Preparation method of high-performance soft magnetic composite material and magnetic ring thereof
阅读说明：本技术 一种高性能软磁复合材料的制备方法及其磁环 (Preparation method of high-performance 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：本发明公开了一种高性能软磁复合材料的制备方法及其磁环,在球形软磁合金颗粒外包覆绝缘层形成混合粉末；将混合粉末装入模具使混合粉末压制成型；在混合粉末成型过程中施加外磁场,磁场平行于工作磁路平面,垂直于工作磁路平面法向方向；去应力退火而获得软磁复合材料。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；非磁性相的非对称分布：沿外磁场方向呈连续链状分布,降低了水平磁路磁阻和损耗；磁性相的非对称分布：沿外磁场方向排列紧密有序,细小的磁性颗粒择优填充在磁环平面方向的气隙,降低了水平磁路磁阻和损耗；高磁导率和低损耗；本发明采用设备少、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 high-performance soft magnetic composite material and a magnetic ring thereof.A spherical soft magnetic alloy particle is coated with an insulating layer 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 parallel to the working magnetic circuit plane and is vertical to the normal direction of the working magnetic circuit plane; and performing stress relief annealing to obtain the soft magnetic composite material. The technical scheme is very simple and convenient, has no strict requirements on magnetic powder and equipment, and can realize high performance; asymmetric distribution of nonmagnetic phases: the magnetic field is distributed in a continuous chain shape along the direction of the external magnetic field, so that the magnetic resistance and the loss of a horizontal magnetic circuit are reduced; asymmetric distribution of magnetic phases: the magnetic field is arranged closely and orderly along the direction of the external magnetic field, and fine magnetic particles are preferentially filled in the air gap in the plane direction of the magnetic ring, so that the magnetic resistance and the loss of a horizontal magnetic circuit are reduced; high magnetic conductivity and low loss; 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 high-performance 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 external magnetic field is parallel to the working magnetic circuit plane and is vertical 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 for preparing a high performance soft magnetic composite material according to claim 1, wherein: the magnetic field intensity is 0.1-10T.
3. The method for preparing a high performance 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 for preparing a high performance 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 for preparing a high performance soft magnetic composite material according to claim 1, wherein: the mass fraction of the spherical soft magnetic alloy particles is 90-99.9 wt.%; the mass fraction of the insulating layer is 0.1 wt.% to 10 wt.%.
6. The method for preparing a high performance 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 for preparing a high performance 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 for preparing a high performance 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 for preparing a high performance 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 magnet ring comprising the high performance soft magnetic composite material as claimed in any of claims 1 to 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;
the non-magnetic phase particles are distributed at the interface of the spherical soft magnetic alloy particles: in the direction along the plane of the magnetic ring, the spherical soft magnetic alloy particles are arranged closely and orderly, and the nonmagnetic phase particles are pushed and repelled by the spherical soft magnetic alloy particles and are continuously distributed; the spherical soft magnetic alloy particles are arranged disorderly and the non-magnetic phase particles are arranged discontinuously along the normal axis direction of the magnetic ring;
the distribution 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 high-performance 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 resistivity of the soft magnetic composite material is higher than that of metal soft magnetism, so that the magnetic loss is low; the saturation magnetization intensity of the soft magnetic composite material is higher than that of ferrite, so that the power density is high, and the soft magnetic composite material has unique advantages and application range.
The soft magnetic composite material is prepared by insulating and coating magnetic particles, insulating and coating the magnetic particles with an organic material and an inorganic material, and making mixed powder into an isotropic block material by using a powder metallurgy technology. The soft magnetic composite material produced by the existing industry is isotropic, and the isotropy means that the magnetic performance along all directions is the same. In practical application, however, only the magnetic performance in the working magnetic path direction needs to be utilized, and the working characteristics of the soft magnetic composite material cannot be influenced by the magnetic performance in other non-working magnetic path directions. Thus, isotropy actually results in a waste of the magnetic properties of the soft magnetic composite material. To increase permeability, the thickness of the nonmagnetic insulating layer may be reduced, but this reduces resistivity, increasing eddy current losses; to reduce losses, the resistivity of the soft magnetic alloy may be increased, and the thickness of the insulating layer may be increased, which in turn reduces the permeability and saturation magnetization. Therefore, it is difficult for the isotropic soft magnetic composite material to satisfy the requirements of high magnetic permeability, high saturation magnetization and low loss at the same time, and on one hand, the performance is improved while the performance on the other hand is generally sacrificed.
However, the technical means of increasing the magnetic permeability or reducing the loss adopted in the prior art generally improve the performance in each direction at the same time, and cause the waste of the magnetic performance in the direction of the non-working magnetic circuit to a certain extent.
Disclosure of Invention
The object of the present invention is to provide a method for preparing a high performance 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 high-performance soft magnetic composite material comprises the steps of coating insulating layers 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 magnetic field is parallel to the working magnetic circuit plane and is vertical to the normal direction of the working magnetic circuit plane; and performing stress relief annealing to obtain the soft magnetic composite material.
In the conventional soft magnetic composite material prepared by the technical scheme without adopting the external magnetic field orientation, because the spherical soft magnetic alloy particles are used, the shape of the spherical soft magnetic alloy particles is isotropic and uniform, and there should be no difference in theory for applying the external magnetic field; therefore, the non-magnetic phase is uniform with respect to the coating of the magnetic powder, and the resistivity, permeability, loss, and magnetic resistance are also uniform in all directions.
In the invention, the magnetic field parallel to the working magnetic circuit plane is creatively added in the process of pressing and forming the composite material, so that the rearrangement of the magnetic phase and the non-magnetic phase is realized; the soft magnetic composite material with better performance is obtained, and the non-magnetic phase of the insulating layer of the composite material is asymmetrically distributed around the spherical magnetic phase: in the direction along 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 and the non-magnetic phase particles are not continuously arranged along the normal axis direction of the magnetic ring. Therefore, the resistivity, permeability, loss and magnetic resistance of the soft magnetic composite material are anisotropic. The magnetic resistance is reduced along the external field direction, the demagnetizing field is reduced, the magnetic conductivity is increased, and the hysteresis loss is reduced. On the other hand, in a sample in which the magnetic field is oriented in parallel, fine magnetic powder is better filled in a horizontal gap, which also reduces the void in the horizontal direction, further reduces the magnetic resistance, and increases the magnetic permeability.
When the magnetic ring is formed by pressing and works, the working magnetic circuit is a closed loop along the circumference of the magnetic ring. The eddy current losses along the direction of the magnetic field are reduced in correspondence of the generated eddy currents being completely perpendicular to the circumference of the magnetic ring, which corresponds to the eddy current losses in the direction parallel to the axial direction. Therefore, the technical scheme has good soft magnetic property.
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 soft magnetic 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
Preferably: the spherical soft magnetic alloy particles are 5-40 mu m; the diameter of the nonmagnetic phase particles is 10nm to 200 nm. The diameter of the nonmagnetic phase particles is far smaller than that of the spherical soft magnetic alloy particles, so that good coating can be formed.
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 the high-performance soft magnetic composite material 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; the non-magnetic phase particles are distributed at the interface of the spherical soft magnetic alloy particles: in the direction along 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 and the non-magnetic phase particles are not continuously arranged along the normal axis direction of the magnetic ring. The distribution 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.
Compared with the uniform distribution of the soft magnetic alloy particles and the non-magnetic phase, the anisotropic distribution of the magnetic ring has higher magnetic permeability and lower loss.
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. asymmetric distribution of nonmagnetic phases: the magnetic field is distributed in a continuous chain shape along the direction of the external magnetic field, so that the magnetic resistance and the loss of a horizontal magnetic circuit are reduced; asymmetric distribution of magnetic phases: the magnetic field is arranged closely and orderly along the direction of the external magnetic field, and fine magnetic particles are preferentially filled in the air gap in the plane direction of the magnetic ring, so that the magnetic resistance and the loss of a horizontal magnetic circuit are reduced;
3. the soft magnetic composite material oriented parallel to the working magnetic circuit plane has high magnetic permeability and low loss;
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 in which the magnetic field is oriented horizontally in example 1, the magnetic field being in the horizontal direction;
FIG. 3 shows a scanning electron micrograph of a sample in example 1 (for comparison) which has not been oriented by a magnetic field;
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 fig. 4-10: normal indicates the curve of the sample oriented without the application of an external magnetic field; parallell represents the curve of the sample with the orientation of the external magnetic field applied.
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 soft magnetic composite material will be exemplified. The soft magnetic composite materials in other shapes have the same properties and are not described in detail.