by a high-speed combustor, and the raw material molten metal in powder form, water or the like as a cooling medium. This is a method of obtaining a powder by cooling with a rapid cooling mechanism. JP, 2014-136807, A can be referred to for a high-speed combustion flame atomization method, for example.

As the atomizing method, a disk atomizing method, a high-speed rotating water atomizing method, or a high-speed combustion flame atomizing method is preferable because it is excellent in cooling efficiency and an amorphous Fe-based alloy can be obtained relatively easily.
Moreover, when applying a water atomizing method or a gas atomizing method, it is preferable to use high-pressure water exceeding 50 MPa.

[Crystalline Fe-based alloy atomized powder]
The crystalline Fe-based alloy atomized powder of the present disclosure has an alloy composition represented by the composition formula (1) described above, and has an alloy structure including nanocrystal grains having an average grain size of 40 nm or less.

The crystalline Fe-based alloy atomized powder of the present disclosure has a wide median diameter d50 range showing a small coercive force.
The reason why such an effect is obtained is considered that the crystalline Fe-based alloy atomized powder of the present disclosure has an alloy composition represented by the composition formula (1). Details are as described above.
The preferred embodiment of the alloy composition of the crystalline Fe-based alloy atomized powder of the present disclosure is the same as the preferred embodiment of the alloy composition of the Fe-based alloy of the present disclosure described above.

<Nanocrystal grains>
In the crystalline Fe-based alloy atomized powder of the present disclosure, the coercive force is reduced when the average grain size of the nanocrystal grains is 40 nm or less.
When the average grain size of the nanocrystal grains is more than 40 nm, it is difficult to adjust the grain size of the nanocrystal grains, and the coercive force is increased.
The average grain size of the nanocrystal grains is preferably 35 nm or less, more preferably 30 nm or less.

  On the other hand, the average grain size of the nanocrystal grains is preferably 5 nm or more. This makes it easy to obtain the required magnetic characteristics.

In the present disclosure, the average grain size of the nanocrystal grains is determined as follows.
Nanocrystal grains have a fine crystal structure, and one nanocrystal grain is considered to be a single crystal. For this reason, in this specification, the magnitude | size of a crystallite is handled as an average particle diameter of a nanocrystal grain.
Specifically, first, the crystalline Fe-based alloy atomized powder of the present disclosure is compacted to prepare a sample for X-ray diffraction having a flat surface. Powder X-ray diffraction is performed on the flat surface of the prepared sample for X-ray diffraction to obtain an X-ray diffraction spectrum.
Powder X-ray diffraction is performed using a Cu-Kα radiation source X-ray diffractometer (for example, RINT2000 manufactured by Rigaku Corporation) under the conditions of 0.02 deg / step and 2step / sec in the range of 2θ of 20 to 60 ° C. .
Using the peak of bccFe-Si [diffractive surface (110)] in the obtained X-ray diffraction spectrum, the size D of the crystallite is obtained by the Scherrer equation shown below.
The size D of the obtained crystallite is defined as the average particle diameter of the nanocrystal grains.

D = (K · λ) / (βcos θ) ... Scherrer's formula [D represents the size of the crystallite, K represents the Scherrer constant, specifically 0.9, and λ represents the X-ray Β represents the full width at half maximum of the peak of the diffraction surface (110), and θ represents the Bragg angle (half of the diffraction angle 2θ). ]

  In the examples described later, in any sample, the main peak, which is the maximum diffraction intensity in the X-ray diffraction spectrum, was in the vicinity of 2θ = 45 °, and was the peak of bccFe—Si [diffractive surface (110)].

As described above, the nanocrystal grains include bccFe—Si.
The nanocrystal grains may further contain an FeB-based compound.

<Content of crystal phase in alloy structure>
In the crystalline Fe-based alloy atomized powder of the present disclosure, the content of the crystal phase in the alloy structure is preferably 30% by volume or more with respect to the entire alloy structure. The concept of the crystal phase here includes the nanocrystal grains described above.
When the content of the crystal phase in the alloy structure is 30% by volume or more, the magnetostriction of the crystalline Fe-based alloy atomized powder can be further reduced.
There is no restriction | limiting in particular in the upper limit of the content rate of the crystal phase in an alloy structure. Magnetostriction may be affected by the balance between the crystalline phase and the amorphous phase. Considering this point, the upper limit of the content of the crystal phase in the alloy structure may be, for example, 95% by volume or 90% by volume or less.

  The method for measuring the crystal phase content in the alloy structure in the crystalline Fe-based alloy atomized powder is the same as the method for measuring the crystal phase content in the alloy structure in the amorphous Fe-based alloy atomized powder described above. .

<Coercivity>
In the crystalline Fe-based alloy atomized powder of the present disclosure, the coercive force at an applied magnetic field of 40 kA / m is preferably 190 A / m or less, more preferably 130 A / m or less, and even more preferably 60 A / m or less. .
The lower limit of the coercive force at an applied magnetic field of 40 kA / m is not particularly limited, but the lower limit may be 5 A / m from the viewpoint of the suitability for manufacturing the crystalline Fe-based alloy atomized powder of the present disclosure, and 10 A / M.
An applied magnetic field of 40 kA / m corresponds to an applied magnetic field of 500 Oe.

<Saturation magnetization>
In the crystalline Fe-based alloy atomized powder of the present disclosure, the saturation magnetization at an applied magnetic field of 800 kA / m is preferably 110 emu / g or more.
Further, in the crystalline Fe-based alloy atomized powder of the present disclosure, the upper limit of the saturation magnetization at an applied magnetic field of 800 kA / m is defined by the amount of Fe composition.

<Median diameter d50>
As described above, the crystalline Fe-based alloy atomized powder of the present disclosure has a wide median diameter d50 that shows a small coercive force (for example, a coercive force with a value of 190 A / m or less at an applied magnetic field of 40 kA / m).
For this reason, there is no restriction | limiting in particular in d50 of the crystalline Fe base alloy atomized powder of this indication.
Examples and preferred ranges of d50 in the crystalline Fe-based alloy atomized powder of the present disclosure are the same as those of d50 in the amorphous Fe-based alloy atomized powder described above.

<(D90-d10) / d50>
The preferable range of (d90-d10) / d50 in the crystalline Fe-based alloy atomized powder of the present disclosure is the same as the preferable range of (d90-d10) / d50 in the amorphous Fe-based alloy atomized powder described above.

<Oxide coating>
The crystalline Fe-based alloy atomized powder of the present disclosure may include an oxide film in the surface layer portion of each particle.
The effect of including the oxide film is as described in the section of amorphous Fe-based alloy atomized powder.
The preferable thickness of the oxide film that can be included in the crystalline Fe-based alloy atomized powder of the present disclosure is the same as the preferable thickness of the oxide film that can be included in the amorphous Fe-based alloy atomized powder.

<Preferred use>
The crystalline Fe-based alloy atomized powder of the present disclosure described above is particularly suitable as a material for a magnetic core.
Examples of the magnetic core include a powder magnetic core and a metal composite core.

  A magnetic core obtained by using the crystalline Fe-based alloy atomized powder of the present disclosure is suitably used for an inductor, a noise filter, a choke coil, a transformer, a reactor, and the like.

As described above, in the crystalline Fe-based alloy atomized powder of the present disclosure, a small coercive force can be obtained in a wide d50 range. Therefore, when the crystalline Fe-based alloy atomized powder of the present disclosure is used as a magnetic core material, the degree of freedom in selecting the magnetic core material (specifically, the degree of freedom in selecting d50) increases.
Moreover, since the crystalline Fe-based alloy atomized powder of the present disclosure has a small coercive force, it contributes to improving characteristics of an inductor, a noise filter, a choke coil, a transformer, a reactor, and the like.

<Example of Method for Producing Crystalline Fe-Based Alloy Atomized Powder (Production Method X)>
Hereinafter, an example of a manufacturing method for manufacturing the crystalline Fe-based alloy atomized powder of the present disclosure (hereinafter referred to as “Production Method X”) will be shown.
The production method X includes a step of obtaining the crystalline Fe-based alloy atomized powder of the present disclosure by performing a heat treatment on the amorphous Fe-based alloy atomized powder which is one embodiment of the Fe-based alloy of the present disclosure described above.

In a preferred embodiment of the process for obtaining the crystalline Fe-based alloy atomized powder of the present disclosure, classification and heat treatment are performed in this order on the amorphous Fe-based alloy atomized powder which is one embodiment of the Fe-based alloy of the present disclosure described above. Alternatively, the crystalline Fe-based alloy atomized powder of the present disclosure is obtained by performing heat treatment and classification in this order.
In this embodiment, classification may be performed before heat treatment or after heat treatment. When classification is performed before heat treatment, classification may be performed after heat treatment (that is, classification, heat treatment, and classification may be performed in this order).

As described above, the crystalline Fe-based alloy atomized powder of the present disclosure has a wide median diameter d50 that shows a small coercive force (for example, a coercive force with a value of 190 A / m or less at an applied magnetic field of 40 kA / m). This effect is an effect brought about by the alloy composition in the Fe-based alloy as the raw material (that is, the alloy composition represented by the composition formula (1)).
Therefore, even if the step of obtaining the crystalline Fe-based alloy atomized powder of the present disclosure includes classification, the number of particles removed by classification can be reduced.
Therefore, production method X is a production method of crystalline Fe-based alloy atomized powder excellent in productivity.

(Heat treatment)
The conditions for the heat treatment are appropriately adjusted to conditions in which the average grain size of the nanocrystal grains is 40 nm or less in the crystalline Fe-based alloy atomized particles obtained by the heat treatment.
The heat treatment can be performed using a known heating furnace such as a batch type electric furnace or a mesh belt type continuous electric furnace.

The heat treatment conditions are adjusted, for example, by adjusting the rate of temperature rise, the maximum temperature reached (holding temperature), the holding time at the maximum temperature reached, and the like.
The temperature rising rate is, for example, 1 ° C / h to 200 ° C / h, preferably 3 ° C / h to 100 ° C / h.
The maximum temperature reached (holding temperature) depends on the crystallization temperature of the alloy structure of the amorphous Fe-based alloy atomized particles to be heat-treated (that is, the alloy structure consisting essentially of the amorphous phase). It is 450 degreeC-550 degreeC, Preferably it is 470 degreeC-520 degreeC.
The holding time at the highest temperature is, for example, 1 minute to 3 hours, preferably 30 minutes to 2 hours.

  The crystallization temperature of the alloy structure of the amorphous Fe-based alloy atomized particles is 600 ° C./hr in a temperature range from room temperature (RT) to 600 ° C. using a differential scanning calorimeter (DSC). It can be determined by conducting a thermal analysis at a rate of temperature increase.

There is no restriction | limiting in particular about the atmosphere which heat-processes.
Examples of the atmosphere for the heat treatment include an air atmosphere, an inert gas (nitrogen, argon, etc.) atmosphere, a vacuum atmosphere, and the like.

There is no particular limitation on the method for cooling the crystalline Fe-based alloy atomized powder obtained by the heat treatment.
Examples of the cooling method include furnace cooling and air cooling.
Alternatively, the crystalline Fe-based alloy atomized powder obtained by the heat treatment may be forcedly cooled by blowing an inert gas.

(Classification)
Examples of the classification method include a method using a sieve, a method using a classification device, a method combining these, and the like.
Examples of the classifier include known classifiers such as a centrifugal airflow classifier and an electromagnetic sieve shaker.
In the centrifugal force type airflow classifier, for example, d50, the ratio of particles having a particle diameter of 2 μm or less, and the like are adjusted by adjusting the rotation speed and air volume of the classification rotor.
In an electromagnetic sieve shaker, for example, d50, the proportion of particles having a particle diameter of 2 μm or less, and the like are adjusted by appropriately selecting a sieve mesh.

In powder classification using a centrifugal airflow classifier, the powder to be classified is a centrifugal force generated by a vortex formed by a classification rotor rotating at high speed, and a drag force of an airflow supplied from an external blower. Receive. Thereby, the said powder is divided into the group of the large particle in which a centrifugal force acts largely, and the group of the small particle in which a drag acts largely.
The centrifugal force can be adjusted by changing the rotation speed of the classifying rotor, and the drag force can be easily adjusted by changing the air volume from the blower. By adjusting the balance between centrifugal force and drag force, the powder can be classified into a predetermined particle size.
When the group of small particles is collected, the group of large particles is removed from the powder. Hereinafter, this classification is also referred to as “overcut”.
When the large particle group is collected, the small particle group is removed from the powder. Hereinafter, this classification is also referred to as “undercut”.

The classification preferably includes a first classification performed using a sieve and a second classification performed using a centrifugal airflow classifier after the first classification.
The second classification in this aspect preferably includes overcutting, more preferably includes both overcutting and undercutting, and further preferably includes an operation of performing overcutting and undercutting in this order.

The sieve opening in the first classification can be selected as appropriate.
From the viewpoint of further reducing the time required for the first classification, the mesh opening is, for example, 90 μm or more, preferably 150 μm or more, and more preferably 212 μm or more.
The upper limit of the mesh opening is, for example, 300 μm, preferably 250 μm, from the viewpoint of further reducing the load applied to the device used for the second classification.
The opening referred to in this specification means a nominal opening defined in JIS Z8801-1.
In the second classification, the rotation speed of the classification rotor of the centrifugal airflow classifier is, for example, 500 rpm (revolution per minute) or more, and preferably 1000 rpm or more. The upper limit of the rotational speed of the classifying rotor depends on the performance of the centrifugal airflow classifier, but the larger the rotational speed, the smaller the number of particles in the powder. For example, 5000 rpm, preferably 4000 rpm, more preferably 3000 rpm. is there.
In the second classification, the supply speed of the powder supplied to the centrifugal airflow classifier is, for example, 0.5 kg / h or more, preferably 1 kg / h or more, and more preferably 2 kg / h or more. The upper limit of the powder supply speed depends on the classification treatment capacity of the centrifugal airflow classifier.
In the second classification, the amount of airflow in the centrifugal airflow classifier is, for example, 0.5 m ³ / s or more, preferably 1.0 m ³ / s or more, and more preferably 2.0 m ³ / s. s or more. The upper limit of the airflow volume depends on the blower capacity of the centrifugal airflow classifier.

〔core〕
The magnetic core of the present disclosure includes the above-described crystalline Fe-based alloy atomized powder of the present disclosure and a binder that binds the crystalline Fe-based alloy atomized powder.
The binder is preferably at least one selected from the group consisting of epoxy resins, unsaturated polyester resins, phenol resins, xylene resins, diallyl phthalate resins, silicone resins, polyamideimides, polyimides, and water glass.

In the magnetic core of the present disclosure, the content of the binder with respect to 100 parts by mass of the crystalline Fe-based alloy atomized powder is preferably 1 part by mass to 10 parts by mass, and more preferably 1 part by mass to 7 parts by mass. More preferably, it is 1 mass part-5 mass parts.
When the content of the binder is 1 part by mass or more, the insulation between the particles and the strength of the magnetic core are further improved.
When the binder content is 10 parts by mass or less, the magnetic properties of the magnetic core are further improved.

There is no restriction | limiting in particular in the shape of the magnetic core of this indication, According to the objective, it can select suitably.
Examples of the shape of the magnetic core of the present disclosure include an annular shape (for example, an annular shape, a rectangular frame shape, etc.), a rod shape, and the like.

The magnetic core of the present disclosure can be manufactured, for example, by the following method.
A mixture of the crystalline Fe-based alloy atomized powder of the present disclosure and a binder is filled in a molding die, and is pressed at a molding pressure of about 1 to 2 GPa with a hydraulic press molding machine or the like to obtain a molded body. The mixture may further include a lubricant such as zinc stearate.
The obtained molded body is heat-treated at a temperature of 200 ° C. to less than the crystallization temperature for about 1 hour to cure the binder and obtain a magnetic core.
The heat treatment atmosphere in this case may be an inert atmosphere or an oxidizing atmosphere.

  A metal composite core that is an example of the magnetic core of the present disclosure can be manufactured, for example, by embedding a coil in a mixture of the crystalline Fe-based alloy atomized powder of the present disclosure and a binder and integrally forming the coil. The integral molding can be performed by a known molding means such as injection molding.

In addition, the magnetic core of the present disclosure may include metal powder other than the crystalline Fe-based alloy atomized powder of the present disclosure.
Other metal powders include soft magnetic powders, specifically, amorphous Fe-based alloy atomized powder, pure Fe powder, Fe-Si alloy atomized powder, Fe-Si-Cr alloy atomized powder, and the like. Can be mentioned.
The d50 of other metal powders may be small, large or equivalent to d50 of the crystalline Fe-based alloy atomized powder of the present disclosure, and can be appropriately selected according to the purpose.

  Examples of the present disclosure will be described below, but the present disclosure is not limited to the following examples.

[Sample No. 1-28]
<Production of ingot>
As raw materials, Fe, Cu, Si, B, at least one of Nb and Mo, and Cr are weighed, placed in an alumina crucible, and placed in a vacuum chamber of a high-frequency induction heating apparatus. The vacuum chamber was evacuated. Next, each raw material was dissolved and mixed by high-frequency induction heating in an inert atmosphere (Ar) in a reduced pressure state, and then cooled to obtain ingots having the following alloy compositions A to G.
The composition of each ingot was analyzed by ICP emission spectrometry.
Among the alloy compositions A to G, the alloy compositions A and D are alloy compositions of comparative examples not included in the range of the alloy composition represented by the composition formula (1), and other alloy compositions are represented by the composition formula (1 It is an alloy composition of the Example contained in the range of the alloy composition represented by this.

(Alloy compositions A to G)
A (comparative example): Fe _74.4 Cu _1.0 Si _13.5 B _7.6 Nb _2.5 Cr _1.0
B (Example): Fe _72.5 Cu _1.0 Si _13.5 B _9.0 Mo _3.0 Cr _1.0
C (Example): Fe _72.5 Cu _1.0 Si _13.5 B _11.0 Mo _1.0 Cr _1.0
D (comparative example): Fe _72.5 Cu _1.0 Si _13.5 B _9.0 Nb _3.0 Cr _1.0
E (Example): Fe _72.5 Cu _1.0 Si _13.5 B _9.0 Mo _1.5 Nb _1.5 Cr _1.0
F (Example): Fe _73.0 Cu _1.0 Si _13.5 B _9.0 Mo _1.3 Nb _1.5 Cr _0.7
G (Example): Fe _71.0 Cu _1.0 Si _15.5 B _9.0 Mo _1.3 Nb _1.3 Cr _1.0

_{Fe 100-a-b-c} -d-e Cu a Si b B c (Mo 1-α Nb α) d Cr e ... formula (1)
[In the composition formula (1), a, b, c, d, e, and α are 0.1 ≦ a ≦ 1.5, 13.0 ≦ b ≦ 15.0, 8.0 <c <12. 0, 0.5 ≦ d <4.0, 0 ≦ e ≦ 2.0, 10.0 <c + d <13.5, 0 ≦ α ≦ 0.9, and 71.0 ≦ 100−ab− c-d-e ≦ 74.0 is satisfied. ]

In addition, operation of the process after this has little influence on the composition of Fe-based alloy.
Therefore, it can be considered that the composition of the ingot is maintained as it is in the amorphous Fe-based alloy atomized powder and the crystalline Fe-based alloy atomized powder.

<Production of amorphous Fe-based alloy atomized powder>
The ingot was redissolved at 1300 to 1700 ° C., and the obtained molten alloy was pulverized by an atomizing method to obtain an amorphous Fe-based alloy atomized powder composed of amorphous Fe-based alloy particles.
Here, as the atomization method, the water atomization method was applied to the alloy compositions A to D, and the high-speed combustion flame atomization method was applied to the alloy compositions E to G.
In the water atomization method, the temperature of water as the spray medium was 20 ° C., and the water injection pressure was 100 MPa.
In the high-speed combustion flame atomization method, the temperature of the flame jet injected from the injection means was 1300 ° C., and the drooping speed of the molten alloy as a raw material was 5 kg / min. Water was used as the cooling medium, and this cooling medium (water) was sprayed as a liquid mist by the cooling means. The cooling rate of the molten alloy was adjusted by adjusting the water injection amount to 4.5 liters / min to 7.5 liters / min.

<Classification>
The amorphous Fe-based alloy atomized powder obtained above (amorphous Fe-based alloy atomized powder before classification) was classified as follows, and each sample in Table 1 was obtained.
Sample No. 5, 6, 11 and 16 are samples subjected to only the following first classification (that is, classification using a sieve).
Sample No. 1-4, 7-10, 12-15, and 17-28 are the samples which performed the following 1st classification and the following 2nd classification in this order.

(Classification using a sieve (first classification))
First, as a first classification common to all samples, the amorphous Fe-based alloy atomized powder before classification obtained above is passed through a sieve having a mesh size of 250 μm, so that it is coarse from the amorphous Fe-based alloy atomized powder. Particles were removed.

The amorphous Fe-based alloy atomized powder after the first classification and the resin were mixed, and the resulting mixture was cured. A smooth surface was formed by subjecting the obtained cured product to polishing and ion milling. A portion where the amorphous Fe-based alloy particles existed on the obtained smooth surface was observed with a transmission electron microscope (TEM) at 500,000 times, and composition mapping was performed.
As a result, it was confirmed that an oxide film having a thickness of 2 nm or more and 30 nm or less exists in the surface layer portion of the amorphous Fe-based alloy particles in any sample.
Moreover, when the oxide film was identified by Auger electron spectroscopy (JAMP-7830F manufactured by JEOL), the oxide film in any sample contained Fe, Si, Cu, and B.

(Classification by centrifugal force type air classifier (second classification))
Sample No. In 1-4, 7-10, 12-15, and 17-28, centrifugal force type airflow classifier (TC-15 manufactured by Nisshin Engineering Co., Ltd.) for the amorphous Fe-based alloy atomized powder after the first classification. The second classification was performed using
Specifically, the air volume of the blower, the rotation speed of the classification rotor, and the powder supply speed are adjusted as shown in Table 1, and the amorphous Fe-based alloy after the first classification is obtained by the second classification in the overcut mode. Large particles were removed from the atomized powder.

<Various measurements>
About each sample after classification, d10, d50, d90, and (d90-d10) / d50 were calculated | required by the method mentioned above.
For each sample, an X-ray diffraction spectrum by powder X-ray diffraction was used under the measurement conditions described in the above-mentioned “Amorphous Fe-based alloy atomized powder” item, “Content ratio of crystal phase in alloy structure”. Was measured. In the X-ray diffraction spectrum, when there is a diffraction peak derived from the crystalline phase, it is judged as “present”, and when there is no diffraction peak derived from the crystalline phase, it is judged as “no”. did.
The results are shown in Table 1.

Further, each sample after classification (namely, classified amorphous Fe-based alloy particles) was observed at a magnification of 100 to 5000 times using a scanning microscope (SEM: Scanning Electron Microscope, S-4700 manufactured by Hitachi, Ltd.). .
As a result, the shape of each particle in each sample was a shape surrounded by a curved surface. Specifically, each sample contained spherical particles, particles close to a spherical shape, teardrop-shaped particles, and gourd-shaped particles.

Using a differential scanning calorimeter (Rigaku DSC8270), each sample after classification (ie, classified amorphous Fe-based alloy atomized particles) was heated at a rate of 10 ° C./min to obtain a DSC curve. .
The crystallization temperature of each sample was determined from the obtained DSC curve.
The results are shown in Table 2.

The following heat treatment hardly affects the particle size distribution of the particles.
Accordingly, the particle size distribution (specifically, d10, d50, d90, and (d90-d10) / d50) of each sample after classification can be considered to be maintained as it is in each sample after the heat treatment. .

<Heat treatment>
Each sample after classification (excluding sample No. 10) is subjected to heat treatment under the conditions shown in Table 2 (temperature increase rate, holding temperature KT, holding time, atmosphere, and oxygen concentration) using an electric heat treatment furnace. gave. This heat treatment was performed in a state where 10 g of each sample (excluding sample No. 10) was placed in an alumina crucible and the crucible was placed in an electric heat treatment furnace.
Here, the holding temperature KT means the highest temperature reached in the heat treatment, and the holding time means a time for holding at the highest temperature (that is, the holding temperature KT).
The heat treatment in the N ₂ atmosphere was performed while introducing N ₂ gas into the electric heat treatment furnace.
The oxygen concentration means the oxygen concentration (% by volume) in the heat treatment atmosphere. The oxygen concentration was measured by an oxygen concentration meter disposed in the electric heat treatment furnace.
The oxygen concentration in the N ₂ atmosphere was adjusted by adjusting the flow rate of N ₂ gas introduced into the electric heat treatment furnace.
After the heat treatment (specifically, after the holding time), heating in the electric heat treatment furnace was stopped, and each sample (except for sample No. 10) was cooled in the furnace.

As described above, a crystalline Fe-based alloy atomized powder was obtained as a sample after heat treatment (excluding sample No. 10).
Sample No. after classification No heat treatment was performed on 10 (that is, amorphous Fe-based alloy atomized powder).
In Table 2, Sample No. 10 was used as a reference example.

<Measurement of average grain size of nanocrystal grains>
For each of the samples after heat treatment (excluding sample No. 10), the average particle size (nm) of the nanocrystal grains contained in the particle structure was measured by the method described above.
The results are shown in Table 2.

Further, for each of the samples after heat treatment (excluding sample No. 10), the content of the crystalline phase in the alloy structure of the crystalline Fe-based alloy atomized powder was measured by the method described above.
As a result, in any sample, the content of the crystalline phase in the alloy structure of the crystalline Fe-based alloy atomized powder was in the range of 50 to 80% by volume.

<Measurement of saturation magnetization and coercivity>
About each sample after heat processing, magnetization measurement is performed to obtain a hysteresis loop, and from the obtained hysteresis loop, saturation magnetization (emu / g) at an applied magnetic field of 800 kA / m and coercivity (A at an applied magnetic field of 40 kA / m) / M) respectively.
Magnetization was measured using a VSM (Vibrating Sample Magnetometer, VSM-5 manufactured by Toei Kogyo).
The results are shown in Table 2.

  As shown in Table 2, it was confirmed that the saturation magnetization was 110 emu / g or more in both Examples and Comparative Examples.

Next, based on the result of Table 2, the relationship between d50 and coercive force was graphed for each alloy composition (A to G) of the crystalline Fe-based alloy atomized powder.
FIG. 1 is a graph showing the relationship between d50 and coercive force for each alloy composition (A to G) in a crystalline Fe-based alloy atomized powder.
In FIG. 1, A to G mean alloy compositions A to G, respectively.

Further, based on FIG. 1, the width (approximate value) in the range of d50 showing a coercive force of 190 A / m or less is estimated for each alloy composition (A to G) of the crystalline Fe-based alloy atomized powder by the following formula. It was. The results are shown in Table 3.
Range of d50 range showing a coercive force of 190 A / m or less (approximate value) = maximum value of d50 showing a coercive force of 190 A / m or less-minimum value of d50 showing a coercive force of 190 A / m or less

As shown in FIG. 1 and Table 3, the crystalline Fe-based alloy atomized powder of the example (ie, the crystalline Fe-based alloy atomized powder obtained from the Fe-based alloy having the alloy compositions B, C, and E to G) Compared to the crystalline Fe-based alloy atomized powder of the comparative example (that is, the crystalline Fe-based alloy atomized powder obtained from the Fe-based alloy having the alloy compositions A and D), the coercive force is 190 A / m or less. It was confirmed that the range of d50 shown is wide.
Further, as shown in FIG. 1, it was confirmed that the crystalline Fe-based alloy atomized powder of the example had a smaller minimum coercive force than the crystalline Fe-based alloy atomized powder of the comparative example.

Specifically, the alloy composition A (comparative example) is a composition that does not contain Mo, the B content is less than the lower limit, and the Fe content exceeds the upper limit. That is, the alloy composition A is 71.0 ≦ 100−ab−c−d−e ≦ 74.0, 0 ≦ α ≦ 0.9, and 8.0 <c < Not satisfying 12.0. As shown in FIG. 1 and Table 3, in the alloy composition A (comparative example), the width of the d50 range showing a coercive force of 190 A / m or less is 0 μm (that is, a coercive force of 190 A / m or less is shown). d50 is not present).
Compared to alloy composition A (comparative example), alloy composition D (comparative example) does not contain Mo, although the Fe content and B content satisfy the requirements. That is, the alloy composition D satisfies 71.0 ≦ 100−ab−c−d−e ≦ 74.0 and 8.0 <c <12.0 in the composition formula (1). 0 ≦ α ≦ 0.9 is not satisfied. In the alloy composition D (comparative example), there is a range of d50 showing a coercive force of 190 A / m or less, but the range of d50 showing a coercive force of 190 A / m or less is narrower than that of the example group. .
Alloy composition B (Example) is a composition in which Nb in alloy composition D (Comparative Example) is replaced with Mo of the same atomic%. In alloy composition B (Example), the range of d50 indicating a coercive force of 190 A / m or less is wider than that in alloy composition D (Comparative Example).

The alloy composition C (Example) is a composition in which the B content is increased and the Mo content is decreased with respect to the alloy composition B (Example). In the alloy composition C (Example), the d50 range showing a coercive force of 190 A / m or less is further widened compared to the alloy composition B (Example). Table 2 also shows that the alloy composition C (Example) is superior in saturation magnetization to the alloy composition B (Example).
The alloy composition E (Example) is a composition in which a part of Mo in the alloy composition B (Example) is replaced with Nb. In the alloy composition E (Example), the range of d50 showing a coercive force of 90 A / m or less is further widened as compared with the alloy composition B (Example).

<Evaluation of magnetostriction constant>
It is difficult to directly measure the magnetostriction constant of powder.
Therefore, as a substitute test for estimating the magnetostriction constant of the crystalline Fe-based alloy atomized powder, the magnetostriction constant was measured for a ribbon having the same structure as that of the crystalline Fe-based alloy atomized powder.
Specifically, an amorphous Fe-based alloy ribbon having a thickness of 15 μm and a width of 5 mm was prepared by a single roll method using each of the above-described alloy compositions A to G using an ingot having each alloy composition. The rapid cooling in the single roll method was performed in Ar gas. The obtained amorphous Fe-based alloy ribbon was heat-treated under the conditions shown in Table 4 to obtain a crystalline Fe-based alloy ribbon.

Each of the obtained crystalline Fe-based alloy ribbons contained nanocrystalline grains having an average grain size of 40 nm or less in the structure in the range of 50% by volume to 80% by volume.
As a result of measuring the magnetostriction constant of each crystalline Fe-based alloy ribbon, the magnetostriction constant of any crystalline Fe-based alloy ribbon was in the range of 0 to + 5 × 10 ⁻⁶ .
Therefore, it is presumed that each sample after heat treatment (that is, crystalline Fe-based alloy atomized powder) has a similar magnetostriction constant.

<Production of magnetic core>
Sample No. in Table 2 To 100 parts by mass (25.00 g) of 21 (crystalline Fe-based alloy atomized powder having an alloy composition E), 5 parts by mass (1.25 g) of a powdery silicone resin as a binder was added and mixed. The obtained mixed powder was filled in a molding die, and a kneaded product was molded by applying a pressure of 400 MPa with a hydraulic press molding machine. The obtained molded body was heat-treated at 200 ° C. for 1 hour.
Thus, an annular magnetic core having an outer diameter of 13.5 mm, an inner diameter of 7.7 mm, and a height of 2.0 mm was obtained.

−Core loss−
The annular core was used as an object to be measured, and the primary side winding and the secondary side winding were each wound 18 turns around the object to be measured. In this state, the core loss (kW / m ³ ) of the magnetic core of the annular body was measured at room temperature under the conditions of a maximum magnetic flux density of 30 mT and a frequency of 2 MHz using a BH analyzer SY-8218 manufactured by Iwatsu Measurement Co., Ltd.
As a result, the magnetic core loss (kW / m ³ ) was 2400 kW / m ³ .

-Space factor (phase density;%)-
The density A of the magnetic core calculated from the weight and volume of the annular magnetic core, the density B of the mixed powder of the crystalline Fe-based alloy atomized powder and the silicone resin obtained by the gas replacement method, and the crystalline Fe-based alloy atomized powder From the density C, the density D of the silicone resin, the weight E of the crystalline Fe-based alloy atomized powder in the mixed powder, and the weight F of the silicone resin in the mixed powder, the space factor P is calculated by the following equation. did.
P = A / B × V × 100 (%)
A: Magnetic core density (× 10 ³ kg / m ³ )
B: Density of mixed powder (× 10 ³ kg / m ³ )
C: Density of crystalline Fe-based alloy atomized powder (× 10 ³ kg / m ³ )
D: Density of silicone resin (× 10 ³ kg / m ³ )
E: Weight of crystalline Fe-based alloy atomized powder in mixed powder (kg)
F: Weight of silicone resin in mixed powder (kg)
V: Volume ratio of crystalline Fe-based alloy atomized powder to the entire mixed powder where V = (E / C) / [(E / C) + (F / D)]
As a result, the space factor (phase body density;%) in the annular magnetic core was 68%.

The disclosure of Japanese Patent Application No. 2017-152561 filed on August 7, 2017 and the disclosure of Japanese Patent Application No. 2017-168911 filed on September 1, 2017 are incorporated by reference in their entirety. Incorporated herein.
All documents, patent applications, and technical standards mentioned in this specification are to the same extent as if each individual document, patent application, and technical standard were specifically and individually stated to be incorporated by reference, Incorporated herein by reference.

Of the crystalline Fe-based alloy atomized particles, particles having a large particle size may have a larger coercive force than particles having a small particle size. The following reasons can be considered as the reason.
As described above, amorphous Fe-based alloy atomized particles that are raw materials for crystalline Fe-based alloy atomized particles are produced by rapidly cooling molten alloy particles. At this time, the molten alloy particles having a small particle diameter have a large specific surface area, so that the whole is rapidly quenched. For this reason, from the molten alloy particles having a small particle diameter, amorphous Fe-based alloy atomized particles that are homogeneous and highly amorphous (that is, crystal grains are not present in the alloy structure or are extremely reduced) are obtained. Easy to obtain.
However, large molten alloy particles particle size, specific surface area small fry, relatively easy cooling rate becomes slow, easily cooling speed of the internal particles is slower than the cooling rate of the particle surface. As a result, from the molten alloy particle having a large particle diameter, an amorphous Fe-based alloy atomized particle having a heterogeneous amorphous phase or an amorphous phase in which crystal grains are partially precipitated can be obtained. There is a case. When such amorphous Fe-based alloy atomized particles are heat-treated, coarse crystals are generated in the alloy structure, and as a result, the coercive force of the obtained crystalline Fe-based alloy atomized particles may increase. .
Regarding the above-described problem, since the Fe-based alloy of the present disclosure has an alloy composition represented by the composition formula (1), it is amorphous in the stage of rapidly cooling the molten alloy particles mainly by the action of Si, B, and Mo. It is considered that the quality improvement effect (hereinafter also referred to as “quick cooling effect”) is excellent. For this reason, when the Fe-based alloy of the present disclosure is used, it is considered that amorphous Fe-based alloy atomized particles that are homogeneous and highly amorphous are easily obtained from molten alloy particles having a relatively large particle size. It is done. As a result, in the crystalline Fe-based alloy atomized powder obtained by heat-treating the amorphous Fe-based alloy atomized powder, it is considered that the coercive force of the particles having a large particle diameter is suppressed from becoming too large.

(Mo, Nb)
In the alloy composition represented by the composition formula (1), Mo is an essential element, contributes to the quenching effect in the stage of quenching the molten alloy particles, and the nanocrystalline grains in the crystalline Fe-based alloy atomized particles. Contributes to uniform particle size. Therefore, Mo contributes to the effect of widening the range of the median diameter d50 showing a small coercive force in the crystalline Fe-based alloy atomized particles.
In the alloy composition represented by the composition formula (1), Nb is an arbitrary element. Although Nb has an effect similar to Mo, it is inferior to the effect of widening the median diameter d50 range showing a small coercive force in crystalline Fe-based alloy atomized particles, compared with Mo. The reason for this is not clear, but it is thought that Nb has a tendency to promote concentration near the surface of the particles as compared to Mo.
“Α” in the composition formula (1) means the ratio of the content of Nb to the total content of Mo and Nb. “Α” satisfies 0 ≦ α ≦ 0.9.
0 ≦ α ≦ 0.9 means that Nb is not contained or, when Nb is contained, the ratio of the content of Nb to the total content of Mo and Nb is 0.9 or less. To do.
As described above, Nb is inferior to Mo in the effect of widening the range of the median diameter d50 showing a small coercive force in the crystalline Fe-based alloy atomized particles. Therefore, when “α” in the composition formula (1) is greater than 0.9 (for example, when α = 1.0, that is, when Mo is not contained and Nb is contained). in crystalline Fe-based alloy Adomaizu powder, there is a case where the range of the median diameter d50 indicating a small coercive magnetic force becomes narrower.

“Α” in the composition formula (1) preferably satisfies 0 <α (that is, the alloy composition includes both Mo and Nb). 0 <a is satisfied α is the crystalline Fe-based alloy Adomaizu powder, the scope of the median diameter d50 indicating a small coercive magnetic force becomes wider.
α is more preferably 0.1 or more, and further preferably 0.2 or more.
The upper limit of α is more preferably 0.8, still more preferably 0.6, and still more preferably 0.5.

In the composition formula (1), “c” (that is, the B content (atomic%)) and “d” (that is, the total content of Mo and Nb (atomic%)) is 10.0 <c + d. <13.5 is satisfied. Thereby, in the crystalline Fe-based alloy atomized particles, the range of the median diameter d50 showing a small coercive force is widened, and the saturation magnetization of the crystalline Fe-based alloy atomized powder is improved.
10.0 <If not satisfied c + d is the crystalline Fe-based alloy Adomaizu powder, there is a case where the range of the median diameter d50 indicating a small coercive magnetic force becomes narrower.
When c + d <13.5 is not satisfied, the Fe content is relatively reduced, and as a result, the saturation magnetization of the crystalline Fe-based alloy admitted powder may be reduced.

<Content of crystal phase in alloy structure>
In the amorphous Fe-based alloy atomized powder, the content of the crystal phase in the alloy structure is preferably 2% by volume or less , more preferably 1% by volume or less, particularly preferably based on the entire alloy structure. , Substantially 0% by volume.
When the content of the crystal phase in the alloy structure in the amorphous Fe-based alloy atomized powder is 2% by volume or less, the crystalline Fe-based alloy atomized powder obtained by heat-treating the amorphous Fe-based alloy atomized powder A lower coercivity can be obtained.

Claims (12)

Used to produce crystalline Fe-based alloy atomized powder,
An Fe-based alloy having an alloy composition represented by the following composition formula (1).
_{Fe 100-a-b-c} -d-e Cu a Si b B c (Mo 1-α Nb α) d Cr e ... formula (1)
[In the composition formula (1), a, b, c, d, e, and α are 0.1 ≦ a ≦ 1.5, 13.0 ≦ b ≦ 15.0, 8.0 <c <12. 0, 0.5 ≦ d <4.0, 0 ≦ e ≦ 2.0, 10.0 <c + d <13.5, 0 ≦ α ≦ 0.9, and 71.0 ≦ 100−ab− c-d-e ≦ 74.0 is satisfied. ]   The Fe-based alloy according to claim 1, wherein d satisfies 0.5 ≦ d ≦ 3.5 in the composition formula (1).   The Fe-based alloy according to claim 1, wherein e satisfies 0.5 <e ≦ 2.0 in the composition formula (1).   The Fe-based alloy according to any one of claims 1 to 3, wherein in the composition formula (1), α satisfies 0 <α ≦ 0.9.   5. The Fe-based alloy according to claim 1, wherein c satisfies 10.0 ≦ c <12.0 in the composition formula (1). It has an alloy composition represented by the following composition formula (1),
A crystalline Fe-based alloy atomized powder having an alloy structure containing nanocrystal grains having an average grain size of 40 nm or less.
_{Fe 100-a-b-c} -d-e Cu a Si b B c (Mo 1-α Nb α) d Cr e ... formula (1)
[In the composition formula (1), a, b, c, d, e, and α are 0.1 ≦ a ≦ 1.5, 13.0 ≦ b ≦ 15.0, 8.0 <c <12. 0, 0.5 ≦ d <4.0, 0 ≦ e ≦ 2.0, 10.0 <c + d <13.5, 0 ≦ α ≦ 0.9, and 71.0 ≦ 100−ab− c-d-e ≦ 74.0 is satisfied. ]   The crystalline Fe-based alloy atomized powder according to claim 6, wherein the coercive force at an applied magnetic field of 40 kA / m is 190 A / m or less.   The crystalline Fe-based alloy atomized powder according to claim 6 or 7, wherein d satisfies 0.5 ≦ d ≦ 3.5 in the composition formula (1).   The crystalline Fe-based alloy atomized powder according to any one of claims 6 to 8, wherein e satisfies 0.5 <e ≦ 2.0 in the composition formula (1).   The crystalline Fe-based alloy atomized powder according to any one of claims 6 to 9, wherein in the composition formula (1), α satisfies 0 <α ≦ 0.9.   11. The crystalline Fe-based alloy atomized powder according to claim 6, wherein c satisfies 10.0 ≦ c <12.0 in the composition formula (1). The crystalline Fe-based alloy atomized powder according to any one of claims 6 to 11,
A binder for binding the crystalline Fe-based alloy atomized powder;
Including
A magnetic core in which the binder is at least one selected from the group consisting of epoxy resins, unsaturated polyester resins, phenol resins, xylene resins, diallyl phthalate resins, silicone resins, polyamideimides, polyimides, and water glass.