Soft magnetic alloy powder, compacted magnetic core and coil components

Abstract

To provide a soft magnetic alloy powder having good saturation magnetization and a coercive force capable of reducing core loss while maintaining good permeability and DC superposition characteristics of a dust core including the soft magnetic alloy powder.SOLUTION: The soft magnetic alloy powder includes soft magnetic alloy particles. The soft magnetic alloy particles include Fe, Si, and P. The soft magnetic alloy particles are composed of a plurality of crystallites and a crystal grain boundary between a plurality of crystallites. The crystallites have a portion where Si is segregated and a portion where P is segregated.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to soft magnetic alloy powder, compacted magnetic core, and coil components. [Background technology]

[0002] Patent Document 1 describes an invention of soft magnetic alloy particles containing Fe and Ni, etc. It also describes segregating a high-resistance layer containing Si, B, Nb, etc., at the grain boundaries between multiple crystallites by heat treatment. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-94272 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] The present invention aims to provide a soft magnetic alloy powder that has good saturation magnetization and coercivity, and furthermore, can reduce core loss while improving the permeability and DC superposition characteristics of a compacted magnetic core containing the soft magnetic alloy powder. [Means for solving the problem]

[0005] To achieve the above objective, the soft magnetic alloy powder of the present invention is a soft magnetic alloy powder containing soft magnetic alloy particles, The soft magnetic alloy particles contain Fe, Si, and P. The soft magnetic alloy particles consist of a plurality of crystallites and grain boundaries between the plurality of crystallites. The crystallite is characterized by the presence of regions where Si is segregated and regions where P is segregated.

[0006] The soft magnetic alloy powder according to the present invention has the above-mentioned characteristics, which allows for good saturation magnetization and coercivity. Furthermore, it is possible to reduce core loss while improving the permeability and DC superposition characteristics of the compacted magnetic core containing the soft magnetic alloy powder.

[0007] The soft magnetic alloy particles may contain only Fe, Si, P, and unavoidable impurities.

[0008] The Si content in the soft magnetic alloy particles may be 3.0% by mass or more and 11.0% by mass or less.

[0009] The P content in the soft magnetic alloy particles may be 0.10% by mass or more and 0.60% by mass or less.

[0010] The compacted magnetic core of the present invention contains the above-mentioned soft magnetic alloy powder.

[0011] The coil component of the present invention includes the above-mentioned powdered magnetic core. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram of soft magnetic alloy particles according to this embodiment. [Figure 2] This is a COMPO image of soft magnetic alloy particles from sample No. 4. [Figure 3] This is a Si mapping image of soft magnetic alloy particles from sample No. 4. [Figure 4] This is a P-mapping image of soft magnetic alloy particles from sample No. 4. [Figure 5] This is a binarized image of Figure 3. [Figure 6] This is a binarized image of Figure 4. [Modes for carrying out the invention]

[0013] Preferred embodiments of the present invention will be described below with reference to the drawings, but the embodiments of the present invention are not limited to those described below.

[0014] The soft magnetic alloy powder according to this embodiment contains soft magnetic alloy particles 2. As shown in FIG. 1, the soft magnetic alloy particles 2 are composed of a plurality of crystallites 4 and grain boundaries 4a existing between the crystallites 4.

[0015] The soft magnetic alloy particles 2 contained in the soft magnetic alloy powder according to this embodiment are characterized in that there are sites where Si is segregated and sites where P is segregated in the crystallites 4. Hereinafter, the site where Si is segregated may be simply referred to as the Si segregation part. The site where P is segregated may be simply referred to as the P segregation part. Also, there may be a part that is both a Si segregation part and a P segregation part.

[0016] The Si segregation part and the P segregation part are parts where the electric resistance is considered to be high compared to the parts of the crystallite 4 that are neither the Si segregation part nor the P segregation part. Since both the Si segregation part and the P segregation part are contained in the crystallite 4, the electric resistance in the crystallite 4 increases. When the electric resistance in the crystallite 4 increases, the generation of eddy currents in the crystallite 4 is suppressed. As a result, the compacted powder core produced using the soft magnetic alloy powder containing the soft magnetic alloy particles 2 in which both the Si segregation part and the P segregation part exist in the crystallite 4 has particularly good permeability at high frequencies and low core loss. Especially when the crystal grain size of the crystallite 4 is large, the effect of suppressing the generation of eddy currents due to the presence of both the Si segregation part and the P segregation part in the crystallite 4 becomes large.

[0017] Also, both the Si segregation part and the P segregation part may exist in the grain boundary 4a. It is considered that the electric resistance in the grain boundary 4a increases when both the Si segregation part and the P segregation part are contained in the grain boundary 4. When the electric resistance in the grain boundary 4a increases, the generation of eddy currents in the soft magnetic alloy particles 2 is suppressed.

[0018] It is particularly preferable that both the Si segregation part and the P segregation part exist in both the crystallite 4 and the grain boundary 4a. The compacted powder core produced using the soft magnetic alloy powder containing the soft magnetic alloy particles 2 in which both the Si segregation part and the P segregation part exist in both the crystallite 4 and the grain boundary 4a has particularly good permeability at high frequencies and low core loss. [[ID=!]]

[0019] There are no particular restrictions on the average particle size of the soft magnetic alloy particles 2, but for example, it is between 1 μm and 50 μm. Similarly, there are no particular restrictions on the average crystallite diameter of the crystallites 4, but for example, it is between 0.5 μm and 20 μm.

[0020] The soft magnetic alloy particles 2 contain at least Fe, Si, and P. Other elements may be included in amounts that do not significantly affect the properties of the soft magnetic alloy powder containing the soft magnetic alloy particles 2. For example, each of the other elements may be included in amounts of 5.0 mass% or less, or 1.0 mass% or less. Alternatively, the total amount of the other elements may be 10.0 mass% or less, or 2.0 mass% or less.

[0021] However, if the soft magnetic alloy particles 2 contain Ni, the crystallites 4 are less likely to contain Si segregation and P segregation. Also, raw materials containing Ni are expensive. Therefore, the Ni content is preferably 5.0% by mass or less, and preferably 0.5% by mass or less.

[0022] The soft magnetic alloy particles 2 may contain only Fe, Si, P, and unavoidable impurities. In this case, the content of unavoidable impurities may be 2.0% by mass or less, or 1.0% by mass or less.

[0023] There are no particular restrictions on the Si content in the soft magnetic alloy particles 2. It may be 2.0% by mass or more and 12.0% by mass or less, or 3.0% by mass or more and 11.0% by mass or less. A Si content of 2.0% by mass or more or 3.0% by mass or more makes it easier to lower the coercivity of the soft magnetic alloy powder containing the soft magnetic alloy particles 2. It also makes it easier to reduce the core loss of the compacted magnetic core containing the soft magnetic alloy powder. A Si content of 12.0% by mass or less or 11.0% by mass or less makes it easier to increase the saturation magnetization of the soft magnetic alloy powder containing the soft magnetic alloy particles 2. It also makes it easier to improve the permeability and DC superposition characteristics of the compacted magnetic core containing the soft magnetic alloy powder.

[0024] There are no particular restrictions on the P content in the soft magnetic alloy particles 2. It may be 0.10% by mass or more and 0.70% by mass or less, or 0.10% by mass or more and 0.60% by mass or less. A P content of 0.10% by mass or more makes it easier to include P segregation regions, making it easier to lower the coercivity of the soft magnetic alloy powder containing the soft magnetic alloy particles 2. If the P content is less than 0.10% by mass, it becomes more difficult to include P segregation regions. In addition, it becomes easier to reduce the core loss of the compacted magnetic core containing the soft magnetic alloy powder, making it easier to improve the DC superposition characteristics. A P content of 0.70% by mass or less or 0.60% by mass or less makes it easier to increase the saturation magnetization of the soft magnetic alloy powder containing the soft magnetic alloy particles 2, making it easier to lower the coercivity. In addition, it becomes easier to improve the permeability of the compacted magnetic core containing the soft magnetic alloy powder.

[0025] The fact that the soft magnetic alloy particles 2 consist of multiple crystallites 4 and grain boundaries 4a existing between the crystallites 4 can be confirmed by observing the backscattered electron image (COMPO image) obtained by EPMA. Figure 2 shows the COMPO image of the soft magnetic alloy particles according to this embodiment. There are no particular restrictions on the magnification of the COMPO image; any magnification and resolution that allows the above-mentioned microstructure of the soft magnetic alloy particles to be confirmed is acceptable. For example, the magnification can be between 500x and 5000x.

[0026] Furthermore, the presence of Si segregation regions at grain boundaries 4a and crystallite 4 can be confirmed by performing Si mapping using EPMA. Figure 3 shows the Si mapping image of the soft magnetic alloy particles shown in Figure 2. In this embodiment, regions with a Si concentration of 105% or more relative to the average Si concentration of the soft magnetic alloy particles are defined as Si segregation regions. The size of one Si segregation region is 0.4 μm. 2 That concludes the explanation. The size is 0.4 μm. 2 The portion less than the specified value is not considered a Si segregation region.

[0027] Furthermore, the presence of P segregation regions at grain boundaries 4a and crystallites 4 can be confirmed by P mapping using EPMA. Figure 4 shows the P mapping image of the soft magnetic alloy particles shown in Figure 2. In this embodiment, regions with a P concentration of 105% or more relative to the average P concentration of the soft magnetic alloy particles are defined as P segregation regions. The size of one P segregation region is 0.4 μm. 2 That concludes the explanation. The size is 0.4 μm. 2 The portion less than the P segregation is not considered a P segregation.

[0028] Figure 5 is a binarized image of the Si mapping image shown in Figure 3, divided into areas with a Si concentration of 105% or more relative to the average Si concentration of the soft magnetic alloy particles and areas with a Si concentration of less than 105%. By comparing Figure 2 and Figure 5, it is possible to confirm whether Si segregation zones exist at the grain boundaries and in the crystallites. As shown in Figures 3 and 5, Si segregation zones exist at the grain boundaries, and furthermore, Si segregation zones exist in a network-like structure in the crystallites.

[0029] Figure 6 is a binarized image of the P mapping shown in Figure 4, divided into areas with a P concentration of 105% or more relative to the average P concentration of the soft magnetic alloy particles and areas with a P concentration of less than 105%. By comparing Figure 2 and Figure 6, it is possible to confirm whether P segregation zones exist at the grain boundaries and in the crystallites. As shown in Figures 4 and 6, P segregation zones exist at the grain boundaries, and furthermore, P segregation zones exist in a network-like structure in the crystallites.

[0030] Figures 2 to 6 show soft magnetic alloy particles with a Si content of 6.5 mass% and a P content of 0.20 mass%. The soft magnetic alloy particles shown in Figures 2 to 6 are the same soft magnetic alloy particles as sample No. 6, which will be described later.

[0031] There are no particular restrictions on the proportion of Si segregation at the grain boundary 4a. In the cross-section of the soft magnetic alloy particle 2, it is preferable that the total area of ​​Si segregation at the grain boundary 4a is 70% or more of the total area of ​​the grain boundary 4a.

[0032] There are no particular restrictions on the proportion of Si segregation in the crystallite 4. In the cross-section of the soft magnetic alloy particle 2, it is preferable that the total area of ​​Si segregation in the crystallite 4 is 5% or more of the total area of ​​the crystallite 4.

[0033] There are no particular restrictions on the proportion of P segregation at the grain boundaries 4a. In the cross-section of the soft magnetic alloy particle 2, it is preferable that the total area of ​​P segregation at the grain boundaries 4a is 70% or more of the total area of ​​the grain boundaries 4a.

[0034] There are no particular restrictions on the proportion of P segregation in the crystallite 4. In the cross-section of the soft magnetic alloy particle 2, it is preferable that the total area of ​​P segregation in the crystallite 4 is 5% or more of the total area of ​​the crystallite 4.

[0035] Furthermore, an oxide film may be present on the particle surface 2a of the soft magnetic alloy particles 2. For example, the thickness of the oxide film may be 5.0 nm or less, or 3.0 nm or less. The thinner the oxide film, the easier it is for the hardness of the soft magnetic alloy particles 2 to decrease, and the easier it is for processability to improve. By improving the processability of the soft magnetic alloy particles 2, it becomes easier to improve the density of the compacted magnetic core containing the soft magnetic alloy particles 2.

[0036] The soft magnetic alloy powder according to this embodiment contains soft magnetic alloy particles 2 according to this embodiment. The soft magnetic alloy powder according to this embodiment does not have to consist only of soft magnetic alloy particles 2 according to this embodiment; it may also contain soft magnetic alloy particles whose crystallites do not contain Si segregation portions and / or P segregation portions. In the soft magnetic alloy powder according to this embodiment, it is preferable that the content of soft magnetic alloy particles whose crystallites contain both Si segregation portions and P segregation portions is 50% or more based on the number of particles. Furthermore, in the soft magnetic alloy powder according to this embodiment, it is preferable that the content of soft magnetic alloy particles whose crystal grain boundaries and crystallites contain both Si segregation portions and P segregation portions is 50% or more based on the number of particles.

[0037] The following describes an example of a method for producing soft magnetic alloy powder consisting of soft magnetic alloy particles according to this embodiment, but the method for producing soft magnetic alloy powder according to this embodiment is not limited to the method described below. In this embodiment, an aggregate of a substance containing multiple particles is used as the powder.

[0038] First, prepare the raw materials for the soft magnetic alloy powder. The raw materials can be individual metals or alloys. There are no particular restrictions on the form of the raw materials. For example, they can be ingots, chunks, or shots.

[0039] Next, the prepared raw materials are weighed and mixed. At this stage, the weighing is done so that the desired composition of soft magnetic alloy powder is ultimately obtained. Then, the mixed raw materials are melted and mixed to obtain a molten material. There are no particular restrictions on the equipment used for melting and mixing. For example, a crucible can be used.

[0040] Next, soft magnetic alloy powder is produced from the molten material. There are no particular restrictions on the method of producing soft magnetic alloy powder from the molten material, but for example, gas atomization, rotating disk method, and water atomization method can be used. Of these, in the gas atomization method, soft magnetic alloy powder can be produced by supplying the molten material as a continuous fluid through a nozzle or the like, and rapidly cooling the supplied molten material by impacting it with high-pressure gas.

[0041] Next, the obtained soft magnetic alloy powder is heat-treated. By performing the heat treatment under appropriate heat treatment conditions, both Si segregation and P segregation can be incorporated into the grain boundaries and crystallites.

[0042] The preferred heat treatment conditions vary depending on the composition of the target soft magnetic alloy powder, but typically the holding temperature during heat treatment is 800°C to 1100°C, preferably 800°C to 900°C. The holding time is 10 minutes to 3 hours, preferably 10 minutes to 2 hours.

[0043] Furthermore, the cooling rate to 300°C after heat treatment should be between 0.1°C / s and 100°C / s. There are no particular restrictions on the heat treatment atmosphere, but it is usually an inert gas atmosphere such as nitrogen or argon, or a vacuum.

[0044] In particular, by setting the holding temperature during heat treatment to a high temperature as described above, and the cooling rate to a fast rate as described above, it is possible to include both Si segregation zones and P segregation zones not only in the grain boundaries but also in the crystallites. If the cooling rate is too slow, it becomes easier to include both Si segregation zones and P segregation zones in the grain boundaries, but it becomes more difficult to include both Si segregation zones and P segregation zones in the crystallites. If the cooling rate is too fast, it becomes more difficult to include both Si segregation zones and P segregation zones in both the grain boundaries and the crystallites. In other words, if the cooling rate is too fast, Si and P tend to be uniformly distributed within the soft magnetic alloy particles.

[0045] If the holding temperature is too high, the crystallites tend to become coarse. If the holding temperature is too low, Si and P segregation zones are more likely to be included at the grain boundaries, but it becomes more difficult to include Si and P segregation zones in the crystallites.

[0046] By the above method, a soft magnetic alloy powder consisting of soft magnetic alloy particles according to this embodiment can be obtained. Furthermore, a compacted magnetic core can be obtained using a method commonly used with the soft magnetic alloy powder according to this embodiment. There are no particular restrictions on the method for obtaining the compacted magnetic core.

[0047] A compacted magnetic core may be obtained using a soft magnetic alloy powder obtained by mixing the soft magnetic alloy powder according to this embodiment with other soft magnetic metal powders. There are no particular restrictions on the type of other soft magnetic metal powder. For example, a soft magnetic metal powder with a smaller average particle size than the soft magnetic alloy powder according to this embodiment can be used. The average particle size of the soft magnetic metal powder with a smaller average particle size may be 0.5 μm or more and 5 μm or less. There are no particular restrictions on the material of the soft magnetic metal powder with a smaller average particle size. For example, metals such as pure iron and alloys such as permalloy can be used.

[0048] There are no particular restrictions on the proportion of the soft magnetic alloy powder according to this embodiment when mixing it with the soft magnetic metal powder with a small average particle size. For example, it may be 50% by mass or more.

[0049] Coil components, such as inductors, reactors, and motors, can be obtained from the powdered magnetic core according to this embodiment using methods commonly employed. In particular, coil components with high saturation current, low coil resistance, and low loss at high frequencies can be obtained. Furthermore, when using the powdered magnetic core according to this embodiment, miniaturization of coil components is also easy. There are no particular restrictions on the method of obtaining the coil components. [Examples]

[0050] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0051] [Preparation of soft magnetic alloy powder] First, ingots, chunks, or shots of elemental Fe and elemental Si were prepared. Next, the elemental Fe and elemental Si were mixed to the Si content shown in Tables 1 to 3 and placed in a crucible located in a gas atomizing apparatus. The P content was controlled by controlling the P content in each of the above raw materials, and further control was achieved by adding Fe-P alloy if necessary. Then, in an inert atmosphere, the crucible was heated to over 1500°C by high-frequency induction using a work coil placed outside the crucible, melting and mixing the ingots, chunks, or shots in the crucible to obtain a melt.

[0052] Next, molten metal from the crucible was supplied through a nozzle in the crucible, and at the same time, the supplied molten metal was rapidly cooled by impacting it with a high-pressure gas of 1 to 10 MPa. This process produced Fe-Si-P (Fe-Si only for sample No. 1) soft magnetic alloy powders with the Si and P content shown in Tables 1 to 3. In all soft magnetic alloy powders, the average particle size of the soft magnetic alloy particles was set to 25 μm.

[0053] Furthermore, the obtained soft magnetic alloy powder was subjected to heat treatment. The heat treatment conditions for each experimental example described in Table 1 are shown in Table 1. In addition, the heat treatment conditions for each experimental example described in Tables 2 and 3 were appropriately controlled within the range of: holding temperature: 800°C to 1100°C, holding time: 10 minutes to 3 hours, and cooling rate to 300°C after heat treatment: 0.1°C / s to 100°C / s.

[0054] [Preparation of powdered magnetic core] Granulated powder was prepared by adding epoxy resin as a binder to heat-treated soft magnetic alloy powder. The type and amount of epoxy resin added were determined appropriately according to the composition of each soft magnetic alloy powder. Using this granulated powder, a toroidal shape with an outer diameter of 18 mm, an inner diameter of 10 mm, and a height of 5 mm was formed at a molding pressure of 6 ton / cm². 2 The material was then molded. Next, the molded body was held at 180°C for 3 hours in an atmospheric environment to cure the resin, thereby obtaining a toroidal-shaped powder magnetic core.

[0055] [Evaluation of soft magnetic alloy powders] The saturation magnetization σs and coercivity Hc of the soft magnetic alloy powders in each experimental example were measured. σs was measured using a vibrating sample magnetometer (VSM) at a magnetic field of 1000 kA / m. Hc was measured using an Hc meter. The results are shown in Tables 1 to 3. A σs of 120 emu / g or higher was considered good, and 145 emu / g or higher was considered even better. A Hc of 1000 A / m or lower was considered good, and 800 A / m or lower was considered even better.

[0056] (Observation of Si segregation and P segregation) The presence or absence of Si segregation zones at grain boundaries and crystallites, and the presence or absence of P segregation zones, was determined by observing the cross-section obtained by cross-polishing a compound obtained by resin-mixing soft magnetic alloy powder. Specifically, the positions of grain boundaries and crystallites in the soft magnetic alloy particles were identified from the COMPO image obtained by observing the compound at a magnification of 2000x using EPMA (JEOL JXA-8500F). Then, the presence or absence of Si segregation zones at grain boundaries and the presence or absence of Si segregation zones in the crystallites of the soft magnetic alloy particles were determined from the Si mapping image obtained by observing the compound at a magnification of 2000x using EPMA (JEOL JXA-8500F). Furthermore, by observing the compound at a magnification of 2000x using EPMA (JEOL JXA-8500F), we were able to determine whether or not P segregation regions exist at the grain boundaries of the soft magnetic alloy particles, and whether or not P segregation regions exist in the crystallites of the soft magnetic alloy particles, based on the P mapping images obtained.

[0057] The measurement conditions for EPMA were: acceleration voltage 15.0kV, irradiation current 1.030 × 10⁻¹⁰ -7 A. The irradiation time was 40.00 ms, the number of measurement points was 200 × 200, and the measurement point interval was 0.20 μm. Furthermore, the Si content and P content were calculated assuming that the sum of the content of the four elements Si, P, O, and Fe was 100 mass%. O is included as an unavoidable impurity. In addition, the composition of the parts other than the soft magnetic alloy particles is inaccurate. This is because the parts other than the soft magnetic alloy particles contain a large amount of carbon (C) derived from the compounded resin.

[0058] In this example, at least 10 soft magnetic alloy particles were observed in the cross-section obtained by polishing the cross-section of a compound obtained by kneading soft magnetic alloy particles with resin. In each example, the proportion of soft magnetic alloy particles with Si segregation and P segregation at the grain boundaries and crystallites was 70% or more on a number basis.

[0059] In the comparative example of Sample No. 1, the proportion of soft magnetic alloy particles with Si segregation regions at grain boundaries was 70% or more on a particle number basis. The proportion of soft magnetic alloy particles with Si segregation regions in crystallites was 70% or more on a particle number basis. However, no soft magnetic alloy particles with P segregation regions at grain boundaries or in crystallites were observed at all.

[0060] In the comparative example of Sample No. 2, no soft magnetic alloy particles with Si segregation regions at grain boundaries, in crystallites, with P segregation regions at grain boundaries, or in crystallites were observed at all.

[0061] In the comparative example of Sample No. 3, the proportion of soft magnetic alloy particles with Si segregation regions at grain boundaries was 70% or more on a particle number basis. The proportion of soft magnetic alloy particles with P segregation regions at grain boundaries was 70% or more on a particle number basis. However, no soft magnetic alloy particles with Si segregation regions in crystallites or with P segregation regions in crystallites were observed at all.

[0062] The results are shown in Tables 1 to 3.

[0063] [Evaluation of Powder Compression Core] (Measurement of Permeability and DC Superposition Characteristics) For the powder compression cores of each example and comparative example, the relative permeability μ´ at a frequency of 1 MHz was measured. An RF impedance material analyzer (manufactured by Agilent Technologies: 4991A) was used for the measurement of the relative permeability μ´. Also, let the relative permeability μ´ when the applied DC current is 0, that is, when no DC current is superimposed, be μ0, and the relative permeability μ´ when a DC magnetic field of 20 kA / m is applied with a DC current superimposed be μ 20k and calculate μ 20k / μ0 to evaluate the DC superposition characteristics. In this example, μ0 of 14.0 or more was regarded as good and 15. or more was regarded as even better. Also, μ 20k / μ0 of 0.60 or more was regarded as good and 0.65 or more was regarded as even better. The results are shown in Tables 1 to 3.

[0064] (Measurement of core loss (power loss) Pcv) For each example and comparative example, the compacted magnetic core was wound with 30 primary turns and 10 secondary turns. The Pcv was then measured at a measurement frequency of 0.3 MHz and a magnetic flux density of 25 mT. It was also measured at a measurement frequency of 3 MHz and a magnetic flux density of 10 mT. Pcv was measured using a BH analyzer (SY-8218, manufactured by Iwasaki Communication Equipment Co., Ltd.). The Pcv measured at a measurement frequency of 0.3 MHz and a magnetic flux density of 25 mT was 700 kW / m². 3 The following conditions are considered good, and 600kW / m 3 The following was further improved: Pcv measured at a measurement frequency of 3 MHz and a magnetic flux density of 10 mT was 1750 kW / m². 3 The following conditions are considered good, and the 1550kW / m² requirement is met. 3 The following were further improved. The results are shown in Tables 1 to 3.

[0065] [Table 1]

[0066] [Table 2]

[0067] [Table 3]

[0068] Tables 1 to 3 show that each example in which the crystallites of the soft magnetic alloy particles contained Si segregation and P segregation exhibited good magnetic properties. Furthermore, when compacted magnetic cores were fabricated from the soft magnetic alloy particles, they showed good relative permeability and DC superposition characteristics, and core loss was small at all frequencies.

[0069] Furthermore, when the Si content was 3.0 mass% or higher, the coercivity of the soft magnetic alloy powder and the core loss of the compacted magnetic core were particularly reduced. Also, when the Si content was 11.0 mass% or lower, the saturation magnetization of the soft magnetic alloy powder and the relative permeability μ' of the compacted magnetic core were particularly increased. In addition, the DC superposition characteristics of the compacted magnetic core were improved.

[0070] Furthermore, when the P content was 0.10 mass% or higher, the Pcv measured at particularly high frequencies was excellent. Also, when the P content was 0.60 mass% or lower, the saturation magnetization of the soft magnetic alloy powder and the relative permeability μ' of the compacted magnetic core were particularly high.

[0071] In contrast, when the crystallites of the soft magnetic alloy particles did not contain P segregation zones (samples No. 1-3), the Pcv measured at high frequencies deteriorated when compacted magnetic cores were fabricated from the soft magnetic alloy particles. [Explanation of symbols]

[0072] 2...Soft magnetic alloy particles 2a...(soft magnetic alloy) particle surface 4. Crystallite 4a...grain boundary

Claims

1. A soft magnetic alloy powder containing soft magnetic alloy particles, The soft magnetic alloy particles contain Fe, Si, and P. The soft magnetic alloy particles consist of a plurality of crystallites and grain boundaries between the plurality of crystallites. A soft magnetic alloy powder having regions in which Si is segregated and regions in which P is segregated in the crystallite.

2. The soft magnetic alloy powder according to claim 1, wherein the soft magnetic alloy particles consist only of Fe, Si, P, and unavoidable impurities.

3. The soft magnetic alloy powder according to claim 1 or 2, wherein the Si content in the soft magnetic alloy particles is 3.0% by mass or more and 11.0% by mass or less.

4. The soft magnetic alloy powder according to claim 1 or 2, wherein the P content in the soft magnetic alloy particles is 0.10% by mass or more and 0.60% by mass or less.

5. A compacted magnetic core comprising the soft magnetic alloy powder according to claim 1 or 2.

6. A coil component comprising a compacted magnetic core as described in claim 5.

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