JP2002249802A - Amorphous soft magnetic alloy compact, and dust core using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology by which the degree of compaction can be improved and the properties required of a compacted magnetic core can be improved by carrying out compaction by the use of flat alloy powder and spherical alloy powder. SOLUTION: At least the flat alloy powder having a structure containing, as a principal phase, an amorphous phase in which the temperature interval ΔTx of supercooled liquid represented by equation ΔTx=Tx-Tg (wherein, Tx is initial crystallization temperature; and Tg is glass transition temperature) is >=20 K is mixed with the spherical alloy powder having a structure containing, as a principal phase, an amorphous phase in which the above temperature interval ΔTx is >=20 K, and the resultant powder mixture is compacted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compacted amorphous soft magnetic alloy, and more particularly, to an alloy powder obtained by an atomizing method and an alloy powder obtained by pulverizing from a quenched ribbon. It is related to the technology made by paying attention.

[0002]

2. Description of the Related Art Conventionally, TM-Al-Ga-P-C-B-S
An alloy having a composition of i-system or the like (TM is a transition metal element such as Fe, Co, Ni, etc.) forms an amorphous phase by rapidly cooling the molten alloy, and these form an amorphous soft magnetic alloy. Known as one. In particular, a specific composition of this amorphous soft magnetic alloy has a wide temperature range in a supercooled liquid state before crystallization, and is known to constitute a so-called metallic glass alloy (glassyalloy). Have been. This type of metallic glass alloy has excellent soft magnetic properties and is capable of forming a bulk plate much thicker than the amorphous soft magnetic alloy ribbon produced by the liquid quenching method. Are known.

[0003] Conventionally, amorphous soft magnetic alloys have
Since the alloy is manufactured by a method such as a liquid quenching method exemplified by a single roll method, it is necessary that the alloy itself has a somewhat high amorphous forming ability. Therefore, the development of metallic glass alloys is mainly aimed at improving the amorphous forming ability of the alloys,
It is being advanced from the viewpoint of searching for an alloy composition that can achieve this purpose.

[0004]

However, the composition capable of increasing the amorphous forming ability of the alloy does not always coincide with the alloy composition capable of enhancing the soft magnetic properties, and therefore, the high saturation magnetization and the soft magnetic properties are high. There is still room for further improvement in order to improve the quality.

A general metallic glass alloy is conventionally manufactured by a single roll method or the like, and has a thickness of several tens.
A ribbon-shaped (ribbon-shaped) shape having a thickness of about 100 μm to several 100 μm is obtained. When the ribbon-shaped metallic glass alloy is applied to a magnetic core such as a transformer or a choke coil, for example, the ribbon is pulverized into powder, and a binder such as resin is mixed with the powder, and The magnetic core is manufactured by solidifying and shaping into a shape as described above. Since the powder obtained here is obtained by pulverizing a ribbon, it contains a large amount of flaky and irregularly shaped particles, so that the molding density of the magnetic core is low and insulation between the powders is reduced. Since it is difficult to secure them, the magnetic characteristics of the magnetic core itself may be deteriorated.

The present invention has been made in view of the above circumstances, and uses a flat type alloy powder which is easily obtained by pulverizing a ribbon and a spherical type alloy powder which is easily obtained by an atomizing method. An object of the present invention is to provide an amorphous soft magnetic alloy compact that can improve the compact density and improve the performance as a compact magnetic core by mixing and compacting. The present invention further provides a soft magnetic alloy compact that can improve the compaction density, improve the performance as a compacted magnetic core, increase the magnetic permeability, and also improve the magnetic properties such as the DC superimposition property. One of the purposes.

[0007]

In order to achieve the above object, the present invention employs the following constitution. The present invention relates to an amorphous material having a temperature interval ΔTx of 20K or more of a supercooled liquid represented by at least ΔTx = Tx−Tg (where Tx represents a crystallization start temperature and Tg represents a glass transition temperature). A flat alloy powder having a structure having a main phase as a phase and a spherical alloy powder having a structure having an amorphous phase having a temperature difference ΔTx of 20 K or more as a main phase are mixed and consolidated. Become. Since the flat-type alloy powder and the spherical-type alloy powder are mixed and compacted, the spherical-type alloy powder is interposed between a large number of flat-type alloy powders, resulting in the flat-type alloy powder. As a result of filling the gaps formed between them with the spherical alloy powder, the compaction density is improved.

According to the present invention, the spherical alloy powder is formed by quenching the molten alloy by an atomizing method, and the flat alloy powder is obtained by crushing a ribbon obtained by rapidly cooling the molten alloy. It is characterized by being an alloy powder formed by. The alloy powder obtained by the atomizing method is an aggregate mainly composed of a large number of spherical alloy powders having different particle diameters, whereas the alloy powder obtained by grinding the ribbon is
Since the flat-type alloy powder is mainly used, the spherical-type alloy powder and the flat-type alloy powder are mixed, and both the alloy powders are consolidated together. As a result, the compaction density of the compact is improved.

The present invention is characterized in that the flat alloy powder obtained by crushing the ribbon has a particle size of 25 μm or less. In the alloy powder obtained by pulverizing the ribbon, as a result of contact between the blade of the pulverizer and the ribbon at the time of pulverization, components of the metal material constituting the blade of the pulverizer are mixed into the pulverized material, which may cause contamination. Many. Since the problem of the contamination becomes more remarkable in a pulverized product having a small particle size, it is preferable to remove a small particle size in the alloy powder obtained by pulverizing the ribbon. Therefore, the problem of contamination can be avoided by removing the thing of 25 μm or less. The present invention is characterized in that the spherical alloy powder has a diameter of 100 μm or less, and the flat alloy powder has a thickness of 15 to 25 μm and a diameter of 45 to 150 μm. If the spherical type alloy powder and the flat type alloy powder are within the above range, the alloy powder tends to be dense during compaction, and the compaction density is surely improved.

The present invention is characterized in that the mixing ratio of the spherical alloy powder and the flat alloy powder is in the range of 1: 9 to 9: 1. By mixing the spherical alloy powder and the flat alloy powder in the above ratio, the spherical alloy powder is efficiently dispersed between the flat alloy powders,
The gap between the flat-type alloy powders is closed by the spherical-type alloy powder, so that the gap can be reduced, and the pressure density is improved. As a result, the soft magnetic properties are improved. According to the present invention,
A soft magnetic alloy compact having a magnetic permeability of 100 or more at MHz is obtained.

The amorphous soft magnetic alloy powder used in the present invention comprises:
At least one of the spherical alloy powder and the flat alloy powder is a supercooled liquid represented by the formula of ΔTx = Tx−Tg (where Tx indicates a crystallization start temperature and Tg indicates a glass transition temperature). Is preferably composed of a structure having a main phase of an amorphous phase having a temperature interval ΔTx of 20K or more, and is represented by the following composition formula. _{Fe 100-xyzw Al x P y} C z B w here, x indicating the composition ratio, y, z, w is 0 atomic% ≦ x
≦ 10 atomic%, 2 atomic% ≦ y ≦ 15 atomic%, 0 atomic% <
z ≦ 11.5 at%, 4 at% ≦ w ≦ 10 at%, 70
Atomic% ≦ (100-xyzw) ≦ 79 atomic%, 1
1 atomic% ≦ (y + z + w) ≦ 30 atomic%.

Further, the amorphous soft magnetic alloy powder of the present invention comprises:
At least one of the spherical alloy powder and the flat alloy powder is a supercooled liquid represented by the formula of ΔTx = Tx−Tg (where Tx indicates a crystallization start temperature and Tg indicates a glass transition temperature). Is characterized by having a structure having a main phase of an amorphous phase having a temperature interval ΔTx of 20K or more and represented by the following composition formula. (Fe _1-a T a) provided that _{100-xyzw Al x P y C} z B w, T is Co, is one or two elements selected from Ni, a showing the composition ratio, x, y, z , W are 0.
1 ≦ a ≦ 0.15, 0 atomic% ≦ x ≦ 10 atomic%, 2 atomic% ≦ y ≦ 15 atomic%, 0 atomic% <z ≦ 11.5 atomic%,
4 atomic% ≦ w ≦ 10 atomic%, 70 atomic% ≦ (100-x
-Yzw) ≦ 79 atomic%, 11 atomic% ≦ (y + z +
w) ≦ 30 atomic%.

Further, the amorphous soft magnetic alloy powder of the present invention comprises:
At least one of the spherical alloy powder and the flat alloy powder is a supercooled liquid represented by the formula of ΔTx = Tx−Tg (where Tx indicates a crystallization start temperature and Tg indicates a glass transition temperature). Is characterized by having a structure having a main phase of an amorphous phase having a temperature interval ΔTx of 20K or more and represented by the following composition formula. Fe _100-xvzw Al _x (P _1-b Si _b ) _v C _z B _{w where} b, x, v, z, and w indicating the composition ratio are 0.1 ≦
b ≦ 0.28, 0 atomic% ≦ x ≦ 10 atomic%, 2 atomic% ≦
v ≦ 15 atomic%, 0 atomic% <z ≦ 11.5 atomic%, 4 atomic% ≦ w ≦ 10 atomic%, 70 atomic% ≦ (100-xy
−z−w) ≦ 79 at%, 11 at% ≦ (v + z + w)
≦ 30 atomic%.

In the amorphous soft magnetic alloy powder according to the present invention, at least one of the spherical type alloy powder and the flat type alloy powder has ΔTx = Tx−Tg (where Tx indicates a crystallization start temperature and Tg Represents a glass transition temperature.) The supercooled liquid has a temperature interval ΔTx of 20 K or more as a main phase, and is represented by the following composition formula. I do. _{(Fe 1-a T a)} 100-xvzw Al x (P 1-b Si b) v C z B
_w where T is one or two elements selected from Co and Ni, and a, b, x, v, z, and w indicating the composition ratio are:
0.1 ≦ a ≦ 0.15, 0.1 ≦ b ≦ 0.28, 0 atomic% ≦ x ≦ 10 atomic%, 2 atomic% ≦ v ≦ 15 atomic%, 0 atomic% <z ≦ 11.5 atomic %, 4 atomic% ≦ w ≦ 10 atomic%, 70 atomic% ≦ (100−x−v−z−w) ≦ 79 atomic%, 11 atomic% ≦ (v + z + w) ≦ 30 atomic%.

The present invention is characterized in that at least one of the spherical alloy powder and the flat alloy powder is represented by the following composition formula. Fe _100-vz P _v C _z here, x indicating the composition ratio, v, z is 5 atomic% ≦ v ≦ 2
0 atomic% and z ≦ 20 atomic%.

According to the amorphous soft magnetic alloy powder of each of the above composition systems, the elements Fe and T exhibiting magnetism and the metalloid elements such as P, Si, C, and B having an ability to form an amorphous phase are included. As a result, it is possible to form an amorphous soft magnetic alloy powder having an amorphous phase as a main phase and exhibiting excellent soft magnetic properties, and Al has an effect of enhancing the amorphous forming ability. This makes it possible to form an amorphous soft magnetic alloy powder in which the entire structure is completely in an amorphous phase. And Fe
The composition ratio of a single substance or the total of Fe and the element T is set to 70 to 79 atomic%, Al is set to 0 to 10 atomic%, and the total of P, C, B and (Si) is set to 11 atomic%.
By setting the content to 30 atomic% or less, Tg / Tm can be increased and the saturation magnetization s can be increased. Incidentally, Tg / Tm is a so-called reduced vitrification temperature and is an index indicating the degree of the ability of an amorphous soft magnetic alloy to form an amorphous phase. This Tg / Tm is relatively high, for example, 0.57 or higher. When the height is increased, an alloy having a structure having an amorphous phase as a main phase can be easily obtained by means such as a gas atomization method.

The powder magnetic core of the present invention is made of any one of the above-mentioned compacted amorphous soft magnetic alloys. The powder magnetic core having high compaction density, high magnetic permeability, and excellent DC superimposition characteristics can be obtained by using the above-described excellent compact.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail, but the present invention is not limited by the following embodiments. The amorphous soft magnetic alloy compact of the present invention,
At least the flat type alloy powder and the spherical type alloy powder are mixed and consolidated. The amorphous soft magnetic alloy powder for constituting the compacted amorphous soft magnetic alloy of the present invention has a flat alloy powder and a spherical alloy powder, both of which are Fe alloy.
Or at least Al, P, C and B, or F
This is a powder having a structure mainly composed of an amorphous phase comprising at least e, P and C. The flat alloy powder is obtained by pulverizing a ribbon obtained by a quenching method from a molten alloy described later, and the spherical alloy powder is atomized from the molten alloy described later. It is obtained by the method. It is preferable that the flat alloy powder and the spherical alloy powder are in the range of 1: 9 to 9: 1 in a weight ratio of both.

These alloy powders are mixed with an insulating agent and / or a lubricant described below as required within the above-mentioned range, and then compacted by a compacting method such as a plasma sintering method described below. . Note that the above-mentioned insulating powder and / or lubricant may be compacted without being mixed with the alloy powder. In addition, the amorphous soft magnetic alloy powder used in the present invention has a temperature interval of a supercooled liquid represented by an equation of ΔTx = Tx−Tg (where Tx indicates a crystallization start temperature and Tg indicates a glass transition temperature). ΔTx indicates 20K or more.

Conventionally, as one kind of amorphous soft magnetic alloy,
BACKGROUND ART Fe-Al-Ga-CP-Si-B-based metallic glass alloys are known. The metallic glass alloy of this conventional composition system is F
e is obtained by adding Al, Ga, C, P, Si and B having an amorphous forming ability to e. In contrast to this kind of conventional amorphous soft magnetic alloy, the amorphous soft magnetic alloy of the present invention is composed of Fe and Al.
Or at least P, C and B, or Fe, P and C
And at least Ni, Co, and Si, if necessary, in addition to these main elements.
Al and Fe were increased by a substitution. The present inventors have confirmed that it is possible to form an amorphous phase even if Ga, which has been conventionally considered to be an essential element, is removed from this type of metallic glass alloy. The present inventors have found that the cooling liquid also exhibits a temperature interval ΔTx, thereby completing the soft magnetic alloy powder used in the present invention.

In particular, regarding the amorphous forming ability, the amorphous soft magnetic alloy of the present invention having the above composition has the amorphous forming ability of the conventional F
The present inventors have found that they are superior to e-Al-Ga-CP-Si-B-based alloys. As described above, the amorphous soft magnetic alloy used in the present invention has a higher amorphous forming ability than the conventional alloy, and a completely amorphous phase is formed even when the cooling rate is slowed down by this property. A spherical alloy powder having an amorphous phase as a main phase can be easily produced by a gas atomizing method or a water atomizing method, which has a slightly lower cooling ability than a roll quenching method or the like.

The amorphous soft magnetic alloy used in the present invention is composed of Fe and Al exhibiting magnetism and P having an amorphous forming ability.
Since it has at least C and B or at least Fe, P and C, it has an amorphous phase as a main phase and exhibits excellent soft magnetic properties. Further, one or both of Ni and Co may be added by Fe substitution, and Si may be added in addition to P, C and B.

The amorphous soft magnetic alloy used in the present invention comprises 20
It is mainly composed of a metallic glass alloy exhibiting a temperature interval ΔTx of a supercooled liquid of K or more. Depending on the composition, ΔTx has a remarkable temperature interval ΔTx of 30K or more, and even 50K or more. This alloy is completely unexpected from the alloys described above, and also has excellent properties at room temperature with respect to soft magnetism, and is a completely new one not seen in the previous findings.

The amorphous soft magnetic alloy used in the present invention has a higher amorphous forming ability than the conventional Fe-Al-Ga-CP-Si-B-based alloy, so that the entire structure can be completely removed. It can be in an amorphous phase and therefore has no crystalline magnetic anisotropy, thereby exhibiting low coercivity and high magnetic permeability, and furthermore Fe, N
Since a large amount of magnetic elements such as i and Co can be contained, high saturation magnetization is exhibited. Therefore, according to the amorphous soft magnetic alloy powder used in the present invention, the magnetic permeability and the saturation magnetization are remarkably improved as compared with the conventional compact of the metallic glass alloy, and the compact of the soft magnetic alloy powder exhibiting excellent soft magnetic properties. Can be obtained. Further, since the entire structure can be completely amorphous, the internal stress can be relaxed without precipitation of the crystalline phase when heat-treated under appropriate conditions, and the soft magnetic properties can be further improved. be able to.

In addition, since the amorphous soft magnetic alloy used in the present invention has a large temperature interval ΔTx of the supercooled liquid, when cooled from the molten state, the supercooled liquid region is wide on the low temperature side of the crystallization start temperature Tx. When the temperature interval .DELTA.Tx in the supercooled liquid region elapses due to a decrease in temperature without crystallization, an amorphous phase is easily formed up to the glass transition temperature Tg. Therefore, even if the cooling rate is relatively slow, it is possible to form an amorphous phase sufficiently. For example, as in a gas atomization method, a method of spraying a molten alloy into an inert gas and rapidly cooling the same is used to form an amorphous phase. A powdery alloy mainly composed of a phase structure can be obtained, which is excellent in practicality. Further, the amorphous soft magnetic alloy used in the present invention has a high Curie temperature and has excellent thermal stability.

As an example of the amorphous soft magnetic alloy used as the alloy powder in the present invention, one represented by the following composition formula can be given. _{Fe 100-xyzw Al x P y} C z B w here, x indicating the composition ratio, y, z, w is 0 atomic% ≦ x
≦ 10 at%, 2 at% ≦ y ≦ 15 at%, 0 at% <
z ≦ 11.5 at%, 4 at% ≦ w ≦ 10 at%, 70
Atomic% ≦ (100-xyzw) ≦ 79 atomic%, 1
1 atomic% ≦ (y + z + w) ≦ 30 atomic%.

Further, as another example of the amorphous soft magnetic alloy, one represented by the following composition formula can be given. (Fe _1-a T a) provided that _{100-xyzw Al x P y C} z B w, T is Co, is one or two elements selected from Ni, a showing the composition ratio, x, y, z , W are 0.
1 ≦ a ≦ 0.15, 0 atomic% ≦ x ≦ 10 atomic%, 2 atomic% ≦ y ≦ 15 atomic%, 0 atomic% <z ≦ 11.5 atomic%,
4 atomic% ≦ w ≦ 10 atomic%, 70 atomic% ≦ (100-x
-Yzw) ≦ 79 atomic%, 11 atomic% ≦ (y + z +
w) ≦ 30 atomic%.

Further, as another example of the above-mentioned amorphous soft magnetic alloy, there can be mentioned one represented by the following composition formula. Fe _100-xvzw Al _x (P _1-b Si _b ) _v C _z B _{w where} b, x, v, z, and w indicating the composition ratio are 0.1 ≦
b ≦ 0.28, 0 atomic% ≦ x ≦ 10 atomic%, 2 atomic% ≦
v ≦ 15 atomic%, 0 atomic% <z ≦ 11.5 atomic%, 4 atomic% ≦ w ≦ 10 atomic%, 70 atomic% ≦ (100-xy
−z−w) ≦ 79 at%, 11 at% ≦ (v + z + w)
≦ 30 atomic%.

Further, other examples of the above-mentioned amorphous soft magnetic alloy include those represented by the following composition formula. _{(Fe 1-a T a)} 100-xvzw Al x (P 1-b Si b) v C z B
_w where T is one or two elements selected from Co and Ni, and a, b, x, v, z, and w indicating the composition ratio are:
0.1 ≦ a ≦ 0.15, 0.1 ≦ b ≦ 0.28, 0 atomic% ≦ x ≦ 10 atomic%, 2 atomic% ≦ v ≦ 15 atomic%, 0 atomic% <z ≦ 11.5 atomic %, 4 atomic% ≦ w ≦ 10 atomic%, 70 atomic% ≦ (100−x−v−z−w) ≦ 79 atomic%, 11 atomic% ≦ (v + z + w) ≦ 30 atomic%. The amorphous soft magnetic alloy having the above composition has a melting point of Tm.
And Tg / Tm ≧ 0.57, and the saturation magnetization s is 180 × 10 ⁻⁶ Wb · m / kg or more.

The preferred composition range of the above-mentioned amorphous soft magnetic alloy containing at least Fe, Al, P, C and B is such that x, y, z and w in the above composition ratio are 0 atom. %
≦ x ≦ 6 at%, 2 at% ≦ y ≦ 15 at%, 0 at%
<Z ≦ 11.5 at%, 4 at% <w ≦ 10 at%, 7
6 atomic% ≦ (100-xyzw) ≦ 79 atomic%,
The range is 18 atomic% ≦ (y + z + w) ≦ 24 atomic%. A preferable range of the amorphous soft magnetic alloy containing at least Fe, Al, P, C, B, and Si is such that x, v, z, and w in the composition ratio are 0 atomic% ≦. x ≦
6 atomic%, 2 atomic% ≦ v ≦ 15 atomic%, 0 atomic% <z ≦
11.5 at%, 4 at% ≦ w ≦ 10 at%, 76 at% ≦ (100-xvzw) ≦ 79 at%, 18 at% ≦ (v + z + w) ≦ 24 at% It is.
In the amorphous soft magnetic alloy having the above preferred composition range, Tg / Tm ≧ 0.57, and the saturation magnetization σs is 200 × 10 ⁻⁶ Wb · m / kg or more.

Further, a more preferable composition range of the above-mentioned amorphous soft magnetic alloy containing at least Fe, Al, P, C, and B is such that x, y, z, and w in the above composition ratio are 0%. Atomic% ≦ x ≦ 5 atomic%, 2 atomic% ≦ y ≦ 15 atomic%, 0 atomic% <z ≦ 11.5 atomic%, 4 atomic% ≦ w ≦ 10 atomic%,
77 atomic% ≦ (100-xyzw) ≦ 79 atomic%, and 18 atomic% ≦ (y + z + w) ≦ 22 atomic%. Furthermore, a more preferable composition range of the above-mentioned amorphous soft magnetic alloy containing at least Fe, Al, P, C, B, and Si is x, v, z, w of the above composition ratio.
Is 0 atomic% ≦ x ≦ 5 atomic%, 2 atomic% ≦ v ≦ 15 atomic%, 0 atomic% <z ≦ 11.5 atomic%, 4 atomic% ≦ w ≦ 1
0 atomic%, 77 atomic% ≦ (100−x−v−z−w) ≦
79 atomic%, 18 atomic% ≦ (v + z + w) ≦ 22 atomic%
Is the range. In the amorphous soft magnetic alloy having the more preferable composition described above, Tg / Tm ≧ 0.57, and the saturation magnetization σs is 210 × 10 ⁻⁶ Wb · m / kg or more.

The composition of the amorphous soft magnetic alloy described above
Instead of the composition formula Fe_100-vzP_vC _zIndicated by the composition ratio
X, v, and z represent 5 atomic% ≦ v ≦ 20 atomic% and z ≦ 2
An alloy having 0 atomic% may be used. In this type of alloy
However, as with the alloys of the previous examples, high Tg / Tm values and excellent
The obtained saturated magnetization s is obtained.

The reasons for limiting the composition of the amorphous soft magnetic alloy used in the present invention will be described below. The reasons for limiting the composition described below are particularly preferable for obtaining excellent magnetic properties. In the concept of mixing a flat alloy powder and a spherical alloy powder to obtain a material having a high compaction density, it goes without saying that an amorphous soft magnetic alloy outside of these composition ranges may be used. Fe is an element responsible for magnetism and is an essential element in the amorphous soft magnetic alloy of the present invention. Further, a part of Fe may be replaced with one or both elements T of Co and Ni. Fe alone or F
When the total composition ratio of e and the element T is increased, the saturation magnetization s of the amorphous soft magnetic alloy can be improved.

The composition ratio of Fe alone or the total composition of Fe and the element T is preferably 70 to 79 atomic%, more preferably 76 to 79 atomic%, and more preferably 77 to 79 atomic%. % Or more and 79 atomic% or less. If the composition ratio of Fe alone or the total composition of Fe and the element T is less than 70 atomic%, the saturation magnetization s
It is not preferable because it is reduced to less than 80 × 10 ⁻⁶ Wb · m / kg. Further, when the composition ratio exceeds 79 atomic%,
Tg / Tm, which indicates the degree of amorphous forming ability of the alloy, is less than 0.57, which is not preferable because the amorphous forming ability is reduced.
If the composition ratio is 76 atomic% or more, the saturation magnetization σ
s can be set to 200 × 10 ⁻⁶ Wb · m / kg or more, and if the composition ratio is 77 atomic% or more, the saturation magnetization σs of the alloy is set to 210.
× 10 ⁻⁶ Wb · m / kg or more.

In addition, when the element T is added by Fe substitution, as shown by the composition ratio a in the above composition formula, the element T is added by substituting 10 to 15% of the added amount of Fe. preferable. By adding the element T, the packing density of the atoms constituting the alloy is improved, and the rearrangement of the atoms is suppressed, so that the thermal stability is improved. In particular, when Co is added, the amorphous forming ability is improved with the improvement of the thermal stability and the lowering of the melting point. If the added amount of the element T is less than 10% of the Fe amount, the effect of adding the element T is not seen, and the added amount is 15% of the Fe amount.
%, The amount of Fe relatively decreases and the saturation magnetization decreases, which is not preferable.

Al is an important element in the amorphous soft magnetic alloy of the present invention, like Fe. Al composition ratio x is 0 atomic%
When the content is in the range of 10 atomic% or less, the amorphous forming ability of the alloy can be improved, and the entire structure can be completely amorphous. Specifically, when the composition ratio x is 0 atomic% or more and 10 atomic% or less, Tg / Tm indicating the degree of amorphous forming ability of the alloy becomes 0.57 or more, and the saturation magnetization σs
Can be 180 × 10 ⁻⁶ Wb · m / kg or more. A
1 is that the enthalpy of mixing with Fe is negative and F
When used together with P, B, and Si having an atomic radius larger than e and smaller than Fe, the amorphous structure is hardly crystallized and the amorphous structure becomes thermally stabilized. A
The composition ratio x of 1 is preferably 0 atomic% or more and 10 atomic% or less, more preferably 0 atomic% or more and 6 atomic% or less, further preferably 0 atomic% or more and 5 atomic% or less. . If the composition ratio x exceeds 10 atomic%, Fe
And the saturation magnetization σs decreases, and Tg /
Tm is less than 0.57, and the amorphous forming ability is undesirably reduced. Further, when Al is not added, the amorphous forming ability of the alloy tends to decrease.

Next, when the composition ratio of Fe alone or the total composition ratio of Fe and the element T is 76 atomic% or more and the composition ratio x of Al is 0 atomic% or more and 6 atomic% or less, the saturation magnetization of the alloy is reduced. σs can be increased to 200 × 10 ⁻⁶ Wb · m / kg or more.
Further, the composition ratio of Fe alone or the total composition of Fe and the element T is 77 atom% or more, and the composition ratio x of Al is 0 atom%.
When the content is not less than 5 atomic% and the alloy has a saturation magnetization σs of 21
0 × 10 ⁻⁶ Wb · m / kg or more.

C, P, B and Si are elements that enhance the ability to form an amorphous phase. By adding these elements to Fe and Al to form a multi-component system, a binary system consisting of only Fe and Al is formed. The amorphous phase is formed more stably than in the case. In particular, P is Fe
And a eutectic composition at a low temperature (about 1050 ° C.), the entire structure becomes an amorphous phase and the temperature interval Δ of the supercooled liquid
Tx is easily developed. Further, when P and Si are added simultaneously, the temperature interval ΔTx of the supercooled liquid becomes larger, the amorphous forming ability is improved, and the manufacturing conditions for obtaining the structure of the amorphous single phase are changed in a relatively simple direction. Can be relaxed.

When Si is not added, the composition ratio y of P is preferably 2 to 15 atomic%, more preferably 5 to 15 atomic%, and more preferably 7 at%. Most preferably, it is at least 13 atomic%. When the composition ratio y of P is within the above range, the temperature interval ΔTx of the supercooled liquid is developed, and the amorphous forming ability of the alloy is improved.

When P and Si are added simultaneously, P and S
The composition ratio v indicating the total amount of i is preferably from 2 to 15 at%, more preferably from 8 to 15 at%, and more preferably from 10 to 14 at%.
It is most preferred that: When the composition ratio v indicating the total amount of P and Si is in the above range, the temperature interval ΔTx of the supercooled liquid is improved, and thereby the amorphous forming ability of the alloy is improved.

In the case where P and Si are added simultaneously,
The composition ratio b representing the ratio of i to P is 0.1 ≦ b ≦ 0.28
It is preferred that If the composition ratio b is less than 0.1, Si
When the composition ratio b exceeds 0.28, the amount of Si becomes excessive and the supercooled liquid region ΔTx may disappear, which is not preferable.
By setting b and v, which indicate the composition ratio of P and Si, to the above ranges, it is possible to improve the temperature interval ΔTx of the supercooled liquid and increase the size of the bulk that becomes an amorphous single phase as compared with the conventional alloy. it can.

The composition ratio w of B is preferably from 4 to 10 at%, more preferably from 6 to 10 at%, and more preferably from 6 to 9 at%. Is most preferred. Further, the composition ratio z of C
Is preferably more than 0 atomic% and 11.5 atomic% or less, more preferably 2 atomic% or more and 8 atomic% or less, most preferably 2 atomic% or more and 5 atomic% or less.

The total composition ratio of these metalloid elements C, P, B and Si (y + z + w) or (v + z +
w) is preferably from 11 at% to 30 at%, more preferably from 18 at% to 24 at%, even more preferably from 18 at% to 22 at%. When the total composition ratio of the metalloid elements is less than 11 atomic%, the amorphous soft magnetic alloy has a low amorphous forming ability and cannot obtain an amorphous single-phase structure. If the total composition ratio of the metal elements exceeds 30 at%, the composition ratio of Fe is relatively decreased, and the saturation magnetization s is undesirably decreased.

When the composition ratio of Fe alone or the total composition of Fe and the element T is 76 atomic% or more, the semimetal elements C and
By setting the total composition ratio (y + z + w) or (v + z + w) of P, B and Si to 18 atomic% or more and 24 atomic% or less, the saturation magnetization σs of the alloy is set to 200 × 10 ⁻⁶ Wb.
・ It can be more than m / kg. Further, when the composition ratio of Fe alone or the total composition ratio of Fe and the element T is 77 atom% or more, the total composition ratio of the metalloid elements C, P, B, and Si (y + z +
w) or (v + z + w) is 18 atomic% or more and 22 atomic%
By setting the saturation magnetization s of the alloy to 210 ×
It can be 10 ^-6 Wb · m / kg or more.

In the above composition, Ge may be contained at 4 atomic% or less, and Nb, Mo, Hf, Ta, W,
0 to 7 atomic% of at least one of Zr and Cr
It may be contained. In any of these compositions, in the present invention, the temperature interval Δ
Tx is 20K or more, and 35K or more depending on the composition. Further, unavoidable impurities may be contained in addition to the elements represented by the above composition.

The amorphous soft magnetic alloy powder used in the present invention is obtained by pulverizing a ribbon-shaped material formed by melting and then quenching by a single roll method or a twin roll method, or gas atomizing. It is possible to select and use those produced as spherical alloy powders by the water atomizing method or the water atomizing method. In particular, in the present invention, for a powder composed of flaky particles obtained by pulverizing a conventionally known amorphous soft magnetic alloy ribbon, the gas atomizing method or the water atomizing method described above uses a method of forming particles having a substantially spherical shape. Alloy powder can be obtained.

The amorphous soft magnetic alloy powder having the above composition obtained by the gas atomization method has magnetism at room temperature,
In addition, it shows better magnetism by heat treatment. For this reason, it is useful for various applications as a material having excellent soft magnetic properties. In addition, as for the manufacturing method, a suitable cooling rate is determined by the composition of the alloy, the means for manufacturing and the size, shape, etc. of the product, but usually a range of about 1 to 10 ⁴ K / s is a standard. It can be. And in fact, the glassy phase (glassy
phase) as Fe ₃ B, Fe ₂ B, Fe ₃ P
It can be determined by confirming whether or not such phases are precipitated. However, even if these crystalline phases are partially precipitated, they may be used for the purpose of the present invention as long as they have excellent soft magnetic properties.

Next, a gas atomizing method will be described as an example of a method for producing a spherical amorphous soft magnetic alloy powder. In the gas atomization method, a melt of an amorphous soft magnetic alloy having the above composition is sprayed in a mist state inside a chamber filled with an inert gas together with a high-pressure inert gas, and rapidly cooled in the inert gas atmosphere. To produce alloy powder. In addition to the gas atomizing method, a spherical amorphous soft magnetic alloy powder can also be manufactured by applying a water atomizing method in which a molten alloy is sprayed at a high speed to a cooling liquid such as water and rapidly cooled. Of course.

FIG. 1 is a schematic sectional view showing an example of a high-pressure gas atomizing apparatus suitably used for producing alloy powder by a gas atomizing method. This high-pressure gas spraying device 1 is mainly composed of a molten metal crucible 2, a gas sprayer 3, and a chamber 4. Inside the molten metal crucible 2 is a molten alloy 5
Is filled. Further, the molten metal crucible 2 is provided with a coil 2a as a heating means, and is configured to heat the molten alloy 5 to keep it in a molten state. A molten metal nozzle 6 is provided at the bottom of the molten metal crucible 2, and the molten alloy 5 is dropped from the molten metal nozzle 6 toward the inside of the chamber 4, or an inert gas is pressurized into the molten metal crucible 2. It is configured such that it can be introduced in a state and the molten alloy 5 can be ejected from the molten metal nozzle 6.

The gas atomizer 3 is provided below the molten metal crucible 2. The gas atomizer 3 is provided with a flow path 7 for introducing an inert gas such as Ar or nitrogen, and a gas injection nozzle 8 which is a tip of the flow path 7. A plurality of injection holes are formed in the gas injection nozzle 8 so as to open obliquely downward so as to surround the periphery of the tip of the molten metal nozzle 6. The inert gas is pre-pressurized to about 2 to 15 MPa by pressurizing means (not shown), is guided to the gas injection nozzle 8 by the introduction flow path 7, and forms a gas flow g from the nozzle 8 into the chamber 4. It is gushing. The inside of the chamber 4 is filled with the same kind of inert gas as the inert gas ejected from the gas atomizer 3. The pressure inside the chamber 4 is kept at about 70-100 kPa, and the temperature is kept at about room temperature.

In order to produce an alloy powder using the gas atomizer 1 shown in FIG. 1, first, an alloy melt 5 filled in a melt crucible 2 is dropped into a chamber 4 from a melt nozzle 6.
At the same time, the inert gas is injected from the plurality of injection holes of the gas injection nozzle 8 of the gas atomizer 3 toward the vicinity of the molten metal nozzle tip. The injected inert gas forms a plurality of gas streams g and reaches the dropped molten metal. At the spray point p, the plurality of gas streams g collide with the molten metal to atomize the molten metal. The atomized alloy melt is rapidly cooled and solidified in the chamber 4 to become a substantially spherical (spherical type) alloy powder having an amorphous phase as a main phase, and is deposited on the bottom of the chamber 4. Thus, an amorphous soft magnetic alloy powder is obtained. The particle size of the alloy powder produced by the gas atomizer 1 can be adjusted by the pressure of the inert gas to be jetted, the dropping speed of the molten metal, the size of the molten metal nozzle 6, and the like. Particle sizes can be obtained. Therefore, the spherical powder having a diameter of 100 μm or less intended in the present invention can be obtained with certainty. Further, when used in the present invention, the particle diameter of the spherical alloy powder is more preferably 62 μm or less. Incidentally, the spherical alloy powder having a particle size of 62 μm or less means that when alloy powder having various particle sizes obtained by the atomization method is classified by sieving or the like, a powder having a particle size of 62 μm or less is selected. The alloy powder classified as described above has an average particle size of 20 to 30 μm, and further contains a large amount of alloy powder having a particle size smaller than 20 μm. The alloy powder obtained as described above may be heat-treated as necessary. By performing the heat treatment, the soft magnetic properties of the amorphous soft magnetic alloy powder can be further improved.

Next, a single roll method will be described as an example of a method for producing a flat amorphous soft magnetic alloy powder.
The apparatus for manufacturing an amorphous ribbon described in this example below is merely an example, and it goes without saying that any of the manufacturing apparatuses that are widely and generally used for this type of quenching method may be used. . FIG. 2 shows an example of an apparatus for manufacturing an amorphous ribbon from a molten alloy by a quenching method based on a single roll method. The manufacturing apparatus 10 of this example is capable of adjusting the inside to a vacuum atmosphere or inert. The apparatus mainly includes a chamber 11 that can be adjusted to a gas atmosphere, a cooling roll 12 rotatably accommodated in the chamber 11, and a crucible 15 in which a molten metal 13 is accommodated. An exhaust pipe 16 connected to the crucible 15 is connected to the bottom of the crucible 15, and a nozzle 17 for jetting molten metal is attached to the bottom of the crucible 15.

In order to produce an amorphous alloy ribbon (thin ribbon) using the production apparatus shown in FIG. 2, the alloy raw material is placed inside the crucible 15 so that the composition ratios of the various soft magnetic alloys described above become the same. Is charged, and the inside of the chamber 11 is heated and melted in a vacuum atmosphere or an inert gas atmosphere to obtain a molten alloy. Next, the cooling roll 12 is rotated, and the molten alloy 13 is rotated.
Is ejected from the nozzle 17 to the surface of the cooling roll 12 to be rapidly cooled, whereby a long ribbon-shaped amorphous ribbon 18 can be obtained.

When the ribbon 18 is obtained, the ribbon 18
Is pulverized with a pulverizing device such as a rotor speed mill to obtain an amorphous soft magnetic alloy powder.
The soft magnetic alloy powder obtained here is mainly composed of a flat type soft magnetic alloy powder because of the pulverization by a pulverizer.For example, by classifying the obtained powder, Thickness 15-25 μm, diameter 45-15
0 μm flat alloy powder can be reliably obtained.
In addition, when the blade of the rotor speed mill crushes the ribbon 18, there is a high possibility that a component of the metal material constituting the blade is mixed into the crushed material to cause contamination. Therefore, in order to prevent this contamination, it is preferable to remove fine powder having a diameter of 25 μm or less. In order to remove fine powder, for example, when classifying by a sieve, a diameter of 45 to 1
It is only necessary to use an eye sieve capable of removing only those having a size of 50 μm, remove fine powder passing through the sieve, and select an alloy powder collected by the sieve. In addition, as a method of obtaining a flat alloy powder, there is a method of spraying a molten alloy onto a rotating disk (not shown) in the atomizing method to rapidly solidify the alloy powder. According to such a method,
A flat amorphous alloy powder can be obtained without undergoing a ribbon pulverizing process. As described above, the flat amorphous soft magnetic alloy powder used in the present invention can be obtained.

Next, the spherical alloy powder obtained by the atomizing method and the flat alloy powder obtained by pulverizing the ribbon are mixed at a desired mixing ratio, for example, spherical powder:
Flat type powder = 1: 10 to 10: 1 at a mixing ratio, an insulating agent such as a silicone elastomer is mixed with the mixed powder, a lubricant such as aluminum stearate is added and mixed, and the mixture is subjected to a consolidation apparatus. Insert and compact to the desired shape. At the time of compacting, a compacting device such as a plasma sintering device may be used to press-mold or heat-press at a temperature at which the insulating agent is not dissolved to obtain a soft magnetic alloy compact.
The pressure conditions here are room temperature to 350 ° C. at several GPa.
The conditions under which the pressure is applied within the range described above can be adopted. After pressure molding,
If necessary, an annealing process may be performed using a heating device such as an infrared image furnace to improve the soft magnetic properties.

As an example of the pressure forming means used here, a discharge plasma sintering apparatus can be used. A discharge plasma sintering device is a device that can sinter a molded object while passing a pulse current with the object sandwiched between an upper punch and a lower punch. This is an apparatus applied by the present inventors when powder sintering is performed under pressure, and an example of the structure is described in the specification of Japanese Patent Application No. 2000-79062. This discharge plasma sintering apparatus is disposed inside a chamber that can be evacuated or adjusted to an inert gas atmosphere, and applies a pulse current in a vacuum atmosphere or an atmosphere gas atmosphere to form a workpiece with upper and lower punches. This is a device that can quickly increase the temperature to the target temperature and perform compression molding while maintaining the amorphous state. The heating temperature for molding the soft magnetic alloy compact is preferably a temperature lower than the melting point of the insulating agent or the lubricant so as not to melt, for example, 350 ° C. or lower.

By the above-described treatment, a compact body in which the flat soft magnetic alloy powder and the spherical soft magnetic alloy powder are compacted can be obtained. In this compact, the spherical alloy powder is interposed between the flat alloy powders, and the gap between the flat alloy powders is closed by the spherical alloy powder. The compaction density can be increased as compared with the case where the compact is manufactured only by using the compact. Further, the compacted body manufactured as described above has high magnetic permeability, excellent soft magnetic characteristics, and excellent DC superimposition characteristics.

[0058]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Fe and Al, Fe-C alloy, Fe-P alloy,
Using B and Si as raw materials, Fe ₇₇ Al ₁ P _9.23 C _2.2 B
_A predetermined amount of each was weighed so as to have a composition ratio of _7.7 Si _2.87 , and these raw materials were melted under a reduced-pressure Ar atmosphere with a high-frequency induction heating device to produce an ingot. This ingot is put into the melting crucible of the high-pressure gas atomizer shown in FIG. 1 and melted by heating to 1300 ° C., and the alloy melt is dropped from the melting nozzle of the melting crucible. Is sprayed at a pressure of 100 kg / cm ² to atomize the molten alloy, and the atomized method of rapidly cooling the molten alloy in the chamber has a particle size of 62.
A spherical alloy powder (atomized powder) of an amorphous soft magnetic alloy having a size of μm or less was obtained. Since the obtained amorphous soft magnetic alloy powder has a particle diameter of 62 μm or less, the substantial average particle diameter is about 30 μm, and includes a spherical powder having a diameter smaller than 30 μm. Next, by using the quenching apparatus shown in FIG. 2, a molten metal was sprayed from an ingot having the same composition as above to a rotating copper roll to obtain a long amorphous soft magnetic alloy ribbon. Then, the ribbon is pulverized by a rotor speed mill, and the pulverized material is classified to 45 to 150 μm.
Was obtained as a flat amorphous soft magnetic alloy powder (ribbon pulverized powder). In the case of this classification, pulverized powder of 45 μm or less was removed.

The spherical alloy powder and the flat alloy powder obtained above were mixed with 100: 0, 75:25, 50:50, 2
Various mixed powders mixed at a ratio of 5:75, 0: 100 (all by weight) were prepared, and a silicone elastomer (SE9140, manufactured by Dow Corning Toray Co., Ltd.) was added as an insulating agent to each of the mixed powders. 0.25% by weight or 0.3% by weight, and further added thereto are aluminum stearate di (St.Al.Di) as a lubricant.
Of 1.25% by weight or 1.5% by weight was added, and these mixed powders were pressure-molded in a plasma sintering device at room temperature under the conditions of 2 GPa × 5 minutes to obtain an outer diameter of 12 m.
It was compacted into a ring shape of m × inner diameter 6 mm × height 2.5 mm. Thereafter, the temperature was raised at a rate of 40 ° C./min in a nitrogen gas flow atmosphere in an infrared image furnace, and the temperature was raised at 410 ° C. to 60 ° C.
A test piece was obtained by performing an annealing treatment for heating for minutes.

The magnetic permeability (μ) of the test piece was measured with an impedance analyzer, and the DC bias characteristics were measured with an LCR meter.

FIG. 3 shows the magnetic permeability (μ ′, 1 MH) of the test piece at various mixing ratios of the spherical alloy powder and the flat alloy powder.
The measurement result of z) is shown. The scale of 0 on the horizontal axis is 10
The magnetic permeability of a test piece composed of 0% by weight spherical alloy powder and having a flat alloy powder of 0 indicates the permeability, and a scale of 100 indicates 1
The measurement results of the magnetic permeability of a test piece made of a 00% by weight flat alloy powder are shown. By mixing and adding alloy powders of different shapes within the range of 10% by weight to 90% by weight with respect to the magnetic permeability indicated by 100% by weight of spherical alloy powder or 100% by weight of flat type alloy powder, the magnetic permeability is increased. It is clear that it has improved. Therefore, it is clear that the magnetic permeability of the compact obtained by adding and mixing the spherical alloy powder with the flat alloy powder in a weight ratio of 1: 9 to 9: 1 can be improved. . Further, from the viewpoint of the addition mixing ratio and the improvement ratio of the magnetic permeability, the addition and mixing of the spherical alloy powder with respect to the flat alloy powder in a weight ratio of 3: 7 to 8: 2 is more effective. A good effect of improving magnetic permeability is obtained. Further, by mixing a spherical alloy powder with a flat alloy powder within a weight ratio of 5: 5 to 8: 2, further magnetic permeability can be obtained. An improvement effect was obtained.

FIG. 4 shows the density (10%) of the test piece (consolidated body) at various mixing ratios of the flat type alloy powder and the spherical type alloy powder.
³ × kg / mm ³ ), but it was found that the density gradually decreased as the proportion of the flat alloy powder increased. As for the density, as the mixing ratio of the flat type alloy powder to the spherical type alloy powder increases, the density decreases, but in view of the fact that the magnetic permeability increases as shown in FIG. It is presumed that the cause of the increase is due to the reduction of the demagnetizing field. On the other hand, since the magnetic permeability is reduced at 100% by weight of the flat type alloy powder, it is estimated that the distance between the magnetic powders is too large at 100% by weight of the flat type alloy powder, and the magnetic coupling force is reduced. So
It seems that a density of 5.4 or more is required. The reason why the density changes due to the mixing of the flat type alloy powder and the spherical type alloy powder will be discussed below with reference to the micrographs of FIGS.

FIG. 5 is a photograph of a cross-sectional structure of a test piece obtained by mixing 50% by weight of a flat alloy powder with 50% by weight of a spherical alloy powder (100 times magnification of a scanning electron microscope (SEM)).
Although various spherical alloy powders having different particle diameters are interposed between the flat alloy powders, the spherical alloy powder exists so as to fill the gaps between the flat alloy powders. You can see that. The spherical type alloy powder has a particle diameter of 62 μm or less, and the particle diameter is about 62 μm to 1 μm.
Since particles having a small particle size of about m are present in a mixed state, it can be assumed that the compactness is improved as a result of satisfactorily filling gaps between these large and small alloy powders. FIG.
The round gaps that appear to exist between the flat alloy powders in Fig. 4 are the portions where the round alloy powders fall off during the processing of test specimens as photographic samples for SEM photograph observation. In the gap portion which looks like a round shape, the portion which was originally densely packed with the round alloy powder was shown. Next, FIG. 6 shows a flat type alloy powder 100.
Cross-sectional micrograph of test specimen (consolidated body) consisting of
FIG. 7 shows a spherical alloy powder 10
Cross-sectional micrograph of a test piece (consolidated body) composed of 0% by weight (S
(× 100 EM photograph).

Looking at the structure shown in FIG. 6, there are many irregular-shaped gaps between the flat alloy powders, and this is considered to be the cause of the decrease in compaction density. From this structure photograph, it can be seen that there is a limit to improving the pressure density by filling the gaps between the flat alloy powders even if the flat alloy powder is pressed at a pressure of 2 GaPa. On the other hand, if the test piece (consolidated body) of the spherical alloy powder shown in FIG.
Since even the following alloy powders are aggregates of alloy powders of various sizes, it is clear that they have a denser structure than flat alloy powders. In view of the results shown in FIGS. 5 to 7, if the flat alloy powder and the round alloy powder are mixed and formed under pressure, the compaction density is improved as compared with the compact body including only the flat alloy powder. It turns out that it can be done.

FIG. 8 shows that the spherical alloy powder and the flat alloy powder are 100: 0, 75:25, 50:50,
25:75 or 0: 100, and further mixed with a silicone elastomer (SE914) as an insulating agent.
0) was added in an amount of 0.25% by weight and aluminum stearate di (St.Al.Di) as a lubricant was added in an amount of 1.25% by weight. Show. FIG. 9 shows a mixture of the same powder as described above, and the addition of a silicone elastomer (SE9140) as an insulating agent to a thickness of 0.1%.
3% by weight, aluminum stearate as lubricant
4 shows the frequency dependence of the magnetic permeability of each test piece compacted after adding 1.5% by weight of di (St.Al.Di). From the results shown in these figures, almost flat characteristics were obtained in all the test pieces, and it is considered that the insulation between the powders was secured. In addition, from the viewpoint of the magnitude of the magnetic permeability, a spherical alloy powder and a flat alloy powder are mixed from a test piece consisting of a spherical alloy powder only sample or a flat alloy powder only sample. The test pieces generally showed higher magnetic permeability.

FIG. 10 shows the direct current superposition characteristics of a test piece formed from a mixed powder obtained by mixing a spherical alloy powder and a flat alloy powder in a ratio of 50:50, and only the spherical alloy powder (atomized powder). The result of having measured the DC superposition characteristic of the formed test piece is shown. In FIG. 10, the DC bias field on the horizontal axis indicates the bias magnetic field when a DC magnetic field is applied, and ΔL (%) on the vertical axis indicates the rate of change of the inductance L. From FIG. 10, it was found that the test piece formed from a mixture of the spherical alloy powder and the flat alloy powder had better DC superposition characteristics than the test piece of the spherical alloy powder alone. . That is, as the DC bias field is increased, ΔL is reduced in the magnetic core of any material, but even in this case, those having excellent DC superimposition characteristics have a low decrease rate of ΔL. Things. According to this, the test piece according to the present invention is ΔL
Was found to be small and the DC superimposition characteristics were excellent.

Next, amorphous soft magnetic alloy powders of various composition systems
The final analysis result will be described. A similar to the previous embodiment
By the tomize method, amorphous soft magnetic
An alloy powder was produced. Powder of the obtained amorphous soft magnetic alloy
Has the composition Fe_100-xrAl_x(P_0.62C_0.1B _0.35Si
_0.13)_r(Where x is 1 to 5, 7, 8 at%, r
Is 24-26, 28-32 atomic%). The above
R in the composition formula indicates the total composition ratio of P, C, B, and Si.
And corresponds to the composition ratio (v + z + w) described above.
You. Of the above alloys, Fe₇₇Al₁P_9.23C_2.2B
_7.7Si_2.87For an amorphous soft magnetic alloy having the following composition, X
The crystal structure was analyzed by the line diffraction method. FIG. 11 shows the results.
Shown in

Further, Fe ₇₇ Al ₁ P _9.23 C _2.2 B _7.7 Si
_An amorphous alloy powder (atomized powder) having a composition of _2.87 was observed with a scanning electron microscope (SEM). FIG. 12 shows the SEM photograph. Further, Fe ₇₇ Al ₁ P _9.23 C _2.2 B
_7.7 Si _2.87 The alloy powder having the composition of _2.87 is sieved and classified, and the DSC measurement (Differential scanning caloriemetr) is performed.
y: differential scanning calorimetry) to measure the glass transition temperature Tg and the crystallization onset temperature Tx. The sieving range was divided into three ranges: 62 to 105 μm, 25 to 62 μm, and 25 μm or less. At the same time, DS ribbons were also obtained for alloy ribbons of the same composition manufactured by the single roll method described above.
C measurement was performed. These results are shown in FIG. Note that D
The heating rate during the SC measurement was 0.67 K / sec.

The obtained amorphous soft magnetic alloy powder was subjected to DSC measurement (Differential scanning calorieme).
try: differential scanning calorimetry) to determine the glass transition temperature Tg,
The crystallization start temperature Tx, the Curie temperature Tc, and the melting point Tm were measured, and the temperature intervals ΔTx and Tg /
Tm was determined. The heating rate during the DSC measurement was 0.6.
7K / sec. FIG. 14 shows the composition dependence of the glass transition temperature Tg, FIG. 15 shows the composition dependence of the crystallization start temperature Tx, FIG. 16 shows the composition dependence of the temperature interval ΔTx of the supercooled liquid, FIG.
7 shows the composition dependence of Tg / Tm, and FIG. 18 shows the Curie temperature Tc.
Shows the composition dependence of

Further, for the obtained amorphous soft magnetic alloy powder, the saturation magnetization σs was measured by VSM, and the magnetic permeability μ at 1 kHz was measured by an impedance analyzer.
e was measured, and the coercive force Hc was measured with a BH loop tracer. The measurement of the magnetic permeability μe was performed using an alloy ribbon manufactured by rapidly cooling a molten alloy having the same composition by a single roll method. FIG. 19 shows the composition dependence of the saturation magnetization σs, and FIG. 20 shows the effective magnetic permeability μ at 1 kHz.
FIG. 21 shows the composition dependency of e, and FIG. 21 shows the composition dependency of the coercive force Hc.

The subscripts of the plots in the triangular composition diagrams in FIGS. 14 to 21 are glass transition temperature Tg, crystallization start temperature Tx, temperature interval ΔTx of supercooled liquid, Tg / Tm, Curie temperature Tc, saturation Magnetization s, effective permeability μe, coercive force H
It shows the value of c. Further, in the triangular composition diagrams of FIGS. 14 to 21, isotherms or isotherms are written, and the numbers attached near these lines indicate the values of these isotherms or isotherms. is there.

As is apparent from FIG. 11, Fe ₇₇ Al ₁
P _9.23 C _2.2 B _7.7 Si _2.87 becomes X-ray diffraction pattern of the amorphous soft magnetic alloy powder of the composition shows a broad pattern, it can be seen that has a structure mainly an amorphous phase . Therefore, it can be seen that even with an alloy composed of Fe, Al, P, C, B and Si, an amorphous alloy having an amorphous phase as a main phase can be formed. In addition, as shown in FIG. 12, it can be seen that the obtained powder is composed of substantially spherical particles. As can be seen from FIG.
m or less and about 100 μm are observed.
Furthermore, as is clear from the SEM photograph of FIG. 12, it is clear that the atomized powder consists of substantially spherical particles.
Further, it can be seen that the atomized powder of this example is an aggregate of a powder having a large particle size of about 50 to 100 μm, a medium-sized powder of about 20 to 50 μm, and a small powder smaller than these. Next, as shown in FIG. 13, the DSC curves of the alloy powders classified by sieving showed no significant difference in any particle size range, and the alloy ribbon and alloy powder obtained by the single roll method showed no difference. There is no difference between them. Therefore, it is understood that no change in the thermal characteristics is observed depending on the difference in the particle size and the difference in the manufacturing method. In each of the samples, the glass transition temperature Tg was 774K (501 ° C), the crystallization start temperature Tx was 811K (538 ° C), and ΔTx was 37K.

Next, looking at the relationship between the various properties and the alloy composition, first, from FIG. 14, the glass transition temperature Tg is determined by increasing the Fe composition ratio (100-x-r) and increasing the (PCBSi) composition ratio r. It has been decreasing with the decrease. T below 760K
The region indicating g, as indicated by the isotherm in FIG.
Is in the range of 74 at% or more and (PCBSi) is in the range of 21 at% or less. Further, as shown in FIG.
When the content of CBSi) is at least 18 atomic% and the content of Fe is at least 79 atomic%, the glass transition temperature Tg disappears, and some of them do not become metallic glass alloy.

From the results shown in FIG. 15, the crystallization start temperature Tx decreases as the Fe composition ratio (100-x-r) increases. As shown by the isotherm in FIG. 15, the region exhibiting Tx of 800K or less has Fe of 75 atomic%.
In the above range, the composition ratio r of (PCBSi) is in the range of 21 atomic% or less.

As shown in FIG. 16, T shown in FIG.
The range surrounded by the isotherm of 760 K of g and the isotherm of 800 K of Tx shown in FIG. 15 substantially corresponds to the range of the isotherm of 40 K of ΔTx, and within this range, the temperature interval ΔTx of the supercooled liquid. Is in the range of 30 to 40K. ΔTx is Fe
It increases with the decrease in the content, and shows a ΔTx of 50 K or more when Fe is 73 atomic% or more.

Next, the composition dependence of Tg / Tm shown in FIG. 17 shows that Tg / Tm is 0.55 to 0.60 for all alloys, and particularly when the content of Fe is 79 atom% or less, the Tg / Tm is not affected. /
Tm shows 0.57 or more. Tg / Tm is a so-called reduced vitrification temperature, and is a numerical value indicating the degree of amorphous forming ability of an alloy. The higher the numerical value, the greater the amorphous forming ability. That is, an increase in Tg / Tm means that the temperature difference between the melting point Tm and the glass transition temperature Tg is small, and it becomes easy to be amorphous at a low cooling rate. Therefore, in an alloy having a composition in which Fe is 79 atomic% or less, an amorphous phase is easily formed even when the cooling rate is reduced, and the critical cooling rate is reduced. Therefore, the amorphous soft magnetic alloy powder used in the present invention has excellent amorphous forming ability.

It should be noted that a comparison between FIG. 17 and FIG.
The region where Tm = 0.56 or more corresponds to ΔTx 3 shown in FIG.
It is considered that there is a certain correlation between Tg / Tm and ΔTx because the region overlaps the region of 0K or more. Next, FIG.
As shown in the graph, the Curie temperature Tc is 600 K or more in the range of Fe of 72 atomic% or more, and it can be seen that the more Fe, the better the magnetic thermal stability.

Next, as shown in FIG.
Means that the composition ratio of Fe (100-x-r) is increased and Al
It can be understood that the ratio increases as the composition ratio x decreases. In particular, when the content of Fe is 70 atomic% or more and the content of Al is 10 atomic% or less, the saturation magnetization σs becomes 180 × 10 ⁻⁶ Wb · m / kg or more,
Further, when the content of Fe is 76 atomic% or more and the content of Al is 6 atomic% or less, the saturation magnetization .sigma.s becomes 200.times.10.sup.- ⁶ Wb.m / kg or more, and when the content of Fe is 78 atomic% or more and Al is 5 atomic% or less, the saturation magnetization .sigma. Is 210 × 10 ⁻⁶ Wb · m / kg or more, indicating that a high saturation magnetization σs is exhibited.

As shown in FIG. 20, the effective magnetic permeability μe at 1 kHz is as follows.
26800 to 270 when Si) is 20 to 22 atomic%.
It shows about 00. For alloys of other compositions, no clear tendency is observed between the composition ratio and the effective magnetic permeability μe.
Therefore, it is considered that the dependence of the magnetic permeability μe on the composition ratio is relatively small. The results shown in FIG. 20 are the results for the ribbon sample. In addition, as shown in FIG.
c shows 1.6 to 3.0 A / m in all the compositions, and shows a low value as a whole. However, there is no clear dependence on the composition ratio such as the saturation magnetization s and other thermal characteristics. I can't.

From the above, Tg, Tx, ΔTx, Tm,
Regarding thermal characteristics such as Tg / Tm and saturation magnetization σs,
It can be seen that the dependency on the composition ratio of the amorphous soft magnetic alloy, particularly the composition ratio of Fe, is extremely high.

FIG. 22 shows the triangular composition diagram of the alloy in which Tg / Tm
= 0.56, 0.57 and saturation magnetization σs = 180
It is the figure which described the contour line of * 10 < ^-6 > Wb * m / kg, respectively. The shaded area in the figure indicates that the saturation magnetization σs is 18
0 × 10 ⁻⁶ Wb · m / kg or more and Tg / Tm of 0.5
A range of 6 or more is shown. In this composition range, Fe is 7
0 atomic% or more and 79 atomic% or less, Al 10 atomic% or less,
The balance is in the range of the composition of the metalloid. If the composition range of this oblique line is, even when an alloy is manufactured by a gas atomization method in which a molten metal is sprayed with an inert gas and quenched, the entire structure is an amorphous phase, and the temperature interval ΔTx of the supercooled liquid region is determined. And the saturation magnetization s is 180 × 10 ⁻⁶ Wb
An amorphous soft magnetic alloy powder of m / kg or more can be obtained.

180 × 10 ⁻⁶ Wb · m / kg is 1.3T
Is equivalent to Therefore, the amorphous soft magnetic alloy powder having the above composition range has a saturation magnetization of 1.3 T or more. Even when this alloy powder is solidified and molded together with a resin to form a magnetic core, the saturation magnetization is about 1.1 T. It is considered to indicate. This value of the saturation magnetization is higher than that of the conventional FeAlSi-based alloy (Sendust), and thus it can be seen that the amorphous soft magnetic alloy having the above composition range has better magnetic properties than Sendust.

[0083]

As described in detail above, the compacted amorphous soft magnetic alloy of the present invention has a high compaction density because a spherical alloy powder and a flat alloy powder are mixed and compacted. , Having a high magnetic permeability. That is, since the flat alloy powder and the spherical alloy powder are mixed and compacted, a large number of flat alloy powders can be interposed between a large number of flat alloy powders. As a result of filling the gaps formed between the alloy powders of the mold with the alloy powder of the spherical shape, the compaction density can be improved. Next, the alloy powder obtained by the atomization method is an aggregate mainly composed of a large number of spherical alloy powders having different particle diameters, whereas the alloy powder obtained by pulverizing the ribbon is a flat type alloy powder. Since the alloy powder is mainly used, the spherical alloy powder and the flat alloy powder are mixed, and both alloy powders are consolidated together, thereby improving the compaction density of the compact.

In the present invention, if the flat alloy powder having a particle size of 25 μm or less is the removed flat alloy powder, there is little possibility of causing contamination of different components from the pulverizer at the time of pulverization. Therefore, the incorporation of unnecessary components into the compact can be prevented, and the composition of the obtained amorphous soft magnetic alloy powder is not adversely affected. In the present invention, the spherical alloy powder has a diameter of 100
μm or less, and the flat type alloy powder has a thickness of 15 to 25 μm.
m and a diameter in the range of 45 to 150 μm, the alloy powder is likely to be dense during compaction, and the compaction density can be reliably improved. If the amorphous soft magnetic alloy compact according to the present invention is used, an excellent one having a magnetic permeability of 100 or more at 1 MHz can be provided.

Next, the amorphous soft magnetic alloy of the present invention has a structure in which the main phase is an amorphous phase in which the temperature interval ΔTx of the supercooled liquid is 20 K or more, and the following (1) to (5) If it is represented by the composition formula of, the amorphous forming ability is increased, it is easy to obtain the amorphous, and the saturation magnetization can be increased,
This makes it possible to obtain an amorphous alloy compact having excellent soft magnetic properties. _{(1) Fe 100-xyzw Al} x P y C z B w (2) (Fe 1-a T a) 100-xyzw Al x P y C z B w
(However, T is one or two elements selected from Co and Ni.) (3) Fe _100-xvzw Al _x (P _1-b Si _b ) _v C _z B _w (4) (Fe _{1- a T a) 100-xvzw Al} x (P 1-b Si b)
_{v C z B w (5)} Fe 100-vz P v C z

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing one structural example of a high-pressure gas atomizer (atomizer) suitable for producing a spherical amorphous soft magnetic alloy powder used in the present invention.

FIG. 2 is a schematic cross-sectional view showing a structural example of a single-roll apparatus suitable for producing a flat amorphous soft magnetic alloy powder used in the present invention.

FIG. 3 is a diagram showing the mixture ratio dependency of the magnetic permeability of each compact test piece obtained when the mixture ratio of the spherical alloy powder and the flat alloy powder according to the present invention is changed.

FIG. 4 is a diagram showing the mixing ratio dependence of the density of each compact test piece obtained when the mixing ratio of the spherical alloy powder and the flat alloy powder according to the present invention is changed.

FIG. 5 is an SEM photograph showing a cross-sectional structure of a compact test piece obtained by mixing a spherical alloy powder and a flat alloy powder according to the present invention.

FIG. 6 is an SEM photograph showing a cross-sectional structure of a compact test piece obtained from a flat alloy powder.

FIG. 7 is an SEM photograph showing a cross-sectional structure of a compact test piece obtained from a spherical alloy powder.

FIG. 8 shows a compacted specimen obtained by mixing the spherical alloy powder and the flat alloy powder according to the present invention, a compacted specimen obtained from the flat alloy powder, and a spherical alloy powder. FIG. 6 is a diagram showing the frequency dependence of the magnetic permeability of each of the compacted test pieces obtained from FIG.

FIG. 9 shows a compacted specimen obtained by mixing the spherical alloy powder and the flat alloy powder according to the present invention, a compacted specimen obtained from the flat alloy powder, and a spherical alloy powder. FIG. 6 is a diagram showing the frequency dependence of the magnetic permeability of each of the compacted test pieces obtained from FIG.

FIG. 10 shows a compacted specimen obtained by mixing the spherical alloy powder and the flat alloy powder according to the present invention, a compacted specimen obtained from the flat alloy powder, and a spherical alloy powder. FIG. 6 is a diagram showing DC superimposition characteristics of each of the compacted test pieces obtained from FIG.

FIG. 11 is a view showing an X-ray diffraction pattern of an amorphous soft magnetic alloy powder (atomized powder) having a composition of Fe ₇₇ Al ₁ P _9.23 C _2.2 B _7.7 Si _2.87 .

FIG. 12 SE of an amorphous soft magnetic alloy powder (atomized powder) having a composition of Fe ₇₇ Al ₁ P _9.23 C _2.2 B _7.7 Si _2.87
It is an M photograph.

FIG. 13 is a view showing a DSC curve of an amorphous soft magnetic alloy powder having a composition of Fe ₇₇ Al ₁ P _9.23 C _2.2 B _7.7 Si _2.87 .

FIG. 14: Fe _100-xr Al _x (P _0.42 C _0.1 B _0.35 S
FIG. 4 is a triangular composition diagram showing the dependence of the glass transition temperature Tg of Fe, Al and (PCBSi) composition of an amorphous soft magnetic alloy powder having a composition of i _0.13 ) _r .

FIG. 15: Fe _100-xr Al _x (P _0.42 C _0.1 B _0.35 S
FIG. 4 is a triangular composition diagram showing the dependence of the crystallization onset temperature Tx of Fe, Al and (PCBSi) composition of an amorphous soft magnetic alloy powder having a composition of i _0.13 ) _r .

FIG. 16: Fe _100-xr Al _x (P _0.42 C _0.1 B _0.35 S
FIG. 9 is a triangular composition diagram showing the dependence of the temperature interval ΔTx of the supercooled liquid of the amorphous soft magnetic alloy powder having the composition of i _0.13 ) _{r on} the Fe, Al, and (PCBSi) compositions.

FIG. 17: Fe _100-xr Al _x (P _0.42 C _0.1 B _0.35 S
FIG. 9 is a triangular composition diagram showing the dependence of Tg / Tm on Fe, Al and (PCBSi) compositions of an amorphous soft magnetic alloy powder having a composition of i _0.13 ) _r .

FIG. 18: Fe _100-xr Al _x (P _0.42 C _0.1 B _0.35 S
FIG. 3 is a triangular composition diagram showing the dependence of the Curie temperature Tc of Fe, Al and (PCBSi) composition on the amorphous soft magnetic alloy powder having the composition of i _0.13 ) _r .

FIG. 19: Fe _100-xr Al _x (P _0.42 C _0.1 B _0.35 S
i _0.13 ) The saturation magnetization σ of the amorphous soft magnetic alloy powder having the composition of _r
FIG. 4 is a triangular composition diagram showing the dependence of s on Fe, Al, and (PCBSi) compositions.

FIG. 20: Fe _100-xr Al _x (P _0.42 C _0.1 B _0.35 S
FIG. 4 is a triangular composition diagram showing the dependence of the effective magnetic permeability μe of the amorphous soft magnetic alloy powder having the composition of i _0.13 ) _{r on} the Fe, Al, and (PCBSi) compositions.

FIG. 21: Fe _100-xr Al _x (P _0.42 C _0.1 B _0.35 S
i _0.13 ) _r The coercive force Hc of the amorphous soft magnetic alloy powder having the composition _r
FIG. 3 is a triangular composition diagram showing the dependence of Fe, Al and (PCBSi) composition on the composition.

FIG. 22: Fe _100-xr Al _x (P _0.42 C _0.1 B _0.35 S
FIG. 4 is a triangular composition diagram showing the dependence of Tg / Tm and saturation magnetization σs of Fe, Al and (PCBSi) composition of an amorphous soft magnetic alloy powder having a composition of i _0.13 ) _r .

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High-pressure gas atomizer (atomizer) 2 Melt crucible 3 Gas atomizer 4 Chamber 5 Alloy melt 6 Melt nozzle 8 Gas injection nozzle 10 Thin strip manufacturing apparatus 11 Chamber 12 Cooling roll 13 Alloy melt 15 Crucible 18 Alloy thin strip (alloy ribbon)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B22F 9/08 B22F 9/08 M C22C 45/02 C22C 45/02 A H01F 1/153 H01F 1/14 C F term (reference) 4K017 AA04 BA06 BB01 BB06 BB13 BB14 BB16 CA03 CA09 DA02 DA05 EA03 EK01 4K018 AA24 BA13 BB01 BB04 BB07 KA44 5E041 AA06 BB03 BD03 CA02

Claims (12)

[Claims] 1. At least ΔTx = Tx−Tg (where Tx
Indicates a crystallization onset temperature, and Tg indicates a glass transition temperature. ), The temperature interval ΔTx of the supercooled liquid is 2
A flat alloy powder having a structure having an amorphous phase of 0 K or more as a main phase and a spherical alloy powder having a structure having an amorphous phase having a temperature interval ΔTx of 20 K or more as a main phase are included. ,
An amorphous soft magnetic alloy compact, characterized by being mixed and compacted. 2. The spherical alloy powder is an alloy powder formed by rapidly cooling an alloy melt by an atomizing method, and the flat alloy powder is obtained by pulverizing a ribbon obtained by rapidly cooling an alloy melt. The amorphous soft magnetic alloy compact according to claim 1, wherein the compact is an formed alloy powder. 3. The amorphous soft magnetic alloy compact according to claim 2, wherein the flat alloy powder obtained by crushing the ribbon has a particle size of 25 μm or less removed. 4. The spherical alloy powder has a diameter of 100 μm.
The flat alloy powder has a thickness of 15 to 25 μm.
The amorphous soft magnetic alloy compact according to any one of claims 1 to 3, wherein m and the diameter are 45 to 150 m. 5. The method according to claim 1, wherein the mixing ratio of the spherical alloy powder and the flat alloy powder is in the range of 1: 9 to 9: 1. Of amorphous soft magnetic alloy. 6. The amorphous soft magnetic alloy compact according to claim 1, wherein the magnetic permeability at 1 MHz is 100 or more. 7. The amorphous soft powder according to claim 1, wherein at least one of the spherical alloy powder and the flat alloy powder is represented by the following composition formula. Magnetic alloy compact. _{Fe 100-xyzw Al x P y} C z B w here, x indicating the composition ratio, y, z, w is 0 atomic% ≦ x
≦ 10 atomic%, 2 atomic% ≦ y ≦ 15 atomic%, 0 atomic% <
z ≦ 11.5 at%, 4 at% ≦ w ≦ 10 at%, 70
Atomic% ≦ (100-xyzw) ≦ 79 atomic%, 1
1 atomic% ≦ (y + z + w) ≦ 30 atomic%. 8. The amorphous soft powder according to claim 1, wherein at least one of the spherical alloy powder and the flat alloy powder is represented by the following composition formula. Magnetic alloy compact. (Fe _1-a T a) provided that _{100-xyzw Al x P y C} z B w, T is Co, is one or two elements selected from Ni, a showing the composition ratio, x, y, z , W are 0.
1 ≦ a ≦ 0.15, 0 atomic% ≦ x ≦ 10 atomic%, 2 atomic% ≦ y ≦ 15 atomic%, 0 atomic% <z ≦ 11.5 atomic%,
4 atomic% ≦ w ≦ 10 atomic%, 70 atomic% ≦ (100-x
-Yzw) ≦ 79 atomic%, 11 atomic% ≦ (y + z +
w) ≦ 30 atomic%. 9. The amorphous soft powder according to claim 1, wherein at least one of the spherical alloy powder and the flat alloy powder is represented by the following composition formula. Magnetic alloy compact. Fe _100-xvzw Al _x (P _1-b Si _b ) _v C _z B _{w where} b, x, v, z, and w indicating the composition ratio are 0.1 ≦
b ≦ 0.28, 0 atomic% ≦ x ≦ 10 atomic%, 2 atomic% ≦
v ≦ 15 atomic%, 0 atomic% <z ≦ 11.5 atomic%, 4 atomic% ≦ w ≦ 10 atomic%, 70 atomic% ≦ (100-xy
−z−w) ≦ 79 at%, 11 at% ≦ (v + z + w)
≦ 30 atomic%. 10. The amorphous soft powder according to claim 1, wherein at least one of the spherical alloy powder and the flat alloy powder is represented by the following composition formula. Magnetic alloy compact. _{(Fe 1-a T a)} 100-xvzw Al x (P 1-b Si b) v C z B
_w where T is one or two elements selected from Co and Ni, and a, b, x, v, z, and w indicating the composition ratio are:
0.1 ≦ a ≦ 0.15, 0.1 ≦ b ≦ 0.28, 0 atomic% ≦ x ≦ 10 atomic%, 2 atomic% ≦ v ≦ 15 atomic%, 0 atomic% <z ≦ 11.5 atomic %, 4 atomic% ≦ w ≦ 10 atomic%, 70 atomic% ≦ (100−x−v−z−w) ≦ 79 atomic%, 11 atomic% ≦ (v + z + w) ≦ 30 atomic%. 11. The amorphous soft powder according to claim 1, wherein at least one of the spherical alloy powder and the flat alloy powder is represented by the following composition formula. Magnetic alloy compact. Fe _100-vz P _v C _z here, x indicating the composition ratio, v, z is 5 atomic% ≦ v ≦ 2
0 atomic% and z ≦ 20 atomic%. 12. A dust core comprising the compacted amorphous soft magnetic alloy according to any one of claims 1 to 11.