阅读说明：本技术 软磁性合金粉末、压粉磁芯、磁性部件及电子设备 (Soft magnetic alloy powder, dust core, magnetic component, and electronic device ) 是由 吉留和宏 松元裕之 长谷川晓斗 熊冈广修 于 2020-04-22 设计创作，主要内容包括：本发明提供一种矫顽力低的软磁性合金粉末且可以获得高导磁率的压粉磁芯的软磁性合金粉末。为由组成式(Fe-((1-(α+β)))X1-(α)X2-(β))-((1-(a+b+c+d+e+f)))M-(a)B-(b)P-(c)Si-(d)C-(e)S-(f)构成的软磁性合金粉末。X1为选自Co及Ni中的一种以上,X2为选自Al、Mn、Ag、Zn、Sn、As、Sb、Cu、Cr、Bi、N、O及稀土元素中的一种以上,M为选自Nb、Hf、Zr、Ta、Mo、W、Ti及V中的一种以上。各成分的含量为特定的范围内。非晶质化率X(％)为85％以上。(The invention provides a soft magnetic alloy powder which has low coercive force and can obtain a dust core with high magnetic permeability. Is represented by the compositional formula (Fe) (1‑(α+β)) X1 α X2 β ) (1‑(a+b+c+d+e+f)) M a B b P c Si d C e S f The soft magnetic alloy powder of the composition. X1 is selected from more than one of Co and Ni, X2 is selected from more than one of Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Cr, Bi, N, O and rare earth elements, and M is selected from more than one of Nb, Hf, Zr, Ta, Mo, W, Ti and V. The content of each component is within a specific range. The amorphization rate X (%) is 85% or more.)

1. A soft magnetic alloy powder in which,

is represented by the compositional formula (Fe)_(1-(α+β))X1_αX2_β)_{(1-(a+b+c+d+e+f))}M_aB_bP_cSi_dC_eS_fThe soft magnetic alloy powder of the composition,

x1 is at least one selected from Co and Ni,

x2 is more than one selected from Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Cr, Bi, N, O and rare earth elements,

m is one or more selected from Nb, Hf, Zr, Ta, Mo, W, Ti and V,

0≤a≤0.150、

0≤b≤0.200、

0≤c≤0.200、

0≤d≤0.200、

0＜e≤0.200、

0＜f≤0.0200、

0.100≤a+b+c+d+e≤0.300、

0.0001≤e+f≤0.220、

α≥0、

β≥0、

0≤α+β≤0.50，

the amorphization rate X (%) shown in the following formula (1) is 85% or more,

X＝100-(Ic/(Ic+Ia))×100…(1)

ic: integral intensity of crystallinity scattering,

Ia: integrated intensity of amorphous scattering.

2. The soft magnetic alloy powder according to claim 1,

the average circularity of soft magnetic alloy particles having a particle size of r to 2r is 0.70 or more, where r is D50 in the particle size distribution on a volume basis.

3. The soft magnetic alloy powder according to claim 1,

the soft magnetic alloy powder having a particle size distribution of r or more and 2r or less has an average circularity of 0.90 or more, where r is D50 in terms of volume-based particle size distribution.

4. The soft magnetic alloy powder according to claim 1,

the soft magnetic alloy powder having a particle diameter of 25 to 30 μm has an average circularity of 0.70 or more.

5. The soft magnetic alloy powder according to claim 1,

the soft magnetic alloy powder having a particle diameter of 25 to 30 μm has an average circularity of 0.90.

6. The soft magnetic alloy powder according to claim 1,

the soft magnetic alloy powder having a particle diameter of 5 to 10 μm has an average circularity of 0.70.

7. The soft magnetic alloy powder according to claim 1,

the soft magnetic alloy powder having a particle diameter of 5 to 10 μm has an average circularity of 0.90.

8. The soft magnetic alloy powder according to any one of claims 1 to 7,

0.0001≤e+f≤0.051。

9. the soft magnetic alloy powder according to any one of claims 1 to 8,

0.080<d<0.100。

10. the soft magnetic alloy powder according to any one of claims 1 to 9,

0.030＜e≤0.050。

11. the soft magnetic alloy powder according to any one of claims 1 to 10,

0≤a＜0.020。

12. the soft magnetic alloy powder according to any one of claims 1 to 11,

the soft magnetic alloy powder contains nanocrystalline particles.

13. A dust core comprising the soft magnetic alloy powder according to any one of claims 1 to 12.

14. A magnetic component comprising the soft magnetic alloy powder according to any one of claims 1 to 12.

15. An electronic device comprising the soft magnetic alloy powder according to any one of claims 1 to 12.

Technical Field

The invention relates to a soft magnetic alloy powder, a dust core, a magnetic component, and an electronic device.

Background

Patent document 1 describes a composite magnetic material in which an insulating binder is mixed with a mixed magnetic powder obtained by mixing an iron-based crystalline alloy magnetic powder and an iron-based amorphous alloy magnetic powder.

Patent document 2 describes a composite magnetic material in which each particle contained in a mixed magnetic powder obtained by mixing a hard amorphous alloy magnetic powder with an Fe — Ni alloy magnetic powder is covered with a thermosetting resin.

[ Prior art documents ]

[ patent document ]

Patent document 1: japanese laid-open patent publication No. 2004-197218

Patent document 2: japanese patent laid-open publication No. 2004-363466

Disclosure of Invention

[ problems to be solved by the invention ]

The purpose of the present invention is to provide a soft magnetic alloy powder having a low coercive force and a soft magnetic alloy powder that can provide a dust core having a high magnetic permeability.

[ means for solving problems ]

In order to achieve the above object, the soft magnetic alloy powder of the present invention is

Is represented by the composition formula (Fe)_(1-(α+β))X1_αX2_β)_{(1-(a+b+c+d+e+f))}M_aB_bP_cSi_dC_eS_fThe soft magnetic alloy powder of the composition,

x1 is at least one selected from Co and Ni,

x2 is more than one selected from Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Cr, Bi, N, O and rare earth elements,

m is one or more selected from Nb, Hf, Zr, Ta, Mo, W, Ti and V,

0≤a≤0.150、

0≤b≤0.200、

0≤c≤0.200、

0≤d≤0.200、

0＜e≤0.200、

0＜f≤0.0200、

0.100≤a+b+c+d+e≤0.300、

0.0001≤e+f≤0.220、

α≥0、

β≥0、

0≤α+β≤0.50，

the amorphization rate X (%) shown in the following formula (1) is 85% or more,

X＝100-(Ic/(Ic+Ia))×100…(1)

ic: integral intensity of crystallinity scattering,

Ia: integrated intensity of amorphous scattering.

The soft magnetic alloy powder of the present invention has the above-described characteristics, and thus has a sufficiently low coercive force HcJ. Further, by using the soft magnetic alloy powder of the present invention, a dust core or the like having high magnetic permeability can be obtained.

The soft magnetic alloy powder of the present invention may be: the average circularity of soft magnetic alloy particles having a particle size of r to 2r is 0.70 or more, where r is D50 in the particle size distribution on a volume basis.

The soft magnetic alloy powder of the present invention may be: the soft magnetic alloy powder having a particle size distribution of r or more and 2r or less has an average circularity of 0.90 or more, where r is D50 in terms of volume-based particle size distribution.

The soft magnetic alloy powder of the present invention may be: the soft magnetic alloy powder having a particle diameter of 25 to 30 μm has an average circularity of 0.70 or more.

The soft magnetic alloy powder of the present invention may be: the soft magnetic alloy powder having a particle diameter of 25 to 30 μm has an average circularity of 0.90.

The soft magnetic alloy powder of the present invention may be: the soft magnetic alloy powder having a particle diameter of 5 to 10 μm has an average circularity of 0.70.

The soft magnetic alloy powder of the present invention may be: the soft magnetic alloy powder having a particle diameter of 5 to 10 μm has an average circularity of 0.90.

It can also be: e + f is more than or equal to 0.0001 and less than or equal to 0.051.

It can also be: d is more than 0.080 and less than 0.100.

It can also be: e is more than 0.030 and less than or equal to 0.050.

It can also be: a is more than or equal to 0 and less than 0.020.

It can also be: the soft magnetic alloy powder of the present invention contains nanocrystalline particles.

The dust core of the present invention includes the soft magnetic alloy powder described above.

The magnetic member of the present invention includes the soft magnetic alloy powder described above.

The electronic device of the present invention includes the soft magnetic alloy powder described above.

Drawings

Fig. 1 is an example of a graph obtained by X-ray crystal structure analysis.

Fig. 2 is an example of a pattern obtained by waveform analysis (profile fitting) of the graph of fig. 1.

Fig. 3 is a graph showing the particle size distribution.

Fig. 4 is a graph showing the particle size distribution.

Fig. 5 is a result of observation according to morpholinogi 3.

Fig. 6A is a schematic diagram of an atomizing device.

Fig. 6B is an enlarged view of a main portion of fig. 6A.

Detailed Description

Hereinafter, embodiments of the present invention will be described.

In order to achieve the above object, a soft magnetic alloy powder according to the present embodiment is characterized in that,

is represented by the composition formula (Fe)_(1-(α+β))X1_αX2_β)_{(1-(a+b+c+d+e+f))}M_aB_bP_cSi_dC_eS_fThe soft magnetic alloy powder of the composition,

x1 is at least one selected from Co and Ni,

x2 is more than one selected from Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Cr, Bi, N, O and rare earth elements,

m is one or more selected from Nb, Hf, Zr, Ta, Mo, W, Ti and V,

0≤a≤0.150、

0≤b≤0.200、

0≤c≤0.200、

0≤d≤0.200、

0＜e≤0.200、

0＜f≤0.0200、

0.100≤a+b+c+d+e≤0.300、

0.0001≤e+f≤0.220、

α≥0、

β≥0、

0≤α+β≤0.50，

the amorphization rate X (%) shown by the following formula (1) is 85% or more:

X＝100-(Ic/(Ic+Ia))×100…(1)

ic: integral intensity of crystallinity scattering,

Ia: integrated intensity of amorphous scattering.

The soft magnetic alloy powder according to the present embodiment has the above-described characteristics, and thus has a sufficiently low coercive force HcJ. Further, a broad particle size distribution is easily achieved. As a result, a dust core or the like having a high magnetic permeability μ can be obtained by using the soft magnetic alloy powder of the present embodiment. In addition, the average circularity of the soft magnetic alloy powder having a particle diameter within a specific range becomes high. As a result, a soft magnetic alloy powder having a good HcJ can be further obtained. Further, a dust core or the like having a high magnetic permeability μ can be obtained.

The respective components of the soft magnetic alloy powder according to the present embodiment will be described in detail below.

M is one or more selected from Nb, Hf, Zr, Ta, Mo, W, Ti and V.

The content (a) of M satisfies a condition that a is more than or equal to 0 and less than or equal to 0.150. That is, the soft magnetic alloy powder according to the present embodiment may not contain M. From the viewpoint of reducing HcJ, it is preferable that 0. ltoreq. a.ltoreq.0.070 is satisfied. As a increases, it becomes easy to lower the saturation magnetization.

Preferably, 0. ltoreq. a <0.020 is satisfied. Or a is more than or equal to 0 and less than or equal to 0.019. When a is within the above numerical range, saturation magnetization can be further improved.

The content (B) of B satisfies that B is more than or equal to 0 and less than or equal to 0.200. That is, the soft magnetic alloy powder according to the present embodiment may not contain B. In addition, b may be 0.060. ltoreq.b.ltoreq.0.200. If b is too large, saturation magnetization tends to be reduced.

The content (c) of P satisfies that c is more than or equal to 0 and less than or equal to 0.200. That is, the soft magnetic alloy powder according to the present embodiment may not contain P. In addition, c can be more than or equal to 0 and less than or equal to 0.150. When c is too large, saturation magnetization is likely to be reduced as in the case where b is too large.

The content (d) of Si satisfies that d is more than or equal to 0 and less than or equal to 0.200. That is, the soft magnetic alloy powder according to the present embodiment may not contain Si. D can be more than 0.080 and less than 0.100, or d can be more than or equal to 0.085 and less than or equal to 0.095. If d is too large, the circularity of the soft magnetic alloy powder tends to be reduced.

The content (e) of C satisfies 0< e < 0.200. That is, the soft magnetic alloy powder according to the present embodiment necessarily includes C. In addition, e can be more than or equal to 0.001 and less than or equal to 0.150, and e can be more than or equal to 0.030 and less than or equal to 0.050. The soft magnetic alloy powder according to the present embodiment includes C, which facilitates reduction of HcJ. When e is too large, the saturation magnetization is likely to be reduced as in the case where b is too large and the case where c is too large.

The content (f) of S satisfies 0< f ≦ 0.0200. That is, the soft magnetic alloy powder according to the present embodiment necessarily includes S. Further, f may be 0.0001. ltoreq. f.ltoreq.0.0200. The soft magnetic alloy powder according to the present embodiment, which includes S, can easily have a broad particle size distribution, and can easily improve the magnetic permeability μ of a powder magnetic core or the like manufactured using the soft magnetic alloy powder. However, when the soft magnetic alloy powder according to the present embodiment contains S without containing C, HcJ becomes excessively large. In addition, the magnetic permeability μ of the powder magnetic core and the like can be easily reduced. If f is too large, the soft magnetic alloy powder tends to contain crystals having a crystal grain size of more than 100 nm. Further, when the soft magnetic alloy powder contains crystals having a crystal grain size of more than 100nm, HcJ increases significantly, and the magnetic permeability μ of a powder magnetic core or the like using the soft magnetic alloy powder tends to be easily lowered.

The soft magnetic alloy powder according to the present embodiment satisfies a requirement of 0.100. ltoreq. a + b + c + d + e. ltoreq.0.300. In addition, a + b + c + d + e may be 0.240. ltoreq.a + b + c + d + e. ltoreq.0.300. When a + b + c + d + e is within the above range, various characteristics can be easily improved. When a + b + c + d + e is too small, the soft magnetic alloy powder tends to contain crystals having a crystal grain size of more than 100 nm. If a + b + c + d + e is too large, saturation magnetization tends to be reduced.

The soft magnetic alloy powder according to the present embodiment satisfies the condition that e + f is 0.0001. ltoreq. e + f.ltoreq.0.220. Or e + f is more than or equal to 0.0001 and less than or equal to 0.051. When e + f is within the above range, various characteristics can be easily improved.

From the above, when only C is contained in C and S is not contained, the particle size distribution of the soft magnetic alloy powder becomes sharp. As a result, HcJ becomes good, but the magnetic permeability μ of a dust core or the like using the soft magnetic alloy powder is not improved. When only S is contained in C and S and C is not contained, HcJ deteriorates, and the effect of improving the magnetic permeability μ of a dust core or the like using the soft magnetic alloy powder is small. In addition, when both C and S are included but e + f is too large, the soft magnetic alloy powder is likely to be crystals including crystals having a crystal grain size of more than 100 nm.

The Fe content (1- (a + b + c + d + e + f)) is not particularly limited, but may be 0.699. ltoreq.1- (a + b + c + d + e + f). ltoreq. 0.8999. By setting 1- (a + b + c + d + e + f) within the above range, the soft magnetic alloy powder becomes less likely to contain crystals having a crystal grain size of more than 100 nm. The content of Fe (1- (a + b + c + d + e + f)) may be 0.740 or more. By setting 1- (a + b + c + d + e + f) to 0.740 or more, saturation magnetization can be easily increased.

In the soft magnetic alloy powder of the present embodiment, a part of Fe may be replaced with X1 and/or X2.

X1 is at least one selected from Co and Ni. The content of X1 may be α ═ 0. That is, X1 may not be contained. The number of atoms in the entire composition may be 100 at%, and the number of atoms in X1 may be 40 at% or less. That is, 0. ltoreq. α {1- (a + b + c + d + e + f) } 0.400 may be satisfied.

X2 is at least one element selected from Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Cr, Bi, N, O and rare earth elements. In addition, X2 may be one or more selected from Al, Zn, Sn, Cu, Cr, and Bi, particularly, from the viewpoint of reducing HcJ. The content of X2 may be β ═ 0. That is, X2 may not be contained. The number of atoms in the entire composition may be 100 at%, and the number of atoms in X2 may be 3.0 at% or less. That is, 0. ltoreq. beta {1- (a + b + c + d + e + f) } 0.030 can be satisfied.

The range of substitution amount for substituting Fe with X1 and/or X2 is equal to or less than half of Fe on the atomic number basis. Namely, 0. ltoreq. alpha. + β. ltoreq.0.50.

The soft magnetic alloy powder according to the present embodiment may contain, as inevitable impurities, elements other than those described above. For example, the content may be 0.1 wt% or less with respect to 100 wt% of the soft magnetic alloy powder.

The soft magnetic alloy powder of the present embodiment has a structure made of an amorphous material. Specifically, the amorphization ratio X shown in the following formula (1) is 85% or more.

X＝100-(Ic/(Ic+Ia))×100…(1)

Ic: integrated intensity of crystallinity scattering

Ia: integral intensity of amorphous scattering

The soft magnetic alloy powder having a high amorphization ratio X has a small crystal anisotropy. Therefore, the magnetic loss of the dust core using the soft magnetic alloy powder having a high amorphization ratio X is reduced.

The amorphous ratio X is calculated from the peak intensity of peaks (Ic: crystalline scattering integrated intensity, Ia: amorphous scattering integrated intensity) of crystallized Fe or compound by performing X-ray crystal structure analysis on the soft magnetic alloy powder by X-ray diffraction (XRD) to identify the phase, and deriving the crystallization ratio from the peak intensity by the above formula (1). The calculation method is described below in more detail.

The soft magnetic alloy powder according to the present embodiment was subjected to X-ray crystal structure analysis by XRD, and a graph as shown in fig. 1 was obtained. On which waveform analysis (profile shaping) was performed using a Lorentzian function (Lorentzian function) of the following formula (2), resulting in a crystalline component pattern α showing crystalline scattering integral intensity as shown in fig. 2_cAmorphous composition pattern alpha showing amorphous scattering integral intensity_aAnd a pattern alpha combining the two_c+a. From the crystalline scattering integral intensity and the amorphous scattering integral intensity of the obtained pattern, the amorphization ratio X was obtained by the above formula (1). The measurement range is a range in which the diffraction angle 2 θ, which can be confirmed by an amorphous halo (halo), is 30 ° to 60 °. In this range, the error between the integrated intensity measured by XRD and the integrated intensity calculated using the Lorentzian function is within 1%.

[ mathematical formula 1]

h: peak height

u: peak position

w: half peak width

b: height of background

The soft magnetic alloy powder according to the present embodiment may include nanocrystalline particles if the amorphization ratio X (%) is 85% or more. The nanocrystal particle is a particle including a nanocrystal having a crystal particle diameter of 50nm or less. In addition, whether or not the soft magnetic alloy powder includes nanocrystalline particles can be confirmed by XRD. When the soft magnetic alloy powder includes nanocrystalline particles, HcJ can be easily further reduced, and the magnetic permeability μ of a dust core or the like using the soft magnetic alloy powder can be easily improved.

In addition, the nanocrystal particle generally includes a plurality of nanocrystals. That is, the particle size of the soft magnetic alloy powder described later is different from the crystal particle size of the nanocrystal.

The soft magnetic alloy powder of the present embodiment may be a soft magnetic alloy powder having a high sphericity. By having the above composition, a soft magnetic alloy powder having a particle shape close to a spherical shape, that is, a soft magnetic alloy powder having a high sphericity can be obtained.

Generally, the higher the amorphization ratio X of the soft magnetic alloy powder, the more difficult plastic deformation tends to occur. Therefore, it becomes difficult to increase the filling ratio in molding of the powder magnetic core or the like. By making the particle shape of the soft magnetic alloy powder approximately spherical, the filling factor of a powder magnetic core or the like using the soft magnetic alloy powder can be increased, and various properties such as the coercive force HcJ and the magnetic permeability μ can be improved.

In the soft magnetic alloy powder of the present embodiment, the powder having a large particle diameter preferably has a high sphericity. The high sphericity of the powder having a large particle diameter can further increase the filling factor of a dust core or the like using the soft magnetic alloy powder, and the magnetic permeability μ can be easily increased.

Hereinafter, a method of evaluating the particle shape and particle size (particle size distribution) of the soft magnetic alloy powder according to the present embodiment will be described.

As described above, the closer the particle shape is to a spherical shape, the higher the filling ratio of a powder magnetic core or the like using the soft magnetic alloy powder, and the higher various properties such as coercive force can be improved.

Generally, the basis of the particle size distribution of the soft magnetic alloy powder is a volume basis and a number basis. The volume-based particle size distribution is represented by a graph in which the horizontal axis represents the particle size and the vertical axis represents the frequency on a volume basis. The number-based particle size distribution is represented by a graph in which the horizontal axis represents the particle size and the vertical axis represents the frequency on the number basis. The two are merged into a graph, for example, as in fig. 3. The solid line is the particle size distribution on a volume basis and the dotted line is the particle size distribution on a number basis. The positions where r, r and 2r are D50 of the particle diameter on a volume basis are shown in fig. 3.

The particle size distribution on a volume basis differs from the particle size distribution on a number basis depending on the degree of reflection of individual particles on the data. The degree to which individual particles are reflected in the data on a volume basis is proportional to their volume. That is, the degree of reflection of the small particles on the data is small. On the other hand, the degree of reflection of the individual particles on the data is equivalent on a number basis. That is, the degree of reflection of the small particles on the data becomes large. Thus, the above-described difference in particle size distribution occurs.

As described above, the soft magnetic alloy powder of the present embodiment is preferably a powder having a large particle diameter and a high sphericity. Specifically, the average circularity of particles having a particle diameter of r to 2r may be 0.70 or more, or 0.90 or more on a number basis. The content of the particles having a particle diameter of r to 2r may be 1% to 25% by number, based on the total soft magnetic alloy powder. In the particle size distribution based on the number, only the particle size distribution of the portion having a particle diameter of r or more and 2r or less is shown in fig. 4.

The soft magnetic alloy powder of the present embodiment may have an average circularity of 0.70 or more, or 0.90 or more, as particles having a particle diameter of 25 μm to 30 μm on a number basis. In this case, D50 may be 0.5 to 25 μm in particle size on a number basis. The content of particles having a particle diameter of 25 μm to 30 μm in the soft magnetic alloy powder as a whole may be 0.1% to 10% by number.

The soft magnetic alloy powder of the present embodiment may have an average circularity of 0.70 or more, or 0.90 or more, as particles having a particle diameter of 5 μm to 10 μm on a number basis. In this case, D50 may be 0.5 to 5 μm in particle size on a number basis. The content of particles having a particle diameter of 5 μm to 10 μm may be 0.1% to 10% by number based on the whole soft magnetic alloy powder.

In the present embodiment, the method of evaluating D50(r) in terms of particle size distribution and particle size on a volume basis is not particularly limited. For example, the evaluation can be performed by a particle size distribution measuring apparatus of a laser diffraction type using Fraunhofer diffraction (Fraunhofer diffraction) theory.

In the present embodiment, the particle size distribution on a number basis was evaluated using morpholinogi G3(Malvern Panalytical). Morphologi G3 is a device that can disperse powder by air, project the shape of each particle, and evaluate it. The shape of the particles in the range of about 0.5 μm to several mm in particle diameter can be evaluated by an optical microscope or a laser microscope. Specifically, as is clear from the particle shape measurement result 1 shown in fig. 5, a plurality of particle shapes can be projected at a time and evaluated. However, in practice, a plurality of particle shapes much larger than those described in the particle shape measurement result 1 shown in fig. 5 can be projected and evaluated at one time.

Since the Morphologi G3 can create and evaluate projection views of a plurality of particles at a time, the shapes of a plurality of particles can be evaluated in a short time as compared with a conventional evaluation method such as SEM (scanning electron microscope) observation. For example, in the example described later, a projection view is created for 20000 particles, the particle size and circularity of each particle are automatically calculated, and the average circularity of particles having particle sizes within a specific range is calculated. In contrast, in conventional SEM observation, since the circularity is calculated for one particle using an SEM image, it is difficult to evaluate the shape of a plurality of particles in a short time.

The circularity of the particle is 4 π S/L where S is the area in the projection view, L is the perimeter in the projection view²And (4) showing. The circularity of the circle is 1, and the circularity of the projection view of the particle becomes closer to 1, the higher the sphericity of the particle.

Whether or not the soft magnetic alloy powder of the present embodiment has a broad particle size distribution can be evaluated by the size of the standard deviation σ of the particle size on a number basis.

In addition, when various particle size distributions of the soft magnetic alloy powder contained in the dust core or the like are evaluated, a method according to conventional SEM observation can be used. The particle diameter and circularity of one particle included in an arbitrary cross section of the dust core or the like may be calculated and evaluated from the SEM image.

The present inventors have found that by controlling the composition of the soft magnetic alloy powder, a soft magnetic alloy powder having a wide particle size distribution can be obtained. Further, by controlling the composition of the soft magnetic alloy powder, HcJ of the whole soft magnetic alloy powder can be controlled.

The present inventors have also found that the magnetic permeability μ of a dust core or the like using a soft magnetic alloy powder in which HcJ of the whole soft magnetic alloy powder is suitable and has a wide particle size distribution is good.

Further, the present inventors have found that, in order to improve the magnetic permeability μ and withstand voltage characteristics of HcJ of the whole soft magnetic alloy powder and a powder magnetic core using the soft magnetic alloy powder, it is more important to control the sphericity of the soft magnetic alloy powder having a large particle diameter than to control the sphericity of the whole soft magnetic alloy powder. Specifically, the higher the average circularity of particles having a particle diameter of r to 2r on a number basis and the higher the average circularity of particles having a particle diameter of 25 to 30 μm on a number basis, the better the magnetic permeability μ and withstand voltage characteristics tend to be.

The sphericity of the whole soft magnetic alloy powder can also be changed by controlling the production method. However, even if the production method is simply controlled, it is difficult to change the sphericity of the soft magnetic alloy powder having a large particle diameter as compared with the soft magnetic alloy powder having a small particle diameter. That is, it was found that, in order to control the sphericity of the soft magnetic alloy powder having a large particle diameter, it is important to control the composition of the soft magnetic alloy powder so as to change the particle shape of the whole soft magnetic alloy powder more easily than in the case of controlling the production method.

Here, the volume distribution of the whole soft magnetic alloy powder is considered for the soft magnetic alloy powder having a small particle size and the soft magnetic alloy powder having a large particle size, which are the same total volume ratio. When the total volume ratios are the same, the number of particles of the soft magnetic alloy powder having a small particle diameter is extremely large relative to the number of particles of the soft magnetic alloy powder having a large particle diameter. For example, if the total volume ratio is the same, the number of particles of the soft magnetic alloy powder having a particle diameter of 10 μm is about 1/1000, which is the number of particles of the soft magnetic alloy powder having a particle diameter of 1 μm.

That is, the sphericity of the whole soft magnetic alloy powder has a small influence on the sphericity of the soft magnetic alloy powder having a large particle diameter and a small number of particles. In addition, the sphericity of the whole soft magnetic alloy powder can be changed regardless of the sphericity of the soft magnetic alloy powder having a large particle diameter.

The method for producing the soft magnetic alloy powder of the present embodiment will be described below.

The method for producing the soft magnetic alloy powder of the present embodiment is not particularly limited. For example, atomization is mentioned. The type of atomization method is also arbitrary, and examples thereof include a water atomization method and a gas atomization method.

The following describes a method for producing a soft magnetic alloy powder by the water atomization method. First, raw materials are prepared. The raw material to be prepared may be a single body of a metal or the like, or may be an alloy. The form of the raw material is not particularly limited. For example, a pig (ingot), a chunk (chunk), or a shot (shot) may be enumerated.

Next, the prepared raw materials were weighed and mixed. At this time, the soft magnetic alloy powder having the final target composition is weighed. Then, the mixed raw materials are melted and mixed to obtain a molten metal. The means for melting and mixing is not particularly limited. For example, a crucible or the like can be used. The temperature of the molten metal may be determined in consideration of the melting point of each metal element, and may be, for example, 1200 to 1600 ℃.

Then, soft magnetic alloy powder was produced from the molten metal by a water atomization method. Specifically, the soft magnetic alloy powder can be produced by ejecting molten metal through a nozzle or the like and rapidly cooling the ejected molten metal by impinging a high-pressure water stream thereon. The molten metal and the soft magnetic alloy powder have substantially the same composition.

Here, in order to obtain the intended particle size of the soft magnetic alloy powder, the particle size can be controlled by controlling the pressure of the high-pressure water flow, the discharge amount of the molten metal, and the like. Then, a soft magnetic alloy powder having the intended particle size distribution was obtained.

The pressure of the high-pressure water stream may be, for example, 50MPa or more and 100MPa or less. The discharge amount of the molten metal may be, for example, 1kg/min to 20 kg/min.

The obtained amorphous soft magnetic alloy powder may be subjected to a heat treatment to precipitate nanocrystalline particles in the soft magnetic alloy powder. The heat treatment conditions are, for example, 350 ℃ to 800 ℃ and 0.1 minute to 120 minutes.

The following describes a method for producing a soft magnetic alloy powder by a gas atomization method.

When the atomization apparatus shown in fig. 6A and 6B is used as the atomization apparatus, the present inventors have made it easy to produce a soft magnetic alloy powder having a large particle size and further have made it easy to obtain an amorphous soft magnetic alloy powder.

As shown in fig. 6A, the atomizing device 10 includes a molten metal supply portion 20 and a cooling portion 30 disposed below the metal supply portion 20 in the vertical direction. In the figure, the vertical direction is a direction along the Z axis.

The molten metal supply 20 has a heat-resistant container 22 that contains molten metal 21. In the heat-resistant container 22, the raw material of each metal element weighed so as to have the composition of the finally obtained soft magnetic alloy powder is melted by the heating coil 24 to obtain the molten metal 21. The temperature at the time of melting, that is, the temperature of the molten metal 21, may be determined in consideration of the melting point of each metal material, and may be, for example, 1200 to 1600 ℃.

The molten metal 21 is discharged as a drop of molten metal 21a from the discharge port 23 toward the cooling portion 30. High-pressure gas is jetted from the gas jet nozzle 26 toward the discharged molten drop 21a, and the molten drop 21a is formed into a plurality of droplets and is transported along the gas flow toward the inner surface of the cylindrical body 32.

As the gas injected from the gas injection nozzle 26, an inert gas or a reducing gas is preferable. As the inert gas, for example, nitrogen, argon, helium, or the like can be used. As the reducing gas, for example, ammonia decomposition gas or the like can be used. However, in the case where the molten metal 21 is a metal that is difficult to oxidize, the gas injected from the gas injection nozzle 26 may be air.

The dripped molten metal 21a transported to the inner surface of the cylindrical body 32 is further broken into fine particles and solidified by cooling to become solid alloy powder by impinging on the coolant flow 50 formed in the cylindrical body 32 in an inverted conical shape. The axis O of the cylinder 32 is inclined at a predetermined angle θ 1 with respect to the vertical line Z. The predetermined angle θ 1 is not particularly limited, and is preferably 0 to 45 degrees. By setting the angle range to this range, the dropped molten metal 21a from the discharge port 23 is easily discharged to the coolant flow 50 formed in the reverse conical shape inside the cylindrical body 32.

A discharge portion 34 is provided below along the axial center O of the cylindrical body 32, and allows the alloy powder contained in the coolant flow 50 to be discharged to the outside together with the coolant. The alloy powder discharged together with the coolant is separated from the coolant in an external storage tank or the like and taken out. The coolant is not particularly limited, and cooling water may be used.

In the present embodiment, the flight time of the molten droplets of the molten metal 21a is shortened as compared with the case where the coolant flow is along the inner surface 33 of the cylindrical body 32 because the dropped molten metal 21a impinges on the coolant flow 50 formed in the inverted conical shape. When the flight time is shortened, the quenching effect is promoted, and the amorphization ratio X of the obtained soft magnetic alloy powder is increased. In addition, the sphericity of the soft magnetic alloy powder having a large particle diameter tends to increase. In addition, since the dropped molten metal 21a is less likely to be oxidized when the flight time is shortened, the miniaturization of the obtained soft magnetic alloy powder is promoted and the quality of the soft magnetic alloy powder is improved.

In the present embodiment, in order to form the coolant flow in the cylindrical body 32 into an inverted conical shape, the flow of the coolant in the coolant introduction portion (coolant discharge portion) 36 for introducing the coolant into the cylindrical body 32 is controlled. Fig. 6B shows the structure of the coolant introduction portion 36.

As shown in fig. 6B, the frame 38 defines an outer portion (outer space) 44 located outside the cylindrical body 32 in the radial direction and an inner portion (inner space) 46 located inside the cylindrical body 32 in the radial direction. The outer portion 44 and the inner portion 46 are partitioned by the partition portion 40, and the outer portion 44 and the inner portion 46 communicate with each other through the passage portion 42 formed at the upper portion in the axial center O direction of the partition portion 40, and the coolant can flow therethrough.

A single or a plurality of shower heads 37 are connected to the outer portion 44, and the cooling liquid enters the outer portion 44 from the shower heads 37. Further, a coolant discharge portion 52 is formed below the inner portion 46 in the axial center O direction, and the coolant in the inner portion 46 is discharged (guided) from the coolant discharge portion 52 to the inside of the cylinder 32.

The outer peripheral surface of the frame 38 serves as a flow path inner peripheral surface 38b for guiding the flow of the coolant in the inner portion 46, and an outer protrusion 38a1 protruding outward in the radial direction is formed at the lower end 38a of the frame 38 so as to continue from the flow path inner peripheral surface 38b of the frame 38. Therefore, the annular gap between the tip of the outer convex portion 38a1 and the inner surface 33 of the cylindrical body 32 serves as the coolant discharge portion 52. A flow path deflecting surface 62 is formed on the flow path side upper surface of the outer convex portion 38a 1.

As shown in fig. 6B, the radial width D1 of the coolant discharge portion 52 is narrower than the radial width D2 of the main portion of the inner portion 46 by the outer protrusion 38a 1. When D1 is narrower than D2, the coolant drops to below the axial center O along the flow path inner peripheral surface 38b inside the inner portion 46, then flows along the flow path deflecting surface 62 of the frame 38, hits the inner surface 33 of the cylindrical body 32, and is reflected. As a result, as shown in fig. 6A, the coolant is discharged from the coolant discharge portion 52 into the interior of the cylindrical body 32 in an inverted conical shape, and a coolant flow 50 is formed. When D1 is D2, the coolant discharged from the coolant discharge portion 52 forms a coolant flow along the inner surface 33 of the cylindrical body 32.

D1/D2 is preferably 2/3 or less, more preferably 1/2 or less, and most preferably 1/10 or more.

The coolant flow 50 flowing out of the coolant discharge portion 52 may be a circular conical flow that linearly advances from the coolant discharge portion 52 toward the axial center O, or may be a spiral circular conical flow.

The discharge amount of the molten metal, the gas injection pressure, the pressure in the cylinder 32, the coolant discharge pressure, D1/D2, and the like may be appropriately set according to the particle size of the soft magnetic alloy powder to be used. The discharge amount of the molten metal may be, for example, 1kg/min to 20 kg/min. The gas injection pressure may be, for example, 0.5MPa or more and 19MPa or less. The pressure in the cylinder 32 may be, for example, 0.5MPa or more and 19MPa or less. The coolant release pressure may be, for example, 0.5MPa or more and 19MPa or less.

As the discharge amount of the molten metal is smaller, the particle diameter tends to be smaller, and the amorphous soft magnetic alloy powder tends to be easily produced.

The higher the gas injection pressure, the pressure in the cylinder 32, and the coolant discharge pressure are, the smaller the particle diameter is, and the smaller the circularity of the particles tends to be.

The particle size can be adjusted by, for example, sieve classification, air classification, or the like. Hereinafter, a method of adjusting the particle size by sieve classification will be described.

The particle size can be adjusted by classifying with a sieve to change, for example, the amount of powder fed per pass, the classifying time, and/or the mesh size. Also, by appropriately controlling the powder feed amount, classification time, and/or mesh size per one turn, a soft magnetic alloy powder having a desired particle size can be obtained.

The more the powder is fed per pass, the more the average circularity of the particles becomes liable to be lowered. The shorter the classification time is, the more easily the average circularity of the particles is reduced. The larger the mesh size is, the more likely the average circularity of the particles is to be reduced.

As another method of adjusting the particle size, there is a method of changing the number of times the powder passes through the mesh. Even with the same mesh size, by increasing the number of times the powder passes through the mesh, it is possible to extract more irregularly shaped particles. The average circularity of the powder can also be improved by extracting more of the irregularly shaped particles.

The particle size may be adjusted by blending a plurality of types of soft magnetic alloy powders.

The use of the soft magnetic alloy powder according to the present embodiment is not particularly limited. For example, a dust core can be cited. When the soft magnetic alloy powder according to the present embodiment is used, an appropriate magnetic permeability μ can be easily obtained even if the pressure ratio at the time of manufacturing the powder magnetic core is made low. This is because, by widening the particle size distribution, the obtained powder magnetic core is easily densified even if the pressure at the time of manufacturing the powder magnetic core is relatively low. Specifically, the pressure at the time of producing the powder magnetic core can be, for example, 98MPa to 1500 MPa.

The powder magnetic core according to the present embodiment can be suitably used as a powder magnetic core for an inductor, particularly a power inductor (power inductor). Further, the present invention can be applied to an inductor in which a powder magnetic core and a coil portion are integrally formed.

In addition, the present invention can be applied to magnetic parts using soft magnetic alloy powder, such as thin film inductors and magnetic heads. Further, a dust core and a magnetic component using the soft magnetic alloy powder can be applied to electronic devices.

[ examples ]

The present invention will be described in detail below with reference to examples.

(Experimental example 1)

Ingots of various materials were prepared and weighed so as to obtain a master alloy having a composition shown in table 1 below. Then, the crucible is accommodated in a crucible disposed in the water atomization apparatus. Next, the crucible was heated to 1500 ℃ by high-frequency induction using a work coil (work coil) provided outside the crucible in an inert atmosphere, and the ingot in the crucible was melted and mixed to obtain molten metal (melt).

Next, the melt in the crucible was discharged from a nozzle provided in the crucible, and the discharged melt was rapidly cooled by impinging a high-pressure water flow of 100MPa, thereby producing soft magnetic alloy powders of examples and comparative examples shown in table 1. In addition, it was confirmed by ICP analysis that the composition of the master alloy substantially agrees with the composition of the soft magnetic alloy powder.

The obtained soft magnetic alloy powders were subjected to sieve classification. The conditions for the sieve classification were set to 0.5kg of the feed amount per pass and 1 minute of the classification time. The mesh size was 38 μm.

It was confirmed that each of the obtained soft magnetic alloy powders was constituted by an amorphous phase or a crystalline phase. The amorphous ratio X of each ribbon was measured by XRD, and it was assumed that X was constituted by amorphous when X was 85% or more, and constituted by crystal when X was less than 85%. The results are shown in Table 1.

The obtained soft magnetic alloy powders were measured for HcJ and Bs. HcJ was measured using a Hc meter (Hc meter). The results are shown in Table 1. In experimental example 1, HcJ of 2.4Oe or less was preferable, and HcJ of 1.0Oe or less was more preferable. Bs is preferably 0.70T or more, and more preferably 1.40T or more.

The shape of the powder particles in each of the obtained soft magnetic alloy powders was evaluated. Specifically, D50(r) on a volume basis, D50 on a number basis, σ on a number basis, and an average circularity with a particle diameter of r or more and 2r or less on a number basis were evaluated. The results are shown in Table 1.

In Experimental example 1, D50(r) was 10 to 11 μm on a volume basis, and D50 was 4to 5 μm on a number basis.

D50(r) on a volume basis was measured using a laser diffraction particle size distribution measuring apparatus (HELOS & RODOS, Sympatec).

D50 and σ on a number basis were measured by observing the shapes of 20000 powder particles at a magnification of 10 times using morpholinogi G3(Malvern Panalytical). Specifically, a projection image through a laser microscope is captured by dispersing soft magnetic alloy powder in an amount of 3cc in volume at an air pressure of 1 to 3 bar. The particle diameters of the respective powder particles were used to calculate D50 and σ on a number basis. The particle diameter of each powder particle is set to a circle equivalent diameter (equivalent circle diameter).

In Experimental example 1, σ is preferably 2.5 μm or more.

The average circularity of the powder particles having a particle diameter of r to 2r on a number basis is calculated by measuring the circularity of each of 20000 powder particles having a particle diameter of r to 2r and averaging the circularities.

Next, a toroidal core (toroidal core) was produced from each of the soft magnetic alloy powders. Specifically, each soft magnetic alloy powder was mixed so that the amount of phenol resin to be an insulating binder became 3 mass% of the whole, granulated by using a general planetary mixer as a mixer, and granulated so as to become a granulated powder of about 500 μm. Next, the resulting granulated powder was subjected to a surface pressure of 4ton/cm²(392MPa) to prepare a toroidal shaped compact having an outer diameter of 13mm, an inner diameter of 8mm and a height of 6 mm. The obtained molded body was hardened at 150 ℃ to prepare an annular core.

Then, UEW wire was wound on the toroidal core, and μ (permeability) was measured at 100kHz using 4284A PRECISION LCR METER (hewlett packard). In experimental example 1, the case where μ is 25 or more was considered to be good.

[ Table 1]

According to table 1, in all examples and comparative examples, the average circularity of the particle diameter of r or more and 2r or less on a number basis was 0.70 or more.

According to table 1, the soft magnetic alloy powder of sample No. 1, which is a comparative example containing no C and no Si, has a high HcJ and a low σ. Also, μ of the toroidal core is low.

The soft magnetic alloy powders of sample nos. 5 to 7, in which only S was added to the soft magnetic alloy powder of sample No. 1, had a higher HcJ than the soft magnetic alloy powder of sample No. 1 by the addition of S. Also, as in sample No. 1, μ of the toroidal core is low.

The soft magnetic alloy powders of sample nos. 2 to 4, in which only C was added to the soft magnetic alloy powder of sample No. 1, had a lower HcJ and a lower σ than the soft magnetic alloy powder of sample No. 1. Also, μ of the toroidal core is reduced as compared with sample No. 1.

The soft magnetic alloy powders of sample nos. 8 to 12, in which S was added to the soft magnetic alloy powder of sample No. 2 within a specific range, were excellent in HcJ and σ. In addition, the μ of the toroidal core using the soft magnetic alloy powder is also good. In sample No. 13 in which the content (f) of S was too large, the soft magnetic alloy powder included crystals having a crystal grain size of 100nm or more, and the amorphization rate X was less than 85%. Also, HcJ rises significantly. In addition, μ of the toroidal core is also low.

Sample nos. 14 to 17 are soft magnetic alloy powders of comparative examples in which M, Si and S are not contained and the content (C) of P and the content (e) of C are varied. Samples 14 to 17 had a low σ and a low μ. Further, HcJ of sample No. 17 having a large C content also increased.

Sample numbers 18 to 21 are the soft magnetic alloy powders of examples having compositions in which the content (f) of S is changed from 0 to 0.0010 with respect to sample numbers 14 to 17, and HcJ and σ are good. In addition, the μ of the toroidal core using the soft magnetic alloy powder is also good.

Sample nos. 22 to 24 are soft magnetic alloy powders of comparative examples having compositions in which M, P and S are not contained and the content (B) of B, the content (d) of Si, and the content (e) of C are varied. Samples 22 to 24 had a low σ and a low μ.

Sample numbers 25 to 27 are the soft magnetic alloy powders of examples having compositions in which the content (f) of S is changed from 0 to 0.0010 with respect to sample numbers 22 to 24, and HcJ and σ are good. Also, μ of the toroidal core using the soft magnetic alloy powder is good.

The Bs are smaller in each of examples in sample No. 25 to 27 than in each of examples in sample No. 8 to 12 and 18 to 21. This is because the content of Fe is small.

Unlike the above examples, sample numbers 28 to 30 and 28a to 28d are soft magnetic alloy powders of examples including Nb as M. In the same manner as in the example containing no M, HcJ and σ were good. In addition, Bs were good for the embodiment satisfying 0. ltoreq. a <0.020 compared to the embodiment satisfying a. gtoreq.0.020. In addition, the μ of the toroidal core using the soft magnetic alloy powder is also good.

In addition, the average circularity of 25 μm to 30 μm in terms of the number-based particle diameter and the average circularity of 5 μm to 10 μm in terms of the number-based particle diameter were calculated in the same manner for each example of experimental example 1. As a result, in all examples, the average circularity of 25 μm to 30 μm in terms of particle size by number was 0.70 or more, and the average circularity of 5 μm to 10 μm in terms of particle size by number was 0.90 or more.

(Experimental example 2)

In experimental example 2, the same procedure as in experimental example 1 was carried out except that the atomization method was changed from the water atomization method to the gas atomization method and the conditions of the sieve classification were changed. The atomizing device shown in fig. 6A and 6B is used.

Ingots of various materials were prepared and weighed so as to obtain a master alloy having a composition shown in table 2 below.

Next, the master alloy is accommodated in the heat-resistant container 22 disposed in the atomizing device 10. Next, after the inside of the cylindrical body 32 was evacuated, the heat-resistant container 22 was heated by high-frequency induction using the heating coil 24 provided outside the heat-resistant container 22, and the raw material metals in the heat-resistant container 22 were melted and mixed to obtain a molten metal (melt) at 1500 ℃.

The obtained melt was jetted at 1500 ℃ into the cylinder 32 of the cooling section 30, and argon gas was jetted at a jet pressure of 7MPa to form a plurality of droplets. The droplets hit an inverted conical cooling water flow formed by cooling water supplied at a pump pressure (coolant release pressure) of 10MPa, and are collected as fine powder. The pressure of the cylinder 32 was set to 0.5 MPa.

In the atomizing device 10 shown in FIG. 6, the inner diameter of the inner surface of the cylinder 32 is 300mm, D1/D2 is 1/2, and the angle θ 1 is 20 degrees.

The obtained soft magnetic alloy powders were subjected to sieve classification. The conditions for the sieve classification were set to 0.05kg of the feed amount per one time and 5 minutes of the classification time. The mesh size was set to a mesh pitch of 63 μm.

In Experimental example 2, unlike in Experimental example 1, D50(r) was 22 to 27 μm on a volume basis and D50 was 8 to 9 μm on a number basis. In experimental example 2, in all of the examples and comparative examples, the average circularity of the particle diameter of r or more and 2r or less on a number basis was 0.90 or more. In experiment example 2, σ is preferably 7.0 μm or more. The toroidal core has a magnetic permeability μ of 33 or more. The results are shown in Table 2.

[ Table 2]

According to table 2, in all examples and comparative examples, the average circularity of the particle diameter of r or more and 2r or less on a number basis was 0.90 or more.

According to table 2, the soft magnetic alloy powder of sample No. 31, which is a comparative example containing no C and S, has a high HcJ and a low σ. Also, μ of the toroidal core is low.

The soft magnetic alloy powders of sample nos. 35 to 37, in which only S was added to the soft magnetic alloy powder of sample No. 31, had a higher HcJ than the soft magnetic alloy powder of sample No. 31 due to the addition of S. Also, as with sample number 31, μ of the toroidal core is low.

The soft magnetic alloy powders of sample nos. 32 to 34, in which only C was added to the soft magnetic alloy powder of sample No. 31, had a lower HcJ and a lower σ than the soft magnetic alloy powder of sample No. 31. Also, μ of the toroidal core was decreased as compared with sample number 31.

The soft magnetic alloy powders of sample nos. 38 to 42, in which S was added to the soft magnetic alloy powder of sample No. 32 within a specific range, were good in HcJ and σ. In addition, the μ of the toroidal core using the soft magnetic alloy powder is also good. In sample No. 43 in which the content (f) of S was too large, the soft magnetic alloy powder consisted of crystals having a crystal grain size of 100nm or more, and HcJ was significantly increased. In addition, μ of the toroidal core is also low.

Sample nos. 44 to 47 are soft magnetic alloy powders of comparative examples in which M, Si and S are not contained and the content of P (C) and the content of C (e) are varied. Samples 44 to 47 had a low σ and a low μ. Further, HcJ of sample No. 47 having a large C content also increased.

Sample numbers 48 to 51 are soft magnetic alloy powders of examples having compositions in which the content (f) of S is changed from 0 to 0.0010 with respect to sample numbers 44 to 47, and HcJ and σ are good. In addition, the μ of the toroidal core using the soft magnetic alloy powder is also good.

Sample numbers 52 to 54 are soft magnetic alloy powders of comparative examples having compositions in which the content (B) of B, the content (d) of Si, and the content (e) of C were varied without containing M, P and S. Samples 52 to 54 had a low σ and a low μ.

Sample numbers 55 to 57 are soft magnetic alloy powders of examples having compositions in which the content (f) of S is changed from 0 to 0.0010 with respect to sample numbers 52 to 54, and HcJ and σ are good. In addition, the μ of the toroidal core using the soft magnetic alloy powder is also good.

The Bs are smaller in the examples of sample No. 55 to 57 than in the examples of sample No. 38 to 42 and 48 to 51. This is because the content of Fe is small.

Unlike the above examples, sample numbers 58 to 60 and 58a to 58d are soft magnetic alloy powders of examples including Nb as M. In the same manner as in the example containing no M, HcJ and σ were good. In addition, Bs were good for the embodiment satisfying 0. ltoreq. a <0.020 compared to the embodiment satisfying a. gtoreq.0.020. In addition, the μ of the toroidal core using the soft magnetic alloy powder is also good.

Sample numbers 60a and 60b are soft magnetic alloy powders of examples having compositions in which the Fe content is higher than that of sample numbers 31 to 60. HcJ and σ were good even if the Fe content was increased. In addition, the μ of the toroidal core using the soft magnetic alloy powder is also good.

In addition, various soft magnetic alloy powders of sample numbers 61 to 70 were produced under the same conditions as sample number 58 except that the type of M was changed. In addition, various soft magnetic alloy powders of sample numbers 61b to 70b were produced under the same conditions as sample number 58b except that the type of M was changed. The results are shown in Table 3.

[ Table 3]

According to table 3, the test results of sample numbers 61 to 70 in which the type of M was changed were as good as the test results of sample number 58. The test results of sample numbers 61b to 70b were as good as those of sample number 58 b.

(Experimental example 3)

In experimental example 3, a soft magnetic alloy powder of sample number 71 was produced which satisfied a ═ 0.000, b ═ 0.120, c ═ 0.090, d ═ 0.030, e ═ 0.010, f ═ 0.0010, and α ═ β ═ 0. Further, sample numbers 72 to 125 were carried out in which the type and content of X1 and/or X2 were appropriately changed from sample number 71. The conditions for producing the soft magnetic alloy powder of experimental example 3 were the same as those of experimental example 2 except for the composition of the soft magnetic alloy powder. The results are shown in Table 4.

[ Table 4]

According to table 4, the soft magnetic alloy powders of sample nos. 71 to 125 having compositions within the range of the present invention have suitable HcJ, Bs and σ. In addition, the μ of the toroidal core using the soft magnetic alloy powder is also good.

(Experimental example 4)

In example 4, soft magnetic alloy powders of sample numbers 126 to 128 were produced under the same conditions as in experimental example 3, except that the average circularity based on the number of soft magnetic alloy powders was changed by changing the amount of powder charged per pass of the sieve classification for sample number 71. The results are shown in Table 5. Table 5 also shows specific numerical values of the average circularity of 25 μm to 30 μm in terms of particle size on a number basis.

In addition, in experimental example 4, the magnetic permeability and withstand voltage characteristics of the toroidal core were measured. In the measurement of the withstand voltage, first, In — Ga electrodes were formed on both surfaces perpendicular to the thickness direction of the toroidal core. Next, a voltage was applied using a Source Meter (Source Meter), and the voltage when a current of 1mA flowed was measured. Then, the withstand voltage characteristics were measured by dividing the voltage by the thickness of the toroidal core.

[ Table 5]

According to table 5, the soft magnetic alloy powders of sample nos. 126 to 128, in which the average circularity of the soft magnetic alloy powder was changed, had appropriate HcJ and σ as in sample No. 71. In addition, the μ of the toroidal core using the soft magnetic alloy powder is also good.

Further, the higher the withstand voltage characteristics of the toroidal core, the higher the average circularity of r or more and 2r or less and the average circularity of 25 μm or more and 30 μm or less, the better the withstand voltage characteristics tend to be.

(Experimental example 5)

In example 5, soft magnetic alloy powders of sample nos. 130 to 136 were produced under the same conditions as in experimental example 1, except that the average circularity of the soft magnetic alloy powder was changed by changing the powder feeding amount and the classification time for each round of the sieve classification for sample No. 8. In addition, the permeability and withstand voltage characteristics of the toroidal core using the soft magnetic alloy powder of each sample were measured in the same manner as in experimental example 4. The results are shown in Table 6. Table 6 also shows specific numerical values of the average circularity of 25 μm to 30 μm in terms of particle size on a number basis and the average circularity of 5 μm to 10 μm in terms of particle size on a number basis.

[ Table 6]

According to table 6, the soft magnetic alloy powders of sample nos. 8 and 130 to 136, in which the average circularity of the soft magnetic alloy powder was changed, had appropriate HcJ and σ as in the examples of experimental example 1. In addition, the μ of the toroidal core using the soft magnetic alloy powder is also good.

Further, the higher the withstand voltage characteristics of the toroidal core, the higher the average circularity of r or more and 2r or less and the average circularity of 25 μm or more and 30 μm or less, the better the withstand voltage characteristics tend to be.

(Experimental example 6)

In experimental example 6, six kinds of samples a to F having different particle sizes and shapes were prepared by changing the injection pressure of the gas spraying method in the range of 2MPa to 15 MPa. Sample numbers 71, 137, and 138 were prepared by blending samples a to F. Samples 137 and 138 were samples in which the average circularity of all the particles contained in the soft magnetic alloy powder was changed while the average circularity of r or more and 2r or less on a number basis and the average circularity of 25 μm or more and 30 μm or less on a number basis were set to values similar to sample 71. The jet gas pressures of the samples a to F, D50 by number, and the average circularities of all particles are shown in table 7B. The compounding ratios (mass ratios) of samples a to F are shown in table 7C. Sample C was the same as sample No. 71, and the production conditions for the gas spraying method for samples a to F except for the jet gas pressure were the same as sample No. 71. The permeability and withstand voltage characteristics of the toroidal core using the soft magnetic alloy powder of each sample were measured. The results are shown in Table 7A.

[ Table 7A ]

[ Table 7B ]

[ Table 7C ]

From table 7A, it can be confirmed that: even if the average circularity of all the particles changes, good results can be obtained as before the change if the composition, the average circularity of the particle size on a number basis of r to 2r, and the average circularity of the particle size on a number basis of 25 to 30 μm are shown to be as high as before the change.

(Experimental example 7)

In experimental example 7, soft magnetic alloy powders of sample numbers 139, 139a, 140 and 140a were produced under the same conditions except that the content (c) of P and the content (d) of Si were appropriately changed from sample number 71. The results are shown in Table 8.

[ Table 8]

According to table 8, sample numbers 71, 139a, and 140a satisfying 0.080< d <0.100 showed a decrease in HcJ as compared with sample numbers 139 and 140 not satisfying 0.080< d <0.100, and the results were good HcJ.

(Experimental example 8)

In experimental example 8, soft magnetic alloy powders of sample numbers 141a, 141 to 143 were produced under the same conditions except that the content (B) of B and the content (C) of C were appropriately changed from sample number 71. The results are shown in Table 9.

[ Table 9]

According to Table 9, the sample numbers 71, 141a, 141, and 142 satisfying 0.0001. ltoreq. e + f. ltoreq.0.051 exhibited a larger σ and a larger magnetic permeability μ of the toroidal core than the sample number 143 not satisfying 0.0001. ltoreq. e + f. ltoreq.0.051.

According to Table 9, the permeability μ of the toroidal core was increased in the sample numbers 141a and 142 satisfying 0.030< e.ltoreq.0.050 as compared with the sample numbers 71, 141, and 143 not satisfying 0.030< e.ltoreq.0.050.

(Experimental example 9)

In experimental example 9, the soft magnetic alloy powder of sample No. 142 was prepared by heat-treating the soft magnetic alloy powder of sample No. 59 to deposit nano crystals of the soft magnetic alloy. The heat treatment conditions were set at 520 ℃ for 60 minutes. In addition, it was confirmed by XRD that: nanocrystalline particles having a crystal grain size of 30nm or less and a body-centered cubic (bcc) crystal structure are precipitated in the soft magnetic alloy powder of sample 151, and the soft magnetic alloy powder of sample 151 has an amorphization ratio X (%) of 85% or more. The results are shown in Table 10.

[ Table 10]

According to table 10, HcJ of sample number 151 in which nanocrystalline particles were precipitated by heat treatment was lower than that of sample number 59 before heat treatment, and magnetic permeability μ of the toroidal core was higher.

[ description of the drawings ]

1 … … measurement results of particle shape

10 … … atomizing device

20 … … molten metal supply part

21 … … molten metal

21a … … dropping molten metal

30 … … cooling part

36 … … coolant inlet

38a1 … … convex part

50 … … flow of liquid coolant