Amorphous alloy soft magnetic powder, compacted magnetic core, magnetic element, and electronic equipment

Abstract

To provide an amorphous alloy soft magnetic powder having low coercivity, high sphericity, and good packing properties; a compacted magnetic core and magnetic element containing the amorphous alloy soft magnetic powder; and an electronic device equipped with the magnetic element. [Solution] Composition formula Fe, expressed by atomic ratio a (Si 1-x B x ) b C c S d [However, a is 100-bcd. Also, b, c, d, x are 16.0 ≤ b ≤ 22.0, 0

Description

Technical Field

[0001] The present invention relates to amorphous alloy soft magnetic powder, compacted magnetic cores, magnetic elements, and electronic devices.

Background Art

[0002] In Patent Document 1, the composition excluding S is represented by the formula: (Fe 1-a TM a ) 100-w-x-y-z P w B x L y Si z (However, inevitable impurities are included, TM is one or more elements selected from Co and Ni, L is one or more elements selected from Al, V, Cr, Y, Zr, Mo, Nb, Ta, and W, where 0 ≦ a ≦ 0.98, 2 ≦ w ≦ 16 atomic%, 2 ≦ x ≦ 16 atomic%, 0 < y ≦ 10 atomic%, 0 ≦ z ≦ 8 atomic%), and an amorphous soft magnetic powder containing 0.01 mass% to 0.2 mass% of S (sulfur) is disclosed.

[0003] According to such amorphous soft magnetic powder, molding at low pressure and high density is possible. Therefore, inductors, toroidal coils, and choke coils with lower losses than conventional ones can be obtained.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, from the perspective of further increasing the packing density, the above amorphous soft magnetic powder still has room for improvement. Also, for reducing the loss of magnetic elements, further reduction of the coercive force of the amorphous soft magnetic powder is necessary.

Means for Solving the Problems

[0006] The amorphous alloy soft magnetic powder according to the application example of the present invention is The composition formula Fe represented by the atomic ratio a (Si 1-x B x ) b C c S d [where a is 100 - b - c - d. Also, b, c, d, x are 16.0 ≦ b ≦ 22.0, 0 < c ≦ 3.0, 0.001 ≦ d ≦ 0.060, 0.5 ≦ x ≦ 0.9.] Composed of the composition and impurities, In the cumulative particle size distribution based on volume obtained using a laser diffraction particle size distribution measuring device, when the particle size at which the cumulative frequency is 10% from the small diameter side is defined as D10 and the particle size at which the cumulative frequency is 50% from the small diameter side is defined as D50, The particle size D10 is 5.0 μm or more and 14.0 μm or less, The particle size D50 is 20.0 μm or more and 39.0 μm or less.

[0007] The compacted powder core according to the application example of the present invention is Including the amorphous alloy soft magnetic powder according to the application example of the present invention.

[0008] The magnetic element according to the application example of the present invention is Equipped with the compacted powder core according to the application example of the present invention.

[0009] The electronic device according to the application example of the present invention is Equipped with the magnetic element according to the application example of the present invention.

Brief Description of the Drawings

[0010] [Figure 1] It is a longitudinal sectional view showing an example of an apparatus for producing amorphous alloy soft magnetic powder by a rotating water flow atomization method. [Figure 2]This is a schematic plan view showing a toroidal coil component. [Figure 3] This is a schematic, transmissive perspective view showing a closed-magnetic-circuit type coil component. [Figure 4] This is a perspective view showing a mobile personal computer, which is an electronic device according to the embodiment. [Figure 5] This is a plan view showing a smartphone, which is an electronic device according to the embodiment. [Figure 6] This is a perspective view showing a digital still camera, which is an electronic device according to an embodiment of this model. [Figure 7] Table 1 shows the composition, manufacturing method, and manufacturing conditions of amorphous alloy soft magnetic powders No. 1 to 9. [Figure 8] Table 2 shows the composition, manufacturing method, and manufacturing conditions of amorphous alloy soft magnetic powders of samples No. 10 to 17. [Figure 9] Table 3 shows the composition and evaluation results of amorphous alloy soft magnetic powders No. 1 to 9. [Figure 10] Table 4 shows the composition and evaluation results of amorphous alloy soft magnetic powders from samples No. 10 to 17. [Modes for carrying out the invention]

[0011] Hereinafter, the amorphous alloy soft magnetic powder, compacted magnetic core, magnetic element, and electronic device of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

[0012] 1. Amorphous alloy soft magnetic powder The amorphous alloy soft magnetic powder according to this embodiment can be applied to any application, but for example, it is used to manufacture compacted magnetic cores used in magnetic elements after the particles are bonded together and formed.

[0013] The amorphous alloy soft magnetic powder according to the embodiment has the compositional formula Fe expressed in atomic ratio. a (Si 1-x B x ) b Cc S d [However, a is 100 - b - c - d. Also, b, c, d, and x are such that 16.0 ≦ b ≦ 22.0, 0 < c ≦ 3.0, 0.001 ≦ d ≦ 0.060, and 0.5 ≦ x ≦ 0.9.] It is a powder composed of the composition and impurities.

[0014] Also, in the cumulative particle size distribution based on volume obtained using a laser diffraction particle size distribution measuring device, when the particle size at which the cumulative frequency is 10% from the small - diameter side is defined as D10, and the particle size at which the cumulative frequency is 50% from the small - diameter side is defined as D50, in the amorphous alloy soft magnetic powder according to this embodiment, the particle size D10 is 5.0 μm or more and 14.0 μm or less, and the particle size D50 is 20.0 μm or more and 39.0 μm or less.

[0015] According to such a configuration, an amorphous alloy soft magnetic powder having low coercive force, high sphericity, and good filling properties can be realized. Therefore, by using such an amorphous alloy soft magnetic powder, miniaturization and high - output of magnetic elements can be achieved.

[0016] 1.1. Composition Hereinafter, the composition of the amorphous alloy soft magnetic powder will be described in detail. As described above, the amorphous alloy soft magnetic powder according to the embodiment has a composition formula Fe a (Si 1-x B x ) b C c S d and has a composition represented by this. This composition formula represents the ratio in terms of the number of atoms in the composition consisting of the five elements Fe, Si, B, C, and S.

[0017] Fe (iron) has a great influence on the basic magnetic properties and mechanical properties of the amorphous alloy soft magnetic powder according to the embodiment.

[0018] The content rate of Fe is not particularly limited, but in the amorphous alloy soft magnetic powder, Fe is the main component, that is, it is set so that the ratio of the number of atoms is the highest.

[0019] a represents the ratio of Fe atoms, preferably 76.0 ≤ a ≤ 81.0, more preferably 77.0 ≤ a ≤ 80.7, and even more preferably 78.0 ≤ a ≤ 80.5. If a falls below the lower limit, the magnetic properties or corrosion resistance may decrease. On the other hand, if a exceeds the upper limit, crystallization may occur more easily during the production of amorphous alloy soft magnetic powder.

[0020] Silicon (Si) promotes the amorphization process when manufacturing amorphous alloy soft magnetic powder from raw materials, and also increases the permeability of the amorphous alloy soft magnetic powder. This makes it possible to achieve high permeability and low coercivity.

[0021] Boron (B) promotes amorphous formation when manufacturing amorphous alloy soft magnetic powder from raw materials. In particular, using Si and B together can synergistically promote amorphous formation based on the difference in their atomic radii. This allows for sufficient improvement in magnetic permeability and low coercivity.

[0022] x represents the ratio of the number of B atoms to the total number of Si atoms, with the sum of the number of Si atoms and B atoms being 1. In the amorphous alloy soft magnetic powder according to this embodiment, x is 0.5 ≤ x ≤ 0.9, but preferably 0.6 ≤ x ≤ 0.8. This allows for the optimization of the balance between the number of Si atoms and the number of B atoms. If x falls below the lower limit or exceeds the upper limit, the balance between the number of Si atoms and the number of B atoms will be disrupted, making it difficult to amorphize the powder, for example, when trying to improve magnetic properties by increasing the proportion of Fe.

[0023] b represents the ratio of the total amount of Si and B, and is 16.0 ≤ b ≤ 22.0, preferably 17.0 ≤ b ≤ 21.0, and more preferably 18.0 ≤ b ≤ 20.0. If b falls below the lower limit or exceeds the upper limit, crystallization is more likely to occur during the production of amorphous alloy soft magnetic powder.

[0024] The Si content is preferably 3.0 atomic % or more and 8.0 atomic % or less, more preferably 5.0 atomic % or more and 7.0 atomic % or less.

[0025] The B content is preferably 10.0 atomic % or more and 15.5 atomic % or less, more preferably 12.5 atomic % or more and 14.5 atomic % or less.

[0026] C (carbon) reduces the viscosity of the melt when melting the raw materials of the amorphous alloy soft magnetic powder, facilitating amorphization and fine powdering. As a result, amorphous alloy soft magnetic powder with a small diameter and high magnetic permeability can be obtained. Consequently, eddy current loss can be suppressed even in the high-frequency range.

[0027] c represents the C content, where 0 < c ≤ 3.0, preferably 1.0 ≤ c ≤ 2.8, and more preferably 1.5 ≤ c ≤ 2.5. If c is below the lower limit, the viscosity of the melt does not decrease sufficiently, and the particle shape becomes irregular. For this reason, the filling property during powder pressing decreases, and the saturation magnetic flux density and magnetic permeability of the compact cannot be increased sufficiently. On the other hand, if c exceeds the upper limit, crystallization tends to occur during the production of the amorphous alloy soft magnetic powder.

[0028] S (sulfur) reduces the viscosity of the melt. As a result, the particles can be made spherical, and the filling property can be improved. Also, S is a semimetal element and contributes to the improvement of the amorphous forming ability. Therefore, even when the Fe content is high, an amorphous alloy soft magnetic powder having a high degree of amorphization, capable of achieving both high magnetic permeability and low coercive force, can be obtained.

[0029] d represents the S content, where 0.001 ≤ d ≤ 0.060, preferably 0.005 ≤ d ≤ 0.050, and more preferably 0.012 ≤ d ≤ 0.040. If d is below the lower limit, the effects such as promoting spheroidization and improving the amorphous forming ability may not be obtained sufficiently. On the other hand, if d exceeds the upper limit, the addition amount becomes excessive, which may inhibit the promotion of spheroidization and the improvement of the amorphous forming ability.

[0030] Furthermore, optimizing the ratio of d to c (d / c) significantly enhances effects such as promoting spheroidization and improving amorphous formation ability. The ratio (d / c) is preferably 0.005 to 0.050, more preferably 0.007 to 0.040, and even more preferably 0.008 to 0.030. If the ratio (d / c) falls below the lower limit, the ratio of d to c decreases, and if the ratio (d / c) exceeds the upper limit, the ratio of d to c becomes excessive, which may make it difficult to further improve effects such as promoting spheroidization and improving amorphous formation ability.

[0031] The amorphous alloy soft magnetic powder according to the embodiment may contain impurities consisting of other elements in addition to the elements described above. The total impurity content is preferably 1.0% by mass or less, more preferably 0.2% by mass or less, and even more preferably 0.1% by mass or less. Furthermore, the individual content of each element is preferably 0.2% by mass or less, more preferably 0.1% by mass or less, and even more preferably 0.05% by mass or less. Within this range, the presence of other elements is acceptable because they are less likely to hinder the effects of the present invention.

[0032] The composition of the amorphous alloy soft magnetic powder according to the embodiment has been described in detail above, but the above composition and impurities can be identified by the following analytical methods.

[0033] Examples of analytical methods include atomic absorption spectrometry for iron and steel as specified in JIS G 1257:2000, ICP emission spectrometry for iron and steel as specified in JIS G 1258:2007, spark discharge emission spectrometry for iron and steel as specified in JIS G 1253:2002, X-ray fluorescence spectrometry for iron and steel as specified in JIS G 1256:1997, and gravimetric titration-absorbance spectrophotometric methods as specified in JIS G 1211 to G 1237.

[0034] Specifically, examples include solid-state emission spectrometers manufactured by SPECTRO, particularly spark discharge emission spectrometers, model: SPECTROLAB, type: LAVMB08A, and the ICP instrument CIROS120 manufactured by Rigaku Corporation.

[0035] Furthermore, in particular, when identifying C (carbon) and S (sulfur), the oxygen-flow combustion (high-frequency induction heating furnace combustion)-infrared absorption method specified in JIS G 1211:2011 is also used. Specifically, the LECO CS-200 carbon-sulfur analyzer is an example.

[0036] Furthermore, when specifically identifying N (nitrogen) and O (oxygen), the methods for determining nitrogen in iron and steel as specified in JIS G 1228:1997 and the general rules for determining oxygen in metallic materials as specified in JIS Z 2613:2006 are also used. Specifically, the LECO TC-300 / EF-300 oxygen / nitrogen analyzer is an example.

[0037] 1.2.Various characteristics The degree of amorphousness in amorphous alloy soft magnetic powder can be determined based on the degree of crystallinity. The degree of crystallinity in amorphous alloy soft magnetic powder is calculated from the spectrum obtained by X-ray diffraction of the amorphous alloy soft magnetic powder based on the following formula. Crystallinity = {Crystal-derived strength / (Crystal-derived strength + Amorphous-derived strength)} × 100

[0038] Furthermore, as an X-ray diffractometer, for example, the RINT2500V / PC manufactured by Rigaku Corporation is used.

[0039] The degree of crystallinity measured by this method is preferably 70% or less, more preferably 60% or less, and even more preferably 40% or less. This makes the improvement in soft magnetism associated with amorphization more pronounced. As a result, an amorphous alloy soft magnetic powder with sufficiently low coercivity is obtained. In other words, it is preferable that the amorphous alloy soft magnetic powder is entirely amorphized, but it may contain crystalline structures in a volume ratio of, for example, 70% or less.

[0040] In the volume-based cumulative particle size distribution of amorphous alloy soft magnetic powder obtained using a laser diffraction particle size distribution analyzer, the particle size at which the cumulative frequency from the smallest diameter side reaches 10% is defined as D10, and the particle size at which the cumulative frequency from the smallest diameter side reaches 50% is defined as D50.

[0041] The particle size D10 of the amorphous alloy soft magnetic powder is 5.0 μm to 14.0 μm, preferably 9.0 μm to 12.0 μm. Because such amorphous alloy soft magnetic powder has a relatively large particle size distribution, it is possible to appropriately combine small and large particles, thereby achieving good packing. This makes it possible to further increase the density of the compacted magnetic core.

[0042] Furthermore, if the particle size D10 falls below the lower limit, there are relatively many small particles, resulting in a large number of secondary particles, and the filling performance during compaction molding cannot be sufficiently improved. On the other hand, if the particle size D10 exceeds the upper limit, there are relatively few small particles, resulting in many gaps during filling, and the filling performance during compaction molding cannot be sufficiently improved.

[0043] The particle size D50 of the amorphous alloy soft magnetic powder is between 20.0 μm and 39.0 μm, preferably between 25.0 μm and 35.0 μm. Because such amorphous alloy soft magnetic powder has a relatively large particle size, it is possible to appropriately combine small and large particles, thereby achieving good packing. This makes it possible to further increase the density of the compacted magnetic core.

[0044] Furthermore, if the particle size D50 falls below the lower limit, the particle size becomes too small, making it impossible to sufficiently improve the filling performance during compaction molding. On the other hand, if the particle size D50 exceeds the upper limit, the particle size becomes too large, making it impossible to sufficiently improve the degree of amorphization.

[0045] Furthermore, in the volume-based cumulative particle size distribution of amorphous alloy soft magnetic powder obtained using a laser diffraction particle size distribution analyzer, the particle size at which the cumulative frequency from the smallest diameter side reaches 90% is defined as D90.

[0046] In amorphous alloy soft magnetic powder, the (D90-D10) / D50 ratio is preferably between 1.8 and 3.0, and more preferably between 2.2 and 2.7. (D90-D10) / D50 is an index indicating the degree of particle size distribution spread, and when this index is within the above range, the packing properties of the amorphous alloy soft magnetic powder become particularly good.

[0047] The coercivity of amorphous alloy soft magnetic powder after heat treatment is preferably 1.2 [Oe] or less (95.49 [A / m] or less), and more preferably 1.0 [Oe] or less (79.58 [A / m] or less). By using amorphous alloy soft magnetic powder with such low coercivity, it is possible to manufacture magnetic elements with sufficiently low hysteresis loss.

[0048] Furthermore, if the coercivity falls below the aforementioned lower limit, it becomes difficult to stably manufacture amorphous alloy soft magnetic powder with such low coercivity, and pursuing low coercivity too much may affect the permeability. On the other hand, if the coercivity exceeds the aforementioned upper limit, hysteresis loss increases, which may lead to increased iron loss in the magnetic element.

[0049] The coercivity of amorphous alloy soft magnetic powder can be measured using a vibrating sample type magnetometer such as the TM-VSM1230-MHHL manufactured by Tamagawa Seisakusho Co., Ltd., after removing coarse particles using a sieve with a mesh size of 150 μm.

[0050] Furthermore, heat treatment is performed to relieve residual stress contained in the amorphous alloy soft magnetic powder after manufacturing. When evaluating coercivity, the heat treatment involves a heating temperature of 410°C, a holding time of 15 minutes, and a nitrogen atmosphere in the furnace.

[0051] The amorphous alloy soft magnetic powder preferably has a tap density within a predetermined range. Specifically, the tap density of the amorphous alloy soft magnetic powder is 4.65 [g / cm³]. 3 ] or more than 5.20[g / cm 3 Preferably it is 4.70 [g / cm³] or less. 3 ] or more than 5.15[g / cm 3 It is more preferable that the tap density is below the above range. When the tap density is within the above range, an amorphous alloy soft magnetic powder is obtained in which there are relatively few irregularly shaped particles, the overall shape is spherical regardless of the particle size, and the particle size distribution has an improved packing ability. Such an amorphous alloy soft magnetic powder can be used to manufacture a high-density compacted magnetic core, and therefore the saturation magnetic flux density and permeability of the magnetic element can be particularly increased.

[0052] Furthermore, if the tap density falls below the lower limit, the packing performance of the amorphous alloy soft magnetic powder may decrease when compacting the powder to obtain a compacted magnetic core. On the other hand, if the tap density exceeds the upper limit, the difficulty of manufacturing the amorphous alloy soft magnetic powder increases, which may reduce the manufacturing yield.

[0053] The tap density of amorphous alloy soft magnetic powder is measured in accordance with the metal powder-tap density measurement method specified in JIS Z 2512:2012, using powder after removing coarse particles with a sieve with a mesh size of 150 μm.

[0054] When amorphous alloy soft magnetic powder is classified using the following procedure, it is preferable that the mass ratio of the resulting classified material satisfies predetermined conditions.

[0055] First, the amorphous alloy soft magnetic powder is classified using a first sieve with a mesh size of 150 μm. The material that passes through the first sieve is designated as -150 particles. Next, the -150 particles are classified using a second sieve with a mesh size of 25 μm. The material that passes through the second sieve is designated as -25 particles.

[0056] In amorphous alloy soft magnetic powder, the mass ratio of -25 particles to -150 particles is preferably 35% to 50%, and more preferably 40% to 47%. This indicates a high proportion of relatively fine particles. In other words, it is possible to realize amorphous alloy soft magnetic powder that exhibits the tap density described above and contains a relatively high proportion of fine particles. As a result, it is possible to realize amorphous alloy soft magnetic powder that has a particularly high packing density and can be used to manufacture magnetic elements with high magnetic permeability and saturation magnetic flux density.

[0057] When amorphous alloy soft magnetic powder is classified using a sieve with a mesh size of 38 μm, it is preferable that the average circularity of the classified material that passes through the sieve is within the following range.

[0058] The average circularity of the classified material is preferably 0.85 to 0.99, more preferably 0.86 to 0.98, and even more preferably 0.88 to 0.97. This allows for spheroidization even if the classified material consists of small-diameter particles, bringing the packing state closer to close-packing. As a result, an amorphous alloy soft magnetic powder can be realized with an optimal particle size distribution and a high contribution of the included small-diameter particles to packing.

[0059] Furthermore, if the average circularity falls below the aforementioned lower limit, it becomes difficult to spheroidize small-diameter particles, which may reduce the packing efficiency of the amorphous alloy soft magnetic powder. On the other hand, if the average circularity exceeds the aforementioned upper limit, the manufacturing difficulty increases, which may reduce the manufacturing efficiency of the amorphous alloy soft magnetic powder.

[0060] The average circularity of amorphous alloy soft magnetic powder is measured as follows: First, an image (secondary electron image) of the amorphous alloy soft magnetic powder is captured using a scanning electron microscope (SEM). Next, the obtained image is loaded into image processing software. For example, image analysis-based particle size distribution measurement software "Mac-View" manufactured by Mountec Co., Ltd. is used as the image processing software. The imaging magnification is adjusted so that 50 to 100 particles are captured in a single image. Then, multiple images are acquired so that a total of 300 or more particle images are obtained.

[0061] Next, the circularity of more than 300 particle images is calculated using software, and the average value is determined. The resulting average value is the average circularity of the amorphous alloy soft magnetic powder. When the circularity is denoted as e, the area of ​​the particle image as S, and the perimeter of the particle image as L, the circularity e can be calculated using the following formula. e = 4πS / L 2

[0062] 2. Method for producing amorphous alloy soft magnetic powder Next, a method for producing amorphous alloy soft magnetic powder according to the embodiment will be described.

[0063] The amorphous alloy soft magnetic powder according to this embodiment may be manufactured by any manufacturing method, for example, by various powdering methods such as atomization, reduction, carbonylation, and pulverization.

[0064] The atomization method is a method for producing powder by pulverizing and cooling molten raw materials by colliding them with a fluid such as liquid or gas that is sprayed at high speed. Depending on the type of coolant and the configuration of the apparatus, there are various atomization methods such as water atomization, gas atomization, and rotary water flow atomization. Of these, amorphous alloy soft magnetic powder is preferably produced by the water atomization method or the rotary water flow atomization method, and more preferably by the rotary water flow atomization method.

[0065] In this specification, "water atomization method" refers to a method of producing metal powder by using a liquid such as water or oil as a coolant, spraying it in an inverted cone shape focused to a single point, and then flowing molten metal down towards this point of focus and causing it to collide with the coolant.

[0066] On the other hand, the rotary water atomization method allows for extremely rapid cooling of the molten metal using a rotary water flow, making it particularly easy to achieve amorphous state.

[0067] When producing amorphous alloy soft magnetic powder, the cooling rate of the molten metal is 10 6 It is preferable that it is greater than [K / sec], and 10 7 A temperature of [K / sec] or higher is more preferable. This allows for the production of amorphous alloy soft magnetic powder with sufficient amorphous properties. In other words, amorphous properties can be achieved even with compositions that have a relatively high Fe content. In particular, the rotating water flow atomization method yields 10 6 Cooling speeds exceeding [K / sec] can be easily achieved.

[0068] The following describes the method for producing amorphous alloy soft magnetic powder using the rotary water atomization method.

[0069] In the rotary water atomization method, a coolant is injected and supplied along the inner surface of a cooling cylinder, and by swirling it along the inner surface of the cooling cylinder, a coolant layer is formed on the inner surface. On the other hand, the raw material for amorphous alloy soft magnetic powder is melted, and while the resulting molten metal is allowed to fall naturally, a jet of liquid or gas is blown onto it. When the molten metal is scattered in this way, the scattered molten metal is incorporated into the coolant layer. As a result, the scattered and finely powdered molten metal is rapidly cooled and solidified, yielding amorphous alloy soft magnetic powder.

[0070] Figure 1 is a longitudinal cross-sectional view showing an example of an apparatus for producing amorphous alloy soft magnetic powder by the rotary water atomization method.

[0071] The powder manufacturing apparatus 30 shown in Figure 1 comprises a cooling cylinder 1, a crucible 15, a pump 7, and a jet nozzle 24. The cooling cylinder 1 is a cylinder for forming a cooling liquid layer 9 on its inner circumferential surface. The crucible 15 is a supply container for supplying molten metal 25 flowing down into the space 23 inside the cooling liquid layer 9. The pump 7 supplies cooling liquid to the cooling cylinder 1. The jet nozzle 24 ejects a gas jet 26 that divides the flowing molten metal 25 into droplets. The molten metal 25 is prepared according to the composition of the amorphous alloy soft magnetic powder.

[0072] The cooling cylinder 1 is cylindrical in shape and is installed so that its axis is aligned with the vertical direction, or tilted at an angle of 30° or less with respect to the vertical direction.

[0073] The upper end opening of the cooling cylinder 1 is closed by a lid 2. The lid 2 has an opening 3 formed therein for supplying the flowing molten metal 25 to the space 23 of the cooling cylinder 1.

[0074] The upper part of the cooling cylinder 1 is provided with a coolant ejection pipe 4 that ejects coolant onto the inner circumferential surface of the cooling cylinder 1. Multiple outlets 5 of the coolant ejection pipe 4 are provided at equal intervals along the circumferential direction of the cooling cylinder 1.

[0075] The coolant discharge pipe 4 is connected to the tank 8 via piping to which the pump 7 is connected. The coolant in the tank 8, drawn up by the pump 7, is discharged into the cooling cylinder 1 via the coolant discharge pipe 4. As a result, the coolant gradually flows down along the inner surface of the cooling cylinder 1 while rotating, forming a coolant layer 9 along the inner surface. Coolers may be interposed in the tank 8 or along the circulation path as needed. In addition to water, oils such as silicone oil can be used as the coolant, and various additives may also be added. Furthermore, by removing dissolved oxygen from the coolant beforehand, oxidation of the manufactured powder can be suppressed.

[0076] Furthermore, a cylindrical draining mesh 17 is attached to the lower part of the cooling cylinder 1, and a funnel-shaped powder collection container 18 is provided on the underside of this draining mesh 17. A coolant collection cover 13 is provided around the draining mesh 17 so as to cover it, and a drain port 14 formed at the bottom of this coolant collection cover 13 is connected to the tank 8 via piping.

[0077] The jet nozzle 24 is located in the space 23. The jet nozzle 24 is attached to the end of a gas supply pipe 27 inserted through the opening 3 of the cover 2, and its nozzle is positioned to direct the flowing molten metal 25.

[0078] To produce amorphous alloy soft magnetic powder using such a powder manufacturing apparatus 30, first, the pump 7 is activated to form a coolant layer 9 on the inner surface of the cooling cylinder 1. Next, the molten metal 25 in the crucible 15 is allowed to flow down into the space 23. When the gas jet 26 is blown onto the flowing molten metal 25, the molten metal 25 is scattered, and the pulverized molten metal 25 is drawn into the coolant layer 9. As a result, the pulverized molten metal 25 cools and solidifies, yielding amorphous alloy soft magnetic powder.

[0079] In the rotary water atomization method, a very high cooling rate can be stably maintained by continuously supplying the cooling liquid, thereby promoting the amorphization of the amorphous alloy soft magnetic powder produced.

[0080] Furthermore, the molten metal 25, which has been refined to a certain size by the gas jet 26, falls by inertia until it is drawn into the coolant layer 9, and during this process, the droplets become spherical. As a result, amorphous alloy soft magnetic powder with a good particle size distribution and excellent packing properties can be produced.

[0081] The temperature of the molten metal 25 (casting temperature) should be above the melting point of the raw material, but it is preferably 200°C to 400°C higher than the melting point of the raw material, more preferably 230°C to 370°C higher, and even more preferably 250°C to 350°C higher. This optimizes the viscosity of the molten metal 25, enabling the production of amorphous alloy soft magnetic powder with finer particles and fewer irregularly shaped particles.

[0082] Furthermore, if the temperature of the molten metal 25 falls below the lower limit, the viscosity of the molten metal 25 will increase, which may make it difficult to produce fine amorphous alloy soft magnetic powder. Also, the content of irregularly shaped particles may increase. On the other hand, if the temperature of the molten metal 25 exceeds the upper limit, special heat resistance is required in the crucible 15, which may make it difficult to stably hold the molten metal 25.

[0083] The prepared molten metal 25 is discharged through the discharge port of the crucible 15 and supplied to the cooling cylinder 1. The inner diameter (nozzle diameter) of the discharge port of the crucible 15 determines the particle size of the flowing molten metal 25 and affects the amount of amorphous alloy soft magnetic powder produced per unit time, particle size, sphericity, etc. The inner diameter of the discharge port of the crucible 15 is preferably 1.5 mm or more and 6.0 mm or less, more preferably 2.0 mm or more and 5.5 mm or less, and even more preferably 2.5 mm or more and 4.0 mm or less. If the inner diameter of the discharge port of the crucible 15 is within the above range, amorphous alloy soft magnetic powder with optimized particle sizes D10, D50, and tap density can be produced.

[0084] Furthermore, if the inner diameter of the discharge port of the crucible 15 falls below the lower limit, the molten metal 25 flowing down will be cooled more easily, which may lead to an increase in oxygen content or a decrease in sphericity. On the other hand, if the inner diameter of the discharge port of the crucible 15 exceeds the upper limit, it becomes difficult to split the molten metal 25 into fine and uniform particles. This may lead to the generation of coarse and irregularly shaped particles, which may result in a decrease in the tap density of the amorphous alloy soft magnetic powder.

[0085] Furthermore, the amount of molten metal 25 flowing down from the crucible 15 varies depending on the size of the apparatus, but it is preferably more than 1.0 kg / min and 20.0 kg / min or less, and more preferably 2.0 kg / min or more and 10.0 kg / min or less. This allows for the optimization of the amount of molten metal 25 flowing down in a given time, so that even amorphous alloy soft magnetic powder having the aforementioned particle size distribution can be sufficiently amorphized.

[0086] Furthermore, the pressure of the gas jet 26 varies slightly depending on the configuration of the jet nozzle 24, but is preferably between 2.0 MPa and 20.0 MPa, and more preferably between 3.0 MPa and 10.0 MPa. This optimizes the particle size when the molten metal 25 is scattered, ensuring sufficient amorphization and enabling the production of amorphous alloy soft magnetic powder having the aforementioned particle size distribution.

[0087] Furthermore, if the pressure of the gas jet 26 falls below the lower limit, it becomes difficult to sufficiently atomize the droplets, resulting in larger droplet sizes and a decrease in the cooling rate inside the droplets, which may lead to insufficient amorphization. On the other hand, if the pressure of the gas jet 26 exceeds the upper limit, the droplet size after atomization may become too small. In this case, the droplets may be cooled slowly by the gas jet 26, preventing rapid cooling by the cooling liquid layer 9, which may lead to insufficient amorphization.

[0088] Furthermore, the flow rate of the gas jet 26 is not particularly limited, but is 1.0 [Nm³]. 3 / min] or more than 20.0[Nm 3 Preferably, it should be less than or equal to 4.0 [Nm] / min. 3 / min] or more than 10.0[Nm 3 It is more preferable that the particle size is less than or equal to [ / min]. This optimizes the particle size when the molten metal 25 is scattered, ensuring sufficient amorphization and enabling the production of amorphous alloy soft magnetic powder having the aforementioned particle size distribution.

[0089] If the flow rate of the gas jet 26 falls below the lower limit, it becomes difficult to disperse the droplets sufficiently finely, resulting in larger droplet sizes and a decrease in the cooling rate inside the droplets, which may lead to insufficient amorphization. On the other hand, if the flow rate of the gas jet 26 exceeds the upper limit, the droplet size after dispersal may become too small. In this case, the droplets may be cooled slowly by the gas jet 26, preventing rapid cooling by the cooling liquid layer 9, which may lead to insufficient amorphization.

[0090] The pressure at which the coolant is ejected from the cooling cylinder 1 is preferably 5 MPa to 200 MPa, more preferably 20 MPa to 100 MPa, and even more preferably 50 MPa to 100 MPa. This optimizes the flow velocity of the coolant layer 9, making it less likely for the pulverized molten metal 25 to take on an irregular shape. As a result, amorphous alloy soft magnetic powder with superior packing properties can be obtained. Furthermore, the cooling rate of the molten metal 25 by the coolant can be sufficiently increased. In this way, amorphous alloy soft magnetic powder can be obtained.

[0091] Furthermore, amorphous alloy soft magnetic powder may be subjected to classification treatment as needed. Examples of classification treatment methods include dry classification such as sieving classification, inertial classification, centrifugal classification, and wind classification, and wet classification such as sedimentation classification.

[0092] Furthermore, if necessary, an insulating film may be formed on the surface of each particle of the obtained amorphous alloy soft magnetic powder. The constituent material of this insulating film is not particularly limited, but examples include inorganic materials such as phosphates such as magnesium phosphate, calcium phosphate, zinc phosphate, manganese phosphate, and cadmium phosphate, and silicates such as sodium silicate.

[0093] 3. Compacted magnetic cores and magnetic elements Next, the powdered magnetic core and magnetic element according to the embodiment will be described.

[0094] The magnetic element according to this embodiment is applicable to various magnetic elements equipped with a magnetic core, such as choke coils, inductors, noise filters, reactors, transformers, motors, actuators, solenoid valves, and generators. Furthermore, the compacted magnetic core according to this embodiment is applicable to the magnetic cores provided in these magnetic elements.

[0095] Below, we will describe two types of coil components as representative examples of magnetic elements. 3.1. Toroidal type First, a toroidal coil component, which is a magnetic element according to the embodiment, will be described.

[0096] Figure 2 is a schematic plan view of a toroidal coil component. The coil component 10 shown in Figure 2 has a ring-shaped powder core 11 and a conductor 12 wound around this powder core 11.

[0097] The compacted magnetic core 11 is obtained by mixing the amorphous alloy soft magnetic powder and a binder as described above, supplying the resulting mixture to a mold, and then pressurizing and molding it. In other words, the compacted magnetic core 11 is a compacted body containing the amorphous alloy soft magnetic powder according to the embodiment. Such a compacted magnetic core 11 has high magnetic permeability and low coercivity. Therefore, when a coil component 10 having the compacted magnetic core 11 is mounted in an electronic device, the power consumption of the electronic device can be reduced, and the electronic device can be made smaller and have higher output.

[0098] Examples of constituent materials for the binder used in the production of the compacted magnetic core 11 include organic materials such as silicone resins, epoxy resins, phenolic resins, polyamide resins, polyimide resins, and polyphenylene sulfide resins, and inorganic materials such as phosphates like magnesium phosphate, calcium phosphate, zinc phosphate, manganese phosphate, and cadmium phosphate, and silicates like sodium silicate.

[0099] The materials used to construct the conductor 12 include highly conductive materials, such as metallic materials containing Cu, Al, Ag, Au, Ni, etc. An insulating film may be provided on the surface of the conductor 12 as needed.

[0100] The shape of the compacted magnetic core 11 is not limited to the ring shape shown in Figure 2; for example, it may be a shape in which a part of the ring is missing, or a shape in which the longitudinal direction is straight.

[0101] The compacted magnetic core 11 may, if necessary, contain soft magnetic powders or non-magnetic powders other than the amorphous alloy soft magnetic powder according to the embodiment. In that case, the proportion of the aforementioned amorphous alloy soft magnetic powder in the mixed powder obtained by mixing each powder is preferably more than 50% by mass, and more preferably 60% by mass or more.

[0102] 3.2. Closed Magnetic Circuit Type Next, we will describe a closed-circuit type coil component, which is a magnetic element according to the embodiment. Figure 3 is a schematic transmission perspective view showing a closed magnetic circuit type coil component.

[0103] The following describes closed-circuit type coil components, focusing on the differences from toroidal type coil components, and omitting explanations of similar aspects.

[0104] The coil component 20 shown in Figure 3 comprises a chip-shaped powder core 21 and a conductor 22 embedded inside the powder core 21 and formed into a coil. That is, the powder core 21 is a powder compact containing amorphous alloy soft magnetic powder according to the embodiment. Such a powder core 21 has high magnetic permeability and low coercivity.

[0105] Furthermore, the coil component 20 is equipped with such a compacted magnetic core 21. Such a coil component 20 contributes to the miniaturization and increased power output of electronic devices.

[0106] The compacted magnetic core 21 may, if necessary, contain soft magnetic powders or non-magnetic powders other than the amorphous alloy soft magnetic powder according to the embodiment. In that case, the proportion of the aforementioned amorphous alloy soft magnetic powder in the mixed powder is preferably more than 50% by mass, and more preferably 60% by mass or more.

[0107] 4.Electronic equipment Next, the electronic device according to the embodiment will be described with reference to Figures 4 to 6.

[0108] Figure 4 is a perspective view showing a mobile personal computer, which is an electronic device according to an embodiment. The personal computer 1100 shown in Figure 4 comprises a main body 1104 equipped with a keyboard 1102 and a display unit 1106 equipped with a display unit 100. The display unit 1106 is rotatably supported by the main body 1104 via a hinge structure. Such a personal computer 1100 incorporates magnetic elements 1000, such as a choke coil or inductor for a switching power supply, and a motor.

[0109] Figure 5 is a plan view showing a smartphone, which is an electronic device according to the embodiment. The smartphone 1200 shown in Figure 5 is equipped with a plurality of operation buttons 1202, an earpiece 1204, and a microphone 1206. A display unit 100 is also positioned between the operation buttons 1202 and the earpiece 1204. Such a smartphone 1200 incorporates magnetic elements 1000, such as an inductor, noise filter, and motor.

[0110] Figure 6 is a perspective view showing a digital still camera 1300, which is an electronic device according to the embodiment. The digital still camera 1300 generates an imaging signal by photoelectric conversion of the light image of the subject using an image sensor such as a CCD (Charge Coupled Device).

[0111] The digital still camera 1300 shown in Figure 6 includes a display unit 100 located on the back of the case 1302. The display unit 100 functions as a viewfinder, displaying the subject as an electronic image. A light-receiving unit 1304, including an optical lens and a CCD, is provided on the front side of the case 1302, i.e., the back side in the figure.

[0112] When the photographer confirms the subject image displayed on the display unit 100 and presses the shutter button 1306, the imaging signal from the CCD at that moment is transferred and stored in the memory 1308. Such a digital still camera 1300 also incorporates magnetic elements 1000, such as an inductor and a noise filter.

[0113] Such electronic devices are equipped with magnetic elements according to the embodiment. This allows for the enjoyment of the magnetic elements' effects of high permeability and low coercivity, enabling miniaturization and increased output of the electronic devices.

[0114] In addition to the personal computer in Figure 4, the smartphone in Figure 5, and the digital still camera in Figure 6, other examples of electronic devices according to this embodiment include mobile phones, tablet terminals, watches, inkjet printers and other inkjet ejection devices, laptop personal computers, televisions, video cameras, video tape recorders, car navigation systems, pagers, electronic organizers, electronic dictionaries, calculators, electronic game consoles, word processors, workstations, video phones, security television monitors, electronic binoculars, POS terminals, electronic thermometers, blood pressure monitors, blood glucose meters, electrocardiogram measuring devices, ultrasound diagnostic devices, medical devices such as electronic endoscopes, fish finders, various measuring instruments, instruments for vehicles, aircraft, and ships, mobile control devices such as automobile control equipment, aircraft control equipment, railway vehicle control equipment, and ship control equipment, and flight simulators.

[0115] 5. Effects of the Embodiment As described above, the amorphous alloy soft magnetic powder according to the embodiment has a compositional formula Fe expressed by atomic ratio. a (Si 1-xB x ) b C c S d [However, a is 100 - b - c - d. Also, b, c, d, and x satisfy 16.0 ≤ b ≤ 22.0, 0 < c ≤ 3.0, 0.001 ≤ d ≤ 0.060, and 0.5 ≤ x ≤ 0.9.] It is composed of such a composition and impurities, and in the volume-based cumulative particle size distribution obtained using a laser diffraction particle size distribution measuring device, when the particle size at which the cumulative frequency is 10% from the small diameter side is defined as D10 and the particle size at which the cumulative frequency is 50% from the small diameter side is defined as D50, the particle size D10 is 5.0 μm or more and 14.0 μm or less, and the particle size D50 is​​​​​​​​​​​​​​​​​​​​​​​​​​​In the amorphous alloy soft magnetic powder according to the embodiment, when the powder is classified using a first sieve with a mesh size of 150 μm, and the classified material that passes through the first sieve is designated as -150 particles, and the -150 particles are then classified using a second sieve with a mesh size of 25 μm, and the classified material that passes through the second sieve is designated as -25 particles, it is preferable that the mass ratio of -25 particles to -150 particles is 35% or more and 50% or less.

[0122] With this configuration, it can be determined that there is a high proportion of relatively small particles, making it possible to realize amorphous alloy soft magnetic powder that has a particularly high packing density and can be used to manufacture magnetic elements with high magnetic permeability and saturation magnetic flux density.

[0123] In the amorphous alloy soft magnetic powder according to the embodiment, it is preferable that the coercivity after heat treatment is 1.2 [Oe] or less (95.49 [A / m] or less).

[0124] With this configuration, it is possible to manufacture magnetic elements with sufficiently low hysteresis loss.

[0125] The compacted magnetic core according to the embodiment includes amorphous alloy soft magnetic powder according to the embodiment. This configuration yields a powdered magnetic core with high permeability and low coercivity.

[0126] Furthermore, the magnetic element according to the above embodiment includes a compacted magnetic core according to the above embodiment. This configuration yields a magnetic element with a powdered magnetic core that has high permeability and low coercivity.

[0127] Furthermore, the electronic device according to the above embodiment includes the magnetic element according to the above embodiment. This configuration allows for the creation of electronic devices that are both smaller and have higher output power.

[0128] The amorphous alloy soft magnetic powder, compacted magnetic core, magnetic element, and electronic device of the present invention have been described above based on preferred embodiments, but the present invention is not limited thereto. For example, the compacted magnetic core and magnetic element according to the present invention may be in which each part of the above embodiment is replaced with any component having a similar function, or any component may be added to the above embodiment.

[0129] Furthermore, although the embodiments described above used a compacted magnetic core as an example of an application for the amorphous alloy soft magnetic powder of the present invention, the application examples are not limited to this, and may include magnetic fluids, magnetic shielding sheets, magnetic heads, and other magnetic devices. Also, the shape of the compacted magnetic core and magnetic element is not limited to those shown in the figures, and may be any shape. [Examples]

[0130] Next, specific embodiments of the present invention will be described. 6. Manufacturing of powdered magnetic cores 6.1. Sample No. 1 First, the raw materials were melted in a high-frequency induction furnace and then powdered by a rotary water atomization method to obtain amorphous alloy soft magnetic powder. The gas jet pressure was set to 3.0-5.0 MPa and the gas jet flow rate to 8.0-12.0 Nm³. 3 The setting was [ / min], and the coolant pressure was set to 40-60 MPa.

[0131] Next, the obtained amorphous alloy soft magnetic powder was subjected to heat treatment. The heating temperature for the heat treatment was 410°C, the heating time was 15 minutes, and the furnace atmosphere was a nitrogen atmosphere.

[0132] Next, classification was performed using a classifier with a mesh opening of 150 μm. The alloy composition of the amorphous alloy soft magnetic powder after classification is shown in Table 1. A solid-state emission spectrometer, model: SPECTROLAB, type: LAVMB08A, manufactured by SPECTRO, was used to determine the alloy composition.

[0133] Next, the obtained amorphous alloy soft magnetic powder was mixed with an epoxy resin as a binder and toluene as an organic solvent to obtain a mixture. The amount of epoxy resin added was 2 parts by mass per 100 parts by mass of amorphous alloy soft magnetic powder.

[0134] Next, the resulting mixture was stirred and then dried for a short time to obtain a lumpy dried body. This dried body was then sieved through a 400 μm mesh to pulverize it and obtain granulated powder. The obtained granulated powder was dried at 50°C for 1 hour.

[0135] Next, the obtained granulated powder was filled into a mold, and a molded body was obtained based on the following molding conditions.

[0136] <Molding conditions> • Forming method: Press forming • Shape of the molded body: ring-shaped • Dimensions of the molded body: Outer diameter 14mm, inner diameter 8mm, thickness 3mm ·Molding pressure: 3t / cm 2 (294 MPa)

[0137] Next, the molded body was heated in an air atmosphere at a temperature of 150°C for 0.50 hours to cure the binder. This yielded a compacted magnetic core.

[0138] 6.2. Samples No. 2-14 A compacted magnetic core was obtained in the same manner as for Sample No. 1, except that the composition and manufacturing conditions of the amorphous alloy soft magnetic powder were changed as shown in Table 1 (Figure 7) or Table 2 (Figure 8).

[0139] In the production of amorphous alloy soft magnetic powders No. 1 to 14, the temperature of the molten metal (casting temperature) was set to +250°C to +350°C relative to the melting point of the raw materials, and the inner diameter of the crucible outlet was set to 2.5 to 3.5 mm.

[0140] Figure 7 is Table 1, showing the composition, manufacturing method, and manufacturing conditions of amorphous alloy soft magnetic powders for samples No. 1 to 9. Figure 8 is Table 2, showing the composition, manufacturing method, and manufacturing conditions of amorphous alloy soft magnetic powders for samples No. 10 to 17.

[0141] 6.3. Samples No. 15-17 A compacted magnetic core was obtained in the same manner as Sample No. 1, except that the method for producing amorphous alloy soft magnetic powder was changed to the water atomization method, and the composition and manufacturing conditions of the amorphous alloy soft magnetic powder were changed to those shown in Table 2.

[0142] In the production of amorphous alloy soft magnetic powders No. 15 to 17, the temperature of the molten metal (casting temperature) was set to +150°C to +250°C relative to the melting point of the raw materials, and the inner diameter of the crucible outlet was set to 1.5 to 2.5 mm.

[0143] In addition, in Tables 1 (Figure 7) and 2 (Figure 8), and in Tables 3 (Figure 9) and 4 (Figure 10) described later, amorphous alloy soft magnetic powders of each sample number that correspond to the present invention are indicated as "Examples," and those that do not correspond to the present invention are indicated as "Comparative Examples."

[0144] 7. Evaluation of amorphous alloy soft magnetic powders and magnetic elements 7.1. Powder properties Next, particle size distribution measurements were performed on the amorphous alloy soft magnetic powders obtained in each example and comparative example. This measurement was carried out using a laser diffraction particle size distribution analyzer, the Microtrac HRA9320-X100, manufactured by Nikkiso Co., Ltd. D10, D50, D90, and (D90-D10) / D50 were then calculated.

[0145] Furthermore, the amorphous alloy soft magnetic powders obtained in each example and comparative example were sequentially classified using a first sieve with a mesh size of 150 μm and a second sieve with a mesh size of 25 μm, and the masses of -150 particles and -25 particles were measured. The mass ratio of -25 particles to -150 particles was then calculated. The calculation results are shown in Table 3 (Figure 9) and Table 4 (Figure 10).

[0146] Figure 9 is Table 3, showing the composition and evaluation results of amorphous alloy soft magnetic powders for samples No. 1 to 9. Figure 8 is Table 4, showing the composition and evaluation results of amorphous alloy soft magnetic powders for samples No. 10 to 17.

[0147] 7.2. Coercivity The amorphous alloy soft magnetic powders obtained in each example and comparative example were classified using a sieve with a mesh size of 150 μm, and the coercivity of the powders that passed through the sieve was measured. The measurement results are shown in Tables 3 and 4. The powders to be measured were subjected to a predetermined heat treatment before measurement.

[0148] 7.3. Mean Circularity The amorphous alloy soft magnetic powders obtained in each example and comparative example were classified using a sieve with a mesh size of 38 μm, and the average circularity was calculated for the powders that passed through the sieve.

[0149] Next, the measured average circularity was evaluated against the following evaluation criteria. The evaluation results are shown in Tables 3 and 4.

[0150] A: The average circularity is 0.88 or higher. B: The average circularity is 0.85 or higher and less than 0.88. C: The average circularity is less than 0.85.

[0151] 7.4. Tap Density The amorphous alloy soft magnetic powders obtained in each example and comparative example were classified using a sieve with a mesh size of 150 μm, and then the tap density was measured for the powder after additional sieving. The measurement results are shown in Tables 3 and 4.

[0152] As is clear from Tables 3 and 4, the amorphous alloy soft magnetic powders of each example exhibited low coercivity and high average circularity and tap density. Therefore, it is confirmed that the present invention makes it possible to realize amorphous alloy soft magnetic powders with low coercivity, high sphericity, and good packing properties. [Explanation of Symbols]

[0153] 1...Cooling cylinder, 2...Lid, 3...Opening, 4...Coolant ejection tube, 5...Discharge port, 7...Pump, 8...Tank, 9...Coolant layer, 10...Cooling components, 11...Powdered magnetic core, 12...Wire, 13...Cooling liquid recovery cover, 14...Drain port, 15...Crucible, 17...Drainage mesh, 18...Powder recovery container, 20...Coil components, 21...Powdered magnetic core, 22...Wire, 23...Space, 24...Jet nozzle, 25...Molten metal, 26...Gas jet, 27...Gas Supply pipe, 30... Powder manufacturing device, 100... Display unit, 1000... Magnetic element, 1100... Personal computer, 1102... Keyboard, 1104... Main unit, 1106... Display unit, 1200... Smartphone, 1202... Operation buttons, 1204... Earpiece, 1206... Transmitter, 1300... Digital still camera, 1302... Case, 1304... Light receiving unit, 1306... Shutter button, 1308... Memory

Claims

1. The composition formula Fe expressed by atomic ratio ａ (Si １－ｘ B ｘ ) ｂ C ｃ S ｄ [However, a is 100-b-c-d.] Also, b, c, d, and x are 16.0 ≤ b ≤ 22.0, 0 < c ≤ 3.0, 0.001 ≤ d ≤ 0.060, 0.5 ≤ x ≤ 0.

9. Composed of the following composition and impurities, In the volume-based cumulative particle size distribution obtained using a laser diffraction particle size distribution analyzer, when the particle size at which the cumulative frequency from the smallest diameter side reaches 10% is defined as D10, and the particle size at which the cumulative frequency from the smallest diameter side reaches 50% is defined as D50, The particle size D10 is 5.0 μm or more and 14.0 μm or less. Amorphous alloy soft magnetic powder characterized by having a particle size D50 of 20.0 μm or more and 39.0 μm or less.

2. The amorphous alloy soft magnetic powder according to claim 1, wherein d in the composition formula is 0.012 ≤ d ≤ 0.

040.

3. Tap density is 4.65 [g / cm³] ３ ] or more 5.20 [g / cm ３ The amorphous alloy soft magnetic powder according to claim 1 or 2, wherein the powder is as follows:

4. The material is classified using a first sieve with a mesh size of 150 μm, and the classified material that passes through the first sieve is designated as -150 particles. When the aforementioned -150 particles are classified using a second sieve with a mesh size of 25 μm, and the classified material that passes through the second sieve is defined as -25 particles, The amorphous alloy soft magnetic powder according to claim 3, wherein the mass ratio of the -25 particles to the -150 particles is 35% or more and 50% or less.

5. The amorphous alloy soft magnetic powder according to claim 1 or 2, wherein the coercivity after heat treatment is 1.2 [Oe] or less (95.49 [A / m] or less).

6. A compacted magnetic core characterized by containing amorphous alloy soft magnetic powder as described in claim 1 or 2.

7. A magnetic element characterized by comprising a compacted magnetic core as described in claim 6.

8. An electronic device characterized by comprising the magnetic element described in claim 7.

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