WO2007052772A1

WO2007052772A1 - Fe-Si TYPE IRON-BASED SOFT MAGNETIC POWDER COATED WITH OXIDE DEPOSIT FILM AND PROCESS FOR PRODUCING THE SAME

Info

Publication number: WO2007052772A1
Application number: PCT/JP2006/322028
Authority: WO
Inventors: Muneaki Watanabe; Ryoji Nakayama
Original assignee: Mitsubishi Materials Pmg Corporation
Priority date: 2005-11-02
Filing date: 2006-11-02
Publication date: 2007-05-10

Abstract

An Fe-Si-type iron-based soft magnetic powder coated with an oxide deposit film which comprises Fe-Si type iron-based soft magnetic particles and, formed on the surface of each particle, an oxide deposit film comprising Mg, Si, Fe, and O. In the oxide deposit film comprising Mg, Si, Fe, and O, the contents of magnesium and oxygen increase toward the surface and the content of iron decreases toward the surface. The oxide deposit film has a silicon concentration gradient in which the content of silicon in a layer around the outermost surface increases toward the outermost surface. The coated magnetic powder contains metallic iron in the base and has a fine crystal structure having an average crystal grain diameter of 200 nm or smaller.

Description

Specification

Deposited oxide film coating Fe-Si based iron-based soft magnetic powder and manufacturing method thereof

[0001] The present invention relates to a deposited oxide film coated Fe-Si based iron-based soft film in which a deposited acid film having Mg, Si, Fe and O forces is coated on the surface of a Fe-S iron-based soft magnetic powder. The present invention relates to a magnetic powder and a method for producing the same. The composite soft magnetic material prepared by using this deposited acid-coating-coated Fe-Si-based iron-based soft magnetic powder is a variety of electromagnetic circuit components that require low iron loss. For example, it is used as a material for various electromagnetic parts such as motors, actuators, yokes, cores, and rear tuttles.

This application claims priority based on Japanese Patent Application No. 2005-319247 filed in Japan on November 2, 2005, the contents of which are incorporated herein by reference.

Background art

[0002] Generally, soft magnetic materials used in various electromagnetic circuit components are required to have low iron loss. Therefore, the electrical resistance is increased to reduce eddy current loss, the coercive force is reduced, and hysteresis is reduced. It is known to reduce losses. Furthermore, in recent years, there has been an increasing need for higher magnetic flux density because of the demand for smaller and more responsive electromagnetic circuits!

[0003] As an example of a raw material powder for producing a soft magnetic material having a high specific resistance, Si: containing 0.1 to 10% by mass, the balance being Fe and an Fe-Si-based iron group having inevitable impurity power A soft magnetic powder is known, and a soft magnetic powder in which a high-resistance material is coated on the surface of this Fe—Si-based iron-based soft magnetic powder is also known. The soft magnetic powder having a high resistance material formed on the surface is compression-molded, and the obtained green compact is sintered to have a structure in which the high resistance material is interposed between the soft magnetic particles and to have a high specific resistance. A method for producing a magnetic material is also known (see JP-A-5-258934).

Disclosure of the invention

Problems to be solved by the invention

[0004] As an example of a high resistance material formed on the surface of the Fe-Si-based iron-based soft magnetic powder, an Mg-containing ferrite oxide film can be considered.匕 Even if a green compact is produced by press-molding a film-coated Fe-Si-based iron-based soft magnetic powder, and the green compact is subjected to high-temperature strain relief firing, a sufficiently high specific resistance cannot be obtained.

This is because Mg-containing ferrite is generally unstable with respect to heat, and when heat is applied, the ferrite structure changes, resulting in a decrease in insulation, and soon the composite soft magnetic material obtained has a decrease in insulation. This is partly due. Furthermore, the conventional Fe-Si-based iron-based soft magnetic powder coated with an Mg-containing ferrite oxide film is coated with an Mg-containing ferrite oxide film by a chemical method. Composite soft magnetic material produced by press-molding and firing Fe-Si-based iron-based soft magnetic powder coated with a conventional Mg-containing ferrite acid film with insufficient adhesion of Mg-containing ferrite acid film to the surface The material had a drawback that the Mg-containing ferrite oxide film was peeled off or torn during press forming, so that a sufficient insulating effect could not be exhibited, and therefore a sufficiently high specific resistance could not be obtained.

Means for solving the problem

[0005] Accordingly, the present inventors have found that a high-resistance material film is formed on the surface of the Fe-Si-based iron-based soft magnetic powder surface that does not break during press-molding. Oxidation that adheres firmly, further reduces the eddy current loss and lowers the coercive force and lowers the hysteresis loss without lowering the surface insulation even if high temperature strain relief firing is performed after press forming Research was carried out to obtain a film-coated Fe-Si-based iron-based soft magnetic powder.

[0006] As a result of the above research, the results obtained are as follows.

By adding Si powder to Fe-Si-based iron-based soft magnetic powder or Fe powder and mixing, and then heating in a non-oxidizing atmosphere, the surface of the Fe-Si-based iron-based soft magnetic powder or Fe powder is A high-concentration Si diffusion layer containing high-concentration Si can also be formed in the SU-containing Fe—Si-based iron-based soft magnetic powder or Fe powder. By oxidizing the Fe-Si-based iron-based soft magnetic powder having a high-concentration Si diffusion layer produced as a result, a surface-oxidation high-concentration Fe-Si system having an oxide layer on the high-concentration Si diffusion layer Iron-based soft magnetic raw material powder can be produced. This mixed powder obtained by adding and mixing Mg powder to this high-oxidized Fe-Si based iron-based soft magnetic raw material powder is mixed with temperature: 150 ~: L 100 ° C, pressure: 1 X 10 ^_12 ~ 1 X When heated in an inert gas atmosphere or vacuum atmosphere of 10 ^_1 MPa, a deposited oxide film with Mg, Si, Fe and O forces is formed on the surface of the Fe-Si-based iron-based soft magnetic powder. (A) The Mg contained in the deposited oxide film that also has Mg, Si, Fe, and O forces has a Mg concentration gradient that increases with increasing Mg content closer to the outermost surface, and O is closer to the outermost surface. The O concentration increases as the O content increases, while Fe has a concentration gradient where the Fe content decreases as it is closer to the outermost surface, and Si is closer to the outermost surface of the deposited oxide film. It has a Si concentration gradient in which the Si content increases closer to the outermost surface.

[0007] (B) The Mg, Si, Fe, and O-force deposited acid film contains MgO solid crystalline wustite (MgO dissolved in wustite (FeO) in the substrate. In other words, part of Fe and Si is contained as metal Fe or Fe-Si alloy. The deposited oxide film having Mg, Si, Fe, and O force has toughness because it contains metallic Fe, and easily follows the deformation of the powder during compacting.

(C) The deposited oxide film with Mg, Si, Fe and O forces has toughness because it has a fine crystal structure with a crystal grain size of 200 nm or less, and follows the deformation of the powder during compacting. Easy

[0008] The deposited acid film covering Fe-Si based iron-based soft magnetic powder in which the deposited acid film including Mg, Si, Fe and O force is formed on this surface is a conventional Fe-Si based iron base. Mg-containing ferrite oxide film coating with Mg-containing ferrite-acid film on the surface of soft magnetic powder Compared with Fe-Si-based iron-based soft magnetic powder, the oxide film for Fe-Si-based iron-based soft magnetic powder Since the adhesion is remarkably excellent, the oxide film, which is an insulating film, is broken during press molding, and Fe—S related iron-based soft magnetic powder is less likely to come into contact with each other. Also, the Mg, Si, Fe and The deposited oxide film made of O is chemically more stable than Mg-containing fried acid film, so that the insulation property of the oxide film is reduced even if high temperature strain relief firing is performed after press molding. High resistance can be maintained without reducing the eddy current loss. Force can be kept low hysteresis losses can be reduced, thus, the composite soft magnetic material to have a low iron loss can be obtained.

[0009] The present invention has been made based on the above research results, and has the following aspects.

A first aspect of the present invention is a deposited acid-coating-coated Fe—S-related iron-based soft magnetic powder, wherein the deposited acid also has Mg, Si, Fe, and O forces on the surface of the Fe—S-related iron-based soft magnetic powder. The film is formed This is a deposited oxide film-coated Fe—Si-based iron-based soft magnetic powder.

A second aspect of the present invention is the deposited oxide film-coated Fe Si-based iron-based soft magnetic powder according to the first aspect, wherein the Fe Si-based iron-based soft magnetic powder is Si: 0.1 to 10% by mass. A deposited oxide film-coated Fe Si -based iron-based soft magnetic powder having a composition comprising a balance of Fe and inevitable impurities.

According to a third aspect of the present invention, there is provided the deposited acid film-coated Fe—Si based iron-based soft magnetic powder according to the first or second aspect, wherein the deposited acid solution also has the Mg, Si, Fe and O forces. In the coating film, the Mg and O contents increase toward the surface, the Fe content decreases toward the surface, and Si is near the outermost surface of the deposited oxide film! This is a deposited oxide film-coated FeSi-based iron-based soft magnetic powder with a Si concentration gradient with increasing content.

A fourth aspect of the present invention is the deposited acid-coating-coated Fe—Si-based iron-based soft magnetic powder according to any one of the first aspect, the second aspect, or the third aspect, wherein the Mg, Si, The deposited oxide film that also has Fe and O forces contains a crystalline MgO solid solution wustite-type phase, which contains metal Fe or Fe-Si alloy, and is deposited oxide film Fe-Si This is an iron-based soft magnetic powder.

According to a fifth aspect of the present invention, there is provided the deposited acid film-coated Fe S-coated iron-based soft magnetic powder according to any one of the first aspect, the second aspect, the third aspect, or the fourth aspect, The deposited oxide film with Mg, Si, Fe and O forces is a deposited Si oxide-based Fe-based soft magnetic powder with a fine crystal structure with an average crystal grain size of 200 nm or less.

To produce a deposited oxide film-coated Fe Si-based iron-based soft magnetic powder in which a deposited oxide film having Mg, Si, Fe and O forces is formed on the surface of the Fe-Si-based iron-based soft magnetic powder of the present invention, First, Si powder is added to Fe Si-based iron-based soft magnetic powder, mixed, and then heated in a non-oxidizing atmosphere, whereby the Fe Si-based iron-based soft magnetic powder is coated on the surface of the Fe Si-based iron-based soft magnetic powder. An Fe Si-based iron-based soft magnetic powder having a high-concentration Si diffusion layer that also contains high-concentration Si in the soft magnetic powder is prepared. By treating the Fe Si-based iron-based soft magnetic powder having the high-concentration Si diffusion layer portion thus obtained with an acid bath, the surface-oxidized Fe Si-based iron-based soft powder having an oxide layer on the high-concentration Si diffusion layer is obtained. Magnetic raw material powder is prepared. This surface-oxidized Fe Si-based iron-based soft magnetic raw material powder is mixed with Mg powder to produce a mixed powder. The resulting mixed powder is heated in an inert gas atmosphere or vacuum atmosphere of temperature: 150 ~: LI 00 ° C, pressure: 1 x 10 1 ¹² ~ 1 x ^10_1 MPa Fe-Si An iron-based soft magnetic powder can be obtained.

In addition, the Fe—Si-based iron-based soft magnetic powder has a high-concentration Si diffusion layer on the surface of the Fe-Si-based iron-based soft magnetic powder, and the SU-containing Fe-Si-based soft magnetic powder also includes a high concentration Si. An iron-based soft magnetic powder can be obtained by adding Si powder to Fe powder, mixing, heating in a non-oxidizing atmosphere, and diffusing and infiltrating Si into the Fe powder.

Therefore, the present invention further has the following aspects.

The sixth aspect of the present invention is a method for producing a deposited oxide film-coated Fe—Si-based iron-based soft magnetic powder, and after adding and mixing Si powder into an Fe—Si-based iron-based soft magnetic powder or Fe powder, By heating in a non-oxidizing atmosphere, the Fe-Si-based iron-based soft magnetic powder or Fe powder has a high concentration of Si on the surface of the Fe-Si-based iron-based soft magnetic powder or Fe powder. The Fe-Si-based iron-based soft magnetic powder having a high-concentration Si diffusion layer containing high-concentration Si was prepared, and the obtained Fe-Si-based iron-based soft magnetic powder having a high-concentration Si diffusion layer was oxidized to obtain a high concentration. A surface oxidized Fe-Si-based iron-based soft magnetic raw material powder having an oxide layer on the Si diffusion layer was prepared, and a surface acid Fe-Si system having an acid layer on the high-concentration Si diffusion layer. the mixed powder obtained by adding and mixing Mg powder iron-based soft magnetic raw powder, temperature: from 150 to 1,100 ° C, pressure: 1 X 10 one ¹² ~ 1 X 10 ^_ This is a method for producing a deposited oxide film-coated Fe-Si-based iron-based soft magnetic powder that is heated in an inert gas atmosphere or a vacuum atmosphere at ¹ MPa.

According to a seventh aspect of the present invention, there is provided the deposited oxide film-coated Fe—Si-based iron-based soft magnetic powder according to any one of the first aspect, the second aspect, the third aspect, the fourth aspect, or the fifth aspect. A surface-oxidized Fe-Si-based iron-based soft magnetic raw material powder for manufacturing, wherein the composition of Si contained in the entire Fe-Si-based iron-based soft magnetic powder on the surface of the Fe-Si-based iron-based soft magnetic powder A surface-oxidized Fe-Si-based iron-based soft magnetic material, in which a high-concentration Si diffusion layer containing a higher concentration of Si is formed, and an oxide layer is further formed on the high-concentration Si diffusion layer It is a powder.

[0012] In general, the term "deposited oxide film" t ヽぅ refers to an oxide film in which atoms constituting the film, which are normally sputtered by vacuum evaporation, are deposited on a substrate, for example. However, the deposited oxide film with Mg, Si, Fe and O force formed on the surface of the Fe-Si based iron-based soft magnetic powder of the present invention is F The film formed on the surface of the Fe-Si iron-based soft magnetic powder with the reaction of Si and Mg on the surface of the e-Si-based iron-based soft magnetic powder. The film thickness of the deposited oxide film with Mg, Si, Fe, and O force formed on the surface of this Fe-Si-based iron-based soft magnetic powder is a composite obtained by compacting and firing. In order to obtain a high magnetic flux density and a high specific resistance of the soft magnetic material, it is preferably in the range of 5 nm to 500 nm. If the film thickness is less than 5 nm, the specific resistance of the powdered composite soft magnetic material is insufficient and the eddy current loss increases. The magnetic flux density is decreased, which is preferable! A more preferable film thickness is 5ηπ! Within the range of ~ 200nm.

[0013] The deposited oxide film coated with the deposited acid film coating Fe-S related iron-based soft magnetic powder according to any one of the first to fifth aspects is formed with Mg, Si, Fe and O force. The finer the crystal grains, the more preferable the crystal grain size is preferably a fine crystal structure of 200 nm or less. By having such a fine crystal structure, it is possible for the microcrystalline deposited oxide film to follow the deformation of the powder during compacting and prevent the coating from being broken. Contact bonding between soft magnetic powders can be prevented, and even if high temperature strain relief firing is performed, the oxide is stable and insulation deterioration can be prevented, resulting in high resistance and low eddy current loss. It is not preferable because the magnetic flux density of the composite soft magnetic material formed by compacting with a crystal grain size larger than 200 ηm is lowered.

[0014] The Fe-Si-based iron-based soft magnetic powder used for producing the deposited oxide film-coated Fe-Si-based iron-based soft magnetic powder according to any one of the first to fifth embodiments has an average particle size of 5 to Preference is given to using powders in the range of 500 m. The reason is that if the average particle size is less than 5 m, the compressibility of the powder is lowered, and the volume ratio of the powder is lowered, so the value of the magnetic flux density is lowered. If it is too large, the eddy current inside the powder increases and the permeability at high frequencies decreases.

[0015] The resistivity and strength of the deposited oxide film-coated Fe-Si based iron-based soft magnetic powder of the present invention described above are mixed with an organic insulating material, an inorganic insulating material, or a mixed material of an organic insulating material and an inorganic insulating material. Further improved composite soft magnetic materials can be produced. In this case, for organic insulating materials, epoxy resin, fluorine resin, phenol resin, urethane resin, silicone resin, polyester resin, phenoxy resin, urea resin, isocyanate resin, Krill resin, polyimide resin, PPS resin, etc. can be used. As the inorganic insulating material, phosphates such as iron phosphate, various glassy insulators, water glass mainly composed of sodium silicate, insulating oxides, and the like can be used.

In addition, the deposited oxide film-coated Fe—Si-based iron-based soft magnetic powder of the present invention is compacted, and the resulting compacted compact is sintered at a temperature of 500 to 1000 ° C. to obtain a composite soft magnetic material. Can be produced.

The composite soft magnetic material produced using the deposited acid-coating-coated Fe—Si-based iron-based soft magnetic powder of the present invention has high density, high strength, high specific resistance and high magnetic flux density. Can be used as a material for various electromagnetic circuit components that have the characteristics of high magnetic flux density and high frequency and low iron loss. Examples of the electromagnetic circuit component include a magnetic core, an electric motor core, a generator core, a solenoid core, an idling core, a rear tuttle, a transformer, a choke coil core, and a magnetic sensor core. In addition, an electric device incorporating an electromagnetic circuit component made of a composite soft magnetic material having high resistance using the oxide film-coated Fe—Si-based iron-based soft magnetic powder of the present invention includes an electric motor, a generator, a solenoid, There are injectors, electromagnetically driven valves, inverters, converters, transformers, relays, magnetic sensor systems, etc., which can improve the efficiency and performance of electric equipment and make it compact and lightweight.

The invention's effect

[0016] When a composite soft magnetic material is produced using the deposited oxide film-coated Fe-Si-based iron-based soft magnetic powder of the present invention, it has a high specific resistance, so it has a low eddy current loss and further has a coercive force. Since it is low, a composite soft magnetic material having a low hysteresis loss can be stably produced at low cost, and it has excellent effects in the electrical and electronic industries.

Brief Description of Drawings

[0017] FIG. 1 is a graph showing the results of measuring the concentration distribution of Mg, 0, Si and Fe in the depth direction of a deposited oxide film using an Auger electron spectrometer.

BEST MODE FOR CARRYING OUT THE INVENTION

[0018] Example 1

Fe-Si based iron-based soft magnetic powder consisting of raw material powder with average particle size: 75 μm, Si: 1% by mass, remaining Fe and inevitable impurities, and average particle size: 1 μm or less Pure Si Powder was prepared. Furthermore, Mg powder having an average particle diameter of 50 μm was prepared.

[0019] First, pure Si powder is mixed with Fe Si-based iron-based soft magnetic powder so that Fe-Si-based iron-based soft magnetic powder: pure Si powder = 99.5% by mass: 0.5% by mass. The mixed powder is mixed to produce high-concentration Si on the surface of the Fe Si-based iron-based soft magnetic powder by heat-treating it in a hydrogen atmosphere at a temperature of 950 ° C for 1 hour. A surface-oxidized Fe-Si-based iron-based soft magnetic raw material powder having an oxide layer on a high-concentration Si diffusion layer by forming a diffusion layer and then holding it in the atmosphere at a temperature of 250 ° C. Produced.

[0020] This surface oxidized Fe Si-based iron-based soft magnetic raw material powder was prepared by using the previously prepared Mg powder as the surface acid FeSi-based iron-based soft magnetic raw material powder: Mg powder = 99.8 mass%: 0.2 mass. % Mixed to make a mixed powder, and the resulting mixed powder is held for 1 hour while rolling under conditions of temperature: 650 ° C and pressure: ^2.7 X 10 ^_4 MPa In this invention, a deposited oxide film with Mg, Si, Fe and O forces is formed on the surface of the Fe Si-based iron-based soft magnetic powder. Invented oxide film coating powder) 1) was prepared.

[0021] The deposited oxide film formed on the deposited oxide film-coated powder 1 of the present invention is a deposited oxide film composed of Mg, Si, Fe and O, and the deposited oxide film is submerged in the substrate. It was confirmed by analyzing with X-ray photoelectron spectrometer that the metal Fe and Fe Si alloy were contained, and analyzing the binding energy. Furthermore, the structure of the deposited oxide film in the deposited oxide film coating powder 1 of the present invention was observed with an electron microscope, the thickness of the deposited oxide film and the maximum crystal grain size were measured, and the results are shown in Table 1. . Further, it was confirmed by electron diffraction pattern that Mg and O contained in the deposited oxide film having Mg, Si, Fe and O forces were contained as crystalline MgO solid solution wustite type phase.

In addition, the concentration distribution of Mg, 0, Si, and Fe in the depth direction of the deposited oxide film consisting of Mg, Si, Fe, and O force was measured using an Auger electron spectrometer, and the results are shown in Table 1. The concentration distribution of Mg, 0, Si and Fe in the depth direction of the deposited oxide film consisting of Mg, Si, Fe and O of the deposited oxide film coated powder 1 of the present invention was measured using an Auger electron spectrometer. Figure 1 shows the measurement diagram at the time. In FIG. 1, the horizontal axis of Etching Time 0 is the outermost surface. Therefore, in FIG. 1, Mg and Si contained in the deposited oxide film containing Mg, Si, Fe, and O force And O increase in Mg and O content toward the surface, Fe decrease toward the surface, Si increases near the outermost surface of the deposited oxide film, and closer to the outermost surface, the Si content increases. It can be seen that it has a Si concentration gradient.

The thus obtained deposited oxide film-coated powder 1 of the present invention was put into a mold and press-molded to obtain a plate-shaped green compact having dimensions of 55 mm in length, 10 mm in width, and 5 mm in thickness, and the outside. Forming a ring-shaped green compact with a diameter of 35 mm, an inner diameter of 25 mm, and a height of 5 mm, and firing the resulting green compact in a nitrogen atmosphere at a temperature of 500 ° C for 30 minutes The composite soft magnetic material having a plate-like and ring-like fired body strength was prepared, the specific resistance of the composite soft magnetic material made of this plate-like fired body was measured, and the results are shown in Table 1. Combined soft magnetic material with sinter strength, magnetic flux density, coercive force, and magnetic flux density 1.5T, iron loss at frequency 50 密度 ζ and magnetic flux density 1.0Τ, iron loss at frequency 400Hz, etc. The magnetic properties were measured and the results are shown in Table 1.

[0022] Conventional Example 1

Conventional Mg-containing ferrite oxide-coated Fe-Si-based iron-based soft magnetic powder (chemically formed Mg-containing ferrite oxide layer on the surface of Fe-S related iron-based soft magnetic powder prepared in Example 1) The conventional deposited oxide film-coated powder is prepared, and this conventional deposited oxide film-coated powder is placed in a mold and press-molded to have a size of 55 mm in length, 10 mm in width, and 5 mm in thickness. Powder and outer diameter: 35mm, inner diameter: 25mm, height: Ring-shaped green compact with a dimension of 5mm was molded, and the resulting green compact was held in nitrogen atmosphere at a temperature of 500 ° C for 30 minutes. The composite soft magnetic material consisting of plate-like and ring-like sintered bodies was prepared, the specific resistance of the composite soft magnetic material also having the plate-like sintered body force was measured, and the results are shown in Table 1. It was shown to. In addition, a composite soft magnetic material having a ring-like sintered body strength is subjected to a winding, and the magnetic flux density, the coercive force, and the magnetic flux density 1.5 T, the iron loss and magnetic flux density 1.0 T at a frequency of 50 Hz, the frequency Magnetic properties such as iron loss at 400 Hz were measured, and the results are shown in Table 1.

[0023] [Table 1] ο

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Original M S i F O e -——

Properties of composite soft magnetic

Specializing in acid deposited acid films

Bundle density magnetic work

Iron loss magnetism retention * Maximum grain size t crystal

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Example 1

Conventional example 1

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From the results shown in Table 1, the deposited oxide film-coated powder 1 of the present invention produced in Example 1 uses the Mg-containing ferrite oxide-coated Fe—Si-based iron-based soft magnetic powder produced in Conventional Example 1. Compared to the prepared composite soft magnetic material, the density is not much different, but the composite soft magnetic material prepared using the deposited oxide film coated powder 1 of the present invention prepared in Example 1 was prepared in Conventional Example 1. Conventionally deposited oxide coating powder Mg-containing ferrite oxide coating Fe-Si-based iron base Compared to composite soft magnetic materials made using soft magnetic powder, the magnetic flux density is high, the coercive force is small, and the specific resistance is remarkably high. It has a characteristic that it has characteristics such as a small loss.

[0025] Example 2

As a raw material powder, an Fe—Si-based iron-based soft magnetic powder having a particle size shown in Table 2 and containing Si: 1% by mass and composed of the remaining Fe and inevitable impurities was prepared. Furthermore, pure Si powder having an average particle size of 1 μm or less and Mg powder having an average particle size of 50 μm were prepared.

Pure Si powder is mixed with Fe-Si-based iron-based soft magnetic powders of different particle sizes so that Fe-Si-based iron-based soft magnetic powder: pure Si powder = 97% by mass: 2% by mass, mixed and mixed A high-concentration Si diffusion layer is formed on the surface of the Fe--S soft iron-based soft magnetic powder by heat-treating the resulting mixed powder in a hydrogen atmosphere at a temperature of 950 ° C for 1 hour. After that, a surface oxidized Fe—Si-based iron-based soft magnetic raw material powder having an oxide layer on a high-concentration Si diffusion layer was prepared by maintaining the temperature at 220 ° C. in the atmosphere. .

[0026] The surface-oxidized Fe-Si-based iron-based soft magnetic raw material powder was prepared by using the Mg powder previously prepared for the surface-oxidized Fe-Si-based iron-based soft magnetic raw material powder: Mg powder = 99.8 mass%: 0 Mixing and mixing to make a ratio of 2% by mass to produce mixed powder, rolling the resulting mixed powder under the conditions of temperature: 650 ° C, pressure: ^2.7 X 10 ^_4 MPa Treatment for 1 hour (this surface acid Fe-Si-based iron-based soft magnetic raw material powder: Mg powder = 99.8 mass%: 0.2 mass% The prepared mixed powder is treated for 1 hour while rolling under the conditions of temperature: 650 ° C and pressure: ^2.7 X 10 ^_4 MPa, hereinafter referred to as “Mg coating treatment”) The Fe-Si-based iron-based soft magnetic powder is formed by depositing a deposited acid-containing film made of Mg, Si, Fe and O on the surface of the Fe-Si-based iron-based soft magnetic powder. The present invention method 1 to 3 Subjecting was.

[0027] The deposited oxide film formed on the deposited oxide film-coated Fe-Si-based iron-based soft magnetic powder obtained by the present invention method 1-3 is a deposited oxide film having Mg, Si, Fe and O forces. It was confirmed by analyzing with X-ray photoelectron spectrometer and binding energy that this deposited oxide film contains metal Fe and Fe-Si alloy in the substrate. . Furthermore, the structure of the deposited acid film in the acid film-coated Fe-S iron-based soft magnetic powder was examined with an electron microscope. It is observed from the electron diffraction pattern that Mg and O contained in the deposited acid film containing Mg, Si, Fe and O force are included as crystalline MgO solid solution wustite phase. confirmed. Furthermore, when the concentration distribution of Mg, 0, Si and Fe in the depth direction of the deposited oxide film with Mg, Si, Fe and O force was measured using an Auger electron spectrometer, it was found to be included in the deposited oxide film. Mg and O content increases and Mg and O content increases on the surface, Fe decreases on the surface and Si content is closer to the outermost surface of the deposited oxide film. It has become a component that it has a Si concentration gradient with increasing amounts.

The deposited acid film coating Fe-Si based iron-based soft magnetic powder obtained by the method of the present invention 1 to 3 was added to and mixed with a silicone resin at a mixing ratio of 2% by mass. — Preparation of a resin-coated composite powder in which the surface of a Si-based iron-based soft magnetic powder is coated with a silicone resin, and this resin-coated composite powder is placed in a mold heated to 120 ° C and press-molded to create a vertical: Obtained by molding a plate-shaped green compact with dimensions of 55 mm, width: 1 Omm, thickness: 5 mm and ring-shaped green compact with dimensions of outer diameter: 35 mm, inner diameter: 25 mm, height: 5 mm The green compact is fired in a vacuum at a temperature of 700 ° C for 30 minutes to produce a composite soft magnetic material consisting of a plate-like and ring-like fired body. The specific resistance of the magnetic material was measured, and the results are shown in Table 2. Further, the composite soft magnetic material having a ring-like fired body strength was subjected to a winding line to obtain a magnetic flux density. , Coercive force, and magnetic flux density 0. 1T, the iron loss at a frequency 20kHz were measured. The results are shown in Table 2.

Conventional example 2

As a raw material powder, an Fe-Si-based iron-based soft magnetic powder having a particle size shown in Table 2 and containing Si: 1% by mass and comprising the remaining Fe and inevitable impurities is prepared. Si-based iron-based soft magnetic powder is coated with silicone resin at a mixing ratio of 2% by mass without Mg coating, and mixed to coat the surface of Fe-Si-based iron-based soft magnetic powder with silicone resin. A coated composite powder was prepared. This resin-coated composite powder is placed in a mold heated to 120 ° C and pressed to form a plate-shaped green compact with dimensions of 55 mm in length, 10 mm in width, and 5 mm in thickness and an outer diameter of 35 mm. A ring-shaped green compact with an inner diameter of 25 mm and a height of 5 mm was molded, and the resulting green compact was fired in vacuum at a temperature of 700 ° C for 30 minutes. A composite soft magnetic material made of a ring-like fired body was produced, and a composite soft magnetic material made of this plate-like fired body was produced. The specific resistance of the magnetic material was measured, and the results are shown in Table 2. Further, the composite soft magnetic material having a ring-shaped sintered body strength was subjected to a line, and the magnetic flux density, coercive force, magnetic flux density 0.1 T, frequency The iron loss at 20 kHz was measured and the results are shown in Table 2.

[0029] [Table 2]

[0030] The composite soft magnetic material produced by the present invention methods 1 to 3 is different from the composite soft magnetic material produced by the conventional method 1. Thus, it can be seen that the magnetic flux density is high, the coercive force is small, and the specific resistance is remarkably high. Therefore, the iron loss is remarkably small.

[0031] Example 3

As a raw material powder, an Fe—Si-based iron-based soft magnetic powder having a particle size shown in Table 3 and containing Si: 3% by mass, and composed of the remaining Fe and inevitable impurities was prepared. Furthermore, pure Si powder having an average particle size of 1 m or less and Mg powder having an average particle size of 50 μm were prepared.

Pure Si powder is mixed with Fe-Si-based iron-based soft magnetic powders with different particle sizes so that Fe-Si-based iron-based soft magnetic powder: pure Si powder = 99.5 mass%: 0.5% mass. A mixed powder is then prepared, and the resulting mixed powder is heat-treated in a hydrogen atmosphere at a temperature of 950 ° C for 1 hour to maintain a high-concentration Si diffusion layer on the surface of the Fe-Si-based iron-based soft magnetic powder. After that, the surface oxidized Fe—Si-based iron-based soft magnetic raw material powder having an oxide layer on the high-concentration Si diffusion layer was produced by maintaining the temperature in the atmosphere at a temperature of 220 ° C.

[0032] By applying Mg coating to this surface oxidized Fe-Si-based iron-based soft magnetic raw material powder, deposition with Mg, Si, Fe and O force on the surface of Fe-Si-based iron-based soft magnetic powder Processes 4 to 6 of the present invention for producing a deposited oxide film-coated Fe—Si-based iron-based soft magnetic powder in which an oxide film was formed were carried out.

The deposited oxide film formed on the Fe-Si based iron-based soft magnetic powder obtained by the method 4-6 of the present invention is a deposited oxide film with Mg, Si, Fe and O forces. It was confirmed by analyzing with X-ray photoelectron spectrometer that the metal oxide and Fe-Si alloy were contained in the substrate and analyzing the binding energy. Furthermore, the structure of the deposited acid film in the Fe-S coated iron-based soft magnetic powder is observed with an electron microscope, and the Mg, Si, Fe and O forces are also included in the deposited acid film. It was confirmed by electron diffraction pattern that Mg and O were included as crystalline MgO solid solution wustite phase. Furthermore, when the concentration distribution of Mg, 0, Si and Fe in the depth direction of the deposited oxide film with Mg, Si, Fe and O force was measured using an Auger electron spectrometer, it was found to be included in the deposited oxide film. Mg and O content increases with increasing force of Mg and O, Fe decreases with force toward the surface, and Si is closer to the outermost surface near the outermost surface of the deposited oxide film. It has been found that it has a Si concentration gradient with increasing Si content.

[0033] Deposited oxide film coated Fe-Si based iron-based soft magnetic powder obtained by the method 4 to 6 of the present invention was added to and mixed with a silicone resin at a mixing ratio of 2% by mass. A resin-coated composite powder in which the surface of an Fe—Si-based iron-based soft magnetic powder was coated with a silicone resin was prepared. This resin-coated composite powder is placed in a mold heated to 120 ° C and pressed to form a plate compact having dimensions of 55mm in length, 10mm in width, 5mm in thickness, and outer diameter: 35mm, inner diameter. : A ring-shaped green compact with dimensions of 25 mm and height: 5 mm is molded, and the resulting green compact is fired in vacuum at a temperature of 700 ° C for 30 minutes. A composite soft magnetic material made of a green fired body was prepared, the specific resistance of the composite soft magnetic material made of this plate fired body strength was measured, and the results are shown in Table 3. The wire was lined, and the magnetic flux density, coercive force, and iron loss at a magnetic flux density of 0.1 T and a frequency of 20 kHz were measured. The results are shown in Table 3.

[0034] Conventional example 3

As a raw material powder, an Fe-Si-based iron-based soft magnetic powder having the particle size shown in Table 3 and containing Si: 1% by mass and comprising the remaining Fe and inevitable impurities is prepared. Si-based iron-based soft magnetic powder is coated with silicone resin at a mixing ratio of 2% by mass without Mg coating, and mixed to coat the surface of Fe-Si-based iron-based soft magnetic powder with silicone resin. A coated composite powder was prepared. This resin-coated composite powder is placed in a mold heated to 120 ° C and pressed to form a plate-shaped green compact with dimensions of 55 mm in length, 10 mm in width, and 5 mm in thickness and an outer diameter of 35 mm. A ring-shaped green compact with an inner diameter of 25 mm and a height of 5 mm was molded, and the resulting green compact was fired in vacuum at a temperature of 700 ° C for 30 minutes. A composite soft magnetic material made of a ring-like fired body was prepared, and the specific resistance of this composite soft magnetic material made of a plate-like fired body was measured. The results are shown in Table 2. In addition, a composite soft magnetic material made of a ring-shaped fired body was wire-lined, and the magnetic flux density, coercive force, and iron loss at a magnetic flux density of 0.1 T and a frequency of 20 kHz were measured. The results are shown in Table 3. It was.

[0035] [Table 3]

[0036] Compared to the composite soft magnetic material produced by the conventional method 2, the composite soft magnetic material produced by the present invention methods 4 to 6 has a lower magnetic flux density, a smaller coercive force, and a significantly higher specific resistance. Therefore, it can be seen that the iron loss is remarkably small, and that the iron loss decreases as the frequency increases.

[0037] Example 4 Fe powder having the particle size shown in Table 4 was prepared as a raw material powder. Further, pure Si powder having an average particle size of 1 μm or less and Mg powder having an average particle size of 50 μm were prepared.

These Si powders with different particle sizes are mixed with pure Si powder such that Fe powder: pure Si powder = 97% by mass: 3% by mass to produce a mixed powder, and the resulting mixed powder is placed in a hydrogen atmosphere. Temperature: Heat treatment at 950 ° C for 1 hour to form a high-concentration Si diffusion layer on the surface of Fe-Si-based iron-based soft magnetic powder, and then hold in air at a temperature of 220 ° C As a result, a surface acid Fe—Si-based iron-based soft magnetic raw material powder having an acid layer on a high-concentration Si diffusion layer was produced.

[0038] By applying Mg coating to this surface-oxidized Fe-Si-based iron-based soft magnetic raw material powder, deposition with Mg, Si, Fe and O forces on the surface of the Fe-Si-based iron-based soft magnetic powder Processes 7 to 9 of the present invention for producing a deposited oxide film-coated Fe—Si-based iron-based soft magnetic powder in which an oxide film was formed were carried out.

The deposited oxide film formed on the Fe-Si based iron-based soft magnetic powder obtained by the method of the present invention 7-9 is a deposited oxide film with Mg, Si, Fe and O forces. It was confirmed by analyzing with X-ray photoelectron spectrometer that the metal oxide and Fe-Si alloy were contained in the substrate and analyzing the binding energy. Furthermore, the structure of the deposited acid film in the Fe-S coated iron-based soft magnetic powder is observed with an electron microscope, and the Mg, Si, Fe and O forces are also included in the deposited acid film. It was confirmed by electron diffraction pattern that Mg and O were included as crystalline MgO solid solution wustite phase. Furthermore, when the concentration distribution of Mg, 0, Si and Fe in the depth direction of the deposited oxide film with Mg, Si, Fe and O force was measured using an Auger electron spectrometer, it was found to be included in the deposited oxide film. Mg and O content increases and Mg and O content increases on the surface, Fe decreases on the surface and Si content is closer to the outermost surface of the deposited oxide film. It has become a component that it has a Si concentration gradient with increasing amounts.

[0039] Deposited oxide film coating Fe-Si based iron-based soft magnetic powders obtained by the present invention methods 7 to 9 were added to and mixed with a silicone resin at a blending ratio of 2% by mass. A resin-coated composite powder in which the surface of an Fe—Si-based iron-based soft magnetic powder was coated with a silicone resin was prepared. This resin-coated composite powder is placed in a mold heated to 120 ° C, press-molded, and length: 55mm, width: Plate-shaped green compact with dimensions of 10 mm, thickness: 5 mm, outer diameter: 35 mm, inner diameter: 25 mm, height: molded into a ring-shaped green compact with dimensions of 5 mm, and the resulting green compact is vacuumed Medium, temperature: 700 ° C, baked for 30 minutes to produce a composite soft magnetic material consisting of plate-like and ring-like fired bodies, and the specific resistance of the composite soft magnetic material due to the strength of this plate-like fired body The results are shown in Table 4. The composite soft magnetic material, which has a small-diameter ring-shaped fired body strength, is further lined, and the magnetic flux density, coercive force, magnetic flux density is 0.1 T, and the frequency is 20 kHz. The loss was measured and the results are shown in Table 4.

[0040] Conventional example 4

Prepare the Fe powder having the particle size shown in Table 4 as the raw material powder, add the silicone resin at a blending ratio of 2 mass% without subjecting this Fe powder to Mg coating treatment, and mix to mix the surface of the Fe powder with silicone. A resin-coated composite powder coated with resin was prepared. This resin-coated composite powder is placed in a mold heated to 120 ° C and pressed to form a plate-shaped green compact with dimensions of 55 mm in length, 10 mm in width, and 5 mm in thickness, outer diameter: 35 mm, inner diameter : Molding a ring-shaped green compact with dimensions of 25mm and height: 5mm, and firing the resulting green compact under vacuum at a temperature of 700 ° C for 30 minutes! And a composite soft magnetic material made of a ring-like fired body, and the specific resistance of the composite soft magnetic material having a plate-like fired body strength was measured. The soft magnetic material was lined, and the magnetic flux density, coercive force, and iron loss at a magnetic flux density of 0.1 T and a frequency of 20 kHz were measured. The results are shown in Table 4.

[0041] [Table 4]

[0042] Compared to the composite soft magnetic material produced by the conventional method 3, the composite soft magnetic material produced by the inventive methods 7 to 9 has a smaller coercive force with a higher magnetic flux density and a much higher specific resistance. For this reason, the iron loss is remarkably small, and it has a characteristic that it has special characteristics (such as the iron loss decreases as the frequency increases).

[0043] Example 5 Ring-shaped compact having outer diameter: 35 mm, inner diameter: 25 mm, height: 5 mm and outer diameter: 50 mm, inner diameter: using the deposited oxide film coating powder 1 of the present invention prepared in Example 1 This small-diameter ring is formed by molding a ring-shaped green compact with dimensions of 25 mm and height: 25 mm, and firing the resulting green compact under vacuum at a temperature of 700 ° C for 30 minutes. A green compact and a large outer diameter ring-shaped green compact were produced.

Using this small-diameter ring-shaped green compact, the magnetic flux density, coercive force and iron loss at 10kT and 10kHz were measured, and the inductance at 20kHz when 20A DC was superimposed was measured to determine the AC permeability. The results are shown in Table 5. Next, the outer diameter ring-shaped powder compact was fired to produce a rear tuttle with substantially constant inductance. This rear tuttle was connected to a general switching power supply with an active filter, and the efficiency (%) of the output power with respect to the input power of 1000W and 1500W was measured. The results are shown in Table 5.

[0044] Conventional example 5

Ring-shaped green compact with outer diameter: 35mm, inner diameter: 25mm, height: 5mm and outer diameter: 50mm, inner diameter: 25mm using conventional deposited oxide film coating powder 1 prepared in Conventional Example 1 The ring-shaped green compact with a height of 25 mm is molded, and the resulting green compact is fired under vacuum at a temperature of 700 ° C for 30 minutes. A powder fired body and a large outer diameter ring-shaped powder fired body were produced.

Using this small-diameter ring-shaped green compact, the magnetic flux density, coercive force and iron loss at 10kT and 10kHz were measured, and the inductance at 20kHz when 20A DC was superimposed was measured to determine the AC permeability. The results are shown in Table 5. Next, the outer diameter ring-shaped powder compact was fired to produce a rear tuttle with substantially constant inductance. This rear tuttle was connected to a general switching power supply with an active filter, and the efficiency (%) of the output power for input power: 1000W and 1500W was measured. The results are shown in Table 5.

[0045] [Table 5]

[0046] From the results shown in Table 5, it can be seen that the deposited oxide film-coated powder 1 of the present invention has superior characteristics as a raw material powder for producing reattoria compared to the conventional deposited oxide film-coated powder 1.

Industrial applicability

[0047] Using the deposited oxide film-coated Fe-Si-based iron-based soft magnetic powder of the present invention, a composite soft magnetic material is formed. When manufactured, a composite soft magnetic material having low eddy current loss due to its high specific resistance and low hysteresis loss due to its low coercive force can be produced stably at low cost. It has excellent effects on the electronics industry.

Claims

The scope of the claims

[1] Deposited oxide film-coated Fe Si-based iron-based soft magnetic powder, and a deposited oxide film with Mg, Si, Fe and O forces formed on the surface of Fe Si-based iron-based soft magnetic powder. In addition, the Fe-S iron-based soft magnetic powder is a deposited oxide film-covered Fe-Si-based iron-based soft layer whose surface layer is a high-concentration Si diffusion surface layer containing Si at a higher concentration than the Si composition contained in the entire powder. Magnetic powder.

[2] The deposited oxide film-coated FeSi-based iron-based soft magnetic powder according to claim 1, wherein the FeSi-based iron-based soft magnetic powder contains Si: 0.1 to 10% by mass, and the balance is Deposited oxide film-coated Fe Si-based iron-based soft magnetic powder having a composition composed of Fe and inevitable impurities.

[3] The deposited oxide film-coated FeSi-based iron-based soft magnetic powder according to claim 1 or 2, wherein the deposited oxide film having Mg, Si, Fe and O forces is directed to the surface. The Mg and O contents increase, the Fe content decreases toward the surface, and Si is deposited near the outermost surface of the deposited oxide film. Oxide film coating F e Si-based iron-based soft magnetic powder.

[4] The deposited oxide film-coated FeSi-based iron-based soft magnetic powder according to any one of claims 1, 2 and 3, wherein the deposited oxide film having Mg, Si, Fe and O force is crystalline. 4. The deposited oxide film-covered Fe—Si-based iron-based soft magnetic powder according to claim 1, wherein the MgO solid solution wustite type phase is contained.

[5] The deposited acid film according to claim 1, 2 or 3, wherein the deposited acid film having Mg, Si, Fe and O force contains metal Fe or Fe—Si alloy. Coated Fe-Si based iron-based soft magnetic powder.

[6] The deposited oxide film having Mg, Si, Fe and O forces has a fine crystal structure with an average crystal grain size of 200 nm or less. 1, 2, 3, 4 or 5 Deposition of the deposited acid film coating Fe-Si based iron-based soft magnetic powder.

[7] Fe Si-based iron-based soft magnetic powder or Fe powder is mixed with Si powder, and then heated in a non-oxidizing atmosphere. A high-concentration Si diffusion layer obtained by producing a Fe-S related iron-based soft magnetic powder having a high-concentration Si diffusion layer containing a high concentration of Si in the Si-based iron-based soft magnetic powder or Fe powder. Of Fe Si-based iron-based soft magnetic powder A surface-oxidized Fe-Si-based iron-based soft magnetic raw material powder with an oxide layer on top is prepared and this high concentration

Surface oxidized Fe—Si-based iron-based soft magnetic raw material powder having an oxide layer on the Si diffusion layer. The mixed powder obtained by adding and mixing Mg powder is temperature: 150 ~: L 100 ° C, pressure: 1 x 10 1 ¹² ~ 1

A method for producing a deposited oxide film-coated Fe-Si-based iron-based soft magnetic powder, characterized by heating in an inert gas atmosphere or a vacuum atmosphere of X 10 ^_1 MPa.

[8] The oxidation treatment of the Fe—Si-based iron-based soft magnetic powder having the high-concentration Si diffusion layer according to claim 7

A method for producing a deposited oxide film coated Fe—Si-based iron-based soft magnetic powder, in which a soft magnetic metal powder is heat-treated in an oxidizing atmosphere at a temperature of 50 to 500 ° C.

[9] Deposition oxidation in which Fe—S related iron-based soft magnetic powder having a high-concentration Si diffusion layer produced by the method according to claim 7 or 8 is further heat-treated in an oxidizing atmosphere at a temperature of 50 to 400 ° C. Film coating Fe—Si production method of iron-based soft magnetic powder.

[10] The deposited oxide film-coated Fe—Si-based iron-based soft magnetism according to any one of claims 1, 2, 3, 4, 5, or 6, wherein the Fe—Si-based iron-based soft magnetic powder is oxidized. Surface-oxidized Fe-Si-based iron-based soft magnetic raw material powder for producing powder.

[11] A high-concentration Si diffusion layer containing Si at a higher concentration than the Si composition contained in the entire Fe-Si-based iron-based soft magnetic powder is formed on the surface of the Fe-Si-based iron-based soft magnetic powder. The deposited oxide film-coated Fe—Si-based iron-based soft magnetic powder according to claim 1, further comprising an oxide layer formed on the high-concentration Si diffusion layer. Surface oxidation for manufacturing Fe—

Si-based iron-based soft magnetic raw material powder.

[12] A composite soft magnetic material comprising a compacted fired body of a deposited oxych film-coated Fe—S iron-based soft magnetic powder according to any one of claims 1, 2, 3, 4, 5, or 6.

[13] Silicone resin, polyimide resin or PPS resin between the particles of the deposited acid film coating Fe—S iron-based soft magnetic powder according to any one of claims 1, 2, 3, 4, 5 or 6. 13. The composite soft magnetic material according to claim 12, wherein the composite soft magnetic material is formed of a sintered compact obtained by interposing a fat insulating material.

[14] Fe-Si-based iron-based soft magnetic particle phase and the grain boundary phase surrounding this Fe-Si-based iron-based soft magnetic particle phase. The grain boundary phase contains a crystalline MgO solid solution wustite-type phase. 14. The composite soft magnetic material according to claim 12, further comprising an acid oxide.

[15] A core for a rear tuttle, which is also the composite soft magnetic material according to any one of claims 12, 13, and 14.

[16] A reactor having a core which is also the composite soft magnetic material cover according to any one of claims 12, 13, and 14.

[17] The magnetic core, the motor core, the generator core, the solenoid core, the idling core, the transformer core, the choke coil core, or the magnetic sensor core that is also the composite soft magnetic material according to any one of claims 12, 13, or 14. Electromagnetic circuit components.

18. An electric device incorporating the electromagnetic circuit component according to claim 17.