JP2020180374A - Soft magnetic alloy powder, dust core, magnetic component and electronic apparatus - Google Patents

Abstract

To provide a soft magnetic alloy powder having a low coercive force capable of obtaining a dust core having a high magnetic permeability.SOLUTION: There is provided a soft magnetic alloy powder composed of a composition formula (Fe(1-(α+β))X1αX2β)(1-(a+b+c+d+e+f))MaBbPcSidCeSf, wherein X1 is one or more selected from the group consisting of Co and Ni, X2 is one or more selected from the group consisting of Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Cr, Bi, N, O and rare earth elements and M is one or more selected from the group consisting of Nb, Hf, Zr, Ta, Mo, W, Ti and V. The content of each component is within a specific range. The rate of the amorphization X (%) is 85% or more.SELECTED DRAWING: Figure 1

Description

The present invention relates to soft magnetic alloy powders, powder magnetic cores, magnetic parts and electronic devices.

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

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 a Fe—Ni alloy magnetic powder is coated with a thermosetting resin. There is.

Japanese Unexamined Patent Publication No. 2004-197218 Japanese Unexamined Patent Publication No. 2004-363466

An object of the present invention is to provide a soft magnetic alloy powder having a low coercive force and capable of obtaining a powder magnetic core having a high magnetic permeability.

In order to achieve the above object, the soft magnetic alloy powder of the present invention is used.
Composition formula (Fe _{(1- (α + β))} X1 _α X2 _β ) _{(1- (a + b + c + d + e + f)) A} soft magnetic alloy powder composed of M _a B _b P _c S _d C _e S _f .
X1 is one or more selected from the group consisting of Co and Ni,
X2 is one or more selected from the group consisting of Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Cr, Bi, N, O and rare earth elements.
M is one or more selected from the group consisting of 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
And
The amorphization rate X (%) represented by the following formula (1) is 85% or more.
X = 100- (Ic / (Ic + Ia)) x 100 ... (1)
Ic: Crystalline scattering integral strength Ia: Amorphous scattering integral strength

The soft magnetic alloy powder of the present invention has the above-mentioned characteristics, so that the coercive force HcJ is sufficiently low. Further, a powder magnetic core having a high magnetic permeability can be obtained by using the soft magnetic alloy powder of the present invention.

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

In the soft magnetic alloy powder of the present invention, the average circularity of the soft magnetic alloy powder having a particle size of r or more and 2r or less may be 0.90 or more, where D50 in the particle size distribution on a volume basis is r.

The soft magnetic alloy powder of the present invention may have an average circularity of 0.70 or more of the soft magnetic alloy powder having a particle size of 25 μm or more and 30 μm or less.

The soft magnetic alloy powder of the present invention may have an average circularity of 0.90 or more of the soft magnetic alloy powder having a particle size of 25 μm or more and 30 μm or less.

The soft magnetic alloy powder of the present invention may have an average circularity of 0.70 or more of the soft magnetic alloy powder having a particle size of 5 μm or more and 10 μm or less.

The soft magnetic alloy powder of the present invention may have an average circularity of 0.90 or more of the soft magnetic alloy powder having a particle size of 5 μm or more and 10 μm or less.

0.0001 ≦ e + f ≦ 0.051 may be set.

It may be 0.080 <d <0.100.

It may be 0.030 <e ≦ 0.050.

0 ≦ a <0.020 may be satisfied.

The soft magnetic alloy powder of the present invention may contain nanocrystal particles.

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

The magnetic component of the present invention includes the above-mentioned soft magnetic alloy powder.

The electronic device of the present invention contains the above-mentioned soft magnetic alloy powder.

FIG. 1 is an example of a chart obtained by X-ray crystal structure analysis. FIG. 2 is an example of a pattern obtained by profile fitting the chart of FIG. FIG. 3 is a graph showing the particle size distribution. FIG. 4 is a graph showing the particle size distribution. FIG. 5 shows the observation results by the mophorogi G3. FIG. 6A is a schematic view of the atomizing device. FIG. 6B is an enlarged schematic view of a main part of FIG. 6A.

Hereinafter, embodiments of the present invention will be described.

In order to achieve the above object, the soft magnetic alloy powder according to this embodiment is
Composition formula (Fe _{(1- (α + β))} X1 _α X2 _β ) _{(1- (a + b + c + d + e + f)) A} soft magnetic alloy powder composed of M _a B _b P _c S _d C _e S _f .
X1 is one or more selected from the group consisting of Co and Ni,
X2 is one or more selected from the group consisting of Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Cr, Bi, N, O and rare earth elements.
M is one or more selected from the group consisting of 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
And
The amorphization rate X (%) represented by the following formula (1) is 85% or more.
X = 100- (Ic / (Ic + Ia)) x 100 ... (1)
Ic: Crystalline scattering integral strength Ia: Amorphous scattering integral strength

The soft magnetic alloy powder according to the present embodiment has the above-mentioned characteristics, so that the coercive force HcJ is sufficiently low. Furthermore, it tends to have a broad particle size distribution. As a result, a powder magnetic core having a high magnetic permeability μ can be obtained by using the soft magnetic alloy powder of the present embodiment. Further, the average circularity of the soft magnetic alloy powder having a particle size within a specific range is increased. As a result, a soft magnetic alloy powder having even better HcJ can be obtained. Then, a powder magnetic core or the like having a higher magnetic permeability μ can be obtained.

Hereinafter, each component of the soft magnetic alloy powder according to the present embodiment will be described in detail.

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

The content (a) of M satisfies 0 ≦ a ≦ 0.150. That is, the soft magnetic alloy powder according to this embodiment does not have to contain M. From the viewpoint of lowering HcJ, it is preferable to satisfy 0 ≦ a ≦ 0.070. As a increases, the saturation magnetization tends to decrease.

It is more preferable to satisfy 0 ≦ a <0.020. 0 ≦ a ≦ 0.019 may be satisfied. When a is within the above numerical range, the saturation magnetization can be further improved.

The content (b) of B satisfies 0 ≦ b ≦ 0.200. That is, the soft magnetic alloy powder according to this embodiment does not have to contain B. Further, 0.060 ≦ b ≦ 0.200 may be satisfied. If b is too large, the saturation magnetization tends to decrease.

The content (c) of P satisfies 0 ≦ c ≦ 0.200. That is, the soft magnetic alloy powder according to this embodiment does not have to contain P. Further, 0 ≦ c ≦ 0.150 may be set. When c is too large, the saturation magnetization tends to decrease as in the case where b is too large.

The Si content (d) satisfies 0 ≦ d ≦ 0.200. That is, the soft magnetic alloy powder according to this embodiment does not have to contain Si. It may be 0.080 <d <0.100, or 0.085 ≦ d ≦ 0.095. If d is too large, the circularity of the soft magnetic alloy powder tends to decrease.

The content (e) of C satisfies 0 <e ≦ 0.200. That is, the soft magnetic alloy powder according to this embodiment always contains C. Further, 0.001 ≦ e ≦ 0.150 may be set, and 0.030 <e ≦ 0.050 may be set. Since the soft magnetic alloy powder according to the present embodiment contains C, HcJ tends to be small. When e is too large, the saturation magnetization tends to decrease as in the case where b is too large and c is too large.

The content (f) of S satisfies 0 <f ≦ 0.0200. That is, the soft magnetic alloy powder according to this embodiment always contains S. Further, 0.0001 ≦ f ≦ 0.0200 may be satisfied. Since the soft magnetic alloy powder according to the present embodiment contains S, it tends to have a broad particle size distribution, and the magnetic permeability μ of the dust core or the like produced by using the soft magnetic alloy powder tends to increase. However, when the soft magnetic alloy powder according to the present embodiment contains S instead of C, HcJ becomes too large. In addition, the magnetic permeability μ of the dust core or the like tends to decrease. When f is too large, the soft magnetic alloy powder tends to contain crystals having a crystal grain size of more than 100 nm. When the soft magnetic alloy powder contains crystals having a crystal particle size of more than 100 nm, HcJ increases remarkably, and the magnetic permeability μ of the dust core or the like using the soft magnetic alloy powder tends to decrease.

Further, the soft magnetic alloy powder according to the present embodiment satisfies 0.100 ≦ a + b + c + d + e ≦ 0.300. Further, 0.240 ≦ a + b + c + d + e ≦ 0.300 may be set. When a + b + c + d + e is within the above range, various characteristics can be easily improved. If a + b + c + d + e is too small, the soft magnetic alloy powder tends to become crystals containing crystals having a crystal grain size of more than 100 nm. If a + b + c + d + e is too large, the saturation magnetization tends to decrease.

Further, the soft magnetic alloy powder according to the present embodiment satisfies 0.0001 ≦ e + f ≦ 0.220. 0.0001 ≦ e + f ≦ 0.051 may be set. When e + f is within the above range, various characteristics can be easily improved.

From the above, when only C is contained and S is not contained among C and S, the particle size distribution of the soft magnetic alloy powder becomes sharp. As a result, although HcJ is improved, the magnetic permeability μ of the dust core or the like using the soft magnetic alloy powder is not improved. Of C and S, when only S is contained and C is not contained, HcJ deteriorates, and the effect of improving the magnetic permeability μ of the dust core or the like using the soft magnetic alloy powder is small. Further, when e + f is too large even though both C and S are contained, the soft magnetic alloy powder tends to be a crystal containing 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 ≦ 1- (a + b + c + d + e + f) ≦ 0.8999. By setting 1- (a + b + c + d + e + f) within the above range, the soft magnetic alloy powder is less likely to contain crystals having a crystal grain size of more than 100 nm. Further, the Fe content (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, the saturation magnetization tends to increase.

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

X1 is one or more selected from the group consisting of Co and Ni. The content of X1 may be α = 0. That is, X1 does not have to be contained. Further, the number of atoms of X1 may be 40 at% or less, assuming that the number of atoms in the entire composition is 100 at%. That is, 0 ≦ α {1- (a + b + c + d + e + f)} ≦ 0.400 may be satisfied.

X2 is one or more selected from the group consisting of Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Cr, Bi, N, O and rare earth elements. Further, from the viewpoint of lowering HcJ in particular, X2 may be one or more selected from the group consisting of Al, Zn, Sn, Cu, Cr and Bi. Regarding the content of X2, β = 0 may be used. That is, X2 does not have to be contained. Further, the number of atoms of X2 may be 3.0 at% or less, assuming that the number of atoms in the entire composition is 100 at%. That is, 0 ≦ β {1- (a + b + c + d + e + f)} ≦ 0.030 may be satisfied.

The range of the substitution amount for substituting Fe with X1 and / or X2 is half or less of Fe on the basis of the number of atoms. That is, 0 ≦ α + β ≦ 0.50.

The soft magnetic alloy powder of the present embodiment may contain elements other than the above as unavoidable impurities. For example, it may be contained in an amount of 0.1% by weight or less with respect to 100% by weight of the soft magnetic alloy powder.

Further, the soft magnetic alloy powder of the present embodiment has a structure made of amorphous material. Specifically, the amorphization rate X represented by the following formula (1) is 85% or more.
X = 100- (Ic / (Ic + Ia) x 100) ... (1)
Ic: Crystalline scattering integral strength Ia: Amorphous scattering integral strength

The soft magnetic alloy powder having a high amorphization rate X has a small crystal magnetic anisotropy. Therefore, the powder magnetic core using the soft magnetic alloy powder having a high amorphization rate X has a small magnetic loss.

The amorphization rate X is determined by performing X-ray crystal structure analysis on the soft magnetic alloy powder by XRD, identifying the phase, and peaking the crystallized Fe or compound (Ic: crystalline scattering integral intensity, Ia). : Amorphous scattering integrated intensity) is read, the crystallinity is calculated from the peak intensity, and calculated by the above equation (1). Hereinafter, the calculation method will be described in more detail.

The soft magnetic alloy powder according to the present embodiment is subjected to X-ray crystal structure analysis by XRD to obtain a chart as shown in FIG. This is profile-fitted using the Lorentz function of the following equation (2), and the crystal component pattern α _c showing the crystalline scattering integral strength and the amorphous scattering integral strength as shown in FIG. 2 are shown. A component pattern α _a and _a combined pattern α _{c + a} are obtained. From the crystalline scattering integral intensity and the amorphous scattering integral intensity of the obtained pattern, the amorphization rate X is obtained by the above formula (1). The measurement range is a diffraction angle of 2θ = 30 ° to 60 ° at which an amorphous halo can be confirmed. Within this range, the error between the integrated intensity actually measured by XRD and the integrated intensity calculated by using the Lorentz function should be within 1%.

The soft magnetic alloy powder of the present embodiment may contain nanocrystal particles as long as the amorphization rate X (%) is 85% or more. The nanocrystal particles are particles containing nanocrystals having a crystal grain size of 50 nm or less. Further, it can be confirmed by XRD whether or not the soft magnetic alloy powder contains nanocrystal particles. When the soft magnetic alloy powder contains nanocrystal particles, HcJ is likely to be further lowered, and the magnetic permeability μ of the dust core or the like using the soft magnetic alloy powder is likely to increase.

It should be noted that the nanocrystal particles usually include a large number of nanocrystals. That is, the particle size of the soft magnetic alloy powder described later and the crystal grain size of the nanocrystals are different.

Further, the soft magnetic alloy powder of the present embodiment may be a soft magnetic alloy powder having a high sphericality. By having the above composition, it is possible to obtain a soft magnetic alloy powder having a particle shape close to a sphere, that is, a soft magnetic alloy powder having a high degree of sphericity.

In general, the higher the amorphization rate X of the soft magnetic alloy powder, the less likely it is that plastic deformation will occur. Therefore, the filling rate is less likely to increase during molding of the dust core or the like. By making the particle shape of the soft magnetic alloy powder close to a sphere, the filling rate of the dust core or the like using the soft magnetic alloy powder can be increased, and various characteristics such as coercive force HcJ and magnetic permeability μ are improved. Can be made to.

Further, the soft magnetic alloy powder of the present embodiment preferably has a large particle size and a high sphericality. Since the sphericity of the powder having a large particle size is high, it is possible to further increase the filling rate of the dust core or the like using the soft magnetic alloy powder, and the magnetic permeability μ is likely to increase.

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

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

Generally, there are a volume standard and a number standard as a standard for the particle size distribution of the soft magnetic alloy powder. The volume-based particle size distribution is represented by a graph in which the horizontal axis is the particle diameter and the vertical axis is the frequency based on the volume. The particle size distribution based on the number is represented by a graph in which the horizontal axis is the particle size and the vertical axis is the frequency based on the number. When both are overlapped, a graph as shown in FIG. 3 is obtained, for example. The solid line is the particle size distribution based on the volume, and the broken line is the particle size distribution based on the number. The positions of r and 2r are shown in FIG. 3, where D50 of the particle diameter on a volume basis is r.

The difference between the volume-based particle size distribution and the number-based particle size distribution depends on the degree to which each particle is reflected in the data. On a volume basis, the degree to which each particle is reflected in the data is proportional to its volume. That is, the degree to which small particles are reflected in the data is reduced. On the other hand, in the number standard, the degree to which each particle is reflected in the data is the same. That is, the degree to which small particles are reflected in the data increases. Therefore, the above-mentioned difference in particle size distribution occurs.

As described above, the soft magnetic alloy powder of the present embodiment preferably has a large particle size and a high sphericality. Specifically, the average circularity of particles having a particle diameter of r or more and 2r or less based on the number of particles may be 0.70 or more, or 0.90 or more. Further, the content ratio based on the number of particles having a particle diameter of r or more and 2r or less with respect to the entire soft magnetic alloy powder may be 1% or more and 25% or less. FIG. 4 shows an excerpt of only the particle size distribution of the portion where the particle size is r or more and 2r or less from the particle size distribution based on the number.

In the soft magnetic alloy powder of the present embodiment, the average circularity of the particles having a particle diameter of 25 μm or more and 30 μm or less based on the number of particles may be 0.70 or more, or 0.90 or more. In this case, the particle size D50 based on the number may be 0.5 μm or more and 25 μm or less. Further, the content ratio based on the number of particles having a particle diameter of 25 μm or more and 30 μm or less with respect to the entire soft magnetic alloy powder may be 0.1% or more and 10% or less.

In the soft magnetic alloy powder of the present embodiment, the average circularity of the particles having a particle diameter of 5 μm or more and 10 μm or less based on the number of particles may be 0.70 or more, or 0.90 or more. In this case, the particle size D50 based on the number of particles may be 0.5 μm or more and 5 μm or less. Further, the content ratio based on the number of particles having a particle diameter of 5 μm or more and 10 μm or less with respect to the entire soft magnetic alloy powder may be 0.1% or more and 10% or less.

In the present embodiment, there is no particular limitation on the method for evaluating the particle size distribution and the particle size D50 (r) on a volume basis. For example, it can be evaluated by a laser diffraction type particle size distribution measuring device using Franhofer's diffraction theory.

In the present embodiment, the particle size distribution based on the number of pieces is evaluated using Mophoroggi G3 (Malburn Panatic). Moforogi G3 is a device capable of dispersing powder with air, projecting individual particle shapes, and evaluating them. It is possible to evaluate the particle shape having a particle diameter in the range of about 0.5 μm to several mm with an optical microscope or a laser microscope. Specifically, as can be seen from the particle shape measurement result 1 shown in FIG. 5, a large number of particle shapes can be projected and evaluated at once. However, in reality, a much larger number of particle shapes than those shown in the particle shape measurement result 1 shown in FIG. 5 can be projected and evaluated at one time.

Since the morphologi G3 can prepare and evaluate a projection drawing of a large number of particles at one time, it is possible to evaluate the shape of a large number of particles in a short time as compared with the evaluation method by conventional SEM observation or the like. For example, in the example described later, a projection drawing is created for 20000 particles, the particle size and circularity of each particle are automatically calculated, and the average circularity of particles whose particle size is within a specific range is calculated. ing. On the other hand, in the conventional SEM observation, since the circularity is calculated for each particle using the SEM image, it is difficult to evaluate the shape of a large number of particles in a short time.

The circularity of a particle is represented by 4πS / L ^2, where S is the area in the projection drawing and L is the peripheral length in the projection drawing. The circularity of the circle is 1, and the closer the circularity of the projection drawing of the particles is to 1, the higher the sphericity of the particles.

Further, 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 based on the number.

In addition, when evaluating various particle size distributions of the soft magnetic alloy powder contained in the dust core or the like, a conventional method by SEM observation can be used. The particle diameter and circularity may be calculated and evaluated from the SEM image for each particle contained in an arbitrary cross section such as a dust core.

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

Then, the present inventors have found that HcJ of the entire soft magnetic alloy powder is suitable, and the magnetic permeability μ in a dust core or the like using the soft magnetic alloy powder having a broad particle size distribution is good.

Further, in order to further improve the magnetic permeability μ and withstand voltage characteristics of the HcJ of the entire soft magnetic alloy powder and the powder magnetic core using the soft magnetic alloy powder, the sphericality of the soft magnetic alloy powder having a large particle size The present inventors have found that controlling the spheroidity of the soft magnetic alloy powder as a whole is more important than controlling the spheroidity. Specifically, the higher the average circularity of particles having a particle size of r or more and 2r or less based on the number of particles and the average circularity of particles having a particle size of 25 μm or more and 30 μm or less based on the number of particles, the greater the magnetic permeability μ and the withstand voltage. The characteristics tend to be good.

The sphericality of the soft magnetic alloy powder as a whole can also be changed by controlling the manufacturing method. However, even if only the manufacturing method is controlled, the soft magnetic alloy powder having a large particle size is less likely to change the sphericity than the soft magnetic alloy powder having a small particle size. That is, in order to control the sphericity of the soft magnetic alloy powder having a large particle size, it is important to control the composition of the soft magnetic alloy powder and make it easy to change the particle shape of the entire soft magnetic powder by the manufacturing method. I found that.

Here, consider a soft magnetic alloy powder having a small particle size and a soft magnetic alloy powder having a large particle size, which are the same total volume ratio with respect to the volume distribution of the entire soft magnetic alloy powder. If the total volume ratio is the same as each other, the soft magnetic alloy powder having a small particle size has a much larger number of particles than the soft magnetic alloy powder having a large particle size. For example, if the total volume ratio is the same as each other, the number of particles in the soft magnetic alloy powder having a particle diameter of 10 μm is about 1/1000 of the number of particles in the soft magnetic alloy powder particles having a particle diameter of 1 μm.

That is, the influence of the sphericity of the entire soft magnetic alloy powder on the sphericity of the soft magnetic alloy powder having a large particle size and a small number of particles is small. Then, regardless of the sphericity of the soft magnetic alloy powder having a large particle size, the sphericity of the entire soft magnetic alloy powder can change.

Hereinafter, a method for producing the soft magnetic alloy powder of the present embodiment will be described.

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

Hereinafter, a method for producing a soft magnetic alloy powder by the water atomizing method will be described. First, prepare the raw materials. The raw material to be prepared may be a simple substance such as metal or an alloy. There are no particular restrictions on the form of the raw material. For example, ingots, chunks, or shots (particles).

Next, the prepared raw materials are weighed and mixed. At this time, weigh the powder so that the soft magnetic alloy powder having the desired composition is finally obtained. Then, the mixed raw materials are melted and mixed to obtain a molten metal. There are no particular restrictions on the equipment used for melting and mixing. For example, a crucible or the like is used. The temperature of the molten metal may be determined in consideration of the melting point of each metal element, and can be, for example, 1200 to 1600 ° C.

Then, a soft magnetic alloy powder is produced from the molten metal by a water atomization method. Specifically, a soft magnetic alloy powder can be produced by ejecting molten metal with a nozzle or the like and causing a high-pressure water stream to collide with the ejected molten metal to quench it. The compositions of the molten metal and the soft magnetic alloy powder are substantially the same.

Here, in order to obtain the target particle size of the soft magnetic alloy powder, it is possible to control the particle size by controlling the pressure of the high-pressure water flow, the amount of molten metal ejected, and the like. Then, a soft magnetic alloy powder having a desired particle size distribution can be obtained.

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

Further, the obtained amorphous soft magnetic alloy powder may be heat-treated to precipitate nanocrystal particles on the soft magnetic alloy powder. The conditions of the heat treatment are, for example, 350 ° C. or higher and 800 ° C. or lower for 0.1 minute or longer and 120 minutes or shorter.

Hereinafter, a method for producing a soft magnetic alloy powder by the gas atomizing method will be described.

When the atomizing apparatus shown in FIGS. 6A and 6B is used as the atomizing apparatus, the present inventors can easily produce a soft magnetic alloy powder having a large particle size, and further obtain an amorphous soft magnetic metal powder. It will be easier.

As shown in FIG. 6A, the atomizing device 10 has a molten metal supply unit 20 and a cooling unit 30 arranged below the metal supply unit 20 in the vertical direction. In the drawings, the vertical direction is the direction along the Z axis.

The molten metal supply unit 20 has a heat-resistant container 22 that houses the molten metal 21. In the heat-resistant container 22, the raw materials of each metal element weighed so as to have the composition of the finally obtained soft magnetic alloy powder are melted by the heating coil 24 to become 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 the raw material of each metal element, and may be, for example, 1200 to 1600 ° C.

The molten metal 21 is discharged as the dropped molten metal 21a from the discharge port 23 toward the cooling unit 30. High-pressure gas is injected from the gas injection nozzle 26 toward the discharged molten metal 21a, and the molten metal 21a becomes a large number of droplets and is carried toward the inner surface of the cylinder 32 along the gas flow. ..

The gas injected from the gas injection nozzle 26 is preferably an inert gas or a reducing gas. As the inert gas, for example, nitrogen gas, argon gas, helium gas and the like can be used. As the reducing gas, for example, an ammonia decomposition gas or the like can be used. However, when 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 dripping molten metal 21a carried toward the inner surface of the tubular body 32 collides with the coolant flow 50 formed in an inverted conical shape inside the tubular body 32, and is further divided into fine particles and cooled and solidified. , Becomes a solid alloy powder. The axial center O of the tubular body 32 is inclined at a predetermined angle θ1 with respect to the vertical straight line Z. The predetermined angle θ1 is not particularly limited, but is preferably 0 to 45 degrees. With such an angle range, the dropped molten metal 21a from the discharge port 23 can be easily discharged toward the coolant flow 50 formed in an inverted conical shape inside the tubular body 32.

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

In the present embodiment, since the dropped molten metal 21a collides with the coolant flow 50 formed in an inverted conical shape, the dropped molten metal 21a is compared with the case where the coolant flow is along the inner surface 33 of the cylinder 32. The flight time of the droplets is shortened. When the flight time is shortened, the quenching effect is promoted, and the amorphization rate X of the obtained soft magnetic alloy powder is improved. Further, the sphericality of the soft magnetic alloy powder having a large particle size tends to increase. Further, when the flight time is shortened, the droplets of the dropped molten metal 21a are less likely to be oxidized, so that the obtained soft magnetic alloy powder is miniaturized and the quality of the soft magnetic alloy powder is improved.

In the present embodiment, in the coolant introduction section (coolant lead-out section) 36 for introducing the coolant into the cylinder 32 in order to form the coolant flow in an inverted conical shape inside the cylinder 32. It controls the flow of coolant. FIG. 6B shows the configuration of the coolant introduction unit 36.

As shown in FIG. 6B, the frame body 38 has an outer portion (outer space portion) 44 located on the outer side in the radial direction of the tubular body 32 and an inner portion (inner space portion) located on the inner side in the radial direction of the tubular body 32. ) 46 is specified. The outer portion 44 and the inner portion 46 are partitioned by a partition portion 40, and a passage portion 42 is formed in the upper portion of the partition portion 40 in the axial direction O direction. The outer portion 44 and the inner portion 46 are in contact with each other. The coolant can be distributed.

A single or a plurality of nozzles 37 are connected to the outer portion 44 so that the coolant enters the outer portion 44 from the nozzles 37. Further, a coolant discharging portion 52 is formed below the inner portion 46 in the axial core O direction so that the cooling liquid in the inner portion 46 is discharged (derived out) into the cylinder 32. It has become.

The outer peripheral surface of the frame body 38 is a flow path inner peripheral surface 38b that guides the flow of the coolant in the inner portion 46, and the lower end surface 38a of the frame body 38 is a flow path inner peripheral surface 38b of the frame body 38. An outward convex portion 38a1 is formed which is continuous from the above and projects outward in the radial direction. Therefore, the ring-shaped gap between the tip of the outward convex portion 38a1 and the inner surface 33 of the tubular body 32 becomes the coolant discharge portion 52. A flow path deflection surface 62 is formed on the flow path side upper surface of the outward convex portion 38a1.

As shown in FIG. 6B, the radial width D1 of the coolant discharging portion 52 is narrower than the radial width D2 in the main portion of the inner portion 46 due to the outward convex portion 38a1. Since D1 is narrower than D2, the coolant that descends inside the inner portion 46 along the inner peripheral surface 38b of the flow path below the axis O then flows along the flow path deflection surface 62 of the frame body 38. It flows and collides with the inner surface 33 of the cylinder 32 and is reflected. As a result, as shown in FIG. 6A, the coolant is discharged from the coolant discharge portion 52 into the inside of the cylinder 32 in an inverted conical shape to form the coolant flow 50. When D1 = D2, the coolant discharged from the coolant discharge unit 52 forms a coolant flow along the inner surface 33 of the cylinder 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 from the coolant discharge unit 52 is a reverse conical flow that travels straight from the coolant discharge unit 52 toward the shaft core O, but may be a spiral reverse conical flow.

Further, the ejection 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 target soft magnetic alloy powder. The amount of molten metal ejected may be, for example, 1 kg / min or more and 20 kg / min or less. The gas injection pressure may be, for example, 0.5 MPa or more and 19 MPa or less. The pressure in the cylinder 32 may be, for example, 0.5 MPa or more and 19 MPa or less. The coolant discharge pressure may be, for example, 0.5 MPa or more and 19 MPa or less.

The smaller the amount of molten metal ejected, the smaller the particle size, and there is a tendency that amorphous soft magnetic alloy powder can be easily produced.

The higher the gas injection pressure, the pressure inside the cylinder 32, and the coolant discharge pressure, the smaller the particle diameter and the circularity of the particles tend to be.

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

In the sieve classification, the particle size can be adjusted by changing, for example, the amount of powder charged at one time, the classification time and / or the mesh size. Then, a soft magnetic alloy powder having a desired particle size can be obtained by appropriately controlling the powder charging amount, the classification time and / or the mesh size at one time.

The larger the amount of powder charged at one time, the easier it is for the average circularity of the particles to decrease. The shorter the classification time, the easier it is for the average circularity of the particles to decrease. The larger the mesh size, the easier it is for the average circularity of the particles to decrease.

Another method for adjusting the particle size is to change the number of times the powder is passed through the mesh. Even if the mesh size is the same, it is possible to extract more irregularly shaped particles by increasing the number of times the powder is passed through the mesh. It is also possible to improve the average circularity of the powder by extracting more 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 this embodiment is not particularly limited. For example, a dust core can be mentioned. When the soft magnetic alloy powder according to the present embodiment is used, a suitable magnetic permeability μ can be easily obtained even if the pressure at the time of producing the dust core is relatively low. This is because the broad particle size distribution makes it easier for the powder magnetic core to be obtained to become dense even if the pressure at the time of producing the powder magnetic core is relatively low. Specifically, the pressure at the time of producing the dust core can be, for example, 98 MPa or more and 1500 MPa or less.

Further, the dust core according to the present embodiment can be suitably used as a dust core for an inductor, particularly a power inductor. Further, it can be suitably used for an inductor in which a dust core and a coil portion are integrally molded.

Further, it can be suitably used for magnetic parts using soft magnetic alloy powder, for example, thin film inductors and magnetic heads. Further, a dust core or a magnetic component using the soft magnetic alloy powder can be suitably used for an electronic device.

Hereinafter, the present invention will be specifically described based on Examples.

(Experimental Example 1)
Ingots of various materials were prepared and weighed so that a mother alloy having the composition shown in Table 1 shown below could be obtained. Then, it was housed in a crucible arranged in a water atomizing device. Next, in an inert atmosphere, the crucible was heated to 1500 ° C. by high-frequency induction using a work coil provided outside the crucible, and the ingot in the crucible was melted and mixed to obtain a molten metal (molten metal).

Next, the molten metal in the crucible is ejected from the nozzle provided in the crucible, and at the same time, a high-pressure water stream of 100 MPa is made to collide with the ejected molten metal to quench the mixture. A powder was prepared. Further, it was confirmed by ICP analysis that the composition of the mother alloy and the composition of the soft magnetic alloy powder were almost the same.

Each of the obtained soft magnetic alloy powders was sieve-classified. The conditions for sieving classification were 0.5 kg for each preparation and 1 minute for the classification time. Further, the mesh size was set to 38 μm.

It was confirmed whether each of the obtained soft magnetic alloy powders consisted of amorphous or crystalline. The amorphization rate X of each thin band was measured using XRD, and when X was 85% or more, it was determined to be amorphous. It was considered to consist of crystals when X was less than 85%. The results are shown in Table 1.

HcJ and Bs were measured for each of the obtained soft magnetic alloy powders. HcJ was measured using an Hc meter. The results are shown in Table 1. In Experimental Example 1, HcJ was defined as good at 2.4 Oe or less, and further improved at 1.0 Oe or less. Bs was defined as good at 0.70 T or higher, and further defined as 1.40 T or higher.

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

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

The volume-based D50 (r) was measured using a laser diffraction type particle size distribution measuring device (HELOS & RODOS, Symboltec).

The number-based D50 and σ were measured by observing the shape of 20000 powder particles at a magnification of 10 times using a moforoggi G3 (Malvern PANalytical). Specifically, a soft magnetic alloy powder having a volume of 3 cc was dispersed at an air pressure of 1 to 3 bar, and a projected image was taken with a laser microscope. From the particle size of each powder particle, D50 and σ on a number basis were calculated. The particle size of each powder particle was a circle-equivalent diameter.

In Experimental Example 1, the case where σ was 2.5 μm or more was considered good.

The average circularity of the particle diameter r or more and 2r or less based on the number of particles was calculated by measuring and averaging the circularity of the powder particles having a particle diameter of r or more and 2r or less among 20000 powder particles.

Next, a toroidal core was prepared from each soft magnetic alloy powder. Specifically, each soft magnetic alloy powder is mixed so that the amount of phenol resin serving as an insulating binder is 3% by mass of the whole, and a general planetary mixer as a stirrer is used to mix the granulated powder with a size of about 500 μm. It was granulated so as to be. Next, the obtained granulated powder was molded at a surface pressure of 4 ton / cm ² (392 MPa) to prepare a toroidal molded product having an outer diameter of 13 mmφ, an inner diameter of 8 mmφ, and a height of 6 mm. The obtained molded product was cured at 150 ° C. to prepare a toroidal core.

Then, a UEW wire was wound around the toroidal core, and μ (permeability) was measured at 100 kHz using a 4284A PRECISION LCR METER (Hewlett-Packard). In Experimental Example 1, the case where μ was 25 or more was considered good.

From Table 1, in all the examples and comparative examples, the average circularity at the particle diameter r or more and 2r or less on the basis of the number was 0.70 or more.

From Table 1, the soft magnetic alloy powder of Sample No. 1, which is a comparative example containing no C and S, had a high HcJ and a low σ. And the μ of the toroidal core was also low.

The soft magnetic alloy powders of sample numbers 5 to 7, which are composed by adding only S to the soft magnetic alloy powder of sample number 1, have a higher HcJ due to the addition of S as compared with the soft magnetic alloy powder of sample number 1. became. And, as with sample number 1, μ of the toroidal core was also low.

The soft magnetic alloy powders of sample numbers 2 to 4, which are composed by adding only C to the soft magnetic alloy powder of sample number 1, have lower HcJ but also lower σ than the soft magnetic alloy powder of sample number 1. did. Then, the μ of the toroidal core was also reduced as compared with the sample number 1.

The soft magnetic alloy powders of the examples of Sample Nos. 8 to 12, which had a composition in which S was added to the soft magnetic alloy powder of Sample No. 2 within a specific range, had good HcJ and σ. Further, the μ of the toroidal core using the soft magnetic alloy powder was also good. In Sample No. 13, in which the S content (f) was too large, the soft magnetic alloy powder contained crystals having a crystal grain size of 100 nm or more, and the amorphization rate X was less than 85%. Then, Hcj increased remarkably. The μ of the toroidal core was also low.

Sample numbers 14 to 17 are soft magnetic alloy powders of Comparative Examples in which the P content (c) and the C content (e) were changed without containing M, Si and S. Sample numbers 14 to 17 had a low σ and a low μ of the toroidal core. In addition, HcJ also increased in sample number 17 having a large C content.

Sample numbers 18 to 21 are soft magnetic alloy powders of Examples having a composition 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. Met. Further, the μ of the toroidal core using the soft magnetic alloy powder was also good.

Sample numbers 22 to 24 are comparative examples having a composition in which the content of B (b), the content of Si (d) and the content of C (e) are changed without containing M, P and S. It is a soft magnetic alloy powder. Sample numbers 22 to 24 had a low σ and a low μ of the toroidal core.

Sample numbers 25 to 27 are soft magnetic alloy powders of Examples having a composition 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. Met. Further, the μ of the toroidal core using the soft magnetic alloy powder was also good.

Each of the examples of sample numbers 25 to 27 had a smaller Bs than each of the examples of sample numbers 8 to 12 and 18 to 21. This is because the Fe content is small.

Sample numbers 28 to 30 and 28a to 28d are soft magnetic alloy powders of Examples containing Nb as M, unlike the above Examples. HcJ and σ were good as in the examples not containing M. Further, the Bs of the example satisfying 0 ≦ a <0.020 was better than the Bs of the example satisfying a ≧ 0.020. Further, the μ of the toroidal core using the soft magnetic alloy powder was also good.

For each example of Experimental Example 1, the average circularity when the particle diameter was 25 μm or more and 30 μm or less based on the number, and the average circularity when the particle diameter was 5 μm or more and 10 μm or less based on the number were calculated in the same manner. .. As a result, in all the examples, the average circularity based on the number of particles having a particle diameter of 25 μm or more and 30 μm or less was 0.70 or more, and the average circularity based on the number of particles having a particle diameter of 5 μm or more and 10 μm or less was 0.90. That was all.

(Experimental Example 2)
In Experimental Example 2, the same procedure as in Experimental Example 1 was carried out except that the atomizing method was changed from the water atomizing method to the gas atomizing method and the conditions for sieving classification. The atomizing apparatus shown in FIGS. 6A and 6B was used.

Ingots of various materials were prepared and weighed so that a mother alloy having the composition shown in Table 2 shown below could be obtained.

Next, the mother alloy was housed in a heat-resistant container 22 arranged in the atomizing device 10. Subsequently, after vacuuming the inside of the cylinder 32, the heat-resistant container 22 is heated by high-frequency induction using a heating coil 24 provided outside the heat-resistant container 22, and the raw metal in the heat-resistant container 22 is melted. , And mixed to obtain a molten metal (molten metal) at 1500 ° C.

The obtained molten metal was injected into the cylinder 32 of the cooling unit 30 at 1500 ° C., and argon gas was injected at an injection gas pressure of 7 MPa to obtain a large number of droplets. The droplets collided with the inverted conical cooling water flow formed by the cooling water supplied at a pump pressure (cooling liquid discharge pressure) of 10 MPa to form a fine powder, which was then recovered. The pressure inside the cylinder 32 was 0.5 MPa.

In the atomizing device 10 shown in FIG. 6, the inner diameter of the inner surface of the tubular body 32 was 300 mm, D1 / D2 was 1/2, and the angle θ1 was 20 degrees.

Each of the obtained soft magnetic alloy powders was sieve-classified. The conditions for sieving were such that the amount charged at one time was 0.05 kg and the classification time was 5 minutes. Further, the mesh size was set to 63 μm.

In Experimental Example 2, unlike Experimental Example 1, D50 (r) on a volume basis was 22 to 27 μm, and D50 on a number basis was 8 to 9 μm. Further, in Experimental Example 2, the average circularity of the particle diameter r or more and 2r or less based on the number of particles was 0.90 or more in all Examples and Comparative Examples. Further, in Experimental Example 2, σ was set to be good at 7.0 μm or more. Further, the magnetic permeability μ of the toroidal core was set to 33 or more. The results are shown in Table 2.

From Table 2, in all the examples and comparative examples, the average circularity at the particle diameter r or more and 2r or less on the basis of the number was 0.90 or more.

From Table 2, the soft magnetic alloy powder of sample number 31, which is a comparative example not containing C and S, had a high HcJ and a low σ. And the μ of the toroidal core was also low.

The soft magnetic alloy powder of sample numbers 35 to 37, which has a composition obtained by adding only S to the soft magnetic alloy powder of sample number 31, has a higher HcJ due to the addition of S than the soft magnetic alloy powder of sample number 31. became. And, as with sample number 31, μ of the toroidal core was also low.

The soft magnetic alloy powders of sample numbers 32 to 34, which are composed by adding only C to the soft magnetic alloy powder of sample number 31, have a lower HcJ but a lower σ as compared with the soft magnetic alloy powder of sample number 31. did. Then, the μ of the toroidal core was also reduced as compared with the sample number 31.

The soft magnetic alloy powders of the examples of Sample Nos. 38 to 42, which had a composition in which S was added to the soft magnetic alloy powder of Sample No. 32 within a specific range, had good HcJ and σ. Further, the μ of the toroidal core using the soft magnetic alloy powder was also good. In Sample No. 43 in which the S content (f) was too large, the soft magnetic alloy powder was composed of crystals having a crystal grain size of 100 nm or more, and Hcj was significantly increased. The μ of the toroidal core was also low.

Sample numbers 44 to 47 are soft magnetic alloy powders of Comparative Examples in which the P content (c) and the C content (e) were changed without containing M, Si and S. Sample numbers 44 to 47 had a low σ and a low μ of the toroidal core. In addition, HcJ also increased in sample number 47 having a large C content.

Sample numbers 48 to 51 are soft magnetic alloy powders of Examples having a composition 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. Met. Further, the μ of the toroidal core using the soft magnetic alloy powder was also good.

Sample numbers 52 to 54 are comparative examples having a composition in which the content of B (b), the content of Si (d) and the content of C (e) are changed without containing M, P and S. It is a soft magnetic alloy powder. Sample numbers 52 to 54 had a low σ and a low μ of the toroidal core.

Sample numbers 55 to 57 are soft magnetic alloy powders of Examples having a composition 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. Met. Further, the μ of the toroidal core using the soft magnetic alloy powder was also good.

Each of the examples of sample numbers 55 to 57 had a smaller Bs than each of the examples of sample numbers 38 to 42 and 48 to 51. This is because the Fe content is small.

Sample numbers 58 to 60 and 58a to 58d are soft magnetic alloy powders of Examples containing Nb as M, unlike the above Examples. HcJ and σ were good as in the examples not containing M. Further, the Bs of the example satisfying 0 ≦ a <0.020 was better than the Bs of the example satisfying a ≧ 0.020. Further, the μ of the toroidal core using the soft magnetic alloy powder was also good.

Sample numbers 60a and 60b are soft magnetic alloy powders of Examples having a composition in which the Fe content is higher than that of Sample Nos. 31-60. Even if the Fe content was increased, HcJ and σ were good. Further, the μ of the toroidal core using the soft magnetic alloy powder was also good.

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

From Table 3, sample numbers 61 to 70 in which the type of M was changed gave good test results as good as sample number 58. In addition, sample numbers 61b to 70b gave good test results as good as sample numbers 58b.

(Experimental Example 3)
In Experimental Example 3, a sample number satisfying a = 0.000, b = 0.120, c = 0.090, d = 0.030, e = 0.010, f = 0.0010, α = β = 0. 71 soft magnetic alloy powders were prepared. Further, sample numbers 72 to 125 in which the type and content of X1 and / or X2 were appropriately changed from sample number 71 were carried out. The production conditions of the soft magnetic alloy powder in Experimental Example 3 were the same as those in Experimental Example 2 except for the composition of the soft magnetic alloy powder. The results are shown in Table 4.

From Table 4, the soft magnetic alloy powders of sample numbers 71 to 125 having a composition within the range of the present invention had suitable HcJ, Bs and σ. Further, the μ of the toroidal core using the soft magnetic alloy powder was also good.

(Experimental Example 4)
In Experimental Example 4, the sample was sampled 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 at one time in the sieve classification for sample No. 71. Soft magnetic alloy powders of Nos. 126 to 128 were prepared. The results are shown in Table 5. Table 5 also shows specific numerical values of the average circularity when the particle size is 25 μm or more and 30 μm or less based on the number of particles.

Further, in Experimental Example 4, the withstand voltage characteristics were measured together with the magnetic permeability of the toroidal core. In the measurement of withstand voltage characteristics, first, In-Ga electrodes were formed on two surfaces perpendicular to the thickness direction of the toroidal core. Next, a voltage was applied using a source meter, and the voltage when a current of 1 mA flowed was measured. Then, the withstand voltage characteristic was measured by dividing the voltage by the thickness of the toroidal core.

From Table 5, the soft magnetic alloy powders of sample numbers 126 to 128 in which the average circularity of the soft magnetic alloy powder was changed had suitable HcJ and σ as in sample number 71. Further, the μ of the toroidal core using the soft magnetic alloy powder was also good.

Further, the withstand voltage characteristics of the toroidal core tended to be improved as the average circularity at r or more and 2r or less and the average circularity at 25 μm or more and 30 μm or less were higher.

(Experimental Example 5)
In Experimental Example 5, the same conditions as in Experimental Example 1 were used for Sample No. 8 except that the average circularity of the soft magnetic alloy powder was changed by changing the amount of powder charged and the classification time at one time in the sieve classification. Soft magnetic alloy powders of sample numbers 130 to 136 were prepared. Further, the magnetic 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 when the particle diameter is 25 μm or more and 30 μm or less based on the number, and the average circularity when the particle diameter is 5 μm or more and 10 μm or less based on the number.

From Table 6, the soft magnetic alloy powders of sample numbers 8, 130 to 136 in which the average circularity of the soft magnetic alloy powder was changed had suitable HcJ and σ as in each of the examples of Experimental Example 1. .. Further, the μ of the toroidal core using the soft magnetic alloy powder was also good.

Further, the withstand voltage characteristics of the toroidal core tended to be improved as the average circularity at r or more and 2r or less and the average circularity at 25 μm or more and 30 μm or less were higher.

(Experimental Example 6)
In Experimental Example 6, the injection gas pressure of gas atomizing was changed in the range of 2 MPa or more and 15 MPa or less to prepare six kinds of samples A to F having different particle sizes and shapes. Sample numbers 71, 137, and 138 were prepared by blending samples A to F. Samples 137 and 138 have a soft magnetic structure in which the average circularity when the particle diameter is r or more and 2r or less based on the number and the average circularity when the particle diameter is 25 μm or more and 30 μm or less based on the number are close to the sample 71. This is a sample in which the average circularity of all particles contained in the alloy powder is changed. Table 7B shows the injection gas pressures of samples A to F, D50 on a number basis, and the average circularity of all particles. The compounding ratios (mass ratios) of the samples A to F are shown in Table 7C. The sample C is the same as the sample number 71, and the preparation conditions other than the injection gas pressure of the gas atomizing of the samples A to F are the same as the sample number 71. Then, the magnetic 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.

From Table 7A, even if the average circularity of all particles changes, the composition, the average circularity when the particle diameter is r or more and 2r or less based on the number, and the average circle when the particle diameter is 25 μm or more and 30 μm or less based on the number. It was confirmed that if the degree and the value were as high as before the change, good results were obtained as before the change.

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

From Table 8, the sample numbers 71, 139a and 140a satisfying 0.080 <d <0.100 have lower HcJ than the sample numbers 139 and 140 not satisfying 0.080 <d <0.100. The result was that it had good HcJ.

(Experimental Example 8)
In Experimental Example 8, soft magnetic alloy powders of Sample Nos. 141a and 141 to 143 were prepared under the same conditions except that the contents (b) of B and the contents (c) of C were appropriately changed from Sample Nos. 71. .. The results are shown in Table 9.

From Table 9, sample numbers 71, 141a, 141, and 142 satisfying 0.0001 ≦ e + f ≦ 0.051 have a larger σ than sample numbers 143 not satisfying 0.0001 ≦ e + f ≦ 0.051. The magnetic permeability μ of the toroidal core also increased.

From Table 9, the sample numbers 141a and 142 satisfying 0.030 <e ≦ 0.050 have the magnetic permeability of the toroidal core as compared with the sample numbers 71, 141 and 143 not satisfying 0.030 <e ≦ 0.050. μ has increased.

(Experimental Example 9)
In Experimental Example 9, the soft magnetic alloy powder of sample number 59 was heat-treated to prepare the soft magnetic alloy powder of sample number 142 in which nanocrystals were precipitated on the soft magnetic alloy. The heat treatment conditions were 520 ° C. for 60 minutes. Further, nanocrystal particles having a crystal grain size of 30 nm or less and a crystal structure of bcc are precipitated in the soft magnetic alloy powder of sample number 151, and the soft magnetic alloy powder of sample number 151 is amorphous. It was confirmed by XRD that the conversion rate X (%) was 85% or more. The results are shown in Table 10.

From Table 10, in Sample No. 151 in which nanocrystal particles were precipitated by heat treatment, HcJ decreased and the magnetic permeability μ of the toroidal core increased as compared with Sample No. 59 before heat treatment.

1 ... Particle shape measurement result 10 ... Atomizing device 20 ... Molten metal supply unit 21 ... Molten metal 21a ... Dripping molten metal 30 ... Cooling unit 36 ... Coolant introduction unit 38a 1 ... Outer convex part 50 ... Coolant flow

Claims (15)

Composition formula (Fe _{(1- (α + β))} X1 _α X2 _β ) _{(1- (a + b + c + d + e + f)) A} soft magnetic alloy powder composed of M _a B _b P _c S _d C _e S _f .
X1 is one or more selected from the group consisting of Co and Ni,
X2 is one or more selected from the group consisting of Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Cr, Bi, N, O and rare earth elements.
M is one or more selected from the group consisting of 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
And
A soft magnetic alloy powder having an amorphization rate X (%) represented by the following formula (1) of 85% or more.
X = 100- (Ic / (Ic + Ia)) x 100 ... (1)
Ic: Crystalline scattering integral strength Ia: Amorphous scattering integral strength The soft magnetic alloy powder according to claim 1, wherein D50 in the particle size distribution on a volume basis is r, and the average circularity of the soft magnetic alloy particles having a particle diameter of r or more and 2r or less is 0.70 or more. The soft magnetic alloy powder according to claim 1, wherein the average circularity of the soft magnetic alloy powder having a particle diameter of r or more and 2r or less is 0.90 or more, where D50 in the particle size distribution on a volume basis is r. The soft magnetic alloy powder according to claim 1, wherein the soft magnetic alloy powder having a particle size of 25 μm or more and 30 μm or less has an average circularity of 0.70 or more. The soft magnetic alloy powder according to claim 1, wherein the soft magnetic alloy powder having a particle size of 25 μm or more and 30 μm or less has an average circularity of 0.90 or more. The soft magnetic alloy powder according to claim 1, wherein the soft magnetic alloy powder having a particle size of 5 μm or more and 10 μm or less has an average circularity of 0.70 or more. The soft magnetic alloy powder according to claim 1, wherein the soft magnetic alloy powder having a particle size of 5 μm or more and 10 μm or less has an average circularity of 0.90 or more. The soft magnetic alloy powder according to any one of claims 1 to 7, wherein 0.0001 ≦ e + f ≦ 0.051. The soft magnetic alloy powder according to any one of claims 1 to 8, wherein 0.080 <d <0.100. The soft magnetic alloy powder according to any one of claims 1 to 9, wherein 0.030 <e ≦ 0.050. The soft magnetic alloy powder according to any one of claims 1 to 10, wherein 0 ≦ a <0.020. The soft magnetic alloy powder according to any one of claims 1 to 11, wherein the soft magnetic alloy powder contains nanocrystal particles. A powder magnetic core containing the soft magnetic alloy powder according to any one of claims 1 to 12. A magnetic component containing the soft magnetic alloy powder according to any one of claims 1 to 12. An electronic device containing the soft magnetic alloy powder according to any one of claims 1 to 12.

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