阅读说明：本技术 一种低损耗软磁复合材料的制备方法及其磁环 (Preparation method of low-loss soft magnetic composite material and magnetic ring thereof ) 是由 彭晓领 李静 王新庆 葛洪良 杨艳婷 徐靖才 金红晓 金顶峰 洪波 于 2019-11-28 设计创作，主要内容包括：本发明公开了一种低损耗软磁复合材料的制备方法,在球形软磁合金颗粒外包覆绝缘层形成混合粉末；将混合粉末装入环形模具压制成为磁环；在磁环成型过程中施加外磁场,所述磁场垂直于磁环平面,与磁环法向相平行；去应力退火而获得软磁复合材料。本发明同时公开了一种低损耗软磁复合材料磁环。该技术方案非常简便,对磁粉、设备都没有严苛要求,即可实现高性能；非磁性相在磁环轴向形成连续分布,增大了磁路方向的电阻和磁阻；细小的磁性颗粒填充了轴向空隙,但磁路方向空隙增大,增加了磁路方向磁阻和电阻；垂直磁场取向的软磁复合材料具有更低的磁损耗；本发明由于采用设备少、工艺步骤少、工艺简单,可以快速实现软磁复合材料的工业应用。(The invention discloses a preparation method of a low-loss soft magnetic composite material, wherein an insulating layer is coated outside spherical soft magnetic alloy particles to form mixed powder; putting the mixed powder into an annular die to be pressed into a magnetic ring; applying an external magnetic field in the magnetic ring forming process, wherein the magnetic field is perpendicular to the magnetic ring plane and is parallel to the normal direction of the magnetic ring; and performing stress relief annealing to obtain the soft magnetic composite material. The invention also discloses a low-loss soft magnetic composite material magnetic ring. The technical scheme is very simple and convenient, has no strict requirements on magnetic powder and equipment, and can realize high performance; the non-magnetic phases form continuous distribution in the axial direction of the magnetic ring, so that the resistance and the magnetic resistance in the direction of a magnetic circuit are increased; the axial gap is filled with fine magnetic particles, but the gap in the magnetic path direction is enlarged, so that the magnetic resistance and the resistance in the magnetic path direction are increased; perpendicular magnetic field oriented soft magnetic composites have lower magnetic losses; the invention has the advantages of less adopted equipment, less process steps and simple process, and can quickly realize the industrial application of the soft magnetic composite material.)

1. A preparation method of a low-loss soft magnetic composite material is characterized by comprising the following steps: coating an insulating layer outside the spherical soft magnetic alloy particles to form mixed powder; filling the mixed powder into a die to press and form the mixed powder; applying an external magnetic field in the mixed powder forming process, wherein the magnetic field is perpendicular to the working magnetic circuit plane and is parallel to the normal direction of the working magnetic circuit plane; and performing stress relief annealing to obtain the soft magnetic composite material.

2. The method of preparing a low loss soft magnetic composite material according to claim 1, wherein: the magnetic field intensity is 0.1-10T.

3. The method of preparing a low loss soft magnetic composite material according to claim 1, wherein: the magnetic field is one of a coil magnetic field, an electromagnet magnetic field or a pulse magnetic field.

4. The method of preparing a low loss soft magnetic composite material according to claim 1, wherein: and applying an external magnetic field all the time in the process of pressing and forming the mixed powder.

5. The method of preparing a low loss soft magnetic composite material according to claim 1, wherein: the mass fraction of the spherical magnetically soft alloy particles is 90-99.9 wt.%; the mass fraction of the insulating layer is 0.1 wt.% to 10 wt.%.

6. The method of preparing a low loss soft magnetic composite material according to claim 1, wherein: the spherical soft magnetic alloy particles are one of Fe, Fe-Si, Fe-Ni-Mo, Fe-Si-Al, Fe-Si-B amorphous and iron-based nanocrystalline alloys.

7. The method of preparing a low loss soft magnetic composite material according to claim 1, wherein: the insulating layer is made of glass powder, water glass, MgO and SiO₂、Al₂O₃ZnO and TiO₂One kind of (1).

8. The method of preparing a low loss soft magnetic composite material according to claim 1, wherein: the spherical soft magnetic alloy particles are 5-40 mu m; the diameter of the nonmagnetic phase particles is 10nm to 200 nm.

9. The method of preparing a low loss soft magnetic composite material according to claim 1, wherein: the spherical magnetically soft alloy particles are prepared by an air atomization method or a water atomization method.

10. A magnetic ring comprising the low loss soft magnetic composite of any of claims 1-9, wherein: the magnetic ring comprises a magnetic ring body, wherein spherical soft magnetic alloy particles and nonmagnetic phase particles are arranged in the magnetic ring body; the non-magnetic phase particles are coated on the spherical soft magnetic alloy particles to be distributed at the interfaces of the spherical soft magnetic alloy particles; in the direction vertical to the plane of the magnetic ring, the spherical soft magnetic alloy particles are arranged closely and orderly, and the nonmagnetic phase particles are pushed by the soft magnetic alloy particles to repel and are continuously distributed; along the plane direction of the magnetic ring, the spherical soft magnetic alloy particles are arranged disorderly, and the non-magnetic phase particles are arranged discontinuously; the arrangement of the spherical soft magnetic alloy particles and the nonmagnetic phase particles in the magnetic ring enables the distribution of the spherical soft magnetic alloy particles and the nonmagnetic phase powder to have anisotropy in the magnetic ring.

Technical Field

The invention relates to the field of magnetic material preparation, in particular to a preparation method of a low-loss soft magnetic composite material and a magnetic ring thereof.

Background

The soft magnetic composite material has high magnetic flux and low loss, and is also called as magnetic powder core in the industrial field. The soft magnetic composite material has a higher resistivity than metal soft magnetism and thus has a low magnetic loss. Thus, soft magnetic composites have unique advantages and application areas.

With the development of informatization, the application of the soft magnetic device gradually expands to higher frequency. Although the use frequency of the soft magnetic composite material is greatly improved, the soft magnetic composite material is easy to generate more loss in the high-frequency application process due to the characteristics of the soft magnetic composite material, so that the use of the soft magnetic composite material in the high-frequency field is still greatly limited. Losses can be reduced in a number of ways known in the art, such as: the design of main phase components improves the basic characteristics of alloy such as coercive force, resistivity and the like; the interface characteristics are improved, and the thickness of the interface layer is increased; the structure and process design of the soft magnetic composite material are improved. However, the improvement effect of the above technical means on the magnetic performance is the same in all directions, i.e. isotropic. In fact, when the soft magnetic composite material is in operation, the performance improvement only in the direction of the operating magnetic circuit is beneficial, while the performance improvement in the other directions is completely wasteful. It is very critical for soft magnetic composites how the magnetic properties, especially the loss characteristics, can be improved specifically only in the direction of the working magnetic circuit.

Disclosure of Invention

The object of the present invention is to provide a method for preparing a low-loss soft magnetic composite material, which solves one or more of the above mentioned technical problems.

In order to achieve the purpose, the technical scheme provided by the invention is as follows:

a preparation method of a low-loss soft magnetic composite material comprises the steps of coating an insulating layer outside spherical soft magnetic alloy particles to form mixed powder; filling the mixed powder into a die to press and form the mixed powder; applying an external magnetic field in the mixed powder forming process, wherein the external magnetic field is perpendicular to the working magnetic circuit plane and is parallel to the normal direction of the working magnetic circuit plane; and performing stress relief annealing to obtain the soft magnetic composite material.

In the soft magnetic composite material prepared by the technical scheme, the non-magnetic phases of the insulating layer are asymmetrically distributed around the spherical magnetic phase, the non-magnetic phases are continuously distributed along the direction of the external magnetic field, and the non-magnetic phases are discontinuously distributed along the plane direction (vertical magnetic field direction) of the magnetic ring.

When the magnetic ring works, the working magnetic circuit is a closed loop along the circumference of the magnetic ring. In the conventional soft magnetic composite material prepared by the technical scheme without adopting the external magnetic field orientation, the non-magnetism is uniform relative to the coating of magnetic powder, and the resistivity, the magnetic conductivity, the loss and the magnetic resistance are also uniform in all directions.

In the soft magnetic composite material obtained by the technical scheme, the resistivity, the magnetic conductivity, the loss and the magnetic resistance are in anisotropic characteristics. The non-magnetic phases are distributed continuously in the direction of the external field and are distributed discontinuously in the direction of the magnetic circuit, so that the non-insulating air gap in the direction of the magnetic circuit is increased, the resistivity is slightly increased, and although the permeability is reduced by some percent (about ten percent), the loss is greatly reduced.

On the other hand, in the sample oriented perpendicular to the working magnetic circuit plane, the filling of fine magnetic powder at the vertical gap is better, which also reduces the gap in the direction perpendicular to the working magnetic circuit plane and increases the gap in the direction opposite to the magnetic circuit direction, thus although increasing part of magnetic resistance and electric resistance, the magnetic permeability is reduced, and the reduction value is an acceptable use range in industrial use and hardly influences the use performance of the working magnetic circuit plane; on the contrary, the loss value of the soft magnetic composite material is greatly reduced, the soft magnetic composite material is more suitable for industrial application in the high-frequency field, and the performance of the existing soft magnetic composite material can be improved by additionally arranging a device for applying an external magnetic field on the basis of not changing the existing industrial production equipment, so that the difficult problem in the prior art is effectively solved.

Preferably: the magnetic field intensity is 0.1-10T.

Preferably: the magnetic field is one of a coil magnetic field, an electromagnet magnetic field or a pulse magnetic field.

Preferably: and applying an external magnetic field all the time in the process of pressing and forming the mixed powder.

Preferably: the mass fraction of the spherical magnetically soft alloy particles is 90-99.9 wt.%; the mass fraction of the insulating layer is 0.1 wt.% to 10 wt.%.

Preferably: the spherical soft magnetic alloy particles are one of Fe, Fe-Si, Fe-Ni-Mo, Fe-Si-Al, Fe-Si-B amorphous and iron-based nanocrystalline alloys.

Preferably: the insulating layer is one of glass powder, water glass, MgO, SiO2, Al2O3, ZnO and TiO 2.

Preferably: the spherical soft magnetic alloy particles are 5-40 mu m; the diameter of the nonmagnetic phase particles is 10nm to 200 nm.

Preferably: the spherical magnetically soft alloy particles are prepared by an air atomization method or a water atomization method.

The invention also aims to provide a magnetic ring made of the soft magnetic composite material, which can be widely applied to devices such as motors, power frequency to high frequency transformers, sensors, choke coils, noise filters, fuel injectors and the like.

A magnetic ring containing any of the low-loss soft magnetic composite materials comprises a magnetic ring body, wherein spherical soft magnetic alloy particles and nonmagnetic phase particles are arranged in the magnetic ring body; the nonmagnetic phase particles are coated on the spherical soft magnetic alloy particles to be distributed at the interface of the spherical soft magnetic alloy particles. In the direction vertical to the plane of the magnetic ring, the spherical soft magnetic alloy particles are arranged closely and orderly, and the nonmagnetic phase particles are pushed by the soft magnetic alloy particles to repel and are continuously distributed; the spherical soft magnetic alloy particles are arranged disorderly along the plane direction of the magnetic ring, and the non-magnetic phase particles are arranged discontinuously. The arrangement of the spherical soft magnetic alloy particles and the nonmagnetic phase particles in the magnetic ring enables the distribution of the spherical soft magnetic alloy particles and the nonmagnetic phase powder to have anisotropy in the magnetic ring.

The invention has the technical effects that:

1. the technical scheme is very simple and convenient, has no strict requirements on magnetic powder and equipment, and can realize high performance;

2. the non-magnetic phases form continuous distribution in the axial direction of the magnetic ring, so that the resistance and the magnetic resistance in the direction of a magnetic circuit are increased; the axial gap is filled with fine magnetic particles, but the gap in the magnetic path direction is enlarged, so that the magnetic resistance and the resistance in the magnetic path direction are increased;

3. the orientation of the magnetic field vertical to the plane of the working magnetic circuit ensures that the soft magnetic composite material has lower magnetic loss and is more suitable for industrial production;

4. the invention has the advantages of less adopted equipment, less process steps and simple process, and can quickly realize the industrial application of the soft magnetic composite material.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention.

In the drawings:

FIG. 1 shows a SEM image of the coated sample of example 1;

FIG. 2 shows a scanning electron micrograph of a sample with a magnetic field oriented vertically in example 1, the magnetic field being in the direction perpendicular to the plane of the working magnetic circuit;

FIG. 3 shows a scanning electron micrograph of a sample which had not been oriented by a magnetic field in example 1 (for comparison)

FIG. 4 shows the effective permeability of the sample of example 1;

FIG. 5 shows the magnetic losses of the samples of example 1;

FIG. 6 shows the real part of the complex permeability of the sample in example 1;

FIG. 7 shows the imaginary part of the complex permeability of the sample in example 1;

FIG. 8 shows the figure of merit for the samples of example 1;

FIG. 9 shows the loss tangent of the sample of example 1;

figure 10 shows the μ Q product for the samples in example 1.

FIG. 11 is a schematic representation of a composite material of the present invention;

in the accompanying fig. 4-10:

normal indicates the sample curve without applied magnetic field; vertical represents the curve of the sample with the applied magnetic field perpendicular to the plane of the working magnetic circuit.

In fig. 11: 1 spherical soft magnetic alloy particles, 2 non-magnetic phase particles.

Detailed Description

The present invention will now be described in detail with reference to the drawings and specific embodiments, wherein the exemplary embodiments and descriptions are provided only for the purpose of illustrating the present invention and are not to be construed as unduly limiting the invention.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

As shown in fig. 1 and 11, fig. 1 is a schematic view of a single spherical soft magnetic alloy particle coated with a non-magnetic phase as an insulating layer; fig. 11 is a schematic cross-sectional view of the ideal state soft magnetic composite material, and in fig. 11, assuming that spherical soft magnetic alloy particles are the same, nonmagnetic phase particles are also the same.

In the following examples, a common annular composite material will be exemplified. Other shapes of soft magnetic composite materials have the same or similar properties and are not described in detail herein.