Composite magnetic materials, magnetic wedges, cores, and rotating electric machines

Abstract

To provide a composite magnetic material, a magnetic wedge, and a rotating electric machine having excellent magnetic and mechanical properties. [Solution] A composite magnetic material 90 comprising a plurality of flattened magnetic metal particles 10 and an intervening phase 20, wherein the plurality of flattened magnetic metal particles have a flattened surface and a magnetic metal phase containing at least one first element selected from the group consisting of Fe, Co and Ni, and have an average thickness of 10 nm to 100 μm, and the average value of the ratio of the average length in the flattened surface to the thickness is 2 to 10000, the intervening phase is present between the plurality of flattened magnetic metal particles and contains at least one second element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N) and fluorine (F), and the composite magnetic material further comprises one or more flattened magnetic metal particle assemblies 12 containing first flattened magnetic metal particles contained in the plurality of flattened magnetic metal particles and second flattened magnetic metal particles contained in the plurality of flattened magnetic metal particles.

Description

Technical Field

[0001] Embodiments of the present invention relate to composite magnetic materials, magnetic wedges, cores, and rotating electrical machines.

Background Art

[0002] Currently, soft magnetic materials are applied to cores and magnetic wedges of components of various systems and devices such as rotating electrical machines (e.g., motors, generators, etc.), transformers, inductors, transformers, magnetic inks, antenna devices, etc., and are very important materials. Soft magnetic materials are required to have high magnetic permeability and low losses in the frequency band used, and also require high saturation magnetization to prevent magnetic saturation. The losses mainly consist of hysteresis losses and eddy current losses. To reduce hysteresis losses, it is important to reduce the coercive force, and to reduce eddy current losses, it is important to improve the electrical resistivity and reduce the size of metal components. Other characteristics required when incorporated into each system and device include high thermal stability and high strength. Also, for application to complex shapes, composite magnetic materials (materials containing magnetic particles (mainly magnetic metal particles) in the intervening phase), such as powder compacts, are more preferable than plates and ribbons. In composite magnetic materials, it is known that the characteristics deteriorate in terms of saturation magnetization, magnetic permeability, losses, strength, etc. compared to plates and ribbons, and improvement of the characteristics is desired. As an example of the application of composite magnetic materials, we will briefly explain the current challenges using magnetic wedges as an example. Normally, the coil windings of a rotating electric machine are housed in iron core slots and supported and fixed by wedges provided at the slot openings. Non-magnetic materials are generally used for these wedges, but because the magnetoresistance value in the air gap between the stator core and the rotor core is discontinuous, pulsation occurs in the magnetic flux distribution on the iron core surface facing the wedge through the air gap, resulting in high harmonic losses. To reduce these harmonic losses, wedges with moderate magnetism (magnetic wedges) are provided. Generally, composite magnetic materials are used for existing magnetic wedges. By applying such magnetic wedges, harmonic losses are reduced and the efficiency of the rotating electric machine is improved. Figure 1 is a schematic diagram of the usage state and effect of magnetic wedges. Figure 1 shows a radial gap type rotating electric machine as an example. Figure 1 shows the magnetic wedge 100, coil 230, iron core teeth 250, and iron core slot 260.

[0003] It goes without saying that the higher the permeability of the magnetic wedge, the lower the harmonic losses can be. However, as shown in Figure 1, magnetic wedges are arranged to bridge adjacent core teeth, which has the disadvantage of increasing the leakage flux flowing between the core teeth through the magnetic wedge. In addition, existing magnetic wedges have low saturation magnetization, making them prone to magnetic saturation, and also have high losses (high coercivity resulting in large hysteresis losses, and low electrical resistivity resulting in large eddy current losses), thus limiting the improvement in the efficiency of rotating electric machines. Furthermore, existing magnetic wedges have low permeability, which limits the improvement in the efficiency of rotating electric machines, and are also insufficient in terms of mechanical properties (strength, etc.). Therefore, it is desirable to improve the characteristics of magnetic wedges in terms of saturation magnetization, permeability, losses, and strength. In particular, it is desirable to improve the magnetic properties and mechanical properties. Furthermore, as mentioned above, magnetic wedges generally use composite magnetic materials consisting of magnetic particles (mainly magnetic metal particles) and an intervening phase; therefore, it is desirable to improve the magnetic and mechanical properties of the magnetic metal particles and the composite magnetic material. In summary, we have used magnetic wedges as an example to explain the challenges of composite magnetic materials. However, the situation is the same when applied to the core components of various systems and devices such as rotating electric machines, transformers, inductors, magnetic inks, and antenna devices, and similarly, improvements in magnetic and mechanical properties are desired. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Utility Model Publication No. 58-6572 [Overview of the project] [Problems that the invention aims to solve]

[0005] The problem that this invention aims to solve is to provide a composite magnetic material, magnetic wedge, core, and rotating electric machine having excellent magnetic and mechanical properties. [Means for solving the problem]

[0006] The composite magnetic material of the embodiment is a composite magnetic material comprising a plurality of flattened magnetic metal particles and an intervening phase, wherein the plurality of flattened magnetic metal particles have a flattened surface and a magnetic metal phase containing at least one first element selected from the group consisting of Fe, Co and Ni, the average thickness is 10 nm to 100 μm, the average value of the ratio of the average length in the flattened surface to the thickness is 2 to 10000, the intervening phase is present between the plurality of flattened magnetic metal particles and contains at least one second element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N) and fluorine (F), and the composite magnetic material comprises a first flattened magnetic metal particle contained in the plurality of flattened magnetic metal particles and a plurality of flattened The present invention comprises one or more flat magnetic metal particle aggregates, each containing a second flat magnetic metal particle contained within a flat magnetic metal particle, wherein in a predetermined cross-section including the first flat magnetic metal particle and the second flat magnetic metal particle, the flattened surface of the second flat magnetic metal particle has a length greater than or equal to the flattened surface of the first flat magnetic metal particle, and in the predetermined cross-section, the flattened surface of the first flat magnetic metal particle is in contact with the flattened surface of the second flat magnetic metal particle for a length of 50% or more of the flattened surface of the first flat magnetic metal particle, and the flat magnetic metal particle aggregate is separated from the nearest adjacent flat magnetic metal particle not included in the flat magnetic metal particle aggregate by an average shortest distance of 1 / 10000 or more of the average thickness. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram illustrating the usage and effects of magnetic wedges. [Figure 2] This is a conceptual diagram showing an example of how to determine the thickness of flattened magnetic metal particles in the first embodiment. [Figure 3] This is a conceptual diagram illustrating how to determine the maximum and minimum lengths of flattened magnetic metal particles within a flattened plane in the first embodiment. [Figure 4] This is a conceptual diagram illustrating another example of how to determine the maximum and minimum lengths of flattened magnetic metal particles within a flattened plane in the first embodiment. [Figure 5]This is a schematic diagram showing the directions used when measuring coercivity in the first embodiment, where the direction is changed every 22.5 degrees with respect to the 360-degree angle within the flattened plane of the flattened magnetic metal particles. [Figure 6] This is a schematic diagram of the flattened magnetic metal particles of the first embodiment. [Figure 7] This is a schematic diagram of the magnetic wedge according to the first embodiment. [Figure 8] This shows a schematic cross-sectional view of the composite magnetic material of the first embodiment and a schematic cross-sectional view of the composite magnetic material of a comparative embodiment. [Figure 9] This is a schematic cross-sectional view showing an example of a reference contour line 11a of the flat magnetic metal particle aggregate 12a of the first embodiment. [Figure 10] This is a schematic cross-sectional view of a flattened magnetic metal particle aggregate of the first embodiment at a predetermined cross-section. [Figure 11] This is a schematic cross-sectional view of a predetermined cross-section of the first embodiment. [Figure 12] This is an example of a cross-sectional photograph of the composite magnetic material according to the first embodiment. [Figure 13] This figure shows the angle between a plane parallel to the flattened plane of the flattened magnetic metal particles and a plane of the composite magnetic material in the first embodiment. [Figure 14] This is a schematic diagram showing an example of a radial gap type rotating electric machine according to the second embodiment. [Figure 15] This is a schematic diagram showing an example of an axial gap type rotating electric machine according to the second embodiment. [Figure 16] This is a schematic diagram showing an example of a generator according to the second embodiment. [Figure 17] This is a schematic diagram showing an example of a linear motor according to the second embodiment. [Modes for carrying out the invention]

[0008] (First Embodiment) Embodiments will be described below with reference to the drawings. In the drawings, identical or similar parts are denoted by the same or similar reference numerals. Unless otherwise specified in this specification, measurements are performed at 25°C.

[0009] In this specification, each of the directions of "axial direction", "rotational direction", and "radial direction" shall be defined based on the rotor of the rotating electrical machine. That is, the "axial direction" means the direction along the rotation axis of the rotor, and the "rotational direction" means the circumferential direction (or the tangential direction thereof) around the rotation axis of the rotor. And the "radial direction" means the direction perpendicular (orthogonally intersecting) to the rotation axis of the rotor.

[0010] The composite magnetic material of the embodiment is a composite magnetic material including a plurality of flat magnetic metal particles and an interposed phase. The plurality of flat magnetic metal particles have a flat plane and a magnetic metal phase containing at least one first element selected from the group consisting of Fe, Co, and Ni. The average thickness is 10 nm or more and 100 μm or less, and the average value of the ratio of the average length in the flat plane to the thickness is 2 or more and 10000 or less. The interposed phase exists between the plurality of flat magnetic metal particles and contains at least one second element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N), and fluorine (F). The composite magnetic material includes one or more aggregates of flat magnetic metal particles including a first flat magnetic metal particle contained in the plurality of flat magnetic metal particles and a second flat magnetic metal particle contained in the plurality of flat magnetic metal particles. In a predetermined cross section including the first flat magnetic metal particle and the second flat magnetic metal particle, the flat plane of the second flat magnetic metal particle has a length greater than that of the flat plane of the first flat magnetic metal particle. In the predetermined cross section, the flat plane of the first flat magnetic metal particle contacts the flat plane of the second flat magnetic metal particle with a length of 50% or more of the flat plane of the first flat magnetic metal particle. The aggregate of flat magnetic metal particles is separated (apart) from the closest adjacent flat magnetic metal particle not included in the aggregate of flat magnetic metal particles by an average shortest distance of 1 / 10000 or more of the average thickness.

[0011] The composite magnetic material of the present embodiment is used, for example, as a magnetic wedge. In other words, the magnetic wedge of the present embodiment includes the composite magnetic material of the present embodiment. In other words, in the present embodiment, the magnetic wedge is an example of the composite magnetic material.

[0012] Flattened magnetic metal particles are flattened particles with a flaky or flattened shape.

[0013] Thickness refers to the average thickness of a single flattened magnetic metal particle. Any method that can determine the average thickness of a single flattened magnetic metal particle is acceptable. For example, one may observe a cross-section perpendicular to the flattened plane of the flattened magnetic metal particle using a transmission electron microscope (TEM), scanning electron microscope (SEM), or optical microscope, select at least 10 arbitrary locations in the direction of the flattened plane on the observed cross-section of the flattened magnetic metal particle, measure the thickness at each selected location, and use the average value. Alternatively, one may select at least 10 locations at intervals in the direction of the flattened plane on the observed cross-section of the flattened magnetic metal particle (in this case, it is preferable not to select the ends and other ends as they are special locations), measure the thickness at each selected location, and use the average value. Figure 2 is a conceptual diagram showing an example of how to determine the thickness of a flattened magnetic metal particle in the first embodiment. The method for determining the thickness in this case is specifically shown below. Select 10 points (excluding the ends) at intervals along the direction of the flattened plane, such as from one end to the other, and define the thickness at each point as t1, t2, ..., t 10 In this case, the thickness of the flattened magnetic metal particles is (t1 + t2 + ... + t 10 ) / 10. It is preferable to measure as many points as possible during measurement, as this allows for obtaining average information. Furthermore, if the cross-sectional contour is highly irregular or the surface contour is rough, making it difficult to determine the average thickness in its current state, it is preferable to smooth the contour with an average straight line or curve, as appropriate depending on the situation, before performing the above method.

[0014] Furthermore, the average thickness refers to the average value of the thicknesses of multiple flattened magnetic metal particles, and is distinct from the simple "thickness" mentioned above. When determining the average thickness, it is preferable to use the average value obtained over 20 or more flattened magnetic metal particles. It is also preferable to determine the average thickness from as many flattened magnetic metal particles as possible, as this allows for obtaining average information. If it is not possible to observe 20 or more flattened magnetic metal particles, it is preferable to observe as many flattened magnetic metal particles as possible and use the average value obtained from them. The average thickness of the flattened magnetic metal particles is preferably 10 nm to 100 μm. More preferably 10 nm to 1 μm, and even more preferably 10 nm to 100 nm. Furthermore, it is preferable that the flattened magnetic metal particles include those with a thickness of 10 nm to 100 μm, more preferably 10 nm to 1 μm, and even more preferably 10 nm to 100 nm. This is preferable because it allows for sufficiently small eddy current losses when a magnetic field is applied in a direction parallel to the flattened plane. Furthermore, a smaller thickness is preferable because the magnetic moment is confined in a direction parallel to the flattened plane, making it easier for magnetization to proceed through rotational magnetization. When magnetization proceeds through rotational magnetization, the magnetization tends to proceed reversibly, resulting in a smaller coercivity, which is preferable because it reduces hysteresis loss.

[0015] The average length of a flattened magnetic metal particle is defined as (a+b) / 2, where a is the maximum length and b is the minimum length within the flattened plane. The maximum length a and minimum length b can be determined as follows: For example, consider the rectangle with the smallest area that circumscribes the flattened plane. The length of the longer side of that rectangle is the maximum length a, and the length of the shorter side is the minimum length b. Figure 3 is a conceptual diagram illustrating how to determine the maximum and minimum lengths of a flattened magnetic metal particle within the flattened plane in the first embodiment. Figure 3 is a schematic diagram showing the maximum length a and minimum length b determined by the above method, using several flattened magnetic metal particles as examples. The maximum length a and minimum length b, like the average thickness, can be determined by observing the flattened magnetic metal particle with a TEM, SEM, or optical microscope. It is also possible to determine the maximum length a and minimum length b by performing image analysis of a microscope image on a computer. In any case, it is preferable to determine these values ​​for 20 or more flattened magnetic metal particles. Furthermore, it is preferable to determine these values ​​for as many flattened magnetic metal particles as possible in order to obtain average information. Furthermore, if it is not possible to observe 20 or more flattened magnetic metal particles, it is preferable to observe as many flattened magnetic metal particles as possible and adopt the average value obtained from them. In this case, since it is preferable to obtain the average value as much as possible, it is preferable to perform observation or image analysis when the flattened magnetic metal particles are uniformly dispersed (in a state in which multiple flattened magnetic metal particles with different maximum and minimum lengths are dispersed as randomly as possible). For example, it is preferable to perform observation or image analysis by thoroughly mixing multiple flattened magnetic metal particles and sticking them onto a tape, or by dropping multiple flattened magnetic metal particles from above and letting them fall and stick onto a tape.

[0016] However, depending on the type of flattened magnetic metal particle, the method used to determine the maximum length a and minimum length b may not capture the essence of the particle. Figure 4 is a conceptual diagram illustrating another example of how to determine the maximum and minimum lengths of a flattened magnetic metal particle within a flattened plane in the first embodiment. For example, in the case shown in Figure 4, the flattened magnetic metal particle is long and curved, but in this case, the maximum and minimum lengths of the flattened magnetic metal particle are essentially the lengths a and b shown in Figure 4. Thus, the method for determining the maximum lengths a and b is not entirely unique, and basically, it is acceptable to "consider the rectangle with the smallest area among the rectangles circumscribing the flattened plane, and set the length of the longer side of that rectangle as the maximum length a and the length of the shorter side as the minimum length b." However, depending on the shape of the particle, if this method does not capture the essence, the maximum length a and minimum length b should be determined flexibly to capture the essence. The thickness t is defined as the length perpendicular to the flattened plane. The ratio A of the average length within a flattened plane to its thickness is defined as A = ((a+b) / 2) / t, where a is the maximum length, b is the minimum length, and t is the thickness.

[0017] The average value of the ratio of the average length within the flattened plane to the thickness of the flattened magnetic metal particles is preferably between 2 and 10000. This is because it increases the magnetic permeability. Furthermore, it allows for a higher ferromagnetic resonance frequency, thereby reducing ferromagnetic resonance losses.

[0018] The ratio of the average length within the flattened plane to the thickness is calculated using the average value. Preferably, the average value obtained over 20 or more flattened magnetic metal particles is used. Furthermore, it is preferable to obtain average information by examining as many flattened magnetic metal particles as possible. If it is not possible to observe 20 or more flattened magnetic metal particles, it is preferable to observe as many flattened magnetic metal particles as possible and use the average value obtained over them. For example, if there are particles Pa, Pb, and Pc, and their respective thicknesses are Ta, Tb, and Tc, and their average lengths within the flattened plane are La, Lb, and Lc, then the average thickness is calculated as (Ta + Tb + Tc) / 3, and the average value of the ratio of the average length within the flattened plane to the thickness is calculated as (La / Ta + Lb / Tb + Lc / Tc) / 3.

[0019] It is preferable that the flattened magnetic metal particles have a difference in coercivity depending on the direction within the flattened plane. The larger the percentage of the difference in coercivity depending on the direction, the better, preferably 1% or more. More preferably, the percentage of the difference in coercivity is 10% or more, even more preferably 50% or more, and even more preferably 100% or more. The percentage of the difference in coercivity referred to here is defined as (Hc(max)-Hc(min)) / Hc(min)×100(%), using the maximum coercivity Hc(max) and minimum coercivity Hc(min) within the flattened plane. The coercivity can be evaluated using a vibrating sample magnetometer (VSM) or the like. If the coercivity is low, it is possible to measure coercivity of 0.1Oe or less by using a low magnetic field unit. Measurement is performed by changing the direction within the flattened plane with respect to the direction of the measurement magnetic field.

[0020] "Having a coercivity difference" means that when a magnetic field is applied in all 360 degrees within a flattened plane and the coercivity is measured, there is a direction in which the coercivity is maximum and a direction in which the coercivity is minimum. For example, when measuring the coercivity by changing the direction every 22.5 degrees with respect to the 360-degree angle within a flattened plane, if a coercivity difference appears, that is, if there is an angle in which the coercivity is greater and an angle in which the coercivity is smaller, then it is said that "a coercivity difference exists." Figure 5 is a schematic diagram showing the directions when measuring the coercivity by changing the direction every 22.5 degrees with respect to the 360-degree angle within the flattened plane of a flattened magnetic metal particle in the first embodiment. Note that in Figure 5, the flattened plane of the flattened magnetic metal particle is shown as viewed from above. Having a coercivity difference within a flattened plane is preferable because it reduces the minimum coercivity value compared to the isotropic case where there is almost no coercivity difference. In materials exhibiting magnetic anisotropy within a flattened plane, the coercivity differs depending on the direction within the plane, resulting in a smaller minimum coercivity value compared to magnetically isotropic materials. This reduces hysteresis loss and improves permeability, which is desirable. Figure 5 shows flattened magnetic metal particles 10 and a flattened plane 6.

[0021] Furthermore, the flattened magnetic metal particles have a magnetic metal phase containing at least one first element selected from the group consisting of Fe, Co, and Ni. It is preferable to select a composition that can achieve a higher saturation magnetization.

[0022] Elements can be easily analyzed using methods such as EDX (Energy Dispersive X-ray spectroscopy) and ICP (Inductively Coupled Plasma) emission spectroscopy.

[0023] The flattened magnetic metal particles preferably contain at least one non-magnetic metal selected from the group consisting of Mg, Al, Si, Ca, Zr, Ti, Hf, Zn, Mn, Ba, Sr, Cr, Mo, Ag, Ga, Sc, V, Y, Nb, Pb, Cu, In, Sn, and rare earth elements. This enhances the thermal stability and oxidation resistance of the flattened magnetic metal particles. Among these, Al and Si are particularly preferred because they readily form solid solutions with Fe, Co, and Ni, which are the main components of the flattened magnetic metal particles, and contribute to improving thermal stability and oxidation resistance.

[0024] Furthermore, in order to induce magnetic anisotropy, there is also a method of making the crystallinity of the flattened magnetic metal particles as amorphous as possible and inducing magnetic anisotropy in one direction in the plane by a magnetic field or strain. In this case, it is desirable to have a composition that makes it easy to make the flattened magnetic metal particles as amorphous as possible. From this viewpoint, it is preferable that the magnetic metal contained in the flattened magnetic metal particles contains at least one additive element selected from B (boron), Si (silicon), Al (aluminum), C (carbon), Ti (titanium), Zr (zirconium), Hf (hafnium), Nb (niobium), Ta (tantalum), Mo (molybdenum), Cr (chromium), Cu (copper), W (tungsten), P (phosphorus), N (nitrogen), Ga (gallium), and Y (yttrium). Additive elements that have a large difference in atomic radius from at least one first element selected from the group consisting of Fe, Co, and Ni are preferred. Furthermore, it is preferable that the additive element is such that the mixed enthalpy of at least one first element selected from the group consisting of Fe, Co, and Ni is negatively large. It is also preferable that the system consists of a total of three or more elements, including the first element and the additive element. In addition, metalloid additive elements such as B and Si are advantageous when mixed into the system because they have a slow crystallization rate and are prone to amorphous formation. From the above viewpoint, B, Si, P, Ti, Zr, Hf, Nb, Y, Cu, etc. are preferred, and it is more preferable that the additive element contains one of B, Si, Zr, Hf, or Y. For example, it is preferable that the magnetic metal phase contains Fe and Co as the first elements and Si and B as the additive elements. Furthermore, it is preferable that the total amount of the additive element is 0.001 at% or more and 80 at% or less relative to the total amount of the first element and the additive element. More preferably, it is 5 at% or more and 80 at% or less, and even more preferably, 10 at% or more and 40 at% or less. Furthermore, while a larger total amount of the aforementioned additive elements is preferable because it promotes amorphization and facilitates the imparting of magnetic anisotropy (i.e., it is preferable from the viewpoint of low loss and high permeability), it is also undesirable because it reduces the proportion of the magnetic metal phase, resulting in a lower saturation magnetization. For these reasons, it is important to select the composition and amount of additive elements by considering all factors, including high saturation magnetization, low loss, and high permeability.

[0025] Figure 6 is a schematic diagram of the flattened magnetic metal particles in the first embodiment. The coating layer 9 and the flattened magnetic metal particles 10 are shown.

[0026] The coating layer preferably contains at least one nonmagnetic metal selected from the group consisting of Mg, Al, Si, Ca, Zr, Ti, Hf, Zn, Mn, Ba, Sr, Cr, Mo, Ag, Ga, Sc, V, Y, Nb, Pb, Cu, In, Sn, and rare earth elements, and more preferably contains at least one second element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N), and fluorine (F). As nonmagnetic metals, Al and Si are particularly preferred from the viewpoint of thermal stability. If the flattened magnetic metal particles contain at least one nonmagnetic metal selected from the group consisting of Mg, Al, Si, Ca, Zr, Ti, Hf, Zn, Mn, Ba, Sr, Cr, Mo, Ag, Ga, Sc, V, Y, Nb, Pb, Cu, In, Sn, and rare earth elements, it is more preferable that the coating layer contains at least one of the same nonmagnetic metals as one of the nonmagnetic metal components of the flattened magnetic metal particles. Among oxygen (O), carbon (C), nitrogen (N), and fluorine (F), the coating preferably contains oxygen (O), and is preferably an oxide or a composite oxide. This is from the viewpoint of ease of coating layer formation, oxidation resistance, and thermal stability. As a result, the adhesion between the flat magnetic metal particles and the coating layer can be improved, and the thermal stability and oxidation resistance of the magnetic wedge, described later, can be improved. The coating layer can not only improve the thermal stability and oxidation resistance of the flat magnetic metal particles, but also improve the electrical resistance of the flat magnetic metal particles. By increasing the electrical resistance, eddy current losses can be suppressed and the frequency characteristics of the magnetic permeability can be improved. For this reason, the coating layer is preferably electrically high-resistive, and preferably has a resistance value of 1 mΩ·cm or more.

[0027] The coating layer preferably contains a silane coupling agent. Preferred silane coupling agents include those having amino groups, methacrylic groups, or epoxy groups, more preferably those having amino groups or epoxy groups, and even more preferably those having amino groups. It is preferable that the silane coupling agent contains at least one of these. Even more preferably, it is preferable that it has two or more amino groups in the molecule. Also, it is preferable that it has a short linear chain. Regarding the molecular weight, it is preferable that it is relatively small, preferably 300 or less, more preferably 250 or less, and even more preferably 230 or less. Such silane coupling agents are particularly preferable because they not only strengthen the binding (bonding) between the flattened magnetic metal particles and the intervening phase, but also easily create a unique state in which the flattened magnetic metal particles tend to aggregate, stick, and bond with each other, that is, they easily create an aggregate of flattened magnetic metal particles.

[0028] Preferably, there are not just one type of coating layer, but two or more types. For example, it is preferable to have a coating layer containing at least one nonmagnetic metal selected from the group consisting of Mg, Al, Si, Ca, Zr, Ti, Hf, Zn, Mn, Ba, Sr, Cr, Mo, Ag, Ga, Sc, V, Y, Nb, Pb, Cu, In, Sn, and rare earth elements, and at least one second element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N), and fluorine (F), and another coating layer containing a silane coupling agent. It is also preferable to have yet another coating layer. When there are multiple coating layers, each coating layer may be coated on the surface of the flattened magnetic metal particles, or one coating layer may be coated on the surface of the flattened magnetic metal particles and then another coating layer may be applied on top of that. In other words, one coating layer may be coated on top of another coating layer. Furthermore, a multilayer coating structure may be formed in which yet another coating layer is coated on top of another coating layer.

[0029] Furthermore, the presence of a coating layer is also preferable from a magnetic standpoint. Since the thickness of the flattened magnetic metal particles is small relative to the size of the flattened surface, they can be considered as a pseudo-thin film. In this case, when a coating layer is formed on the surface of the flattened magnetic metal particles and integrated, it can be considered as a pseudo-layered thin film structure, and the magnetic domain structure is energetically stabilized. This makes it possible to reduce coercivity (which reduces hysteresis loss), which is preferable. At this time, the permeability is also increased, which is preferable. From this viewpoint, it is even more preferable that the coating layer is non-magnetic, as this makes it easier to stabilize the magnetic domain structure.

[0030] From the viewpoint of thermal stability, oxidation resistance, and electrical resistance, a thicker coating layer is preferable. However, if the coating layer is too thick, the saturation magnetization decreases, which is undesirable as it reduces the permeability. Also, from a magnetic viewpoint, if the thickness is too thick, the effect of "stabilizing the magnetic domain structure to reduce coercivity, loss, and permeability" is reduced. Considering the above, the preferred thickness of the coating layer is 0.1 nm to 1 μm, more preferably 0.1 nm to 100 nm.

[0031] The intervening phase contains at least one second element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N), and fluorine (F). This is because it can increase electrical resistance. Preferably, the electrical resistivity of the intervening phase is higher than that of the flattened magnetic metal particles. This is because it can reduce eddy current losses in the flattened magnetic metal particles. Since the intervening phase surrounds the flattened magnetic metal particles, it is preferable that it can improve the oxidation resistance and thermal stability of the flattened magnetic metal particles. Among these, those containing oxygen are more preferable from the viewpoint of high oxidation resistance and high thermal stability. The intervening phase also plays a role in mechanically bonding the flattened magnetic metal particles together, so it is also preferable from the viewpoint of high strength.

[0032] The intervening phase preferably contains a resin. Suitable resins include thermoplastic resins, thermosetting resins, polyester resins, vinyl ester resins, polyethylene resins, polystyrene resins, polyvinyl chloride resins, polyvinyl butyral resins, polyvinyl alcohol resins, polybutadiene resins, Teflon® resins, polyurethane resins, cellulose resins, ABS resins, nitrile-butadiene rubbers, styrene-butadiene rubbers, silicone resins, other synthetic rubbers, natural rubbers, epoxy resins, phenolic resins, allyl resins, polybenzimidazole resins, amide resins, polyimide resins, polyamideimide resins, bismaleimide resins, or copolymers thereof. In particular, to achieve high thermal stability, it is preferable to include heat-resistant silicone resins, polyimide resins, imide resins, or bismaleimide resins. Epoxy resins, phenolic resins, and polyester resins are preferred because they are relatively heat-resistant, high-strength, and versatile resins. Furthermore, it is preferable that the material contains at least one resin selected from the group consisting of bismaleimide resins, polyimide resins, imide resins, polyester resins, phenolic resins, epoxy resins, and silicone resins. It is also preferable, and more preferably, that the weight increase rate after exposure to air at room temperature for one week following exposure at 120°C for 30 minutes is 1% or less. Furthermore, it is preferable, and more preferably, that the water absorption rate as defined in ISO 62:1999 (JIS K7209:2000) is 1% or less. In addition, to increase strength, materials such as FRP (Fiber-Reinforced Plastics) mixed with fibers such as glass fibers, aramid fibers, carbon fibers, Zylon fibers, polyethylene fibers, and boron fibers are also preferred. As a result, the bonding between the flat magnetic metal particles and the intervening phase becomes stronger, and thermal stability and mechanical properties such as strength and toughness are easily improved. Furthermore, the intervening phase surrounding the flattened magnetic particles provides excellent oxidation resistance, and the deterioration of magnetic properties due to oxidation of the flattened magnetic metal particles is less likely to occur, which is desirable.Furthermore, the type of resin can be identified using methods such as IR (Infrared Spectroscopy) and NMR (Nuclear Magnetic Resonance).

[0033] Furthermore, it is preferable that the intervening phase 20 contains a phenolic resin and the coating layer 9 contains a silane coupling agent having an amino group, in order to achieve excellent magnetic and mechanical properties. However, the intervening phase 20 does not necessarily have to contain a phenolic resin, and the coating layer 9 does not necessarily have to contain a silane coupling agent having an amino group.

[0034] Figure 7 is a schematic diagram of the magnetic wedge of this embodiment. As shown in Figure 7, magnetic wedges can be not only simple rectangular parallelepiped shapes (rectangular cross-sections), but also various shapes such as trapezoidal, hexagonal, and convex cross-sections. The closer the magnetic wedge is placed to the gap surface between the rotor and stator, the more effective it becomes (improving the efficiency of the rotating electric machine). From this viewpoint, trapezoidal, convex, and hexagonal shapes are preferable to rectangular shapes. Also, from the viewpoint of "shapes that easily draw magnetic flux towards the magnetic wedge (which improves the efficiency of the rotating electric machine)," trapezoidal and convex shapes are preferable to hexagonal shapes. On the other hand, from the viewpoint of ease of manufacture and high reliability as a material (mechanical properties, thermal properties), the rectangular shape is the most preferred, followed by the trapezoidal and hexagonal shapes. In that sense, the trapezoidal shape is very preferable because it is easy to position close to the gap surface between the rotor and stator, the trapezoidal shape makes it easier to draw magnetic flux towards the magnetic wedge, and furthermore, it is easy to manufacture and the reliability of the material (mechanical properties, thermal properties) is easily improved.

[0035] Regardless of the shape, three axial directions that intersect each other orthogonally or perpendicularly are defined as the width direction, thickness direction, and longitudinal direction. The longitudinal direction of a magnetic wedge is the direction in which the length of the magnetic wedge is longer. For example, if the shape of the magnetic wedge in question is approximately a rectangular parallelepiped, the direction along the longest side of this approximately rectangular parallelepiped shape is determined as the longitudinal direction of the magnetic wedge. The thickness direction and width direction of a magnetic wedge are directions perpendicular to the longitudinal direction of the magnetic wedge. The thickness direction and width direction of a magnetic wedge can be distinguished as follows: If the magnetic wedge in question is installed inside a rotating electric machine, the magnetic wedge in question is removed from inside the rotating electric machine. Here, the direction of rotation of the rotating electric machine is the width direction of the magnetic wedge in question. The thickness direction is the direction perpendicular to the width direction.

[0036] Figure 8 shows a schematic cross-sectional view of the composite magnetic material of the first embodiment and a schematic cross-sectional view of the composite magnetic material of a comparative embodiment. The composite magnetic material 90 of the first embodiment, shown on the right side of Figure 8, comprises flattened magnetic metal particles 10, a flattened magnetic metal particle aggregate 12, and an intervening phase 20. The flattened magnetic metal particles 10 may have a coating layer 9. The flattened magnetic metal particle aggregate 12 includes, for example, a first flattened magnetic metal particle contained in a plurality of flattened magnetic metal particles and a second flattened magnetic metal particle contained in a plurality of flattened magnetic metal particles. In this case, the flattened surface of the first flattened magnetic metal particle is in contact with the flattened surface of the second flattened magnetic metal particle for a length of 50% or more of the length of the flattened surface of the first flattened magnetic metal particle (details will be described later), and such an aggregate structure is called a flattened magnetic metal particle aggregate. If the flattened surface of the first flattened magnetic metal particle is in contact with the flattened surface of the second flattened magnetic metal particle for a length of less than 50% of the length of the flattened surface of the first flattened magnetic metal particle, it is not called a flattened magnetic metal particle aggregate. Note that the flattened magnetic metal particle aggregate 12 may have three or more flattened magnetic metal particles. For example, the flattened magnetic metal particle aggregate 12 may have a first flattened magnetic metal particle, a second flattened magnetic metal particle, and a third flattened magnetic metal particle that are included in multiple flattened magnetic metal particles. When a flattened magnetic metal particle aggregate contains multiple flattened magnetic metal particles, it is not necessary for all adjacent flattened magnetic metal particles within the aggregate to be in contact for a length of 50% or more of the flattened plane; it is sufficient if they are in contact for a length of 50% or more of the flattened plane at just one point. On the other hand, the left side of Figure 8 (upper left and lower left) is a schematic cross-sectional view of the composite magnetic material in the comparative form, and does not include an aggregate of flattened magnetic metal particles. The upper left of Figure 8 shows the case where individual flattened magnetic metal particles are isolated, and the lower left of Figure 8 shows that some flattened magnetic metal particles are in contact with each other, but the flattened surface of the first flattened magnetic metal particle is in contact with the flattened surface of the second flattened magnetic metal particle for a length of less than 50% of the flattened surface of the first flattened magnetic metal particle. In this case as well, an aggregate of flattened magnetic metal particles is not included. Thus, among the flattened magnetic metal particles not included in the flattened magnetic metal particle aggregate, there are flattened magnetic metal particles that are not in contact with any other flattened magnetic metal particles within the composite magnetic material, and such flattened magnetic metal particles are also called isolated flattened magnetic metal particles. Furthermore, among the flattened magnetic metal particles not included in the flattened magnetic metal particle aggregate, there are particles that are in contact with other flattened magnetic metal particles within the composite magnetic material, but in a manner in which "the flattened surface of the first flattened magnetic metal particle is in contact with the flattened surface of the second flattened magnetic metal particle for a length of less than 50% of the flattened surface of the first flattened magnetic metal particle."

[0037] Preferably, the flattened magnetic metal particle aggregate is separated from the nearest flattened magnetic metal particle not included in the flattened magnetic metal particle aggregate by an average shortest distance of 1 / 10000 or more of the average thickness of the flattened magnetic metal particles, more preferably by an average shortest distance of 1 / 1000 or more of the average thickness, even more preferably by an average shortest distance of 1 / 100 or more of the average thickness, even more preferably by an average shortest distance of 1 / 10 or more of the average thickness, and even more preferably by an average shortest distance greater than or equal to the average thickness. The distance between a flattened magnetic metal particle aggregate and the nearest flattened magnetic metal particle not included in the aggregate is measured using the outer contour line of the flattened magnetic metal particle aggregate as a reference, and the distance from this reference contour line to the nearest flattened magnetic metal particle not included in the aggregate is measured. Figure 9 is a schematic cross-sectional view showing an example of a reference contour line 11a of a flattened magnetic metal particle aggregate 12a in the first embodiment. The shortest distance from this reference contour line 11a to the nearest flattened magnetic metal particle is determined. In Figure 9, candidates for the nearest flattened magnetic metal particle to the flattened magnetic metal particle aggregate 12a include 10a, 10b, 10c, 10d, 10e, and the flattened magnetic metal particles included in the flattened magnetic metal particle aggregate 12b. Next, the shortest distance between the flattened magnetic metal particle aggregate 12a and the candidate flattened magnetic metal particles is determined. From Figure 9, the shortest distance to the flat magnetic metal particle 10a is L1, the shortest distance to the flat magnetic metal particle 10b is L2, the shortest distance to the flat magnetic metal particle 10c is L3, the shortest distance to the flat magnetic metal particle aggregate 12b is L4, the shortest distance to the flat magnetic metal particle 10d is L5, and the shortest distance to the flat magnetic metal particle 10e is L6. Of these, the shortest distance is L3. Therefore, the flat magnetic metal particle closest to the flat magnetic metal particle aggregate 12a is 10c, and its shortest distance is L3. If there are multiple flat magnetic metal particle aggregates contained in the composite magnetic material, the shortest distance to the nearest flat magnetic metal particle (L3 in Figure 9) is determined for each flat magnetic metal particle aggregate, and then the average value (average shortest distance) is calculated. It is preferable that this average value (average shortest distance) satisfies the above distance. When calculating the average value, it is preferable to select multiple (for example, 10 or more) arbitrary flat magnetic metal particle aggregates that have been observed and calculate the average value. However, as long as average information can be obtained, there is no need to be particular about the number of particles observed. Note that in the case of a single aggregate of flattened magnetic metal particles, the "average shortest distance" is interpreted as "the shortest distance to the nearest adjacent flattened magnetic metal particle." More preferably, all flattened magnetic metal particle aggregates are separated by the above-mentioned distance from the nearest adjacent flattened magnetic metal particle not included in the flattened magnetic metal particle aggregate. Furthermore, for example in Figure 9, it is preferable that the average value of the shortest distances between all flat magnetic metal particles (all particles that could be candidates for the nearest neighbor particle) arranged around the flat magnetic metal particle aggregate 12a is separated by the above-mentioned distance. In Figure 9, the average value of the shortest distances between all flat magnetic metal particles (all particles that could be candidates for the nearest neighbor particle) arranged around the flat magnetic metal particle aggregate 12a is (L1+L2+L3+L4+L5+L6) / 6. Thus, it is preferable that after calculating the average value of the shortest distances for each flat magnetic metal particle aggregate, the average value of these values ​​is then calculated and that they are separated by the above-mentioned distance. For example, if there are three flattened magnetic metal particle aggregates A, B, and C, and the average of the shortest distances for A is LA(ave) = (LA1 + LA2 + LA3 + LA4 + LA5 + LA6) / 6, the average of the shortest distances for B is LB(ave) = (LB1 + LB2 + LB3 + LB4 + LB5 + LB6) / 6, and the average of the shortest distances for C is LC(ave) = (LC1 + LC2 + LC3 + LC4 + LC5 + LC6) / 6, then it is preferable that the average of LA(ave), LB(ave), and LC(ave), i.e., (LA(ave) + LB(ave) + LC(ave)) / 3, satisfies the above distance. More preferably, it is preferable that the "average of the shortest distances" for all flattened magnetic metal particle aggregates has the above distance. In other words, it is preferable that LA(ave), LB(ave), and LC(ave) all satisfy the above distance. When the average shortest distance between a flattened magnetic metal particle aggregate and the nearest adjacent flattened magnetic metal particle not included in the aggregate becomes small (smaller than the distance mentioned above), the interface of the flattened magnetic metal particle aggregate is not completely covered by the intervening phase, making it easier for the flattened magnetic metal particles to connect and form a network. This leads to increased eddy current losses and iron losses, and a decrease in the degree of efficiency improvement as a rotating electric machine, which is undesirable. Furthermore, because the interface of the flattened magnetic metal particle aggregate is not completely covered by the intervening phase, the interface strength decreases, resulting in a decrease in strength, which is also undesirable.

[0038] Figure 10 is a schematic cross-sectional view of a flattened magnetic metal particle aggregate of the first embodiment in a predetermined cross-section. In the predetermined cross-section including the first flattened magnetic metal particles and the second flattened magnetic metal particles, the flattened surface of the second flattened metal particle has a length greater than or equal to the flattened surface of the first flattened magnetic metal particle. Note that the schematic diagrams in Figures 10(a) and (b) show the case where the flattened surface of the first flattened magnetic metal particle and the flattened surface of the second flattened magnetic metal particle have the same length. Furthermore, the schematic diagrams in Figures 10(c) and (d) show the case where the flattened surface of the second flattened magnetic metal particle has a length longer than the flattened surface of the first flattened magnetic metal particle. In the first embodiment, the flattened surface of the first flattened magnetic metal particle is in contact with the flattened surface of the second flattened magnetic metal particle for a length of 50% or more of the length of the flattened surface of the first flattened magnetic metal particle. The schematic diagram in Figure 10(a) shows the case where the flattened surfaces of the first flattened magnetic metal particle and the flattened surfaces of the second flattened magnetic metal particle are of the same length, and the flattened surface of the first flattened magnetic metal particle is in contact with the flattened surface of the second flattened magnetic metal particle for a length of 50% of the length of the flattened surface of the first flattened magnetic metal particle. The schematic diagram in Figure 10(b) shows the case where the flattened surface of the first flattened magnetic metal particle is in contact with the flattened surface of the second flattened magnetic metal particle for a length of 80% of the length of the flattened surface of the first flattened magnetic metal particle. The schematic diagram in Figure 10(c) shows the case where the flattened surface of the second flattened magnetic metal particle is longer than the flattened surface of the first flattened magnetic metal particle, and the flattened surface of the first flattened magnetic metal particle is in contact with the flattened surface of the second flattened magnetic metal particle for 100% of the length of the flattened surface of the first flattened magnetic metal particle. The schematic diagram in Figure 10(d) shows the case where the flattened surface of the first flattened magnetic metal particle is in contact with the flattened surface of the second flattened magnetic metal particle for 80% of the length of the flattened surface of the first flattened magnetic metal particle.

[0039] The specified cross-section refers to the cross-section that contains the most "cross-sections perpendicular to the flattened plane of the flattened magnetic metal particles" among the three cross-sections at the center in the length, thickness, and width directions of the composite magnetic material (a cross-section including the length and thickness directions, a cross-section including the thickness and width directions, and a cross-section including the width and length directions). In other words, as shown in Figure 8, it is the cross-section from which the most "cross-sections perpendicular to the flattened plane of the flattened magnetic metal particles" can be observed. If "cross-sections perpendicular to the flattened plane of the flattened magnetic metal particles" are equally abundant in two of the three cross-sections, then either of those cross-sections is referred to. If the flattened plane of the flattened magnetic metal particles is oriented and the direction perpendicular to the flattened plane is the thickness direction, it is preferable to refer to the "cross-section including the thickness and width directions."

[0040] Here, "contact" between the first flattened magnetic metal particle and the second flattened magnetic metal particle includes cases where the first flattened magnetic metal particle and the second flattened magnetic metal particle are in direct contact, and cases where the first flattened magnetic metal particle and the second flattened magnetic metal particle are indirectly in contact via the coating layer 9. Furthermore, if the coating layer 9 is partially provided on a flattened surface, there may be both a portion where the first flattened magnetic metal particle and the second flattened magnetic metal particle are in direct contact, and a portion where the first flattened magnetic metal particle and the second flattened magnetic metal particle are indirectly in contact via the coating layer 9. If the flat magnetic metal particles contained in the flat magnetic metal particle aggregate, or the flat magnetic metal particles adjacent to the flat magnetic metal particle aggregate that are not included in the flat magnetic metal particle aggregate, have a coating layer 9, then the average shortest distance in the explanation above, "the flat magnetic metal particle aggregate is separated from the nearest flat magnetic metal particle not included in the flat magnetic metal particle aggregate by an average shortest distance of 1 / 10000 or more of the average thickness of the flat magnetic metal particles," refers to the average shortest distance from the flat magnetic metal particles, not the coating layer 9 being interpreted as part of the flat magnetic metal particles. However, if it is difficult to identify the coating layer 9, for convenience, the coating layer 9 may be interpreted as part of the flat magnetic metal particles, and the average shortest distance from the coating layer 9 may be used.

[0041] Figures 11(a) and 11(b) are schematic cross-sectional views of a predetermined cross-section of the first embodiment. In the composite magnetic material, it is preferable that flattened magnetic metal particle aggregates are included at a number ratio of 1% or more, more preferably 10% or more, even more preferably 20% or more, and even more preferably 40% or more. Here, the number ratio of flattened magnetic metal particle aggregates is evaluated by counting each isolated flattened magnetic metal particle and flattened magnetic metal particle aggregate as one in the predetermined cross-section. Flattened magnetic metal particles that are in contact with each other but are not flattened magnetic metal particle aggregates are counted as one individual flattened magnetic metal particle. For example, in the schematic diagram of Figure 11(a), there are 4 flattened magnetic metal particle aggregates and 4 isolated flattened magnetic metal particles, so the number ratio of flattened magnetic metal particle aggregates is 4 (particles) / 8 (particles) × 100 (%) = 50%. Furthermore, in the schematic diagram of Figure 11(b), there are 2 flattened magnetic metal particle aggregates, 3 isolated flattened magnetic metal particles, and 5 flattened magnetic metal particles that are in contact with each other and are not part of an aggregate. Therefore, the proportion of flattened magnetic metal particle aggregates is 2 (particles) / 10 (particles) × 100 (%) = 20%.

[0042] Figure 12 is an example of a cross-sectional photograph of the composite magnetic material of the first embodiment. It can be seen that the composite magnetic material contains multiple flattened magnetic metal particle aggregates 12.

[0043] By incorporating such flattened magnetic metal particle aggregates into a composite magnetic material, the magnetic interactions between the flattened magnetic metal particles become stronger compared to when the particles are isolated. This facilitates magnetization, increases permeability, and reduces coercivity. A reduction in coercivity means a reduction in hysteresis loss. On the other hand, eddy current loss does not increase significantly even with the presence of flattened magnetic metal particle aggregates, because the particles are aggregated, fixed, and bonded at interfaces. In other words, compared to the case of isolated flattened magnetic metal particles, eddy current loss remains at a similar level while hysteresis loss is reduced, resulting in a reduction in iron loss. Furthermore, as mentioned above, permeability also increases. Therefore, when such a composite magnetic material is used as a magnetic wedge, magnetic flux can be efficiently guided, improving the efficiency of rotating electric machines.

[0044] To further suppress eddy current losses in the composite magnetic material, it is desirable that the electrical resistivity of the composite magnetic material is greater than that of the flattened magnetic metal particles. More preferably, it is desirable that the electrical resistivity of the composite magnetic material is 10 times or more the electrical resistivity of the flattened magnetic metal particles. Furthermore, it is desirable that the electrical resistivity of the flattened magnetic metal particle aggregate is greater than that of the flattened magnetic metal particles. More preferably, it is desirable that the electrical resistivity of the flattened magnetic metal particle aggregate is 10 times or more the electrical resistivity of the flattened magnetic metal particles. These conditions are preferable because they effectively suppress eddy current losses in the composite magnetic material and reduce iron loss.

[0045] Furthermore, the inclusion of flattened magnetic metal particle aggregates in composite magnetic materials significantly improves mechanical properties such as strength. This effect is particularly pronounced. As described above, flattened magnetic metal particle aggregates consist of multiple flattened magnetic metal particles in contact with each other. This results in the flattened magnetic metal particle aggregates becoming pseudo-thick and long particles. This improves the fracture stress. Generally, the fracture stress of a material (when stress is applied to the flattened surface of a flattened material) during three-point bending is expressed by the following formula.

number

[0046] Here, F is the fracture stress, σ is the material strength, L is the distance between external supports, w is the length of the flattened plane, and t is the thickness of the material. Since a flattened magnetic metal particle aggregate is formed by the aggregation, bonding, and establishment of multiple flattened magnetic metal particles, w and t can be considered to be pseudo-larger compared to individual flattened magnetic metal particles. As a result, the fracture stress of a flattened magnetic metal particle aggregate increases compared to individual flattened magnetic metal particles. This also improves the strength of the composite magnetic material containing the flattened magnetic metal particle aggregate. The effects described above (improvement of magnetic permeability, reduction of coercivity, reduction of iron loss, improvement of the efficiency of rotating electric machines, and improvement of strength) are particularly more pronounced when the proportion of flattened magnetic metal particle aggregates is high in the composite magnetic material. Preferably, the flattened magnetic metal particle aggregates are present at a number ratio of 1% or more, more preferably at a number ratio of 10% or more, even more preferably at 20% or more, and even more preferably at 40% or more.

[0047] Furthermore, it is preferable that the average orientation angle between the flattened surface of the first or second flattened magnetic metal particle and the plane of the composite magnetic material is 10 degrees or less. Here, "plane of the composite magnetic material" refers to, for example, the surfaces provided on the surface of the composite magnetic material used as a magnetic wedge, as shown in Figure 7. It is desirable that the average orientation angle between any one of these planes and the flattened surface of the first or second flattened magnetic metal particle is preferably 0 degrees or more and 45 degrees or less, more preferably 0 degrees or more and 30 degrees or less, even more preferably 0 degrees or more and 20 degrees or less, and even more preferably 0 degrees or more and 10 degrees or less. By reducing the average orientation angle in this way, not only is the bending strength increased, but the magnetic loss is also reduced, making it possible to obtain a composite magnetic material with excellent properties.

[0048] A method for manufacturing the magnetic wedge of this embodiment will now be described. Note that the manufacturing method is not particularly limited and is described merely as an example.

[0049] The first step is to produce a magnetic metal ribbon containing at least one first element selected from the group consisting of Fe, Co, and Ni. This step involves producing a ribbon or thin film using a film deposition apparatus such as a roll quenching apparatus or a sputtering apparatus. In this case, when using a film deposition apparatus, it is desirable to deposit a film that imparts uniaxial anisotropy to the film surface by methods such as magnetic field deposition or rotational deposition. Furthermore, when using a film deposition apparatus, it is desirable to use a film deposition method when producing a rotationally magnetized type, as it allows for thinner films, a more refined structure, and easier rotational magnetization. Roll quenching apparatuses are suitable for large-scale synthesis and are therefore desirable when synthesizing bulk materials. In the case of roll quenching apparatuses, single-roll quenching apparatuses are simple and preferred.

[0050] The second step involves rolling the rapidly cooled magnetic metal ribbon to reduce the thickness of the flattened magnetic metal particles. If the ribbon has already reached the desired thickness in the first step, the rolling process can be omitted. The rolling can be cold-rolled or hot-rolled, and the rolling process is carried out to achieve the desired thickness. Before this step, the ribbon may be cut to an appropriate size or crushed. The third step is to heat-treat the magnetic metal ribbon at a temperature of 50°C to 800°C. In this step, the ribbon may be cut to an appropriate size to make it easier to place in the electric furnace for heat treatment. For example, it may be cut to an appropriate size using a mixer device. Performing this step is desirable because it improves the pulverability in the subsequent pulverization step, but this step can also be omitted. The atmosphere for heat treatment is preferably a vacuum atmosphere with a low oxygen concentration, an inert atmosphere, or a reducing atmosphere, and more preferably a reducing atmosphere such as H2 (hydrogen), CO (carbon monoxide), or CH4 (methane). This is because even if the magnetic metal ribbon is oxidized, heat treatment in a reducing atmosphere can reduce the oxidized metal and return it to its original metal state. In this way, it is also possible to reduce a magnetic metal ribbon that has been oxidized and whose saturation magnetization has decreased, and restore its saturation magnetization. Furthermore, in the case of amorphous magnetic metal ribbons, if the crystallization of the magnetic metal ribbon progresses significantly due to heat treatment, the properties will deteriorate (increased coercivity, decreased permeability). Therefore, it is preferable to select conditions that suppress excessive crystallization. Moreover, it is even more preferable to perform the heat treatment in a magnetic field. The larger the applied magnetic field, the better, but it is preferable to apply a magnetic field of 1 kOe or more, and even more preferable to apply a magnetic field of 10 kOe or more. This is preferable because it allows magnetic anisotropy to be expressed within the plane of the magnetic metal ribbon, thereby achieving excellent magnetic properties.

[0051] The fourth step involves grinding the heat-treated magnetic metal ribbon to produce flattened magnetic metal particles. In this step, grinding is carried out using a grinding device such as a bead mill or a planetary mill. The type of grinding device is not particularly limited. Examples include planetary mills, bead mills, rotary ball mills, vibrating ball mills, agitated ball mills (attritors), jet mills, centrifugal separators, or methods combining milling and centrifugal separation.

[0052] In the fourth step, the thickness of the flat magnetic metal particles can be reduced not only by simple crushing but also by combining it with rolling. If the desired thickness has been achieved by the third step, the rolling process can be omitted. Rolling can be performed simultaneously, or after crushing, or after rolling. In this case, a device that can apply a strong gravitational acceleration is preferable, but this can be done using, for example, a planetary mill, bead mill, rotary ball mill, vibrating ball mill, agitated ball mill (attritor), jet mill, centrifuge, or a method that combines a mill and centrifuge.

[0053] The above cutting, crushing, and rolling processes are carried out (rolling is performed as needed; it is omitted if unnecessary). In some cases, it is desirable to repeat the cutting, crushing, and rolling processes until flattened magnetic metal particles of the specified thickness and aspect ratio are obtained.

[0054] Furthermore, it is desirable to remove lattice strain from the obtained flattened magnetic metal particles by heat treatment. This heat treatment is preferably carried out at a temperature of 50°C to 800°C, similar to the third step. The atmosphere for the heat treatment is preferably a vacuum atmosphere with a low oxygen concentration, an inert atmosphere, or a reducing atmosphere, and more preferably a reducing atmosphere such as H2, CO, or CH4. This is because it is possible to reduce the oxidized metal back into a metal. Moreover, it is even more desirable to perform the heat treatment in a magnetic field.

[0055] Next, as the fifth step, a process is carried out to form an aggregate of flattened magnetic metal particles. Here, an aggregate of flattened magnetic metal particles is formed from multiple flattened magnetic metal particles, but it is acceptable for some to remain as flattened magnetic metal particles without forming an aggregate. There is no particular choice of method for the fifth step, but a preferred method is to coat the flattened magnetic metal particles with a silane coupling agent to agglomerate, fix, and bond the flattened magnetic metal particles together. The flattened magnetic metal particles are dispersed in an organic solvent containing a silane coupling agent (for example, ethanol or methanol), and the organic solvent is evaporated by heat treatment, thereby coating the surface of the flattened magnetic metal particles with the silane coupling agent and agglomerating and fixing the flattened magnetic metal particles together.

[0056] For heat treatment, a temperature of 50°C or higher in air is preferred, more preferably 50°C to 250°C, even more preferably 50°C to 200°C, and even more preferably 50°C to 180°C. At this time, the silane coupling agent is preferably one having an amino group, a methacrylic group, or an epoxy group, more preferably one having an amino group or an epoxy group, and even more preferably one having an amino group. Even more preferably, it is preferable that the molecule has two or more amino groups. Also, a short linear chain is preferred. Regarding the molecular weight, a relatively small one is preferred, preferably 300 or less, more preferably 250 or less, and even more preferably 230 or less.

[0057] Generally, silane coupling agents have reactive groups within their molecules that readily chemically bond with organic materials and reactive groups that readily chemically bond with inorganic materials (such as metals and oxides). Therefore, they are used to improve the bonding between organic and inorganic materials. In other words, the bonding is improved through the organic material-silane coupling agent-inorganic material connection. For this reason, when flattened magnetic metal particles (corresponding to inorganic materials) are simply coated with a silane coupling agent, only the inorganic material-silane coupling agent connection exists, and basically, an aggregate of flattened magnetic metal particles is not formed. However, by selecting a specific silane coupling agent and applying a specific heat treatment, the silane coupling agent can bond multiple flattened magnetic metal particles together, or the silane coupling agents can bond with each other. This creates bonds such as silane coupling agent-inorganic material-silane coupling agent-inorganic material, resulting in a unique state where flattened magnetic metal particles readily aggregate, adhere, and bond with each other.

[0058] To further facilitate the occurrence of this unique state, it is preferable to perform a pressing or hot pressing treatment after coating with a silane coupling agent. Hot pressing, which allows for the simultaneous application of heat and pressure, is particularly preferable. This promotes the aggregation, adhesion, and bonding of the flattened magnetic metal particles, making it easier to form an aggregate of flattened magnetic metal particles.

[0059] The above describes a method for forming flattened magnetic metal particle aggregates using a silane coupling agent, but it is also possible to form flattened magnetic metal particle aggregates without using a silane coupling agent. For example, by slightly modifying the surface of the flattened magnetic metal particles, for example by forming hydroxyl groups, and then performing a pressing or hot pressing process, it is possible to similarly form flattened magnetic metal particle aggregates. In any case, flattened magnetic metal particle aggregates can be formed using any method. The flattened magnetic metal particle aggregates can be crushed as needed to produce flattened magnetic metal particle aggregates of the desired size.

[0060] Next, as the sixth step, the intervening phase described above and the flattened magnetic metal particle aggregate (which may partially contain flattened magnetic metal particles) are mixed to form a mixed powder.

[0061] Next, in the seventh step, the mixed powder is molded. Heat treatment may be performed before or after the above steps as appropriate. Alternatively, heat treatment may be performed simultaneously with molding. Heat treatment may also be performed before or after processing. The heat treatment conditions are as described above. Furthermore, it is more desirable to perform the heat treatment in a magnetic field. In the seventh step, it is preferable to use a method that applies press pressure in a uniaxial direction, such as uniaxial press molding or hot press molding. In the case of hot press, it is more preferable to perform the hot press while applying a magnetic field.

[0062] The molded body produced in the seventh step may, if necessary, be subjected to heat treatment such as that in the third step.

[0063] When measuring the coercivity with respect to direction in a plane parallel to the flattened plane of the flattened magnetic metal particles of a magnetic wedge, for example, the coercivity is measured by changing the direction every 22.5 degrees for a 360-degree angle within the plane.

[0064] Having a difference in coercivity within the plane of the magnetic wedge is preferable because it reduces the minimum coercivity value compared to the isotropic case where there is almost no difference in coercivity. In materials that have magnetic anisotropy within a plane, there is a difference in coercivity depending on the direction within the plane, and the minimum coercivity value is smaller compared to magnetically isotropic materials. This reduces hysteresis loss and improves permeability, which is preferable.

[0065] In a plane parallel to the flattened plane of the flattened magnetic metal particles of the magnetic wedge, the larger the ratio of the coercivity difference depending on the direction, the more preferable it is, preferably 1% or more. More preferably, the ratio of the coercivity difference is 10% or more, even more preferably 50% or more, and even more preferably 100% or more. The ratio of the coercivity difference referred to here is defined as (Hc(max)-Hc(min)) / Hc(min)×100(%), using the maximum coercivity Hc(max) and the minimum coercivity Hc(min) within the flattened plane.

[0066] In a composite magnetic material, it is preferable that the flattened surface of the flattened magnetic metal particles is oriented substantially parallel to the plane of the composite magnetic material.

[0067] In this specification, "parallel" includes "approximately parallel," that is, "generally parallel." "Approximately parallel" and "generally parallel" mean that the angle with respect to the parallel direction is preferably 45 degrees or less, more preferably 30 degrees or less, even more preferably 20 degrees or less, and even more preferably 10 degrees or less. Furthermore, "orientation" means being parallel to the reference line or reference plane, but this includes being approximately parallel (generally parallel). That is, it means that the angle with respect to the reference line or reference plane is preferably 45 degrees or less, more preferably 30 degrees or less, even more preferably 20 degrees or less, and even more preferably 10 degrees or less.

[0068] Orientation is defined as the angle between the plane parallel to the flattened surface of a flattened magnetic metal particle and the plane of the composite magnetic material being as close to 0 degrees as possible. Figure 13 shows the angle between the plane parallel to the flattened surface of a flattened magnetic metal particle and the plane of the composite magnetic material. The above angle is determined for a number of flattened magnetic metal particles of 10 or more, and it is desirable that the average value is preferably 45 degrees or less, more preferably 30 degrees or less, even more preferably 20 degrees or less, and even more preferably 10 degrees or less. In other words, in the composite magnetic material, it is preferable that the flattened surfaces of the plurality of flattened magnetic metal particles are oriented in layers so that they are parallel to each other. This is preferable because it can reduce the eddy current loss of the composite magnetic material. It is also preferable because the demagnetizing field can be reduced, thus increasing the permeability of the composite magnetic material. Furthermore, it is preferable because the ferromagnetic resonance frequency can be increased, thus reducing the ferromagnetic resonance loss. Moreover, in such a layered structure, the magnetic domain structure is stabilized, and low magnetic loss can be achieved, which is preferable.

[0069] Furthermore, coercivity can be easily evaluated using a vibrating sample magnetometer (VSM). If the coercivity is low, it can be measured even below 0.1 Oe by using a low-field unit. The measurement is performed by changing the direction of the magnetic wedge within the aforementioned plane (a plane parallel to the flattened plane of the flattened magnetic metal particle) with respect to the direction of the measurement magnetic field.

[0070] When calculating coercivity, the difference between the magnetic fields at two points where the horizontal axis intersects (magnetic fields H1 and H2 where magnetization is zero) can be divided by 2 (i.e., coercivity can be calculated as |H2-H1| / 2).

[0071] As described above, this embodiment makes it possible to provide a composite magnetic material and a magnetic wedge with excellent properties.

[0072] (Second Embodiment) The rotating electric machine of this embodiment comprises the composite magnetic material or magnetic wedge or core of the first embodiment. Therefore, descriptions that overlap with the first embodiment are omitted. In this specification, the term "rotating electric machine" refers to a concept that includes electric motors, generators, and motor-generators that perform both motor and generator functions as needed.

[0073] Figure 14 shows an example of a radial gap motor according to this embodiment. A radial gap motor has a rotor and a stator that is positioned opposite the rotor with a predetermined radial gap. In Figure 14, the rotor is positioned inside the stator, but it may also be positioned outside. The rotor has a rotor core and a shaft and is supported so that it can rotate. The stator, on the other hand, has a stator core, field coils inserted into slots in the stator core, and magnetic wedges held in wedge grooves in the slot openings. Figure 14 shows an example of the arrangement of magnetic wedges according to the first embodiment, but is not limited to this. In the case of a radial gap rotating electric machine, since the stator is positioned opposite the rotor with a predetermined radial gap, the "gap surface" is a surface parallel to the cylindrical surface centered on the rotor's axis of rotation. Therefore, the radial direction is perpendicular to the gap surface, and the axial direction and rotational direction are parallel to the gap surface. Figure 14 shows flattened magnetic metal particles 10, intervening phase 20, magnetic wedge 100, rotating electric machine 200, rotor 210, stator 220, coil 230, air gap surface 240, and iron core teeth 250.

[0074] By arranging the magnetic wedge of the first embodiment, it becomes possible to reduce harmonic losses occurring on the rotor surface while suppressing leakage flux. In addition, the torque of the radial gap type motor is increased because the magnetic flux passing through the air gap increases. High efficiency can be achieved through either or both of the above loss reduction effect and torque increase effect.

[0075] Furthermore, radial gap motors can be any of the following: those with a conductor in the rotor (induction motor), those with a permanent magnet (permanent magnet motor), or those with a magnetic material (reluctance motor).

[0076] Figure 15 shows an example of an axial gap motor according to this embodiment. The axial gap motor has a rotor and a stator that is positioned opposite the rotor with a predetermined gap in the axial direction. The stator includes a stator core, field coils inserted into slots in the stator core, and magnetic wedges held in wedge grooves in the slot openings. By arranging the magnetic wedges in this embodiment, it is possible to reduce harmonic losses occurring on the rotor surface while suppressing the increase in leakage flux. In addition, the torque of the axial gap motor is increased because the magnetic flux passing through the gap increases. As a result, high efficiency can be achieved. In Figure 15, the rotor is positioned between two stators, but it may also be positioned on one side or both sides of a single stator. In the case of an axial gap rotating electric machine, since the stators are positioned opposite the rotor with a predetermined gap in the axial direction, the "gap surface" is a surface perpendicular to the rotor's rotation axis. Therefore, the axial direction is perpendicular to the gap surface, and the rotational and radial directions are parallel to the gap surface. Figure 15 shows the flattened magnetic metal particles 10, the intervening phase 20, the magnetic wedge 100, the rotating electric machine 200, the rotor 210, the coil 230, the gap surface 240, the iron core teeth 250, the stator 270, and the shaft 280.

[0077] Figure 16 is a schematic diagram showing an example of a generator according to this embodiment. The generator typically has a rotor in which excitation coils are housed in slots of the rotor core (in addition, a rotor using permanent magnets as an excitation source may be used), and a stator in which armature coils are housed in four slots of the stator core. Power is generated in the armature coils by rotating the rotor and passing an excitation current through the excitation coils. The rotor comprises a rotor core, field coils inserted into slots of the rotor core, and magnetic wedges held in wedge grooves of the slot openings, and is supported by bearings so that it can rotate. By arranging the magnetic wedges in this embodiment, it is possible to reduce harmonic losses occurring on the surface of the stator while suppressing the increase in leakage flux. In addition, since the magnetic flux passing through the air gap and linking with the armature coil increases, the generated voltage induced in the armature coil increases. As a result, high efficiency can be achieved. In Figure 16, the magnetic wedge is positioned in the slot opening of the rotor core, but it may also be positioned in the slot opening of the stator core. Also, although the figure shows a wound-type generator with an excitation coil on the rotor, it may also be a permanent magnet type generator with a permanent magnet on the rotor. In this case, the magnetic wedge is positioned in the slot opening of the stator core. Figure 16 shows flat magnetic metal particles 10, intervening phase 20, magnetic wedge 100, rotating electric machine 200, rotor 210, stator core 222, excitation coil 232, armature coil 234, air gap surface 240, and core teeth 250.

[0078] Since a linear motor is a radial gap type motor unfolded into a flat plate structure, the magnetic wedge of the present invention can also be applied to a linear motor. That is, the stator comprises a stator core and field coils inserted into slots in the stator core, and a magnetic wedge may be provided at the slot opening. Figure 17 is a schematic diagram showing an example of a linear motor of this embodiment. In a linear motor, the direction of travel of the movable element, the direction perpendicular to the direction of travel of the movable element, and the direction perpendicular to the stator correspond to the rotational direction, axial direction, and radial direction of the radial gap type motor, respectively. By arranging the magnetic wedge of this embodiment, it is possible to reduce harmonic losses occurring on the surface of the movable element while suppressing the increase in leakage flux. In addition, since the magnetic flux passing through the air gap increases, the thrust of the linear motor is improved. As a result, high efficiency can be achieved. Figure 17 shows the flattened magnetic metal particles 10, the intervening phase 20, the magnetic wedge 100, the stator 220, the coil 230, the gap surface 240, the iron core teeth 250, and the movable element 290.

[0079] As described above, the rotating electric machine of this embodiment can suppress the increase in leakage flux due to the use of magnetic wedges and effectively mitigate the pulsation of the magnetic flux distribution on the surface of the iron core, thereby achieving high efficiency. The slot shape of the rotating electric machine of this embodiment may be a semi-closed slot, but it is preferably an open slot. In this case, harmonic losses can be significantly reduced, which is preferable. Similarly, using it as a core can also improve the characteristics of the rotating electric machine, which is preferable.

[0080] The rotating electric machine of this embodiment can be applied to transportation systems such as railways, electric vehicles, and hybrid cars; social systems such as elevators and air conditioners; industrial systems such as robots, pumps, compressors, and blowers; energy systems such as thermal power generators, hydroelectric power generators, wind power generators, nuclear power generators, and geothermal power generators; and home appliances such as washing machines, thereby improving the efficiency of the system. In particular, for large-capacity industrial machines, open slots are generally used for the slot shape, so it is preferable to provide the magnetic wedge of the first embodiment. Also, for main motors for railways, type-wound coils are used due to the need to withstand high voltage and vibration, and open slots are adopted for the slot shape, so it is preferable to provide the magnetic wedge of the first embodiment.

[0081] In railways, losses in rotating electric machinery account for approximately half of the power consumption during train operation, so reducing losses in rotating electric machinery has a significant effect on improving efficiency. Furthermore, in electric vehicles and hybrid cars, using the magnetic wedge of the first embodiment can improve the efficiency of the main motor, thereby extending the driving range.

[0082] In the field of power generation, significant improvements are expected for hydroelectric generators, particularly variable-speed pumped-storage generators. Significant improvements are also expected for wind turbines.

[0083] (Examples) Examples 1 to 10 are described in more detail below, in comparison with Comparative Examples 1 to 7.

[0084] (Example 1) First, using a single-roll quenching device, Fe-Co-Si-B(Fe 70 Co 30 B 25A ribbon of (at%)-4wt%Si is prepared. Next, the obtained ribbon is heat-treated at 300°C in an H2 atmosphere. Then, this ribbon is crushed using a mixer to obtain flattened magnetic metal particles (average thickness was 15 μm, and the average ratio of the average length in the flattened plane to the thickness was 20). After that, the obtained flattened magnetic metal particles are dispersed in an ethanol solvent containing a silane coupling agent (containing amino groups), and then the ethanol solvent is evaporated by heat treatment. After coating the flattened magnetic metal particles with the silane coupling agent, a hot press treatment is performed and a crushing treatment is performed to prepare an aggregate of flattened magnetic metal particles (containing flattened magnetic metal particles). After that, classification and sorting of the aggregate of flattened magnetic metal particles and the flattened magnetic metal particles is performed. After that, the aggregate of flattened magnetic metal particles (containing flattened magnetic metal particles) is mixed with a phenolic resin and hot press molding is performed to obtain a composite magnetic material. Furthermore, the composite magnetic material contained aggregates of flattened magnetic metal particles. In these aggregates, the flattened surface of the first flattened magnetic metal particle was in contact with the flattened surface of the second flattened magnetic metal particle for a length of 50% or more of the length of the flattened surface of the first flattened magnetic metal particle. In addition, the proportion of flattened magnetic metal particle aggregates in the composite magnetic material was 1%, and the average shortest distance (ratio to average thickness) between an aggregate of flattened magnetic metal particles and the nearest adjacent flattened magnetic metal particle not included in the aggregate was 1.1.

[0085] (Example 2) The process is the same as in Example 1, except that the proportion of flat magnetic metal particle aggregates in the composite magnetic material is set to 10% through the classification and sorting of flat magnetic metal particle aggregates and flat magnetic metal particles, and the average value of the shortest distance (ratio to average thickness) between a flat magnetic metal particle aggregate and the nearest flat magnetic metal particle not included in the flat magnetic metal particle aggregate (average shortest distance) is set to 1.2.

[0086] (Example 3) The process is the same as in Example 1, except that the proportion of flat magnetic metal particle aggregates in the composite magnetic material is set to 20% through the classification and sorting of flat magnetic metal particle aggregates and flat magnetic metal particles, and the average value of the shortest distance (ratio to average thickness) between a flat magnetic metal particle aggregate and the nearest flat magnetic metal particle not included in the flat magnetic metal particle aggregate (average shortest distance) is set to 1.2.

[0087] (Example 4) The process is the same as in Example 1, except that the proportion of flat magnetic metal particle aggregates in the composite magnetic material is set to 40% through the classification and sorting of flat magnetic metal particle aggregates and flat magnetic metal particles, and the average value of the shortest distance (ratio to average thickness) between a flat magnetic metal particle aggregate and the nearest flat magnetic metal particle not included in the flat magnetic metal particle aggregate (average shortest distance) is set to 1.3.

[0088] (Example 5) The process is the same as in Example 1, except that after producing ribbons, rolling is performed, the pulverization conditions are adjusted using a mixer device, and the flat magnetic metal particle aggregates and flat magnetic metal particles are classified and sorted. As a result, the average thickness of the flat magnetic metal particles obtained is 10 nm, the average ratio of the average length within the flattened plane to the thickness is 200, the proportion of flat magnetic metal particle aggregates in the composite magnetic material is 41%, and the average value of the shortest distance (ratio to average thickness) between a flat magnetic metal particle aggregate and the nearest flat magnetic metal particle not included in the flat magnetic metal particle aggregate (average shortest distance) is 120.

[0089] (Example 6) The process is the same as in Example 1, except that after producing ribbons, rolling is performed, the pulverization conditions are adjusted using a mixer device, and the flat magnetic metal particle aggregates and flat magnetic metal particles are classified and sorted. As a result, the average thickness of the flat magnetic metal particles obtained is 1 μm, the average ratio of the average length within the flattened plane to the thickness is 100, the proportion of flat magnetic metal particle aggregates in the composite magnetic material is 42%, and the average value of the shortest distance (ratio to average thickness) between a flat magnetic metal particle aggregate and the nearest flat magnetic metal particle not included in the flat magnetic metal particle aggregate (average shortest distance) is 14.

[0090] (Example 7) Except for adjusting the ribbon manufacturing conditions and performing classification and sorting operations on the flat magnetic metal particle aggregates and flat magnetic metal particles, the final flat magnetic metal particles obtained had an average thickness of 100 μm, an average ratio of the average length within the flattened plane to the thickness of 2, a number proportion of flat magnetic metal particle aggregates in the composite magnetic material of 40%, and an average value of the shortest distance (ratio to average thickness) between a flat magnetic metal particle aggregate and the nearest flat magnetic metal particle not included in the flat magnetic metal particle aggregate (average shortest distance) of 0.1, the result was the same as in Example 1.

[0091] (Example 8) The procedure is the same as in Example 7, except that the conditions for mixing the flat magnetic metal particle aggregate (containing flat magnetic metal particles) with the phenolic resin and the hot press molding conditions were adjusted to set the proportion of flat magnetic metal particle aggregates in the composite magnetic material to 41%, and the average value of the shortest distance (ratio to average thickness) between a flat magnetic metal particle aggregate and the nearest flat magnetic metal particle not included in the flat magnetic metal particle aggregate (average shortest distance) to 0.0001 (=1 / 10000).

[0092] (Example 9) The process is the same as in Example 1, except that after producing ribbons, rolling is performed, the pulverization conditions are adjusted using a mixer device, and the flat magnetic metal particle aggregates and flat magnetic metal particles are classified and sorted. As a result, the average thickness of the flat magnetic metal particles obtained is 10 nm, the average ratio of the average length within the flattened plane to the thickness is 1000, the proportion of flat magnetic metal particle aggregates in the composite magnetic material is 41%, and the average value of the shortest distance (ratio to average thickness) between a flat magnetic metal particle aggregate and the nearest flat magnetic metal particle not included in the flat magnetic metal particle aggregate (average shortest distance) is 110.

[0093] (Example 10) The process is the same as in Example 1, except that after producing ribbons, rolling is performed, the pulverization conditions are adjusted using a mixer device, and the flat magnetic metal particle aggregates and flat magnetic metal particles are classified and sorted. As a result, the average thickness of the flat magnetic metal particles obtained is 10 nm, the average ratio of the average length within the flattened plane to the thickness is 10000, the number of flat magnetic metal particle aggregates contained in the composite magnetic material is 42%, and the average value of the shortest distance (ratio to average thickness) between a flat magnetic metal particle aggregate and the nearest flat magnetic metal particle not included in the flat magnetic metal particle aggregate (average shortest distance) is 115.

[0094] (Comparative Example 1) In Example 1, the process was the same as in Example 1, except that after coating with a silane coupling agent, a pulverization process was performed without hot pressing, and then classification and sorting of flat magnetic metal particle aggregates and flat magnetic metal particles was carried out to completely remove the flat magnetic metal particle aggregates, thereby reducing the proportion of flat magnetic metal particle aggregates in the composite magnetic material to 0%. In other words, the composite magnetic material did not contain any flat magnetic metal particle aggregates in which the flattened surface of the first flat magnetic metal particle was in contact with the flattened surface of the second flat magnetic metal particle for a length of 50% or more of the flattened surface of the first flat magnetic metal particle.

[0095] (Comparative Example 2) In Example 5, the process was the same as in Example 5, except that after coating with the silane coupling agent, a pulverization process was performed without hot pressing, and then the flattened magnetic metal particle aggregates and flattened magnetic metal particles were classified and sorted to completely remove the flattened magnetic metal particle aggregates, thereby reducing the proportion of flattened magnetic metal particle aggregates in the composite magnetic material to 0%. In other words, the composite magnetic material did not contain any flattened magnetic metal particle aggregates in which the flattened surface of the first flattened magnetic metal particle was in contact with the flattened surface of the second flattened magnetic metal particle for a length of 50% or more of the flattened surface of the first flattened magnetic metal particle.

[0096] (Comparative Example 3) In Example 6, the process was the same as in Example 6, except that after coating with the silane coupling agent, a pulverization process was performed without hot pressing, and then the flattened magnetic metal particle aggregates and flattened magnetic metal particles were classified and sorted to completely remove the flattened magnetic metal particle aggregates, thereby reducing the proportion of flattened magnetic metal particle aggregates in the composite magnetic material to 0%. In other words, the composite magnetic material did not contain any flattened magnetic metal particle aggregates in which the flattened surface of the first flattened magnetic metal particle was in contact with the flattened surface of the second flattened magnetic metal particle for a length of 50% or more of the flattened surface of the first flattened magnetic metal particle.

[0097] (Comparative Example 4) In Example 7, the process was the same as in Example 7 except that after coating with the silane coupling agent, a pulverization process was performed without hot pressing, and then the flattened magnetic metal particle aggregates and flattened magnetic metal particles were classified and sorted to completely remove the flattened magnetic metal particle aggregates, thereby reducing the proportion of flattened magnetic metal particle aggregates in the composite magnetic material to 0%. In other words, the composite magnetic material did not contain any flattened magnetic metal particle aggregates in which the flattened surface of the first flattened magnetic metal particle was in contact with the flattened surface of the second flattened magnetic metal particle for a length of 50% or more of the flattened surface of the first flattened magnetic metal particle.

[0098] (Comparative Example 5) In Example 7, the conditions for mixing the flat magnetic metal particle aggregate (containing flat magnetic metal particles) with the phenolic resin and the hot press molding conditions were adjusted to set the proportion of flat magnetic metal particle aggregates in the composite magnetic material to 41%, and the average value of the shortest distance (ratio to average thickness) between a flat magnetic metal particle aggregate and the nearest flat magnetic metal particle not included in the flat magnetic metal particle aggregate (average shortest distance) to 0.

[0099] (Comparative Example 6) In Example 9, the process was the same as in Example 9, except that after coating with a silane coupling agent, a pulverization process was performed without hot pressing, and then classification and sorting of the flattened magnetic metal particle aggregates and flattened magnetic metal particles were carried out to completely remove the flattened magnetic metal particle aggregates, thereby reducing the proportion of flattened magnetic metal particle aggregates in the composite magnetic material to 0%. In other words, the composite magnetic material did not contain any flattened magnetic metal particle aggregates in which the flattened surface of the first flattened magnetic metal particle was in contact with the flattened surface of the second flattened magnetic metal particle for a length of 50% or more of the flattened surface of the first flattened magnetic metal particle.

[0100] (Comparative Example 7) In Example 10, the process was the same as in Example 10, except that after coating with a silane coupling agent, a pulverization process was performed without hot pressing, and then classification and sorting of the flattened magnetic metal particle aggregates and flattened magnetic metal particles was carried out to completely remove the flattened magnetic metal particle aggregates, thereby reducing the proportion of flattened magnetic metal particle aggregates in the composite magnetic material to 0%. In other words, the composite magnetic material did not contain any flattened magnetic metal particle aggregates in which the flattened surface of the first flattened magnetic metal particle was in contact with the flattened surface of the second flattened magnetic metal particle for a length of 50% or more of the flattened surface of the first flattened magnetic metal particle.

[0101] Table 1 shows the average thickness, the average ratio of the average length within the flattened plane to the thickness, the average shortest distance (ratio to average thickness) between a flattened magnetic metal particle aggregate and the nearest flattened magnetic metal particle not included in the flattened magnetic metal particle aggregate (average shortest distance), and the number ratio of flattened magnetic metal particle aggregates contained in the composite magnetic material of this embodiment, along with comparative examples.

[0102] Table 2 shows the permeability, iron loss, degree of efficiency improvement as a rotating electric machine, and strength of the composite magnetic material of this embodiment, along with comparative examples.

[0103] (1) Permeability: The permeability at 100 Hz is measured in the direction midway between the width and thickness directions of the composite magnetic material. Note that the permeability of Examples 1 to 4 is shown as a ratio based on the permeability of Comparative Example 1. The permeability of Example 5 is shown as a ratio based on the permeability of Comparative Example 2. The permeability of Example 6 is shown as a ratio based on the permeability of Comparative Example 3. The permeability of Examples 7, 8, and Comparative Example 5 is shown as a ratio based on the permeability of Comparative Example 4. The permeability of Example 9 is shown as a ratio based on the permeability of Comparative Example 6. The permeability of Example 10 is shown as a ratio based on the permeability of Comparative Example 7.

[0104] (2) Iron loss: The iron loss is measured using a BH analyzer under operating conditions of 100 Hz and 1 T. If direct measurement is not possible under the conditions of 100 Hz and 1 T, the frequency dependence and magnetic flux density dependence of the iron loss are measured, and the iron loss at 100 Hz and 1 T is estimated from that data (and this estimated value is adopted). Note that the iron losses of Examples 1 to 4 are shown as a ratio based on the iron loss of Comparative Example 1. The iron loss of Example 5 is shown as a ratio based on the iron loss of Comparative Example 2. The iron loss of Example 6 is shown as a ratio based on the iron loss of Comparative Example 3. The iron losses of Examples 7, 8, and Comparative Example 5 are shown as a ratio based on the iron loss of Comparative Example 4. The iron loss of Example 9 is shown as a ratio based on the iron loss of Comparative Example 6. The iron loss of Example 10 is shown as a ratio based on the iron loss of Comparative Example 7.

[0105] (3) Efficiency Improvement as a Rotating Electric Machine: Using a standard radial gap motor as a model, the efficiency improvement when using the composite material of the Examples and Comparative Examples as a magnetic wedge is calculated based on the efficiency when using a non-magnetic wedge. The efficiency improvement of the Examples is calculated using the formula (efficiency improvement of Examples - efficiency improvement of Comparative Examples) / (efficiency improvement of Comparative Examples) × 100 (%), based on the efficiency improvement of the Comparative Examples. Note that the efficiency improvement of Examples 1 to 4 is shown as a percentage based on the efficiency improvement of Comparative Example 1. The efficiency improvement of Example 5 is shown as a percentage based on the efficiency improvement of Comparative Example 2. The efficiency improvement of Example 6 is shown as a percentage based on the efficiency improvement of Comparative Example 3. The efficiency improvement of Examples 7, 8 and Comparative Example 5 is shown as a percentage based on the efficiency improvement of Comparative Example 4. The efficiency improvement of Example 9 is shown as a percentage based on the efficiency improvement of Comparative Example 6. The degree of efficiency improvement in Example 10 is shown as a percentage based on the efficiency improvement of Comparative Example 7.

[0106] (4) Strength: For the examples and comparative examples, the flexural strength was measured at 25°C and is shown as a ratio to the flexural strength of the comparative example at 25°C (= flexural strength of the example sample at 25°C / flexural strength of the comparative example sample at 25°C). Note that the strengths of Examples 1 to 4 are shown as a ratio based on the strength of Comparative Example 1. The strength of Example 5 is shown as a ratio based on the strength of Comparative Example 2. The strength of Example 6 is shown as a ratio based on the strength of Comparative Example 3. The strengths of Examples 7, 8 and Comparative Example 5 are shown as a ratio based on the strength of Comparative Example 4. The strength of Example 9 is shown as a ratio based on the strength of Comparative Example 6. The strength of Example 10 is shown as a ratio based on the strength of Comparative Example 7.

[0107] [Table 1]

[0108] [Table 2]

[0109] In each of the examples, the composite magnetic material contained one or more flattened magnetic metal particle aggregates. From Table 2, it can be seen that, compared to Comparative Example 1, Examples 1-4, compared to Comparative Example 2, Example 5, compared to Comparative Example 3, Example 7 and 8, compared to Comparative Example 4, Example 9, compared to Comparative Example 6, and compared to Comparative Example 7, Example 10 showed lower iron loss and higher permeability, which reflected a greater improvement in efficiency as a rotating electric machine, and a significant improvement in strength. In particular, it can be seen that the composite magnetic material exhibits excellent properties in terms of strength. In the composite magnetic material of this embodiment, the presence of the flattened magnetic metal particle aggregates allows for magnetic interaction between the flattened magnetic metal particles compared to when the flattened magnetic metal particles are isolated, making magnetization easier to proceed and increasing the permeability. Even with the presence of flattened magnetic metal particle aggregates, the flattened magnetic metal particles are aggregated, fixed, and bonded at interfaces, so the eddy current loss does not increase significantly. Rather, it was found that the aggregation, adhesion, and bonding of the flattened magnetic metal particles facilitated magnetic interactions between them, promoting magnetization and reducing coercivity (i.e., reducing hysteresis loss), resulting in a reduction in iron loss. Furthermore, these factors enable efficient guidance of magnetic flux when the composite magnetic material of this embodiment is used as a magnetic wedge, leading to a significant improvement in the efficiency of the rotating electric machine. In terms of strength, the material becomes pseudo-thick and long, making it extremely resistant to stress, resulting in very high strength. Moreover, these effects become more pronounced as the number of flattened magnetic metal particle aggregates increases, and it was found that the properties improved as the number of aggregates increased in Examples 1, 2, 3, and 4.

[0110] On the other hand, in Comparative Examples 1-4, 6, and 7, since the flattened magnetic metal particle aggregate is not present, the above-mentioned specific effects (improvement of magnetic permeability, reduction of coercivity, reduction of iron loss, increased degree of efficiency improvement as a rotating electric machine, and improvement of strength) do not occur. In Comparative Example 5, although a flattened magnetic metal particle aggregate was present, the average value (average shortest distance) of the shortest distance (ratio to average thickness) between the flattened magnetic metal particle aggregate and the nearest flattened magnetic metal particle not included in the flattened magnetic metal particle aggregate was 0. In such a state, the interface of the flattened magnetic metal particle aggregate is not completely covered by the intervening phase, and the flattened magnetic metal particles connect to form a network, resulting in increased eddy current loss and iron loss, and a decrease in the degree of efficiency improvement as a rotating electric machine. In addition, because the interface of the flattened magnetic metal particle aggregate is not completely covered by the intervening phase, the interface strength decreases, and as a result, the strength decreases. On the other hand, compared to Comparative Example 5, as in Examples 7 and 8, the properties are greatly improved when the average value (average shortest distance) of the shortest distance (ratio to average thickness) between the flat magnetic metal particle aggregate and the nearest flat magnetic metal particle not included in the flat magnetic metal particle aggregate becomes 0.1 (=1 / 10) and 0.0001 (=1 / 10000), respectively. Therefore, it is preferable that the average value (average shortest distance) of the shortest distance (ratio to average thickness) between the flat magnetic metal particle aggregate and the nearest flat magnetic metal particle not included in the flat magnetic metal particle aggregate is 1 / 10000 or greater.

[0111] From the above, it was found that the composite magnetic material containing the flattened magnetic metal particle aggregate can achieve excellent properties such as high permeability, low coercivity, low iron loss, a high degree of efficiency improvement as a rotating electric machine, and high strength.

[0112] While several embodiments and examples of the present invention have been described, these embodiments and examples are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents.

[0113] Furthermore, the above embodiments can be summarized in the following technical proposal. (Technical proposal 1) A composite magnetic material comprising a plurality of flattened magnetic metal particles and an intervening phase, The plurality of flattened magnetic metal particles each have a flattened surface and a magnetic metal phase containing at least one first element selected from the group consisting of Fe, Co, and Ni, with an average thickness of 10 nm to 100 μm, and an average ratio of the average length within the flattened surface to the thickness of 2 to 10000. The intervening phase is present between the plurality of flattened magnetic metal particles and contains at least one second element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N), and fluorine (F). The composite magnetic material includes one or more flattened magnetic metal particle aggregates, each comprising a first flattened magnetic metal particle contained in the plurality of flattened magnetic metal particles and a second flattened magnetic metal particle contained in the plurality of flattened magnetic metal particles. In a predetermined cross-section including the first flattened magnetic metal particle and the second flattened magnetic metal particle, the flattened surface of the second flattened magnetic metal particle has a length greater than or equal to the flattened surface of the first flattened magnetic metal particle. In the predetermined cross-section, the flattened surface of the first flattened magnetic metal particle is in contact with the flattened surface of the second flattened magnetic metal particle for a length of 50% or more of the flattened surface of the first flattened magnetic metal particle. The flattened magnetic metal particle aggregate is separated from the nearest flattened magnetic metal particle not included in the flattened magnetic metal particle aggregate by an average shortest distance of 1 / 10000 or more of the average thickness. Composite magnetic material. (Technical proposal 2) The composite magnetic material according to Technical Proposal 1, wherein the electrical resistivity of the composite magnetic material is greater than the electrical resistivity of the flattened magnetic metal particles. (Technical proposal 3) A composite magnetic material according to Technical Proposal 1 or Technical Proposal 2, wherein the electrical resistivity of the flattened magnetic metal particle aggregate is greater than the electrical resistivity of the flattened magnetic metal particles. (Technical proposal 4) A composite magnetic material according to any one of Technical Proposals 1 to 3, wherein the average orientation angle between the flattened surface of the first flattened magnetic metal particle or the flattened surface of the second flattened magnetic metal particle and the plane of the composite magnetic material is 10 degrees or less. (Technical proposal 5) The composite magnetic material according to any one of Technical Proposals 1 to 4, wherein the flattened magnetic metal particle aggregate is contained in the composite magnetic material in a number ratio of 1% or more. (Technical proposal 6) The composite magnetic material according to any one of Technical Proposals 1 to 5, wherein the flattened plane of the flattened magnetic metal particles is oriented substantially parallel to the plane of the composite magnetic material, and the composite magnetic material has a difference in coercivity depending on the direction within the plane. (Technical proposal 7) A composite magnetic material according to any one of Technical Proposals 1 to 6, wherein at least a portion of the surface of the flattened magnetic metal particles is covered with a coating layer having a thickness of 0.1 nm to 1 μm and containing at least one second element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N), and fluorine (F). (Technical proposal 8) The composite magnetic material according to Technical Proposal 7, comprising a silane coupling agent having an amino group in the coating layer. (Technical proposal 9) The composite magnetic material according to any one of Technical Proposals 1 to 8, wherein the intervening phase comprises at least one resin selected from the group consisting of imide resins, polyester resins, phenolic resins, epoxy resins, and silicone resins. (Technical proposal 10) A magnetic wedge comprising a composite magnetic material as described in any one of Technical Proposals 1 to 9. (Technical proposal 11) A core comprising a composite magnetic material as described in any one of Technical Proposal 1 to Technical Proposal 10. (Technical proposal 12) A rotating electric machine equipped with a composite magnetic material as described in any one of Technical Proposal 1 to Technical Proposal 11. [Explanation of Symbols]

[0114] 6: flat surface 9: Covering layer 10: Flat magnetic metal particles 12: Flat magnetic metal particle aggregate 20: Intervening phase 22 :Void 26: Surface layer 90: Composite magnetic material 100:Magnetic wedge 200: Rotating Electric Machine 210: Rotor 220: Stator 222: Stator core 230: Coil 232: Excitation coil 234: Armature coil 240 :Void surface 250: Iron Core Teeth 260: Iron Core Slot 270: Stator 280: Axis 290: Mover A: Virtual line

Claims

1. A composite magnetic material comprising a plurality of flattened magnetic metal particles and an intervening phase, The plurality of flattened magnetic metal particles each have a flattened surface and a magnetic metal phase containing at least one first element selected from the group consisting of Fe, Co, and Ni, with an average thickness of 10 nm or more and 100 μm or less, and an average ratio of the average length within the flattened surface to the thickness of 2 or more and 10000 or less. The intervening phase is present between the plurality of flattened magnetic metal particles and contains at least one second element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N), and fluorine (F). The composite magnetic material includes one or more flattened magnetic metal particle aggregates, each comprising a first flattened magnetic metal particle contained in the plurality of flattened magnetic metal particles and a second flattened magnetic metal particle contained in the plurality of flattened magnetic metal particles. In a predetermined cross-section of the composite magnetic material comprising the first flattened magnetic metal particles and the second flattened magnetic metal particles, the flattened surface of the second flattened magnetic metal particle has a length greater than or equal to the flattened surface of the first flattened magnetic metal particle. In the predetermined cross-section, the flattened surface of the first flattened magnetic metal particle is in contact with the flattened surface of the second flattened magnetic metal particle for a length of 50% or more of the flattened surface of the first flattened magnetic metal particle. The flattened magnetic metal particle aggregate is separated from the nearest flattened magnetic metal particle not included in the flattened magnetic metal particle aggregate by an average shortest distance of 1 / 10000 or more of the average thickness. Composite magnetic material.

2. The composite magnetic material according to claim 1, wherein the electrical resistivity of the composite magnetic material is greater than the electrical resistivity of the flat magnetic metal particles.

3. The composite magnetic material according to claim 1, wherein the electrical resistivity of the flattened magnetic metal particle aggregate is greater than the electrical resistivity of the flattened magnetic metal particles.

4. The composite magnetic material according to claim 1, wherein the average orientation angle between the flattened surface of the first flattened magnetic metal particle or the flattened surface of the second flattened magnetic metal particle and the plane of the composite magnetic material is 10 degrees or less.

5. The composite magnetic material according to claim 1, wherein the flattened magnetic metal particle aggregate is contained in the composite magnetic material in a number ratio of 1% or more.

6. The composite magnetic material according to claim 1, wherein the flattened plane of the flattened magnetic metal particles is oriented substantially parallel to the plane of the composite magnetic material, and the composite magnetic material has a difference in coercivity depending on the direction within the plane.

7. The composite magnetic material according to claim 1, wherein at least a portion of the surface of the flattened magnetic metal particles is covered with a coating layer having a thickness of 0.1 nm to 1 μm and containing at least one second element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N), and fluorine (F).

8. The composite magnetic material according to claim 7, wherein the coating layer comprises a silane coupling agent having an amino group.

9. The composite magnetic material according to claim 1, wherein the intervening phase comprises at least one resin selected from the group consisting of imide resins, polyester resins, phenolic resins, epoxy resins, and silicone resins.

10. A magnetic wedge comprising the composite magnetic material according to claim 1.

11. A core comprising the composite magnetic material according to claim 1.

12. A rotating electric machine comprising the composite magnetic material according to claim 1.

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