Amorphous alloy soft magnetic powder, powder magnetic core, magnetic element, and electronic device

Abstract

Provided are: an amorphous alloy soft magnetic powder having a low coercive force, a high sphericity degree, and good filling properties; a powder magnetic core containing the amorphous alloy soft magnetic powder; a magnetic element; and an electronic device provided with the magnetic element. The amorphous alloy soft magnetic powder is represented by the composition formula Fia (Si1-xBx) bCcSd (wherein a is 100-b-c-d), represented by the atomic ratio of Fia (Si1-xBx) bCcSd. In addition, 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. In a cumulative particle size distribution on a volume basis obtained using a laser diffraction particle size distribution measurement device, the particle size D10 is from 5.0 [mu] m to 14.0 [mu] m (where D10 is the particle size for 10% of the cumulative frequency from the small diameter side and D50 is the particle size for 50% of the cumulative frequency from the small diameter side), and the particle size D10 is from 5.0 [mu] m to 14.0 [mu] m (where D50 is the particle size for 50% of the cumulative frequency from the small diameter side). The particle diameter (D50) is from 20.0 [mu] m to 39.0 [mu] m (inclusive).

Description

Technical Field

[0001] This invention relates to amorphous alloy soft magnetic powder, pressed magnetic core, magnetic components, and electronic devices. Background Technology

[0002] Patent document 1 discloses an amorphous soft magnetic powder, the composition of which, except for S, is based on the formula: (Fe 1- a TM a ) 100-w-x-y-z P w B x L y Si z (Among which, unavoidable 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, 0≤a≤0.98, 2≤w≤16 atomic%, 2≤x≤16 atomic%, 0<y≤10 atomic%, 0≤z≤8 atomic%), and the alloy contains 0.01% to 0.2% by mass of sulfur.

[0003] Based on this amorphous soft magnetic powder, high-density molding can be performed under low pressure. Therefore, capacitors, toroidal coils, and chokes with lower losses than before are obtained.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2011-023673

[0007] However, from the perspective of achieving further high fill power, there is still room for improvement in the aforementioned amorphous soft magnetic powder. Furthermore, to reduce the loss of magnetic components, further reduction in the coercivity of the amorphous soft magnetic powder is also required. Summary of the Invention

[0008] The amorphous alloy soft magnetic powder involved in the application examples of this invention is composed of Fe, expressed in atomic ratio. a (Si 1-x B x ) b C c S d

[0009] [Where, a is 100-bcd.]

[0010] In addition, b, c, d, and x are

[0011] 16.0≤b≤22.0,

[0012] 0 < c ≤ 3.0,

[0013] 0.001≤d≤0.060,

[0014] 0.5 ≤ x ≤ 0.9.

[0015] The composition and impurities,

[0016] In the cumulative particle size distribution under volume reference obtained using a laser diffraction particle size distribution measuring device, when the particle size at which the cumulative frequency reaches 10% from the small diameter side is defined as D10, and the particle size at which the cumulative frequency reaches 50% from the small diameter side is defined as D50,

[0017] Particle size D10 is greater than 5.0 μm and less than 14.0 μm.

[0018] The particle size D50 is above 20.0 μm and below 39.0 μm.

[0019] The powder cores involved in the application examples of the present invention comprise the amorphous alloy soft magnetic powders involved in the application examples of the present invention.

[0020] The magnetic element involved in the application example of the present invention has the powder core involved in the application example of the present invention.

[0021] The electronic device described in the application examples of the present invention includes the magnetic element described in the application examples of the present invention. Attached Figure Description

[0022] Figure 1 This is a longitudinal sectional view showing an example of an apparatus for producing amorphous alloy soft magnetic powder by a rotating water jet atomization method.

[0023] Figure 2 This is a schematic top view showing a loop-shaped coil component.

[0024] Figure 3 It is a schematic perspective view of a coil component with a closed magnetic circuit.

[0025] Figure 4 This is a perspective view of a mobile personal computer, which is an electronic device according to an embodiment.

[0026] Figure 5 This is a top view showing a smartphone, which is an electronic device involved in the implementation.

[0027] Figure 6 This is a perspective view of a digital camera, which is an electronic device according to an embodiment.

[0028] Figure 7Table 1 shows the composition, manufacturing method, and manufacturing conditions of the amorphous alloy soft magnetic powders for samples No. 1 to 9.

[0029] Figure 8 Table 2 shows the composition, manufacturing method, and manufacturing conditions of the amorphous alloy soft magnetic powders for samples No. 10 to 17.

[0030] Figure 9 Table 3 shows the composition and evaluation results of the amorphous alloy soft magnetic powders of samples No.1 to No.9.

[0031] Figure 10 Table 4 shows the composition and evaluation results of the amorphous alloy soft magnetic powders of samples No. 10 to 17.

[0032] Explanation of reference numerals in the attached figures

[0033] 1: Cooling cylinder; 2: Cover; 3: Opening; 4: Coolant spray pipe; 5: Spray outlet; 7: Pump; 8: Tank; 9: Coolant layer; 10: Coil assembly; 11: Powder-pressed magnetic core; 12: Wire; 13: Coolant recovery cover; 14: Drain outlet; 15: Crucible; 17: Dewatering mesh; 18: Powder recovery container; 20: Coil assembly; 21: Powder-pressed magnetic core; 22: Wire; 23: Space section; 24: Spray nozzle; 25: Molten metal; 26: Gas 27: Gas supply pipe; 30: Powder manufacturing apparatus; 100: Display unit; 1000: Magnetic component; 1100: Personal computer; 1102: Keyboard; 1104: Body unit; 1106: Display unit; 1200: Smartphone; 1202: Operation button; 1204: Earpiece; 1206: Microphone; 1300: Digital camera; 1302: Housing; 1304: Light receiving unit; 1306: Shutter button; 1308: Memory. Detailed Implementation

[0034] The amorphous alloy soft magnetic powder, pressed magnetic core, magnetic element, and electronic device of the present invention will now be described in detail based on the preferred embodiments shown in the accompanying drawings.

[0035] 1. Amorphous alloy soft magnetic powder

[0036] The amorphous alloy soft magnetic powder involved in the embodiments can be applied to any purpose, such as in the fabrication of pressed magnetic cores for magnetic components by bonding particles together to form a shape.

[0037] The amorphous alloy soft magnetic powder involved in the implementation method is composed of Fe, expressed in atomic ratio. a (Si 1-x B x ) b Cc S d [Where a is 100-bcd. Furthermore, 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.] The powder consists of a composition and impurities.

[0038] Furthermore, in the cumulative particle size distribution under volume reference obtained using a laser diffraction particle size distribution measuring device, when the particle size at 10% of the cumulative frequency from the small diameter side is defined as D10 and the particle size at 50% of the cumulative frequency from the small diameter side is defined as D50, in the amorphous alloy soft magnetic powder involved in 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.

[0039] Based on this configuration, it is possible to obtain amorphous alloy soft magnetic powder with low coercivity, high sphericity, and good filling properties. Therefore, by using the aforementioned amorphous alloy soft magnetic powder, it is possible to achieve miniaturization and high output of magnetic components.

[0040] 1.1. Composition

[0041] The composition of the amorphous alloy soft magnetic powder will be described in detail below. As described above, the amorphous alloy soft magnetic powder according to the embodiments has a composition of Fe... a (Si 1-x B x ) b C c S d The composition is represented by this formula. It indicates the ratio of the number of atoms in the composition consisting of the five elements Fe, Si, B, C, and S.

[0042] Fe (iron) has a significant impact on the basic magnetic and mechanical properties of the amorphous alloy soft magnetic powder involved in the implementation method.

[0043] There is no particular limit to the Fe content. In amorphous alloy soft magnetic powder, Fe is the main component, that is, the ratio of the number of atoms is set to be the highest.

[0044] 'a' represents the proportion 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' is below the lower limit, the magnetic properties or corrosion resistance may decrease. On the other hand, if 'a' exceeds the upper limit, crystallization may be more likely during the manufacture of amorphous alloy soft magnetic powder.

[0045] When silicon (Si) is used to manufacture amorphous alloy soft magnetic powder from raw materials, it promotes amorphization and increases the permeability of the amorphous alloy soft magnetic powder. This enables the achievement of high permeability and low coercivity.

[0046] Boron (B) promotes amorphization when manufacturing amorphous alloy soft magnetic powders from raw materials. In particular, by combining Si and B, amorphization can be synergistically promoted based on the difference in their atomic radii. As a result, high permeability and low coercivity can be achieved.

[0047] x represents the ratio of the number of B atoms to the total number of B atoms when the total number of Si and B atoms is set to 1. In the amorphous alloy soft magnetic powder according to this embodiment, x is 0.5 ≤ x ≤ 0.9, preferably 0.6 ≤ x ≤ 0.8. This optimizes the balance between the number of Si and B atoms. Furthermore, if x is below the lower limit or exceeds the upper limit, the balance between the number of Si and B atoms is disrupted, making amorphization difficult, for example, when increasing the Fe ratio to improve magnetic properties.

[0048] b represents the total ratio of Si and B, which is 16.0 ≤ b ≤ 22.0, preferably 17.0 ≤ b ≤ 21.0, and more preferably 18.0 ≤ b ≤ 20.0. When b is below the lower limit or above the upper limit, crystallization is more likely to occur during the manufacture of amorphous alloy soft magnetic powder.

[0049] 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.

[0050] The content of B 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.

[0051] When carbon (C) is used to melt the raw materials for amorphous alloy soft magnetic powder, it reduces the viscosity of the melt, facilitating amorphization and micronization. This results in amorphous alloy soft magnetic powders with small diameters and high permeability. Consequently, eddy current losses can be suppressed even in the high-frequency region.

[0052] c represents the content of carbon, which is 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 will not be sufficiently reduced, and the particle shape will become irregular. Therefore, the filling properties during powder pressing are reduced, and the saturation magnetic flux density and permeability of the pressed powder cannot be sufficiently improved. On the other hand, if c exceeds the upper limit, crystallization is likely to occur when manufacturing amorphous alloy soft magnetic powder.

[0053] Sulfur (S) reduces the viscosity of the melt. As a result, spheroidization of particles can be achieved, improving filling properties. Furthermore, S is a half-metallic element, which contributes to the improvement of amorphous formation ability. Therefore, even with a high Fe content, a high degree of amorphization is achieved, resulting in amorphous alloy soft magnetic powder that can achieve both high magnetic permeability and low coercivity.

[0054] d represents the content of S, which is 0.001 ≤ d ≤ 0.060, preferably 0.005 ≤ d ≤ 0.050, and more preferably 0.012 ≤ d ≤ 0.040. If d is lower than the lower limit, the effect of promoting spheroidization and improving amorphous formation ability may not be sufficiently obtained. On the other hand, if d exceeds the upper limit, the amount added is excessive, which may hinder the promotion of spheroidization and the improvement of amorphous formation ability.

[0055] Furthermore, optimizing the ratio of d to c (d / c) significantly promotes spheroidization and enhances amorphous formation capability. The ratio (d / c) is preferably 0.005 or higher and 0.050 or lower, more preferably 0.007 or higher and 0.040 or lower, and even more preferably 0.008 or higher and 0.030 or lower. If the ratio (d / c) is below the lower limit, the ratio of d to c decreases; if the ratio (d / c) exceeds the upper limit, the ratio of d to c becomes excessive, making it difficult to further enhance the effects of promoting spheroidization and improving amorphous formation capability.

[0056] In addition to the elements mentioned above, the amorphous alloy soft magnetic powder involved in the embodiments may also contain impurities composed of other elements. The total content of impurities 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, it is less likely that other elements will hinder the effects of the present invention, and therefore their presence is permissible.

[0057] The composition of the amorphous alloy soft magnetic powder involved in the embodiments has been described in detail above. The above composition and impurities were determined by the following analytical methods.

[0058] Examples of analytical methods include the atomic absorption spectrometry method for iron and steel specified in JIS G1257:2000, the ICP emission spectrometry method for iron and steel specified in JIS G1258:2007, the spark discharge emission spectrometry method for iron and steel specified in JIS G1253:2002, the fluorescence X-ray analysis method for iron and steel specified in JIS G1256:1997, and the gravimetric, titration, and absorbance spectrophotometric methods specified in JIS G1211 to G1237.

[0059] Specifically, examples include solid-state emission spectrometers manufactured by SPECTRO Corporation, particularly spark discharge emission spectrometers, model: SPECTROLAB, type: LAMVB08A, and ICP devices CIROS120 manufactured by Rigaku Corporation.

[0060] Furthermore, particularly in determining C (carbon) and S (sulfur), the oxygen flow combustion (high-frequency induction furnace combustion)-infrared absorption method specified in JIS G1211:2011 is also used. Specifically, the carbon and sulfur analysis device CS-200 manufactured by LECO can be cited as an example.

[0061] Furthermore, especially in determining N (nitrogen) and O (oxygen), the quantitative methods for nitrogen analysis of iron and steel as specified in JIS G1228:1997 and the general rules for the quantitative methods of oxygen analysis of metallic materials as specified in JIS Z 2613:2006 are also used. Specifically, the oxygen and nitrogen analysis device TC-300 / EF-300 manufactured by LECO can be cited as an example.

[0062] 1.2. Various characteristics

[0063] The degree of amorphization 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 based on the spectrum obtained by X-ray diffraction of the powder, using the following formula: Degree of crystallinity = {Intensity from crystallinity / (Intensity from crystallinity + Intensity from amorphous state)} × 100

[0064] In addition, as an X-ray diffraction device, for example, the RINT2500V / PC manufactured by Rigaku Corporation is used.

[0065] 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. As a result, the improvement in soft magnetic properties associated with amorphization becomes significant. Consequently, an amorphous alloy soft magnetic powder with sufficiently low coercivity is obtained. In other words, the amorphous alloy soft magnetic powder is preferably entirely amorphized, but for example, it may contain crystalline structures at a volume ratio of 70% or less.

[0066] In the cumulative particle size distribution of amorphous alloy soft magnetic powder obtained using a laser diffraction particle size distribution measuring device, the particle size at which the cumulative frequency reaches 10% from the small diameter side is defined as D10, and the particle size at which the cumulative frequency reaches 50% from the small diameter side is defined as D50.

[0067] The amorphous alloy soft magnetic powder has a particle size D10 of 5.0 μm or more and 14.0 μm or less, preferably 9.0 μm or more and 12.0 μm or less. Because of its relatively large particle size distribution, this amorphous alloy soft magnetic powder can appropriately combine small and large particles, thereby achieving good filling properties. This enables further high-density production of pressed magnetic cores.

[0068] Furthermore, if the particle size D10 is below the lower limit, there are more small particles, resulting in more secondary particles and insufficient filling performance during powder pressing. On the other hand, if the particle size D10 exceeds the upper limit, there are fewer small particles, resulting in more gaps during filling and insufficient filling performance during powder pressing.

[0069] The particle size D50 of the amorphous alloy soft magnetic powder is 20.0 μm or larger and 39.0 μm or smaller, preferably 25.0 μm or larger and 35.0 μm or smaller. Because of its relatively large particle size, this amorphous alloy soft magnetic powder can appropriately combine small and large particles, thereby achieving good filling properties. This enables further high-density production of pressed magnetic cores.

[0070] Furthermore, if the particle size D50 is below the lower limit, the particle size becomes too small, thus failing to adequately improve the filling properties during powder pressing. On the other hand, if the particle size D50 exceeds the upper limit, the particle size becomes too large, thus failing to adequately improve the degree of amorphization.

[0071] Furthermore, in the cumulative particle size distribution of amorphous alloy soft magnetic powder obtained using a laser diffraction particle size distribution measuring device, the particle size at which the cumulative frequency reaches 90% from the small diameter side is set as D90.

[0072] In amorphous alloy soft magnetic powder, the (D90-D10) / D50 is preferably about 1.8 or more and about 3.0 or less, more preferably about 2.2 or more and about 2.7 or less. (D90-D10) / D50 is an index indicating the degree of diffusion of particle size distribution. By keeping this index within the range described above, the filling properties of the amorphous alloy soft magnetic powder are particularly good.

[0073] The coercivity of the heat-treated amorphous alloy soft magnetic powder 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). In this way, by using amorphous alloy soft magnetic powder with low coercivity, it is possible to manufacture magnetic components with sufficiently low hysteresis loss.

[0074] Furthermore, when the coercivity is below the lower limit, it is difficult to stably manufacture such low-coercivity amorphous alloy soft magnetic powder, and excessive pursuit of low coercivity may affect the permeability. On the other hand, if the coercivity exceeds the upper limit, hysteresis loss increases, and therefore the iron loss of the magnetic element may increase.

[0075] 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 Corporation, after removing coarse particles through a sieve with a mesh size of 150μm.

[0076] Furthermore, the heat treatment is performed to alleviate the residual stress contained in the manufactured amorphous alloy soft magnetic powder. In the heat treatment for evaluating coercivity, the heating temperature is 410°C, the holding time at this temperature is 15 minutes, and the furnace atmosphere (heating atmosphere) is a nitrogen atmosphere.

[0077] The tap density of the amorphous alloy soft magnetic powder is preferably within a specified range. Specifically, the tap density of the amorphous alloy soft magnetic powder is preferably 4.65 g / cm³. 3 Above 5.20 g / cm³ 3 Below, more preferably 4.70 g / cm³ 3 Above and 5.15 g / cm³ 3 Below. Within the stated tap density range, fewer irregularly shaped particles are obtained, achieving sphericity as a whole regardless of particle size, resulting in an amorphous alloy soft magnetic powder with a particle size distribution that improves filling properties. Such amorphous alloy soft magnetic powder can be used to manufacture high-density pressed powder cores, thus significantly improving the saturation flux density and permeability of magnetic components.

[0078] Furthermore, if the tap density is lower than the lower limit, the filling properties of the amorphous alloy soft magnetic powder may decrease when the amorphous alloy soft magnetic powder is pressed into a powder core. On the other hand, if the tap density exceeds the upper limit, the manufacturing difficulty of the amorphous alloy soft magnetic powder increases, and the manufacturing yield may decrease.

[0079] The tap density of amorphous alloy soft magnetic powder was determined according to the metal powder tap density determination method specified in JIS Z 2512:2012, after removing coarse particles with a sieve with a mesh size of 150 μm.

[0080] When amorphous alloy soft magnetic powder is classified according to the following steps, the mass ratio of the graded products preferably meets the specified conditions.

[0081] First, the amorphous alloy soft magnetic powder was classified using a first sieve with a mesh size of 150 μm. The fraction that passed through the first sieve was designated as -150 particles. Next, the -150 particles were classified using a second sieve with a mesh size of 25 μm. The fraction that passed through the second sieve was designated as -25 particles.

[0082] In the amorphous alloy soft magnetic powder, the mass ratio of -25 particles to -150 particles is preferably 35% or more and 50% or less, more preferably 40% or more and 47% or less. This indicates a high proportion of relatively small particles. That is, it is possible to achieve an amorphous alloy soft magnetic powder exhibiting the aforementioned tap density and containing a relatively high proportion of small particles. As a result, it is possible to manufacture amorphous alloy soft magnetic powder capable of producing magnetic components with particularly high fill power, high permeability, and high saturation flux density.

[0083] When amorphous alloy soft magnetic powder is classified using a sieve with a mesh size of 38 μm, the average roundness of the graded particles that pass through the sieve is preferably within the following range.

[0084] The average sphericity of the graded particles is preferably 0.85 or higher and 0.99 or lower, more preferably 0.86 or higher and 0.98 or lower, and even more preferably 0.88 or higher and 0.97 or lower. This achieves sphericity even for small-diameter particles, thus enabling a near-dense filling state. As a result, an amorphous alloy soft magnetic powder with optimal particle size distribution and a high contribution to the filling performance of the contained small-diameter particles can be achieved.

[0085] Furthermore, if the average sphericity is below the lower limit, spheroidizing small-diameter particles becomes difficult, potentially reducing the filling properties of the amorphous alloy soft magnetic powder. On the other hand, if the average sphericity exceeds the upper limit, manufacturing difficulty increases, potentially reducing the manufacturing efficiency of the amorphous alloy soft magnetic powder.

[0086] The average sphericity of amorphous alloy soft magnetic powder was determined as follows.

[0087] First, images (secondary electron images) of the amorphous alloy soft magnetic powder are captured using a scanning electron microscope (SEM). Next, the obtained images are imported into image processing software. For example, image resolution particle size distribution measurement software such as "Mac-View" manufactured by Mounttech Co., Ltd. is used. Furthermore, the magnification is adjusted to reflect 50 to 100 particles in a single image. Then, multiple images are acquired to obtain a total of more than 300 particle images.

[0088] Next, using software, the roundness of more than 300 particle images was calculated, and the average value was obtained. The obtained average value is the average roundness of the amorphous alloy soft magnetic powder. In addition, when the roundness is set as e, the area of ​​the particle image is set as S, and the circumference of the particle image is set as L, the roundness e is calculated by the following formula.

[0089] e = 4πS / L 2

[0090] 2. Method for manufacturing amorphous alloy soft magnetic powder

[0091] Next, the method for manufacturing the amorphous alloy soft magnetic powder involved in the embodiment will be described.

[0092] The amorphous alloy soft magnetic powder involved in the embodiments can be manufactured by any manufacturing method, such as by various powdering methods such as atomization, reduction, carbonylation, and pulverization.

[0093] Atomization is a method of manufacturing powder by pulverizing molten raw materials through collision with a fluid such as a high-speed jet of liquid or gas, while simultaneously cooling the material. Depending on the type of cooling medium and the structure of the apparatus, atomization methods include water atomization, gas atomization, and rotating water jet atomization. Amorphous alloy soft magnetic powder is preferably manufactured using water atomization or rotating water jet atomization, and more preferably using rotating water jet atomization.

[0094] In addition, the "water atomization method" in this specification refers to the following method: using a liquid such as water or oil as a coolant, and spraying it into an inverted cone shape that is concentrated at a single point, so that molten metal flows down and collides with that concentrated point, thereby producing metal powder.

[0095] On the other hand, according to the rotating water flow atomization method, the molten liquid can be cooled at extremely high speeds using rotating water flow, making it particularly easy to achieve amorphization.

[0096] When manufacturing amorphous alloy soft magnetic powder, the cooling rate of the molten metal is preferably greater than 10. 6 [K / sec], more preferably 10 7[K / sec] or higher. Thus, amorphous alloy soft magnetic powder with fully realized amorphization was obtained. That is, amorphization can be achieved even with a relatively high Fe content. In particular, using the rotating water jet atomization method, values ​​exceeding 10 K / sec can be easily achieved. 6 Cooling rate of [K / second].

[0097] The following section further explains the manufacturing method of amorphous alloy soft magnetic powder based on rotating water jet atomization.

[0098] In the rotating water jet atomization method, coolant is sprayed along the inner circumferential surface of a cooling cylinder, causing it to swirl and form a coolant layer on the inner circumferential surface. Meanwhile, the raw material for amorphous alloy soft magnetic powder is melted, and while the resulting molten metal falls naturally, a jet of liquid or gas is sprayed onto it. If the molten metal is thus dispersed, the dispersed molten metal is introduced into the coolant layer. As a result, the dispersed and micronized molten metal is rapidly cooled and solidified, yielding amorphous alloy soft magnetic powder.

[0099] Figure 1 This is a longitudinal sectional view showing an example of an apparatus for producing amorphous alloy soft magnetic powder by a rotating water jet atomization method.

[0100] Figure 1 The powder manufacturing apparatus 30 shown includes a cooling cylinder 1, a crucible 15, a pump 7, and a jet nozzle 24. The cooling cylinder 1 is a cylinder used to form a coolant layer 9 on its inner circumferential surface. The crucible 15 is a supply container for supplying molten metal 25 to flow down into the space 23 inside the coolant layer 9. The pump 7 supplies coolant to the cooling cylinder 1. The jet nozzle 24 ejects a gas jet stream 26 that breaks the flowing molten metal 25 into droplets. The molten metal 25 is prepared based on the composition of an amorphous alloy soft magnetic powder.

[0101] The cooling cylinder 1 is cylindrical and is installed with its axis inclined at an angle of less than 30° relative to the vertical direction.

[0102] The upper opening of the cooling cylinder 1 is closed by the cover 2. An opening 3 is formed in the cover 2 for supplying the flowing molten metal 25 into the space 23 of the cooling cylinder 1.

[0103] A coolant spray pipe 4 is provided at the upper part of the cooling cylinder 1 to spray coolant onto the inner circumferential surface of the cooling cylinder 1. Multiple outlets 5 of the coolant spray pipe 4 are provided at equal intervals along the circumference of the cooling cylinder 1.

[0104] The coolant spray pipe 4 is connected to the tank 8 via a piping connected to the pump 7. The coolant drawn from the tank 8 by the pump 7 is sprayed out through the coolant spray pipe 4 and supplied to the cooling cylinder 1. As a result, the coolant gradually flows down along the inner circumferential surface of the cooling cylinder 1 while rotating, thereby forming a coolant layer 9 along the inner circumferential surface. Alternatively, a cooler can be installed in the tank 8 or midway through the circulation path as needed. In addition to water, oils such as silicone oil can be used as the coolant, and various additives can be added. Furthermore, by removing dissolved oxygen from the coolant beforehand, oxidation of the manufactured powder can be suppressed.

[0105] Furthermore, a cylindrical descaling mesh 17 is connected to the lower part of the cooling cylinder 1, and a funnel-shaped powder recovery container 18 is provided on the lower side of the descaling mesh 17. A coolant recovery hood 13 is provided around the descaling mesh 17 to cover it, and a drain port 14 formed at the bottom of the coolant recovery hood 13 is connected to the tank 8 via a pipe.

[0106] The injection nozzle 24 is disposed in the space 23. The injection nozzle 24 is installed at the front end of the gas supply pipe 27 inserted through the opening 3 of the cover 2, and the nozzle outlet is configured to point towards the thin stream of molten metal 25.

[0107] In manufacturing amorphous alloy soft magnetic powder using such a powder manufacturing apparatus 30, firstly, pump 7 is activated to form a coolant layer 9 on the inner circumferential surface of the cooling cylinder 1. Next, molten metal 25 in crucible 15 is allowed to flow down into the space 23. If a gas jet 26 is injected into the flowing molten metal 25, the molten metal 25 disperses, and the micronized molten metal 25 is entrained in the coolant layer 9. As a result, the micronized molten metal 25 cools and solidifies, yielding amorphous alloy soft magnetic powder.

[0108] In the rotating water jet atomization method, a very high cooling rate can be maintained stably by continuously supplying coolant, thus promoting the amorphization of the manufactured amorphous alloy soft magnetic powder.

[0109] Furthermore, the molten metal 25, miniaturized by the gas jet 26, falls inertially until it is entrained in the coolant layer 9, thus achieving droplet spheroidization. As a result, it is possible to manufacture amorphous alloy soft magnetic powder with good particle size distribution and excellent filling properties.

[0110] The temperature of the molten metal 25 (casting temperature) only needs to be above the melting point of the raw material, but preferably it is a temperature 200°C or higher but less than 400°C above the melting point of the raw material, more preferably it is a temperature 230°C or higher but less than 370°C above the melting point, and even more preferably it is a temperature 250°C or higher but less than 350°C above the melting point. This optimizes the viscosity of the molten metal 25, enabling the production of amorphous alloy soft magnetic powders with finer particles and fewer irregular shapes.

[0111] Furthermore, if the temperature of the molten metal 25 is below the lower limit, the viscosity of the molten metal 25 increases, making it potentially difficult to manufacture fine amorphous alloy soft magnetic powder. Additionally, 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, making it potentially difficult to stably maintain the molten metal 25.

[0112] The prepared molten metal 25 is ejected through the nozzle of the crucible 15 and supplied to the cooling cylinder 1. The inner diameter (nozzle diameter) of the nozzle of the crucible 15 determines the particle size of the flowing molten metal 25, affecting the production quantity, particle size, and sphericity of the amorphous alloy soft magnetic powder per unit time. The inner diameter of the nozzle 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. As long as the inner diameter of the nozzle of the crucible 15 is within the above range, it is possible to produce amorphous alloy soft magnetic powder with optimized particle size D10, D50, and tap density.

[0113] Furthermore, if the inner diameter of the nozzle of crucible 15 is lower than the lower limit, the flowing molten metal 25 is easily cooled, potentially leading to an increase in oxygen content or a decrease in sphericity. On the other hand, if the inner diameter of the nozzle of crucible 15 exceeds the upper limit, it is difficult to finely and uniformly break down the molten metal 25. As a result, coarse and irregularly shaped particles are easily generated, potentially leading to a decrease in the tap density of the amorphous alloy soft magnetic powder.

[0114] Furthermore, the amount of molten metal 25 flowing down from the crucible 15 varies depending on the size of the apparatus, but is preferably more than 1.0 kg / min and less than 20.0 kg / min, more preferably more than 2.0 kg / min and less than 10.0 kg / min. This optimizes the amount of molten metal 25 flowing down within a given time, thus ensuring sufficient amorphization even for amorphous alloy soft magnetic powders with the aforementioned particle size distribution.

[0115] Furthermore, the pressure of the gas jet 26 varies slightly depending on the structure of the jet nozzle 24, and is preferably 2.0 MPa or more and 20.0 MPa or less, more preferably 3.0 MPa or more and 10.0 MPa or less. This optimizes the particle size of the molten metal 25 as it disperses, fully achieving amorphization, and enabling the manufacture of amorphous alloy soft magnetic powder with the aforementioned particle size distribution.

[0116] Furthermore, if the pressure of the gas jet 26 is below the lower limit, it is difficult to disperse the droplets sufficiently and finely, resulting in larger droplet sizes. On the other hand, the cooling rate inside the droplets decreases, and amorphization may become insufficient. Conversely, if the pressure of the gas jet 26 exceeds the upper limit, the size of the dispersed droplets may become too small. Consequently, the droplets are slowly cooled by the gas jet 26 and cannot undergo rapid cooling based on the coolant layer 9, potentially leading to insufficient amorphization.

[0117] Furthermore, the flow rate of the gas jet 26 is not particularly limited, but is preferably 1.0 [Nm³]. 3 [ / minute] or more and 20.0 [Nm] 3 [Nm] or less, more preferably 4.0 [Nm] 3 [ / minute] or more and 10.0 [Nm] 3 [ / minute] or less. This optimizes the particle size during the dispersion of molten metal 25, fully achieving amorphization, and enabling the manufacture of amorphous alloy soft magnetic powder with the aforementioned particle size distribution.

[0118] Furthermore, if the flow rate of the gas jet 26 is below the lower limit, it is difficult to disperse the droplets sufficiently and finely, resulting in larger droplet sizes. On the other hand, the cooling rate inside the droplets decreases, and amorphization may become insufficient. Conversely, if the flow rate of the gas jet 26 exceeds the upper limit, the size of the dispersed droplets may become too small. Consequently, the droplets are slowly cooled by the gas jet 26 and cannot undergo rapid cooling based on the coolant layer 9, potentially leading to insufficient amorphization.

[0119] The pressure of the coolant supplied to the cooling cylinder 1 at the time of ejection is preferably 5 MPa or more and about 200 MPa or less, more preferably 20 MPa or more and about 100 MPa or less, and even more preferably 50 MPa or more and about 100 MPa or less. This optimizes the flow rate of the coolant layer 9, preventing the micronized molten metal 25 from becoming irregularly shaped. As a result, an amorphous alloy soft magnetic powder with superior filling properties is obtained. Furthermore, the cooling rate of the molten metal 25 based on the coolant can be significantly improved. The amorphous alloy soft magnetic powder is obtained in the above manner.

[0120] In addition, amorphous alloy soft magnetic powders can be classified as needed. Examples of classification methods include dry classification such as sieving, inertial classification, centrifugal classification, and air classification, and wet classification such as sedimentation classification.

[0121] Furthermore, depending on the requirements, an insulating film can also 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; examples include inorganic materials such as phosphates like magnesium phosphate, calcium phosphate, zinc phosphate, manganese phosphate, and cadmium phosphate, and silicates like sodium silicate.

[0122] 3. Powder-pressed magnetic cores and magnetic components

[0123] Next, the pressed powder core and magnetic elements involved in the embodiments will be described.

[0124] The magnetic components involved in the embodiments can be applied to various magnetic components with magnetic cores, such as chokes, capacitors, noise filters, reactors, transformers, motors, actuators, solenoid valves, and generators. Furthermore, the powder-pressed magnetic cores involved in the embodiments can be applied to the magnetic cores of these magnetic components.

[0125] The following description uses two types of coil components as examples of magnetic elements.

[0126] 3.1. Circular

[0127] First, the ring-shaped coil component, which is the magnetic element involved in the embodiment, will be described.

[0128] Figure 2 This is a schematic top view showing a loop-shaped coil component. Figure 2 The coil component 10 shown has an annular pressed powder core 11 and a wire 12 wound around the pressed powder core 11.

[0129] The pressed powder magnetic core 11 is obtained by mixing the aforementioned amorphous alloy soft magnetic powder and a bonding material, feeding the resulting mixture into a forming mold, and then pressing and shaping it. In other words, the pressed powder magnetic core 11 is a pressed powder body containing the amorphous alloy soft magnetic powder described in the embodiment. Such a pressed powder magnetic core 11 has high permeability and low coercivity. Therefore, when a coil component 10 having the pressed powder magnetic core 11 is mounted in an electronic device or the like, the power consumption of the electronic device or the like can be reduced, and miniaturization and high output of the electronic device can be achieved.

[0130] The constituent materials used as bonding materials in the fabrication of the pressed powder magnetic core 11 include, for example, organic materials such as silicone resins, epoxy resins, phenolic resins, polyamide resins, polyimide resins, and polyphenylene sulfide resins, as well as inorganic materials such as phosphates such as magnesium phosphate, calcium phosphate, zinc phosphate, manganese phosphate, and cadmium phosphate, and silicates such as sodium silicate.

[0131] Materials with high conductivity can be used as constituent materials for the conductor 12, such as metallic materials including Cu, Al, Ag, Au, Ni, etc. Furthermore, an insulating film may be provided on the surface of the conductor 12 as needed.

[0132] Furthermore, the shape of the pressed powder core 11 is not limited to Figure 2 The ring shape shown can be, for example, a missing part of a ring, or a shape in which the long side is a straight line.

[0133] The pressed powder core 11 may, as needed, contain soft magnetic powders other than the amorphous alloy soft magnetic powder involved in the embodiments, or non-magnetic powders. In this case, the proportion of the aforementioned amorphous alloy soft magnetic powder in the mixed powder after mixing the powders is preferably more than 50% by mass, and more preferably more than 60% by mass.

[0134] 3.2. Closed magnetic circuit type

[0135] Next, a closed magnetic circuit type coil component, which is a magnetic element according to the embodiment, will be described.

[0136] Figure 3 It is a schematic perspective view of a coil component with a closed magnetic circuit.

[0137] The following description focuses on the differences between the closed magnetic circuit type coil component and the toroidal type coil component, and omits descriptions of the same points.

[0138] Figure 3 The coil component 20 shown has a chip-shaped pressed powder core 21 and a wire 22 embedded inside the pressed powder core 21 and formed into a coil shape. That is, the pressed powder core 21 is a pressed powder body containing the amorphous alloy soft magnetic powder involved in the embodiment. Such a pressed powder core 21 has high permeability and low coercivity.

[0139] Furthermore, the coil component 20 includes such a pressed powder core 21. Such a coil component 20 contributes to the miniaturization and high output of electronic devices.

[0140] The pressed powder core 21 may, as needed, contain soft magnetic powder or non-magnetic powder other than the amorphous alloy soft magnetic powder involved in the embodiments. In this 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 more than 60% by mass.

[0141] 4. Electronic devices

[0142] Next, based on Figures 4-6 The electronic equipment involved in the implementation method will be described.

[0143] Figure 4 This is a perspective view of a mobile personal computer, which is an electronic device according to an embodiment. Figure 4 The personal computer 1100 shown includes: a main body 1104 with a keyboard 1102; and a display unit 1106 with a display section 100. The display unit 1106 is supported by a hinge structure and is rotatable relative to the main body 1104. Such a personal computer 1100 may include, for example, magnetic components 1000 such as a choke coil for a switching power supply, a capacitor, and a motor.

[0144] Figure 5 This is a top view showing a smartphone, which is an electronic device involved in the implementation. Figure 5 The smartphone 1200 shown includes multiple operation buttons 1202, an earpiece 1204, and a microphone 1206. Furthermore, a display unit 100 is disposed between the operation buttons 1202 and the earpiece 1204. Such a smartphone 1200 may incorporate, for example, magnetic components 1000 such as capacitors, noise filters, and motors.

[0145] Figure 6 This is a perspective view showing a digital camera 1300, an electronic device according to an embodiment. The digital camera 1300 generates an image signal by photoelectric conversion of the light image of the subject using an imaging element such as a CCD (Charge Coupled Device).

[0146] Figure 6 The digital camera 1300 shown includes a display unit 100 located on the back of the housing 1302. The display unit 100 functions as a viewfinder that displays the subject as an electronic image. In addition, a light-receiving unit 1304, including an optical lens and a CCD, is provided on the front side of the housing 1302, i.e., the back side shown in the figure.

[0147] If the photographer confirms the image of the subject displayed on the display unit 100 and presses the shutter button 1306, the CCD's image capture signal at that moment is transmitted and stored in the memory 1308. Such a digital camera 1300 also incorporates, for example, magnetic components 1000 such as capacitors and noise filters.

[0148] Such an electronic device incorporates the magnetic element involved in the implementation method. Therefore, it can enjoy the advantages of a magnetic element with high permeability and low coercivity, enabling miniaturization and high output of the electronic device.

[0149] In addition, as an electronic device involved in the implementation method, besides Figure 4 Personal computers Figure 5 smartphones, Figure 6 Besides digital cameras, other examples include mobile phones, tablets, watches, inkjet printers and other inkjet printing devices, laptops, televisions, video cameras, video recorders, car navigation systems, pagers, electronic notebooks, electronic dictionaries, calculators, video game consoles, word processors, workstations, video phones, burglarproof television monitors, electronic telescopes, POS terminals, electronic thermometers, blood pressure monitors, blood glucose meters, electrocardiogram measuring devices, ultrasound diagnostic devices, electronic endoscopes and other medical devices, fish detectors, various measuring devices, measuring instruments for vehicles, aircraft, and ships, mobile control devices such as automotive control equipment, aircraft control equipment, railway vehicle control equipment, and ship control equipment, as well as flight simulators, etc.

[0150] 5. Effects of the implementation method

[0151] As described above, the amorphous alloy soft magnetic powder involved in the embodiments is composed of Fe, expressed in atomic ratios. a (Si 1-x B x ) b C c S d [Where, a is 100-bcd. Furthermore, 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.] The composition and impurity composition of the particles, in the cumulative particle size distribution under a volume reference obtained using a laser diffraction particle size distribution measuring device, when the particle size representing 10% of the cumulative frequency from the small diameter side is defined as D10, and the particle size representing 50% of the cumulative frequency 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 20.0 μm or more and 39.0 μm or less.

[0152] Based on this composition, it is possible to achieve amorphous alloy soft magnetic powder with low coercivity, high sphericity, and good filling properties.

[0153] In the amorphous alloy soft magnetic powder involved in the embodiments, the composition d is preferably 0.012≤d≤0.040.

[0154] Based on this composition, an amorphous alloy soft magnetic powder that can balance high permeability and low coercivity is obtained.

[0155] In the amorphous alloy soft magnetic powder involved in the embodiments, the tap density is preferably 4.65 g / cm³. 3 Above 5.20 g / cm³ 3 ]the following.

[0156] Based on this composition, fewer irregularly shaped particles are obtained, and sphericalization is achieved as a whole regardless of particle size, resulting in an amorphous alloy soft magnetic powder with a particle size distribution that can improve filling performance.

[0157] In the amorphous alloy soft magnetic powder involved in the embodiment, when the powder is classified using a first sieve with a mesh size of 150 μm and the particles that pass through the first sieve are classified as -150 particles, and the -150 particles are classified using a second sieve with a mesh size of 25 μm and the particles that pass through the second sieve are classified as -25 particles, the mass ratio of -25 particles to -150 particles is preferably 35% or more and 50% or less.

[0158] Based on this composition, it can be determined that the ratio of relatively small particles is high, thus enabling the production of amorphous alloy soft magnetic powders that can manufacture magnetic components with particularly high filler ratio, high permeability, and high saturation magnetic flux density.

[0159] In the amorphous alloy soft magnetic powder involved in the embodiments, the coercivity after heat treatment is preferably 1.2 [Oe] or less (95.49 [A / m] or less).

[0160] With this configuration, it is possible to manufacture magnetic components with sufficiently low hysteresis losses.

[0161] The powder-pressed magnetic core according to the embodiments comprises the amorphous alloy soft magnetic powder involved in the embodiments. Based on this configuration, a powder-pressed magnetic core with high permeability and low coercivity is obtained.

[0162] Furthermore, the magnetic element involved in the embodiment includes the pressed powder magnetic core involved in the embodiment.

[0163] Based on this configuration, a magnetic element with a powder core possessing high permeability and low coercivity is obtained.

[0164] Furthermore, the electronic device according to the embodiments includes the magnetic element according to the embodiments.

[0165] Based on this configuration, an electronic device that achieves miniaturization and high output was obtained.

[0166] The amorphous alloy soft magnetic powder, pressed powder 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 pressed powder core and magnetic element involved in the present invention may be a pressed powder core and magnetic element with any constituent parts having the same function, replacing each part of the embodiments described above, or a pressed powder core and magnetic element with any constituent parts added to the embodiments described above.

[0167] Furthermore, in the embodiments described above, pressed powder magnetic cores are cited as examples of applications of the amorphous alloy soft magnetic powder of the present invention, but the applications are not limited to this. For example, they can also be used in magnetic fluids, magnetic shielding sheets, magnetic heads, and other magnetic devices. Moreover, the shape of the pressed powder magnetic core and magnetic element is not limited to the shape shown in the figures, and can be any shape.

[0168] Example

[0169] Next, specific embodiments of the present invention will be described.

[0170] 6. Manufacturing of Powder-Powdered Magnetic Cores

[0171] 6.1. Sample No. 1

[0172] First, the raw materials are melted in a high-frequency induction furnace and then pulverized using a rotating water jet atomization method to obtain amorphous alloy soft magnetic powder. Additionally, the pressure of the gas jet is set to 3.0–5.0 MPa, and the flow rate is set to 8.0–12.0 Nm³. 3 [ / minute], set the coolant pressure to 40-60 MPa.

[0173] Next, the obtained amorphous alloy soft magnetic powder was subjected to heat treatment. The heating temperature for heat treatment was 410℃, and the time to maintain this temperature (heating time) was 15 minutes. The atmosphere inside the furnace was nitrogen.

[0174] Next, the amorphous alloy soft magnetic powder was classified using a classifier with a mesh size of 150 μm. The alloy composition of the classified amorphous alloy soft magnetic powder is shown in Table 1. Furthermore, to determine the alloy composition, a solid-state emission spectrometer manufactured by SPECTRO Corporation, model: SPECTROLAB, type: LAMVB08A, was used.

[0175] Next, the obtained amorphous alloy soft magnetic powder, epoxy resin as a binder, and toluene as an organic solvent are mixed to obtain a mixture. Furthermore, the amount of epoxy resin added is 2 parts by mass relative to 100 parts by mass of the amorphous alloy soft magnetic powder.

[0176] Next, after stirring, the mixture is dried for a short time to obtain a block-shaped dried body. Then, the dried body is passed through a 400 μm sieve and pulverized to obtain granulated powder. The obtained granulated powder is dried at 50°C for 1 hour.

[0177] Next, the obtained granulated powder is filled into a molding die, and a molded body is obtained based on the following molding conditions.

[0178] <Molding conditions>

[0179] Forming method: compression molding

[0180] Shape of the molded body: ring-shaped

[0181] The dimensions of the molded body are: outer diameter 14mm, inner diameter 8mm, thickness 3mm.

[0182] Forming pressure: 3t / cm 2 (294MPa)

[0183] Next, the molded body is heated in an atmospheric atmosphere at 150°C for 0.50 hours to solidify the bonding material. This yields the pressed powder magnetic core.

[0184] 6.2. Samples No. 2 to 14

[0185] In addition to the above as shown in Table 1 ( Figure 7 ) or Table 2 ( Figure 8 Except for changes to the composition and manufacturing conditions of the amorphous alloy soft magnetic powder shown in the figure, a pressed powder magnetic core was obtained in the same manner as in sample No. 1.

[0186] In addition, in the manufacture of amorphous alloy soft magnetic powders for samples No.1 to No.14, the temperature of the molten metal (casting temperature) was kept at +250°C to +350°C relative to the melting point of the raw material, and the inner diameter of the crucible nozzle was kept at 2.5 to 3.5 mm.

[0187] Figure 7 Table 1 shows the composition, manufacturing method, and manufacturing conditions of the amorphous alloy soft magnetic powders for samples No. 1 to 9. Figure 8 Table 2 shows the composition, manufacturing method, and manufacturing conditions of the amorphous alloy soft magnetic powders for samples No. 10 to 17.

[0188] 6.3. Samples No. 15~17

[0189] Except for changing the manufacturing method of the amorphous alloy soft magnetic powder to water atomization, and changing the composition and manufacturing conditions of the amorphous alloy soft magnetic powder to the conditions shown in Table 2, the pressed powder magnetic core was obtained in the same manner as in Sample No. 1.

[0190] In addition, in the manufacture of amorphous alloy soft magnetic powders for samples No.15 to No.17, the temperature of the molten metal (casting temperature) was kept at +150°C to +250°C relative to the melting point of the raw material, and the inner diameter of the crucible nozzle was kept at 1.5 to 2.5 mm.

[0191] Additionally, in Table 1 ( Figure 7 ) and Table 2 ( Figure 8 ) and Table 3 (described later) Figure 9 ) and Table 4 ( Figure 10 In the present invention, the amorphous alloy soft magnetic powders that are equivalent to the present invention in each sample No. are referred to as "Examples", and the amorphous alloy soft magnetic powders that are not equivalent to the present invention are referred to as "Comparative Examples".

[0192] 7. Evaluation of amorphous alloy soft magnetic powders and magnetic components

[0193] 7.1.Powder characteristics

[0194] Next, the particle size distribution of the amorphous alloy soft magnetic powders obtained in each embodiment and each comparative example was measured. This measurement was performed using a particle size distribution measuring device based on laser diffraction, namely the Mickey HRA9320-X100 manufactured by Nikkiso Corporation. Then, D10, D50, D90, and (D90-D10) / D50 were calculated respectively.

[0195] Furthermore, the amorphous alloy soft magnetic powders obtained in each embodiment 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. Then, the mass ratio of -25 particles to -150 particles was calculated. The calculation results are shown in Table 3. Figure 9 ) and Table 4 ( Figure 10 ).

[0196] Figure 9 Table 3 shows the composition and evaluation results of the amorphous alloy soft magnetic powders of samples No.1 to No.9. Figure 10 Table 4 shows the composition and evaluation results of the amorphous alloy soft magnetic powders of samples No. 10 to 17.

[0197] 7.2. Coercivity

[0198] The amorphous alloy soft magnetic powders obtained in each embodiment 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. In addition, the powders to be measured were subjected to a prescribed heat treatment before the measurement.

[0199] 7.3. Average roundness

[0200] After classifying the amorphous alloy soft magnetic powders obtained in each embodiment and each comparative example using a sieve with a mesh size of 38 μm, the average sphericity of the powders that passed through the sieve was calculated.

[0201] Next, the measured average roundness was evaluated against the following evaluation criteria. The evaluation results are shown in Tables 3 and 4.

[0202] A: Average roundness is 0.88 or higher.

[0203] B: Average roundness is 0.85 or higher and less than 0.88.

[0204] C: Average roundness is less than 0.85

[0205] 7.4. Tapped density

[0206] The amorphous alloy soft magnetic powders obtained in each embodiment and comparative example were classified using a sieve with a mesh size of 150 μm, and the tap density of the powders with the added sieves was measured. The measurement results are shown in Tables 3 and 4.

[0207] As shown in Tables 3 and 4, the amorphous alloy soft magnetic powders of each embodiment exhibit low coercivity and high average sphericity and tap density. Therefore, according to the present invention, it has been demonstrated that amorphous alloy soft magnetic powders with low coercivity, high sphericity, and good filling properties can be achieved.

Claims

1. An amorphous alloy soft magnetic powder, characterized by comprising a composition formula: aFe100-b-c-d-xMbNxSicMd wherein a is 100-b-c-d, The composition formula Fe a (Si 1-x B x ) b C c S d of the composition expressed by the atomic ratio and impurities In the composition formula, a is 100-b-c-d, Further, b, c, d, x are 16.0≤b≤22.0, 0＜c≤3.0， 0.001≤d≤0.060， 0.5≤x≤0.9， In a cumulative particle size distribution on a volume basis obtained using a laser diffraction type particle size distribution measuring device, when a particle size at which the cumulative frequency from the small diameter side is 10% is set as D10, and a particle size at which the cumulative frequency from the small diameter side is 50% is set 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.

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

040.

3. The amorphous alloy soft magnetic powder according to claim 1 or 2, wherein x in the composition formula is 0.0005≤x≤0.

005.

4. The amorphous alloy soft magnetic powder according to claim 3, wherein the composition formula is aFe100-b-c-d-xMbNxSicMd wherein a is 100-b-c-d, Tap density is 4.65 g / cm 3 Above and 5.20 g / cm 3 Below. When a first sieve having a mesh size of 150 μm is used for classification, the classified material that passes through the first sieve is used as -150 particles, and When a second sieve having a mesh size of 25 μm is used for classification of the -150 particles, the classified material that passes through the second sieve is used as -25 particles, the mass ratio of the -25 particles with respect 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 coercive force after heat treatment is 1.2 Oe or less, that is, 95.49 A / m or less.

6. A powder magnetic core, characterized by comprising the amorphous alloy soft magnetic powder according to claim 1 or 2.

7. A magnetic element, characterized by comprising the powder magnetic core according to claim 6.

8. An electronic device, characterized by comprising the magnetic element according to claim 7. ​ ​ ​ ​ ​ ​

Images