阅读说明：本技术 一种高磁导率、低磁损的复合材料及其制备方法 (Composite material with high magnetic conductivity and low magnetic loss and preparation method thereof ) 是由 倪江利 冯双久 刘先松 胡峰 阚绪材 朱守金 李勇 于 2021-01-14 设计创作，主要内容包括：本发明提供一种高磁导率、低磁损的复合材料及其制备方法,涉及软磁复合材料加工技术领域。所述高磁导率、低磁损的复合材料为FeAlSi/羰基铁复合材料,其制备方法主要包括：金属粉制备、原料钝化、复合材料制备等步骤。本发明克服了现有技术的不足,通过羰基铁颗粒的存在增强了FeAlSi之间的磁耦合,导致磁导率增加,磁滞损耗降低,同时羰基铁本身的磁滞损耗大于FeAlSi,当含量为4％时,样品的磁损耗最低,磁导率高,具有优良的商业应用价值。(The invention provides a composite material with high magnetic conductivity and low magnetic loss and a preparation method thereof, and relates to the technical field of soft magnetic composite material processing. The composite material with high magnetic permeability and low magnetic loss is a FeAlSi/carbonyl iron composite material, and the preparation method mainly comprises the following steps: preparing metal powder, passivating raw materials, preparing a composite material and the like. The invention overcomes the defects of the prior art, enhances the magnetic coupling between FeAlSi by the existence of carbonyl iron particles, leads to the increase of magnetic conductivity and the reduction of hysteresis loss, simultaneously, the hysteresis loss of the carbonyl iron is larger than that of the FeAlSi, and when the content is 4 percent, the magnetic loss of the sample is the lowest, the magnetic conductivity is high, and the invention has excellent commercial application value.)

1. The composite material with high magnetic permeability and low magnetic loss is characterized in that the composite material with high magnetic permeability and low magnetic loss is a FeAlSi/carbonyl iron composite material, wherein the content of carbonyl iron is 4%, the content of Fe in FeAlSi is 85 wt%, the content of Si is 9.6 wt%, and the content of Al is 5.4 wt%.

2. A preparation method of a composite material with high magnetic permeability and low magnetic loss is characterized by comprising the following steps: the preparation method of the composite material with high magnetic permeability and low magnetic loss comprises the following steps:

(1) preparing metal powder: mixing 85 wt% of iron powder, 9.6 wt% of silicon powder and 5.4 wt% of aluminum powder according to the mass ratio, smelting at high temperature, and mechanically grinding to obtain alloy powder for later use;

(2) passivating raw materials: mixing 85% phosphoric acid solution and ethanol, stirring in water bath, adding the mixed metal powder, continuously stirring, drying in a 200 ℃ oven, and sieving with a 100-mesh sieve to obtain a passivation raw material;

(3) preparing a composite material: and mixing carbonyl iron and the passivation raw materials, adding a release agent, uniformly mixing again, placing in a mold, pressing into a ring under the pressure of 1800MPa, taking out, and carrying out vacuum annealing to obtain the composite material.

3. The method of claim 2, wherein the composite material has high magnetic permeability and low magnetic loss, and the method comprises the following steps: the average particle size of the alloy powder obtained by mechanical grinding in the step (1) is 50 μm.

4. The method of claim 2, wherein the composite material has high magnetic permeability and low magnetic loss, and the method comprises the following steps: in the step (2), the mixing mass ratio of the phosphoric acid solution, the ethanol and the mixed metal powder is 0.1: 7.5: 50.

5. The method of claim 2, wherein the composite material has high magnetic permeability and low magnetic loss, and the method comprises the following steps: and (3) stirring the water bath in the step (2) at 80 ℃, stirring for 30min, and adding the mixed metal powder and continuously stirring for 30 min.

6. The method of claim 2, wherein the composite material has high magnetic permeability and low magnetic loss, and the method comprises the following steps: the release agent added in the step (3) is zinc stearate, and the addition amount of the release agent is 0.5% of the mass of the passivation raw material.

7. The method of claim 2, wherein the composite material has high magnetic permeability and low magnetic loss, and the method comprises the following steps: the vacuum annealing mode in the step (3) is that the temperature is increased to 660 ℃ at the speed of 3-4 ℃/min, then the temperature is kept for 2h, and then the temperature is reduced along with the furnace.

Technical Field

The invention relates to the technical field of soft magnetic composite material processing, in particular to a composite material with high magnetic conductivity and low magnetic loss and a preparation method thereof.

Background

Soft magnetic composite materials are widely used in magnetic devices due to their excellent properties, including high permeability and low core loss. With the development of miniaturization and high frequency of power electronic equipment, magnetic devices are also developing toward high frequency, high power, low power consumption and good electromagnetic compatibility.

The high magnetic conductivity can increase the application range of the device, the low loss can consume less energy, and meanwhile, the performance reduction of the composite material caused by loss and heating is avoided, and the requirements of green electronic products are met. The magnetic loss is the sum of the hysteresis loss, eddy current loss and residual loss.

The prior documents have disclosed a number of methods relating to the use of different materials to form insulating layers between ferromagnetic metal particles to reduce eddy current losses in composite materials; wherein glass is used as an insulating agent to reduce eddy current losses; although the addition of the insulating material can reduce eddy current loss, the introduction of the insulating material causes a decrease in magnetic permeability and saturation magnetization, which is detrimental to the magnetic properties of the soft magnetic composite material.

In order to obtain a soft magnetic material with high permeability and low magnetic losses, a FeAlSi/carbonyl iron composite is reported herein. As the carbonyl iron content increases, the permeability of the sample increases, but the magnetic loss of the sample decreases first and then increases. When the content is 4%, the magnetic loss of the sample is the lowest, the magnetic conductivity is high, and the practical application value is very high.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a composite material with high magnetic conductivity and low magnetic loss and a preparation method thereof, so that the FeAlSi/carbonyl iron composite material with high magnetic conductivity and low magnetic loss is obtained, and has high practical application value.

In order to achieve the above purpose, the technical scheme of the invention is realized by the following technical scheme:

a FeAlSi/carbonyl iron composite material with high magnetic permeability and low magnetic loss is prepared by the following steps:

(1) preparing metal powder: mixing 85 wt% of iron powder, 9.6 wt% of silicon powder and 5.4 wt% of aluminum powder according to the mass ratio, smelting at high temperature, and mechanically grinding to obtain alloy powder for later use;

(2) passivating raw materials: mixing 85% phosphoric acid solution and ethanol, stirring in water bath, adding the mixed metal powder, stirring, oven drying at 200 deg.C, and sieving with 100 mesh sieve to obtain passivation raw material;

(3) preparing a composite material: and mixing carbonyl iron and the passivation raw materials, adding a release agent, uniformly mixing again, placing in a mold, pressing into a ring under the pressure of 1800MPa, taking out, and carrying out vacuum annealing to obtain the composite material.

Preferably, the alloy powder obtained by mechanical milling in the step (1) has an average particle size of 50 μm.

Preferably, the mixing mass ratio of the phosphoric acid solution, the ethanol and the mixed metal powder in the step (2) is 0.1: 7.5: 50.

Preferably, the temperature of the water bath stirring in the step (2) is 80 ℃, the stirring time is 30min, and the time for adding the mixed metal powder and continuing stirring is 30 min.

Preferably, the release agent added in the step (3) is zinc stearate, and the addition amount of the release agent is 0.5% of the mass of the passivation raw material.

Preferably, the vacuum annealing mode in the step (3) is to heat up to 660 ℃ at a speed of 3-4 ℃/min, then preserve heat for 2h, and then cool down along with the furnace.

The invention provides a composite material with high magnetic conductivity and low magnetic loss and a preparation method thereof, and compared with the prior art, the composite material has the advantages that:

the magnetic coupling between FeAlSi is enhanced by the carbonyl iron particles, so that the magnetic conductivity is increased, the hysteresis loss is reduced, the hysteresis loss of the carbonyl iron is larger than that of the FeAlSi, and when the content of the carbonyl iron is 4%, the magnetic loss of a sample is the lowest, the magnetic conductivity is high, and the carbonyl iron has high commercial application value in a high-power electrical system.

Description of the drawings:

FIG. 1: is a FeAlSi electron microscope scanning image without carbonyl iron;

FIG. 2: a FeAlSi electron microscope scanning image of the invention added with 4 wt% carbonyl iron;

FIG. 3: data of mu a to H of the composite material obtained by measuring carbonyl iron with different contents under the condition of 10 kHz;

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

a FeAlSi/carbonyl iron composite material with high magnetic permeability and low magnetic loss is prepared by the following steps:

(1) preparing metal powder: mixing 85 wt% of iron powder, 9.6 wt% of silicon powder and 5.4 wt% of aluminum powder according to the mass ratio, smelting at high temperature, and mechanically grinding until the average particle size is 50 micrometers to obtain alloy powder for later use;

(2) passivating raw materials: mixing 85% phosphoric acid solution and ethanol, stirring in 80 deg.C water bath for 30min, adding the mixed metal powder, stirring for 30min, wherein the mixing mass ratio of phosphoric acid solution, ethanol and mixed metal powder is 0.1: 7.5: 50, oven drying in 200 deg.C oven, and sieving with 100 mesh sieve to obtain passivation raw material;

(3) preparing a composite material: mixing carbonyl iron and the passivation raw material, adding zinc stearate accounting for 0.5% of the mass of the passivation raw material, uniformly mixing again, placing in a mold, pressing to form a ring under the pressure of 1800MPa, taking out, heating to 660 ℃ at the speed of 3-4 ℃/min, then preserving heat for 2h, and then cooling along with a furnace and carrying out vacuum annealing to obtain the composite material for later use.

Example 2:

according to the preparation method described in the above example 1, 0% and 4% carbonyl iron were added respectively to prepare FeAlSi/carbonyl iron composite powder, and then scanning by electron microscope was performed, and the results are shown in FIG. 1 and FIG. 2;

as can be seen from fig. 1 and 2, the particles in the mixed powder are irregular, it is easy to shape, and a compressed core with smaller air gaps and higher magnetic permeability is obtained, compared to the conventional spherical particles.

Example 3:

the magnetic permeability of FeAlSi/carbonyl iron composite materials prepared from 0%, 2% and 4% carbonyl iron is detected, and the result is shown in FIG. 3;

as can be seen from fig. 3, the magnetic permeability of the FeAlSi/carbonyl iron composite material is highest when the carbonyl iron content is 4%.

Example 4:

the magnetic losses of FeAlSi/carbonyl iron composites prepared from 0%, 2%, 4%, 6%, 8% carbonyl iron were measured in different test environments, and the results are shown in the following table:

as can be seen from the above table, the hysteresis loss of the sample is lowest when the carbonyl iron content is 4%.

In summary, by studying the characteristics of FeAlSi/carbonyl iron soft magnetic composite materials with different carbonyl iron contents, it is found that the magnetic permeability of the sample is increased and the magnetic loss of the sample is increased after being reduced along with the increase of the carbonyl iron content. The presence of carbonyl iron particles enhances the magnetic coupling between FeAlSi, resulting in increased permeability and reduced hysteresis losses, while the hysteresis losses of the carbonyl iron itself are greater than those of FeAlSi. When the content is 4%, the magnetic loss of the sample is lowest, the magnetic conductivity is high, and the sample has high commercial application value in a high-power electrical system.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.