CN115798855A - Soft magnetic composite material compositely coated by amorphous silicon oxide and preparation method thereof - Google Patents
Soft magnetic composite material compositely coated by amorphous silicon oxide and preparation method thereof Download PDFInfo
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Abstract
The invention discloses a preparation method of a soft magnetic composite material compositely coated by amorphous silicon oxide, belonging to the technical field of magnetic materials. The method comprises the steps of firstly preparing amorphous alloy powder with a fine median grain size through coarse grinding and fine grinding; then the magnetic powder is compounded and insulated by combining with the nano silicon oxide; then, a special annealing heat treatment process is set based on the crystallization temperature of the amorphous alloy, and the soft magnetic composite material clad by the amorphous alloy powder and the silicon oxide is prepared. The relative magnetic permeability of the soft magnetic composite material at 100kHz/1V is 60.7-63.2, and the volume resistivity is 6.942-8.565 multiplied by 10 10 Mu omega cm, the loss of 50kHz/100mT is 188-582 mW/cm 3 The DC bias performance under the magnetic field strength of 100Oe is 61.4-90.2%. The preparation method can obtain the soft magnetic composite material with optimized magnetic conductivity, resistivity, loss and direct current bias performance.
Description
Technical Field
The invention belongs to the technical field of magnetic materials, and relates to a preparation method of a soft magnetic composite material compositely coated by amorphous silicon oxide.
Background
With the rapid development of new energy industries, soft magnetic composite materials are increasingly paid more attention by people as core components of power electronic equipment such as photovoltaic inverters, vehicle-mounted chargers, variable frequency air conditioners and the like. Especially for high-frequency and high-power applications, the soft magnetic composite material is required to have higher resistivity, magnetic conductivity, direct current bias performance and lower loss. To achieve this goal, it is critical that the surface of the magnetic powder is uniformly coated with a dense, high resistivity insulating layer, and the insulating layer preferably also has certain magnetic properties. At present, the high-resistivity insulating material used for the soft magnetic composite material is mainly an inorganic oxide, and silicon oxide is the best insulating oxide recognized at present from the viewpoints of both the process operability of uniform coating and the basic physical properties of high resistivity. But the pure silicon oxide coating cannot realize the synchronous improvement of the resistivity and the magnetic permeability. The silicon oxide is a non-magnetic substance, and although the coating layer of the silicon oxide can effectively improve the resistivity of the soft magnetic composite material, the coating layer can also cut off a magnetic path among magnetic powder particles, so that the demagnetizing field of the internal structure of the soft magnetic composite material is increased, the magnetostatic coupling field is reduced, the magnetic conductivity of the soft magnetic composite material is reduced, the loss of a magnetic core is increased, and the direct current bias performance is enhanced.
Disclosure of Invention
The invention aims to provide a preparation method of a soft magnetic composite material compositely coated by amorphous silicon oxide.
The method comprises the steps of firstly, carrying out ball milling on coarse grinding and fine grinding to manufacture amorphous magnetic powder with a median particle size of 4-6 mu m, mixing the amorphous alloy powder with a controlled particle size range and nano silicon oxide powder according to a certain proportion, then carrying out composite insulation on the iron-based alloy magnetic powder, and finally pressing and forming the insulated magnetic powder to manufacture the soft magnetic composite material compositely coated by the amorphous alloy powder and the silicon oxide, so that the synchronous optimization of the resistivity, the magnetic conductivity, the loss and the direct current bias performance is realized. The key of the preparation method is that the ball milling and heat treatment process route is designed in a targeted manner, and the crystallization of the amorphous alloy powder in the preparation process is prevented while the grain size of the amorphous magnetic powder is controlled.
A preparation method of a soft magnetic composite material compositely coated by amorphous and silicon oxide comprises the following specific operation steps:
(1) Preparation of amorphous alloy powder
Placing an amorphous alloy thin strip prepared by a single-roller rapid quenching method in a planetary ball mill for ball milling twice respectively, wherein the ball milling twice is coarse grinding and fine grinding, and the ball milling medium is ethanol; preparing amorphous alloy powder with the median particle size of 4-6 mu m;
the amorphous alloy powder is one of iron-silicon-boron, iron-silicon-boron-carbon and iron-silicon-boron-phosphorus-carbon;
(2) Cleaning of
Cleaning the amorphous alloy powder with acetone for 1-3 times to remove impurities on the surface of the amorphous alloy powder, thereby obtaining clean amorphous alloy powder;
(3) Insulating coating
Putting the iron-based alloy magnetic powder with the particle size of 40-180 mu m into an acetone solution, uniformly mixing the clean amorphous alloy powder and the nano silicon oxide powder, pouring the mixture into the acetone solution, fully stirring, and drying at 80 ℃ to obtain insulating powder;
the mass of the nano silicon oxide powder is 2% of that of the iron-based alloy magnetic powder, and the mass of the clean amorphous alloy powder is 2-6% of that of the iron-based alloy magnetic powder;
the mass ratio of the iron-based alloy magnetic powder to the acetone solution is 10;
(4) Preparation of the Green bodies
Uniformly mixing the insulating powder with a release agent, wherein the amount of the release agent is 3-6 per mill of the mass of the insulating powder, uniformly mixing, and performing press forming in a mold to obtain a green body;
(5) Heat treatment of
Performing stress annealing on the green body under the protection of argon atmosphere, and cooling to obtain the soft magnetic composite material compositely coated by the amorphous alloy powder and the silicon oxide;
the relative magnetic permeability of the soft magnetic composite material under the condition of 100kHz/1V is 60.7-63.2, and the volume resistivity is 6.942-8.565 multiplied by 10 10 Mu omega cm, the loss under the condition of 50kHz/100mT is 188-582 mW/cm 3 The DC bias at 100Oe magnetic field strength is 61.4-90.2%.
The further technical scheme is as follows:
in the step (1), the rough grinding conditions are as follows: the grinding ball is zirconia ball with the diameter of 10-20 cm, the rotating speed is 150-300 r/min, the ball milling time is 9-18 h, the ball-to-material ratio is 20:1; the fine grinding conditions are as follows: the grinding ball is zirconia ball with the diameter of 5-10 cm, the rotating speed is 300-500 r/min, the ball milling time is 9-32 h, the ball-to-material ratio is 30:1.
in the step (3), the iron-based alloy magnetic powder is one of gas-atomized iron-silicon magnetic powder, gas-atomized iron-silicon-aluminum magnetic powder and iron-nickel magnetic powder.
In the step (4), the pressure intensity of the compression molding is 1000-1200 MPa.
In the step (5), annealing conditions are as follows: keeping the temperature for 40-60 min at 100-200 ℃; keeping the temperature for 60-80 min at 350-420 ℃.
The beneficial technical effects of the invention are embodied in the following aspects:
1. the amorphous alloy is a magnetic material with excellent soft magnetic performance, has the resistivity which is obviously higher than that of magnetic powder particles of a soft magnetic composite material, and simultaneously has very high magnetic conductivity and low loss. Therefore, the invention utilizes the characteristics of high resistivity, high magnetic conductivity and low loss of the amorphous alloy, and mixes the amorphous alloy with the silicon oxide powder with high resistivity according to a certain proportion to realize high-quality composite insulation of the iron-based alloy magnetic powder, thereby simultaneously endowing the soft magnetic composite material with higher resistivity, excellent magnetic conductivity, lower loss and higher direct current bias performance. According to the invention, the amorphous alloy powder with the median grain diameter of 4-6 microns is prepared by a two-step mechanical ball milling method of coarse grinding and fine grinding of the amorphous alloy strip, and the two-step ball milling method can be used for crushing the amorphous alloy powder into the required median grain diameter by adjusting the ball-to-material ratio and the ball milling rotating speed, so that the amorphous alloy powder can be uniformly filled in gaps of iron-based alloy magnetic powder particles with large grain diameters, and the forming of the soft magnetic composite material is facilitated. Fig. 1 shows X-ray diffraction (XRD) spectra of the iron-nickel soft magnetic composite material prepared in example 3 and the iron-nickel magnetic powder and the amorphous alloy powder before insulation treatment, and as can be seen from fig. 1, the XRD spectrum of the finished iron-nickel soft magnetic composite material is obviously more than that of the iron-nickel magnetic powder before insulation treatment by one steamed bun peak signal. The signal is consistent with the XRD spectrogram signal of the amorphous alloy powder, which indicates that the amorphous alloy powder enters the iron-nickel soft magnetic composite material through composite insulation.
2. The invention also ensures the uniformity of the composite insulation coating to a certain extent by adjusting the mass ratio of the nano silicon oxide powder to the amorphous alloy powder, and the set special ball milling and heat treatment process conditions can effectively prevent the crystallization of the amorphous alloy, but can well remove the internal stress brought by the pressing process.
3. Under the same magnetic permeability level (60 +/-8%), the soft magnetic composite material compositely coated with the amorphous alloy powder and the silicon oxide prepared in the example 1 is compared with the gas atomization iron-silicon-aluminum soft magnetic composite material prepared by the conventional insulation process in loss, volume resistivity and direct current bias performance.
TABLE 1 comparison of the magnetoelectric Properties of Soft magnetic composites prepared by the Process of example 1 with conventional insulation Process
Comparative data are shown in table 1, wherein No. 1 is a sample prepared by a conventional insulation process, and No. 2 is a soft magnetic composite material compositely coated with amorphous alloy powder and silicon oxide prepared by the process of the present invention. It can be seen that the soft magnetic composite material compositely coated with the amorphous alloy powder and the silicon oxide prepared by the invention has higher magnetic permeability, higher resistivity, lower loss and higher direct current bias performance under the same magnetic permeability level.
Drawings
Fig. 1 is an X-ray diffraction (XRD) spectrum of the iron-nickel soft magnetic composite material prepared in example 3 and the iron-nickel alloy magnetic powder and amorphous powder before insulation treatment.
Detailed Description
The present invention will be described with reference to specific examples.
Example 1
The preparation operation steps of the soft magnetic composite material compositely coated by amorphous and silicon oxide are as follows:
(1) Preparation of amorphous alloy powder
Selecting iron-silicon-boron (Fe) prepared by single-roller rapid quenching method 78 Si 9 B 13 ) And placing the amorphous alloy thin strip in a planetary ball mill for ball milling twice, wherein the ball milling twice is coarse grinding and fine grinding. The diameter of a grinding ball used for coarse grinding is 10cm, the ball-milling rotating speed is 150r/min, the ball-milling time is 9h, and the ball-material ratio is 20; the diameter of a grinding ball used for fine grinding is 5cm, the ball-milling rotating speed is 300r/min, the ball-milling time is 9h, the ball-material ratio is 30 78 Si 9 B 13 ) Amorphous alloy powder.
(2) Cleaning of
Iron, silicon and boron (Fe) 78 Si 9 B 13 ) Cleaning the amorphous alloy powder with acetone for 1 time to remove Fe, si and B (Fe) 78 Si 9 B 13 ) And impurities on the surface of the amorphous alloy powder are removed to obtain clean amorphous alloy powder.
(3) Insulating coating
Weighing 1000g of gas-atomized iron-silicon-aluminum magnetic powder with the particle size of 40-180 mu m, placing the gas-atomized iron-silicon-aluminum magnetic powder into 300g of acetone solution, uniformly mixing 20g of clean amorphous alloy powder and 20g of nano silicon oxide powder, pouring the mixture into the acetone solution, fully stirring, and drying at 80 ℃ to obtain the insulating powder.
(4) Preparation of the Green bodies
1040g of insulating powder and 3.12g of release agent are mixed evenly and pressed into a magnetic ring green body with the standard external diameter of 1.06 inch in a mould by the pressing pressure of 1000 MPa.
(5) Thermal treatment
Stress annealing is carried out on the magnetic ring green body under the protection of argon, and heat preservation is carried out for 40min at the temperature of 100 ℃; heating to 350 deg.C, holding the temperature for 60min, and furnace cooling to obtain Fe-Si-B (Fe) 78 Si 9 B 13 ) Amorphous alloy powder and silicon oxide are compounded and coated to form the gas atomization Fe-Si-Al soft magnetic composite material.
The relative permeability of the gas atomized iron-silicon-aluminum soft magnetic composite material at 100kHz/1V is 63.2, and the volume resistivity is 8.565 multiplied by 10 10 Mu omega cm, the loss of 50kHz/100mT is 188mW/cm 3 The dc bias performance at 100Oe field strength was 61.4%.
Example 2
The preparation operation steps of the soft magnetic composite material compositely coated by the amorphous alloy powder and the silicon oxide are as follows:
(1) Preparation of amorphous alloy powder
Selecting iron-silicon-boron-carbon (Fe) prepared by single-roller rapid quenching method 82 Si 4 B 13 C) And placing the amorphous alloy thin strip in a planetary ball mill for ball milling twice, wherein the ball milling twice is coarse grinding and fine grinding. The diameter of a grinding ball used for coarse grinding is 15cm, the ball milling rotation speed is 200r/min, the ball milling time is 15h, the ball-to-material ratio is 20 82 Si 4 B 13 C) Amorphous alloy powder.
(2) Cleaning of
Iron silicon boron carbon (Fe) 82 Si 4 B 13 C) Cleaning the amorphous alloy powder with acetone for 2 times to remove Fe, si, B and C (Fe) 82 Si 4 B 13 C) And impurities on the surface of the amorphous alloy powder are removed to obtain clean amorphous alloy powder.
(3) Insulating coating
Weighing 1000g of gas-atomized iron-silicon magnetic powder with the particle size of 40-180 mu m, placing the gas-atomized iron-silicon magnetic powder into 300g of acetone solution, uniformly mixing 40g of clean amorphous alloy powder and 20g of nano silicon oxide powder, pouring the mixture into the acetone solution, fully stirring, and drying at 80 ℃ to obtain the insulating powder.
(4) Preparation of the Green bodies
1060g of insulating powder and 5.3g of release agent are mixed evenly and pressed into a magnetic ring green body with the standard external diameter of 1.06 inch in a die by using the pressing pressure of 1100 MPa.
(5) Thermal treatment
Firstly, keeping the temperature of a magnetic ring green body for 50min at the temperature of 150 ℃ in the protective atmosphere of argon; heating to 390 deg.C, holding the temperature for 70min, and furnace cooling to obtain Fe-Si-B-C (Fe) 82 Si 4 B 13 C) Amorphous alloy powder and silicon oxide are compounded and coated with the gas atomization iron-silicon soft magnetic composite material.
The relative magnetic permeability of the gas atomized iron-silicon soft magnetic composite material at 100kHz/1V is 61.2, and the volume resistivity is 7.632 multiplied by 10 10 Mu.omega cm, a loss of 50kHz/100mT of 582mW/cm 3 The dc bias performance at 100Oe field strength was 77.3%.
Example 3
The preparation operation steps of the soft magnetic composite material compositely coated by the amorphous alloy powder and the silicon oxide are as follows:
(1) Preparation of amorphous alloy powder
Selecting iron-silicon-boron-phosphorus-carbon (Fe) prepared by single-roller rapid quenching method 83 Si 2 B 11 P 3 C) And placing the amorphous alloy thin strip into a planetary ball mill for ball milling twice, wherein the ball milling twice is coarse grinding and fine grinding. The diameter of a grinding ball used for coarse grinding is 20cm, the ball grinding rotating speed is 300r/min, the ball grinding time is 18h, and the ball-to-material ratio is 20; the diameter of a grinding ball used for fine grinding is 10cm, the ball-milling rotating speed is 500r/min, the ball-milling time is 32h, the ball-material ratio is 30 83 Si 2 B 11 P 3 C) Amorphous alloy powder;
(2) Cleaning of
Iron silicon boron phosphorus carbon (Fe) 83 Si 2 B 11 P 3 C) Cleaning the amorphous alloy powder with acetone for 3 times to remove Fe-Si-B-P-C (Fe) 83 Si 2 B 11 P 3 C) Impurities on the surface of the amorphous alloy powder to obtain clean amorphous alloy powder;
(3) Insulating coating
Weighing 1000g of iron-nickel magnetic powder with the particle size of 40-180 mu m, placing the iron-nickel magnetic powder in 300g of acetone solution, uniformly mixing 60g of clean amorphous alloy powder and 20g of nano silicon oxide powder, pouring the mixture into the acetone solution, fully stirring, and drying at 80 ℃ to obtain the insulating powder.
(4) Preparation of the Green bodies
1080g of insulating powder and 5.40g of release agent are uniformly mixed, and the mixture is pressed into a magnetic ring green body with the standard outer diameter of 1.06 inches in a die by using the pressing pressure of 1200MPa.
(5) Thermal treatment
Firstly, keeping the temperature of the magnetic ring green body at 200 ℃ for 60min under the protection atmosphere of argon; heating to 420 deg.C, holding the temperature for 80min, and furnace cooling to obtain Fe-Si-B-P-C (Fe) 83 Si 2 B 11 P 3 C) Amorphous alloy powder and silicon oxide composite coated iron-nickel soft magnetic composite material.
The relative magnetic permeability of the iron-nickel soft magnetic composite material at 100kHz/1V is 60.7, and the volume resistivity is 6.942 multiplied by 10 10 Mu omega cm, the loss of 50kHz/100mT is 230mW/cm 3 The dc bias performance at 100Oe field strength was 90.2%.
It will be understood by those skilled in the art that the foregoing is merely a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included within the scope of the present invention.
Claims (5)
1. A method for preparing soft magnetic composite material compositely coated by amorphous and silicon oxide is characterized by comprising the following operation steps:
(1) Preparation of amorphous alloy powder
Placing an amorphous alloy thin strip prepared by a single-roller rapid quenching method in a planetary ball mill for ball milling twice respectively, wherein the ball milling twice is coarse grinding and fine grinding, and the ball milling medium is ethanol; preparing amorphous alloy powder with the median grain diameter of 4-6 mu m;
the amorphous alloy powder is one of iron silicon boron, iron silicon boron carbon and iron silicon boron phosphorus carbon;
(2) Cleaning of
Cleaning the amorphous alloy powder with acetone for 1-3 times, and removing impurities on the surface of the amorphous alloy powder to obtain clean amorphous alloy powder;
(3) Insulating coating
Putting iron-based alloy magnetic powder with the particle size of 40-180 mu m into an acetone solution, uniformly mixing clean amorphous alloy powder and nano silicon oxide powder, pouring the mixture into the acetone solution, fully stirring, and drying at 80 ℃ to obtain insulating powder;
the mass of the nano silicon oxide powder is 2% of that of the iron-based alloy magnetic powder, and the mass of the clean amorphous alloy powder is 2-6% of that of the iron-based alloy magnetic powder;
the mass ratio of the iron-based alloy magnetic powder to the acetone solution is 10;
(4) Preparation of the Green bodies
Uniformly mixing the insulating powder and a release agent, wherein the use amount of the release agent is 3-6 per mill of the mass of the insulating powder, uniformly mixing, and performing press forming in a mold to obtain a green body;
(5) Heat treatment of
Performing stress annealing on the green body under the protection of argon atmosphere, and cooling to obtain the soft magnetic composite material compositely coated by the amorphous alloy powder and the silicon oxide;
the relative magnetic permeability of the soft magnetic composite material under the condition of 100kHz/1V is 60.7-63.2, and the volume resistivity is 6.942-8.565 multiplied by 10 10 Mu omega cm, the loss under the condition of 50kHz/100mT is 188-582 mW/cm 3 The DC bias at 100Oe magnetic field strength is 61.4-90.2%.
2. The method for preparing a soft magnetic composite material compositely coated with amorphous silicon and silicon oxide according to claim 1, wherein: in the step (1), the rough grinding conditions are as follows: the grinding ball is zirconia ball with the diameter of 10-20 cm, the rotating speed is 150-300 r/min, the ball milling time is 9-18 h, and the ball-material ratio is 20:1; the fine grinding conditions are as follows: the grinding ball is zirconia ball with the diameter of 5-10 cm, the rotating speed is 300-500 r/min, the ball milling time is 9-32 h, the ball-to-material ratio is 30:1.
3. the method for preparing a soft magnetic composite material compositely coated with amorphous silicon and silicon oxide according to claim 1, wherein: in the step (3), the iron-based alloy magnetic powder is one of gas-atomized iron-silicon magnetic powder, gas-atomized iron-silicon-aluminum magnetic powder and iron-nickel magnetic powder.
4. The method for preparing a soft magnetic composite material compositely coated with amorphous silicon and silicon oxide according to claim 1, wherein: in the step (4), the pressure intensity of the compression molding is 1000-1200 MPa.
5. The method for preparing a soft magnetic composite material compositely coated with amorphous silicon and silicon oxide according to claim 1, wherein: in the step (5), annealing conditions are as follows: keeping the temperature for 40-60 min at 100-200 ℃; keeping the temperature for 60-80 min at 350-420 ℃.
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| CN117079967A (en) * | 2023-10-16 | 2023-11-17 | 通友微电(四川)有限公司 | Composite ceramic soft magnetic powder and preparation method thereof |
| CN117079967B (en) * | 2023-10-16 | 2023-12-22 | 通友微电(四川)有限公司 | Composite ceramic soft magnetic powder and preparation method thereof |
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