JP2023152791A - Powder magnetic core and magnetic component - Google Patents

Abstract

To provide a powder magnetic core having high initial permeability μ i.SOLUTION: A powder magnetic core includes: soft magnetic metal particles; and a grain boundary phase present between the soft magnetic metal particles, and Si and Ti are present in the grain boundary phase.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to powder magnetic cores and magnetic components.

Patent Document 1 describes that the aspect ratio of the flat powder is controlled and that an insulating coating covering the flat powder is made of a polymer containing titanium alkoxides.

Patent Document 2 describes an invention relating to a magnetic material including soft magnetic alloy particles coated with a plurality of types of oxide films.

International Publication No. 2015/033825 JP 2018-11043 Publication

One embodiment of the present disclosure provides a powder magnetic core with a high initial permeability μi.

A powder magnetic core according to an embodiment of the present disclosure includes soft magnetic metal particles and a grain boundary phase existing between the soft magnetic metal particles,
Si and Ti are present in the grain boundary phase.

In the above powder magnetic core, the content ratio of Ti present in the grain boundary phase may be 100 ppm or more and 3000 ppm or less based on the mass of the powder magnetic core.

In any of the powder magnetic cores described above, the soft magnetic metal particles may contain Fe.

In any of the powder magnetic cores described above, the soft magnetic metal particles may include a core particle and an insulating film formed on a surface of the core particle.

In any of the powder magnetic cores described above, the insulating film may contain an oxide of Si.

In any of the powder magnetic cores described above, the insulating film may contain an oxide of Si and Ti.

In any of the powder magnetic cores described above, the core particles may contain Fe.

A magnetic component according to the present disclosure includes any of the powder magnetic cores described above.

FIG. 1 is a schematic diagram of a cross section of a powder magnetic core according to an embodiment of the present disclosure.

Embodiments of the present disclosure will be described below with reference to the drawings. The embodiments of the present disclosure described below are examples for explaining the present disclosure. Various components related to the embodiments of the present disclosure, such as numerical values, shapes, materials, manufacturing processes, etc., can be modified or changed within a range that does not cause any technical problems.

Further, the shapes etc. shown in the drawings of the present disclosure do not necessarily match the actual shapes etc. This is because the shapes and the like may have been changed for the sake of explanation.

A powder magnetic core 1 according to an embodiment of the present disclosure includes metal magnetic particles (core particles) 11 and a grain boundary phase 12, as shown in FIG. Furthermore, an insulating film 13 formed on the surface 11a of the core particle 11 may be included.

A soft magnetic metal particle according to an embodiment of the present disclosure may include a core particle 11 and an insulating film 13 formed on a surface 11a of the core particle 11. In this case, the insulating film 13 covers the core particles 11.

The components of the core particles 11 are not particularly limited as long as they contain a magnetic material, but the core particles 11 may contain Fe. When the core particles 11 contain Fe as a main component, the saturation magnetization tends to be high. When the core particles 11 contain Fe and Si as main components, the initial magnetic permeability μi tends to be high. When the core particles 11 contain Fe and Ni as main components, the initial magnetic permeability μi tends to be high. When the core particles 11 contain Fe and Co as main components, the initial magnetic permeability μi tends to be high.

In addition, "contained as a main component" means that the content ratio of each element contained as a main component is 1% by weight or more, and the total content ratio of elements contained as a main component is 40% by weight or more, and This means that the content ratio of each element other than the elements included as the main component is lower than the content ratio of the element with the lowest content ratio among the elements included as the main component.

When the core particles 11 contain Fe as a main component, the content ratio of Fe is 40% by weight or more, and the content ratio of each element other than Fe is lower than the content ratio of Fe. Note that there are no particular restrictions on the types of components other than the main component in the core particles 11. Examples of the types of components other than the main component (Fe) include Ni, Co, Si, Zr, and V.

When the core particles 11 contain Fe and Si as main components, the content ratio of Fe is 1% by weight or more, the content ratio of Si is 1% by weight or more, and the total content ratio of Fe and Si is 40% by weight. % or more, and the content ratio of each element other than Fe and Si is lower than the content ratio of the element with a lower content ratio among Fe and Si. Note that there are no particular restrictions on the types of components other than the main component in the core particles 11. Examples of the types of components other than the main components (Fe and Si) include Ni, Co, Zr, and V.

When the core particles 11 contain Fe or Fe and Si as main components, there is no particular restriction on the content ratio of Fe and Si in the core particles 11. The weight ratio of Si/Fe may be 0/100 to 20/80. When the weight ratio of Si/Fe is 0/100 to 10/90, saturation magnetization tends to be high.

When the core particles 11 contain Fe and Ni as main components, the content ratio of Fe is 1% by weight or more, the content ratio of Ni is 1% by weight or more, and the total content ratio of Fe and Ni is 40% by weight. % or more, and the content ratio of each element other than Fe and Ni is lower than the content ratio of the element with a lower content ratio among Fe and Ni. Note that there are no particular restrictions on the types of components other than the main component in the core particles 11. Examples of the types of components other than the main components (Fe and Ni) include Co, Si, Zr, and V.

When the core particles 11 contain Fe or Fe and Ni as main components, the content ratio of Fe and Ni in the core particles 11 is not particularly limited. The weight ratio of Ni/Fe may be 0/100 to 75/25.

When the core particles 11 contain Fe and Co as main components, the content ratio of Fe is 1% by weight or more, the content ratio of Co is 1% by weight or more, and the total content ratio of Fe and Co is 40% by weight. % or more, and the content ratio of each element other than Fe and Co is lower than the content ratio of the element with a lower content ratio among Fe and Co. Note that there are no particular restrictions on the types of components other than the main component in the core particles 11. Examples of the types of components other than the main components (Fe and Co) include Ni, Si, Zr, and V.

When the core particles 11 contain Fe or Fe and Co as main components, the content ratio of Fe and Co in the core particles 11 is not particularly limited. The weight ratio of Co/Fe may be 0/100 to 50/50.

The powder magnetic core 1 according to this embodiment includes soft magnetic metal particles and a grain boundary phase 12 existing between the soft magnetic metal particles. Further, Si and Ti are present in the grain boundary phase 12.

There is no particular restriction on the method of making Si and Ti exist in the grain boundary phase 12. For example, the grain boundary phase 12 may be formed by including Ti in a resin containing Si (eg, silicone resin) and mixing it with soft magnetic metal particles. Examples of silicone resins include methyl-based silicone resins.

When the grain boundary phase 12 contains Ti, the initial magnetic permeability μi of the powder magnetic core 1 is more likely to be improved at the same density, compared to the case where the grain boundary phase 12 does not contain Ti.

In addition to the Si-containing resin, the grain boundary phase 12 may contain components other than the Si-containing resin. For example, even if epoxy resin, imide resin, Si-O oxide, Ca-O oxide, Ba-O oxide, and/or Bi-O oxide are mixed with resin containing Si, good. Examples of the epoxy resin include cresol novolac. Examples of the imide resin include bismaleimide.

Note that due to the heat treatment described below, part or all of the silicone resin contained in the grain boundary phase 12 may be modified into a Si--O-based oxide such as SiO ₂ .

There are no particular limitations on the content of core particles 11 and the content of compounds contained in grain boundary phase 12. The content of the core particles 11 in the entire powder magnetic core 1 may be 90% by weight to 99.9% by weight. The content of the compound contained in the grain boundary phase 12 in the entire powder magnetic core 1 may be 0.1% by weight to 10% by weight.

Although there is no particular restriction on the content ratio of Ti present in the grain boundary phase 12, it may be 100 ppm or more and 3000 ppm or less based on the mass of the powder magnetic core 1.

When the content ratio of Ti is within the above range, the initial magnetic permeability μi can be further improved.

The insulating film 13 does not need to cover the entire surface 11a of the core particle 11, and may cover 90% or more of the entire surface 11a of the core particle 11.

The insulating film 13 may contain Si oxide. There is no particular restriction on the type of Si oxide contained in the insulating film 13. For example, it may be a Si—O-based oxide (silicon oxide). Further, there is no particular restriction on the type of Si--O based oxide. For example, in addition to Si oxides such as SiO ₂ , composite oxides containing Si and other elements may be used. Examples of other elements include Ba, Ca, Mg, Al, Ti, Nb, Ta, Zr, Ni, Mn, and Zn whose oxides have insulating properties. For example, the content of the other elements may be 1 mol % or less relative to the Si content.

The insulating film 13 is formed directly or indirectly on the surface of the core particle 11. That is, the surface 11a of the core particle 11 and the insulating film 13 may be in contact with each other, or a film other than the insulating film 13 may be interposed between the surface 11a of the core particle 11 and the insulating film 13.

There are no particular restrictions on the materials of the films other than the insulating film 13. For example, a film other than the insulating film 13 may contain Si and O, and may also contain an element (for example, Fe) contained in the core particles 11. Further, the film other than the insulating film 13 may be a film containing a phosphoric acid compound. In the case where a film other than the insulating film 13 is present, the thickness of the film other than the insulating film 13 may be 20 nm or less.

The insulating film 13 may contain Si oxide and Ti. In this case, the films other than the above-mentioned insulating film 13 may be films containing an oxide of Si and not containing Ti.

There is no particular restriction on how Ti is contained in the insulating film 13. For example, the insulating film 13 may be dotted with Ti alone. Further, the insulating film 13 may contain a compound containing Ti. There are no particular restrictions on the type of compound containing Ti. Examples include organometallic compounds containing Ti, such as titanium alkoxides and titanates (metal complexes with Ti as the central metal). Further, the compound containing Ti may be a simple oxide of Ti or a complex oxide of Ti and other elements.

There is no particular restriction on the content ratio of Ti in the insulating film 13.

In addition to Ti, the insulating film 13 may contain a metal element other than Ti. Examples include Ba, Ca, Mg, Al, Zr, Ni, Mn, Zn, etc. whose oxides have insulating properties. Among them, Ca, Mg, Zr, Ni, Mn, and Zn are relatively easy to introduce into the insulating film. There is no particular restriction on the content of metal elements other than Ti. For example, the content ratio with respect to the Ti content may be 1 mol% or less.

There is no particular limit to the thickness of the insulating film 13. For example, the thickness may be greater than or equal to 5 nm and less than or equal to 500 nm.

There is no particular restriction on the method of observing the cross section of the powder magnetic core 1. For example, the powder magnetic core 1 may be observed at an appropriate magnification using SEM or TEM. Furthermore, by performing EDS analysis, the composition at each location of the powder magnetic core 1, particularly the content of Ti and the content of Si, can be measured. Then, Ti/(Si+Ti) in the insulating film 13 can be measured. The Ti content in the core particles 11 can also be measured in a similar manner.

When measuring the content ratio of Ti present in the grain boundary phase 12, first, for example, the Ti content in the core particles 11 and the Ti content in the insulating film 13 are measured by the above measurement. Thereafter, the Ti content of the entire dust core 1 is determined by ICP. Then, by subtracting the Ti content in the entire core particles 11 and the Ti content in the entire insulating film 13 from the Ti content in the entire powder magnetic core 1, the content ratio of Ti present in the grain boundary phase 12 can be measured.

A method for manufacturing the powder magnetic core 1 according to this embodiment is shown below, but the method for manufacturing the powder magnetic core 1 is not limited to the following method.

First, core particles 11 are produced. There are no particular limitations on the method for producing the core particles 11, and examples thereof include gas atomization, water atomization, and the like. There are no particular restrictions on the particle size and circularity of the core particles 11. When the median particle diameter (D50) is 1 μm to 100 μm, the initial magnetic permeability μi tends to be high. The circularity of the core particles 11 may be, for example, 0.5 or more and 1 or less, 0.7 or more and 1 or less, or 0.8 or more and 1 or less.

A film containing a phosphoric acid compound may be formed on the surface 11a of the core particle 11 if necessary. There are no particular limitations on the method for forming a film containing a phosphoric acid compound.

Next, when forming the insulating film 13 containing Si oxide and Ti, coating is performed on the surface 11a of the core particle 11 to form the insulating film 13 containing Si oxide and Ti. Note that when a film containing a phosphoric acid compound is formed on the surface 11a of the core particle 11, coating is performed to form the insulating film 13 on the surface of the film containing the phosphoric acid compound. Although there are no particular limitations on the coating method, for example, a method of applying a coating solution containing alkoxysilane and Ti to the core particles 11 is exemplified. There are no particular limitations on the method of applying the coating solution to the core particles 11, and examples include a method using spray diffusion. There are no particular restrictions on the state in which Ti is contained in the coating solution. For example, Ti may be contained as a titanium alkoxide, or Ti may be contained as a titanate. When Ti is included as titanate or titanium alkoxide and the green compact described below is heat-treated, the titanate or titanium alkoxide is decomposed by the heat treatment. The case where titanium alkoxide is added to the coating solution will be described below.

There are also no particular limitations on the concentration of alkoxysilane, the concentration of titanium alkoxide, and the type of solvent in the coating solution.

Examples of the alkoxysilane include monoalkoxysilane, dialkoxysilane, trialkoxysilane, and tetraalkoxysilane. Examples of the monoalkoxysilane include trimethylmethoxysilane, trimethylethoxysilane, and trimethyl(phenoxy)silane. Examples of the dialkoxysilane include dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, diisobutyldimethoxysilane, t-butylmethyldimethoxysilane, and t-butylmethyldiethoxysilane. Examples of trialkoxysilane include ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane, n-propyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, phenyltrimethoxysilane, etc. be done. Examples of the tetraalkoxysilane include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetraisopropoxysilane. As the alkoxysilane, one type of alkoxysilane may be used, or two or more types of alkoxysilane may be used in combination.

Examples of the titanium alkoxide include titanium tetramethoxide, titanium tetraethoxide, titanium tetra-n-propoxide, titanium tetraisopropoxide, and titanium tetra-n-butoxide. As the titanium alkoxide, one type of titanium alkoxide may be used, or two or more types of titanium alkoxide may be used in combination. From the viewpoint of availability, the titanium alkoxide may be titanium tetraethoxide or titanium tetra-n-butoxide.

The concentration of alkoxysilane and the concentration of titanium alkoxide may be determined based on the desired value of Ti/(Si+Ti), the desired thickness of the insulating film 13, and the like. Furthermore, there are no particular limitations on the type of solvent used in the coating solution. Examples include water, ethanol, and isopropyl alcohol.

Further, during spray diffusion, the proportion of alkoxysilane to the total amount of core particles 11 may be 0.1% by weight to 5% by weight. Furthermore, the film thickness of the insulating film 13 tends to increase as the amount of alkoxysilane increases.

Although there are no particular restrictions on the conditions for spray diffusion, the sol-gel reaction that forms the insulating film 13 is likely to be promoted by performing spray diffusion while performing heat treatment at 50° C. to 90° C.

The core particles 11 after spraying and diffusing the coating solution are dried to remove the solvent, and then heated at 200°C to 400°C for 1 to 10 hours to advance the sol-gel reaction and remove Si oxides and Ti. An insulating film 13 containing the above is formed. At this time, the higher the heating temperature and the longer the heating time, the higher the density of the insulating film 13 tends to be. Moreover, before heating the core particles 11, the core particles 11 may be passed through a mesh sieve to size them.

Next, if the grain boundary phase 12 in the green compact before heat treatment, which will be described later, contains a resin, a resin solution is prepared. In addition to the silicone resin, epoxy resin and/or imide resin described above, a curing agent may be added to the resin solution. There are no particular restrictions on the type of curing agent, and examples include epichlorohydrin. Further, there are no particular limitations on the solvent for the resin solution, but a volatile solvent may be used. For example, acetone, ethanol, etc. can be used. Furthermore, when the entire resin solution is 100% by weight, the total concentration of the resin and curing agent is preferably 10 to 80% by weight.

Furthermore, by adding Ti to the resin solution at this point, a powder magnetic core in which Si and Ti are present in the grain boundary phase 12 can be obtained. There is no particular restriction on the state in which Ti is contained in the resin solution. For example, Ti may be contained as a titanium alkoxide, or Ti may be contained as a titanate. Examples of the titanium alkoxide include titanium tetramethoxide, titanium tetraethoxide, titanium tetra-n-propoxide, titanium tetraisopropoxide, and titanium tetra-n-butoxide. As the titanium alkoxide, one type of titanium alkoxide may be used, or two or more types of titanium alkoxide may be used in combination. From the viewpoint of availability, the titanium alkoxide may be titanium tetraethoxide or titanium tetra-n-butoxide. Furthermore, by controlling the amount of Ti added, the content ratio of Ti present in the grain boundary phase 12 can be controlled.

Next, the core particles 11 on which the insulating film 13 has been formed, that is, the soft magnetic metal particles, are mixed with a resin solution. Then, the solvent of the resin solution is evaporated to obtain granules. The obtained granules may be filled into a mold as they are, or they may be sized and then filled into a mold. There is no particular restriction on the method for sizing particles, and for example, a mesh with an opening of 45 to 500 μm may be used.

Next, the obtained granules are filled into a mold of a predetermined shape and pressed to obtain a green compact. The pressure during pressurization (molding pressure) is not particularly limited, and can be set to, for example, 500 to 1500 MPa. The higher the compacting pressure, the higher the initial magnetic permeability μi of the powder magnetic core 1 finally obtained.

Comparing the case where Ti is present in the grain boundary phase 12 and the case where Ti is not present, the initial magnetic permeability μi of the powder magnetic core 1 is higher when Ti is present in the grain boundary phase 12 even if the compacting pressure is the same. Become.

The produced powder compact may be used as a powder magnetic core. Alternatively, the produced powder compact may be heat-treated, and the sintered compact produced by the heat treatment may be used as the powder magnetic core. There are no particular restrictions on the heat treatment conditions. When a silicone resin is used as the resin, heat treatment may be performed under conditions that sinter the silicone resin. For example, heat treatment may be performed at 400° C. to 1000° C. for 0.1 hour to 10 hours. Further, there is no particular restriction on the atmosphere during the heat treatment, and the heat treatment may be performed in the air or in a nitrogen atmosphere.

When the compact contains titanate or titanium alkoxide, part or all of the titanate or titanium alkoxide may be decomposed by the above heat treatment. In particular, titanate can be completely decomposed by heat treatment at 700°C or more and 1000°C or less. That is, by heat treatment at 700° C. or more and 1000° C. or less, titanate can be prevented from being contained in the sintered body.

Although the powder magnetic core and the method for manufacturing the same according to the present embodiment have been described above, the powder magnetic core and the method for manufacturing the same according to the present disclosure are not limited to the above embodiment.

Further, there is no particular restriction on the use of the powder magnetic core of the present disclosure. Examples include magnetic components such as inductors, reactors, choke coils, and transformers. The magnetic component of the present disclosure includes the powder magnetic core described above.

Hereinafter, the present disclosure will be described based on more detailed examples, but the present disclosure is not limited to these examples.

(Experiment example 1)
As metal magnetic particles (core particles), Fe-Si alloy particles (Fe and Si (alloy particles containing as the main component) were produced by gas atomization method. Note that the median particle diameter (D50) of the Fe--Si alloy particles was 30 μm.

Next, a coating solution for forming an insulating film on the surface of the metal magnetic particles was prepared. A coating solution was prepared by mixing 15 parts by weight of ethanol, trimethoxysilane, and 2.0 parts by weight of pure water, with the total amount of the metal magnetic particles being 100 parts by weight. The content of trimethoxysilane was determined such that the thickness of the final insulating film was 50 nm.

The metal magnetic particles and the coating solution were mixed and heat-treated while being sprayed and diffused. The heat treatment temperature was 80°C and the heat treatment time was 1 hour. Further, by drying after heat treatment, metal magnetic particles having an insulating film on the surface were obtained.

The obtained metal magnetic particles were passed through a 140 mesh sieve and then heat-treated. The heat treatment temperature was 300°C and the heat treatment time was 5 hours.

Next, a resin solution was prepared by mixing silicone resin and acetone. Shin-Etsu Silicone KR-242A (Shin-Etsu Chemical Co., Ltd.) was used as the silicone resin. The silicone resin and acetone were mixed in a weight ratio of 34:66.

Furthermore, titanium tetra-n-butoxide was added to the obtained resin solution. The amount of titanium tetra-n-butoxide added was such that the content ratio of Ti present in the grain boundary phase was the value listed in Table 1 based on the mass of the dust core.

The total amount of the above metal magnetic particles was 100 parts by weight, and 6 parts by weight of the above resin solution was added and mixed. Next, it was dried to volatilize the acetone to obtain granules. Next, the granules were sized by passing through a 42 mesh sieve. The obtained granules were dried on a hot plate at 50° C. for 0.5 hours to produce granulated powder.

0.1 part by weight of zinc stearate was added to 100 parts by weight of the granulated powder, and molding was performed to obtain a toroidal core. The amount of granulated powder filled was 5 g. The molding pressure was adjusted as appropriate so that the density of the toroidal powder magnetic core finally obtained was approximately 6.4 g/cm ³ . The shape of the mold was a toroidal shape with an outer diameter of 17.5 mm, an inner diameter of 10.0 mm, and a thickness of 4.8 mm.

The obtained toroidal core was heat-treated at 700° C. for 1 hour to obtain a toroidal powder magnetic core. The metal magnetic particles were made to account for about 98% by weight, assuming that the entire powder magnetic core finally obtained was 100% by weight.

It was confirmed by TEM-EDS observation that there was an insulating film covering the metal magnetic particles. It was also confirmed that Ti was substantially contained only in the grain boundary phase and was not substantially contained in the insulating film. Furthermore, the content of Ti present in the grain boundary phase was determined by ICP and divided by the total weight of the toroidal dust core to calculate the content ratio of Ti present in the grain boundary phase. The results are shown in Table 1.

The thickness of the insulating film was measured by TEM observation. Measurement points were set on the surface of the metal magnetic particles. Then, a perpendicular line was drawn in the direction of the insulating film from the measurement point, and the length of the portion of the perpendicular line located on the insulating film was defined as the thickness of the insulating film at the measurement point. Ten measurement points were set, and the thickness of the insulating film was measured at each measurement point. Then, the average of the measured thicknesses of the insulating film was defined as the thickness of the insulating film in the metal magnetic particles. It was confirmed that the thickness of the insulating film was approximately 50 nm in all Examples and Comparative Examples.

The initial magnetic permeability μi of the toroidal powder magnetic core was measured by winding a wire around the toroidal powder magnetic core with a number of turns of 50 using an LCR meter (HP LCR428A). An initial magnetic permeability μi of 45.0 or more was considered good, and a value of 50.0 or more was considered even better.

The density of the toroidal powder magnetic core was calculated from the dimensions and weight of the obtained powder magnetic core. It was confirmed that it was about 6.4 g/cm ³ in all Examples and Comparative Examples.

From Table 1, when the density of the toroidal powder magnetic core is approximately the same, each example in which Si and Ti are present in the grain boundary phase has a higher initial permeability than Comparative Example 1 in which Ti is not present in the grain boundary phase. μi became high. In each example in which the content ratio of Ti present in the grain boundary phase was 100 ppm or more and 3000 ppm or less based on the mass of the powder magnetic core, the initial magnetic permeability μi was higher than that of other examples.

(Experiment example 2)
In Experimental Example 2, a toroidal powder magnetic core was produced in the same manner as in Experimental Example 1 except that titanium tetra-n-butoxide was added to the coating solution. The ratio of trimethoxysilane and titanium tetra-n-butoxide was such that Ti/(Si+Ti) in the final coating film had the value shown in Table 2.

In Experimental Example 2, it was confirmed by TEM-EDS observation that there was an insulating film covering the metal magnetic particles. It was also confirmed that Ti was substantially contained only in the insulating film and the grain boundary phase. Furthermore, Ti/(Si+Ti) in the insulating film was quantified by EDS. Ten measurement points were set in the insulating film, and Table 2 shows the results of averaging Ti/(Si+Ti) at each measurement point.

A method for calculating the content ratio of Ti present in the grain boundary phase in Experimental Example 2 will be explained. First, the Ti content in the entire insulating film and the Ti content in the entire core particle were determined by EDS, and the Ti content in the entire toroidal dust core was determined by ICP. Then, the Ti content present in the grain boundary phase was calculated by subtracting the sum of the Ti content in the entire insulating film and the Ti content in the entire core particle from the Ti content in the entire toroidal dust core. Then, the content ratio of Ti present in the grain boundary phase was calculated by dividing it by the total weight of the toroidal powder magnetic core. The results are shown in Table 2.

From Table 2, good initial magnetic permeability μi was obtained even when the insulating film contained Ti in addition to the grain boundary phase.

1...Powder magnetic core 11...Metal magnetic particles (core particles)
11a... Surface of metal magnetic particles 12... Grain boundary phase 13... Insulating film

Claims (8)

comprising soft magnetic metal particles and a grain boundary phase existing between the soft magnetic metal particles,
A powder magnetic core in which Si and Ti are present in the grain boundary phase. The powder magnetic core according to claim 1, wherein the content ratio of Ti present in the grain boundary phase is 100 ppm or more and 3000 ppm or less based on the mass of the powder magnetic core. The powder magnetic core according to claim 1 or 2, wherein the soft magnetic metal particles contain Fe. The powder magnetic core according to claim 1 or 2, wherein the soft magnetic metal particles include a core particle and an insulating film formed on the surface of the core particle. The powder magnetic core according to claim 4, wherein the insulating film contains an oxide of Si. The powder magnetic core according to claim 4, wherein the insulating film contains an oxide of Si and Ti. The powder magnetic core according to claim 4, wherein the core particles contain Fe. A magnetic component comprising the dust core according to claim 1 or 2.

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