CN108305737B - A kind of compound soft magnetic material and preparation method thereof - Google Patents

Abstract

The invention relates to a composite soft magnetic material and a preparation method thereof. The material is coated with a CoFe ₂ O ₄ coated magnetic powder layer and a silicone resin layer on the outside of Fe ₈₅ Si ₈ Al ₄ Ni ₃ from inside to outside in sequence. The invention has the advantages of high magnetic permeability and low core loss. The present invention can be formed according to the actual required shape during use, and has obvious advantages in the preparation of heterogeneous materials, simple operation, no need for cutting, no leftover material, and cost saving. The synthesis method of the invention is simple, low in cost and mild in reaction conditions. The results of laser particle size test show that the D50 of Fe ₈₅ Si ₈ Al ₄ Ni ₃ powder obtained by gas atomization is about 36 microns.

Description

A kind of composite soft magnetic material and preparation method thereof

technical field

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

Background technique

Soft magnetic materials are magnetic materials that are easy to magnetize and demagnetize, and have low coercive force. Soft magnetic materials are required to have: high magnetic permeability, high saturation magnetic flux density, high resistivity, high stability, low coercive force, low loss, low magnetostriction coefficient and low magnetocrystalline anisotropy. Soft magnetic materials are widely used in various power equipment and electronic devices. The miniaturization, light weight, energy saving and high sensitivity of power and electronic equipment make people's lives more convenient and have less and less impact on the environment. In the field of AC application of soft magnetic materials, silicon steel sheets have occupied a large market for a long time. These materials have excellent magnetic properties at DC, but at high frequency AC, the core loss accompanied by eddy current will increase rapidly with the increase of frequency, which limits their use at high frequency. Soft ferrite is widely used in the high frequency field, but it has the disadvantage of low magnetic flux density.

Contents of the invention

In order to solve the above technical problems, the present invention provides a composite soft magnetic material and a preparation method thereof. The composite soft magnetic material of the present invention is coated with CoFe ₂ O ₄ inorganic coating layer and silicone resin layer on the outside of Fe ₈₅ Si ₈ Al ₄ Ni ₃ from the inside to the outside, and it uses in-situ oxidation to generate magnetic inorganic oxides The coating layer insulates the magnetic powder particles to increase the resistivity, thereby reducing the core loss; and then organically coats with silicone resin to increase the strength of the molded material, and at the same time plays an insulating role to further reduce the core loss, so , the composite soft magnetic material prepared by the invention has the advantages of high magnetic permeability and low core loss.

Option One)

A preparation method of composite soft magnetic material: 1) Fe powder, Si powder, Al powder and Ni powder are mixed evenly according to the atomic ratio of 85:8:4:3, and then put into a vacuum atomization furnace, and the setting temperature is 1800 -2200°C, heating for 2-3 hours, and then under the protection of Ar gas, use the gas atomization powder making method to make powder, and prepare Fe ₈₅ Si ₈ Al ₄ Ni ₃ powder with high magnetic permeability;

2) Prepare an ammonia solution with a mass fraction of 2-3%, then add 0.01mol CoCl ₂ ·6H ₂ O for every 250-300ml of the ammonia solution, and then add 0.01mol CoCl ₂ ·6H ₂ O to the aforementioned solution 100g Fe ₈₅ Si ₈ Al ₄ Ni ₃ powder, stir evenly, add the above materials into the hydrothermal reaction kettle, keep warm at 170-190°C for 1-2 hours, cool to room temperature naturally, filter with suction and wash with alcohol for more than 2 times, then put Dry in an oven at 50-70°C to obtain CoFe ₂ O ₄ coated magnetic powder;

3) At room temperature, sequentially add silicone resin, xylene and alcohol into the reactor, after stirring and dissolving, add the inorganic oxide CoFe ₂ O ₄ coated magnetic powder described in step 2), and finally mix the above The material is kept at a constant temperature of 60-70°C until the solvent is completely evaporated to obtain the composite soft magnetic material;

Wherein, 2-3mL of xylene and 15-17mL of alcohol are added for every 2-3g of silicone resin, and 100-120g of CoFe ₂ O ₄ coated magnetic powder is added for every 2-3g of silicone resin.

Option II)

A composite soft magnetic material is a composite soft magnetic material prepared from the composite soft magnetic material.

The principle of the present invention: the present invention utilizes in-situ oxidation to generate a magnetic inorganic oxide CoFe ₂ O ₄ coating layer to insulate and coat magnetic powder particles to increase resistivity, thereby reducing core loss. Organic coating with silicone resin increases the strength of the molded material and also reduces core loss. Therefore, the preparation of inorganic-organic double-clad FeSiAlNi-based composite soft magnetic materials with low core loss has important practical value.

Compared with the prior art, the present invention has the following beneficial effects:

1. The FeSiAlNi-based composite soft magnetic material of the present invention has the advantages of high magnetic permeability and low core loss.

2. The product of the present invention has lower core loss especially at high frequencies.

3. The FeSiAlNi-based composite soft magnetic material of the present invention can be shaped according to the actual required shape during use, and has obvious advantages in the preparation of heterogeneous materials, simple operation, no need for cutting, no scraps, and cost saving.

4. The synthesis method of the present invention is simple, with low cost and mild reaction conditions.

Detailed ways

Description of drawings

Fig. 1. Laser particle size measurement diagram of Fe ₈₅ Si ₈ Al ₄ Ni ₃ powder.

Fig. 2. Scanning electron micrograph of Fe ₈₅ Si ₈ Al ₄ Ni ₃ powder.

Fig. 3, the scanning electron microscope picture of the product of the present invention.

Fig. 4. X-ray photoelectron spectroscopy analysis diagram of Fe ₈₅ Si ₈ Al ₄ Ni ₃ powder surface after inorganic oxidation treatment. (a, b, c are Co2p binding energy map, Fe2p binding energy map, O1s binding energy map respectively)

Fig. 5, the hysteresis loop of the product of the present invention and 130i-1P.

Figure 6, the core loss of the product of the present invention and 130i-1P at different frequencies.

The raw materials of each component of the following examples are purchased from distributors. The atomization equipment used in the experiment is a close-coupled vacuum atomization furnace manufactured by British PSI company, and the atomization gas is high-pressure pure argon. Atomization powder production The atomization method belongs to the mechanical powder production method, which is a method of directly crushing liquid metal or alloy to obtain powder, and is widely used. For the gas atomization powder making process, the greater the energy transmitted to the metal flow, the finer the powder prepared. The process of gas atomization powder making is actually a process of gradual change in the shape of small droplets, and the shape order of small droplets depends on the nozzle. The distance is different, followed by cylindrical, conical, sheet-shaped, lace-shaped, spherical.

Example 1

A preparation method of composite soft magnetic material:

A method for preparing a composite soft magnetic material: 1) Mix Fe powder, Si powder, Al powder and Ni powder according to the atomic ratio of 85:8:4:3 and add them into a vacuum atomization furnace, set the temperature at 1800°C, Insulate for 2 hours, and then use the gas atomization pulverization process to carry out spray pulverization under the protection of Ar gas, and prepare Fe ₈₅ Si ₈ Al ₄ Ni ₃ powder with high magnetic permeability;

2) Prepare an ammonia solution with a mass fraction of 2%, then add 0.01mol CoCl ₂ ·6H ₂ O for every 250ml of the ammonia solution, and then add 100g Fe ₈₅ Si ₈ Al ₄ Ni ₃ for every 0.01mol CoCl ₂ ·6H ₂ O Powder, stir evenly, add the above materials into a hydrothermal reaction kettle, keep warm at 170°C for 1 hour, then cool naturally to room temperature, filter with suction and wash with alcohol for 3 times, then dry in an oven at 50°C to obtain ₄ packets of inorganic oxide CoFe ₂ O Coated magnetic powder;

3) At room temperature, add silicone resin, xylene and alcohol to the reactor in turn, after stirring and dissolving, add the magnetic powder coated with inorganic oxide CoFe ₂ O ₄ , and finally, keep the above mixed material at a constant temperature of 70°C Until the solvent is completely evaporated, that is;

Wherein, 2 mL of xylene and 15 mL of alcohol are added per 2 g of silicone resin, and 100 g of inorganic oxide CoFe ₂ O ₄ coated magnetic powder is added per 2 g of silicone resin.

Example 2

A method for preparing a composite soft magnetic material: 1) Mix Fe powder, Si powder, Al powder and Ni powder according to the atomic ratio of 85:8:4:3 and add them into a vacuum atomization furnace, set the temperature at 2200°C, Insulate for 3 hours, and then use the gas atomization pulverization process to carry out spray pulverization under the protection of Ar gas, and prepare Fe ₈₅ Si ₈ Al ₄ Ni ₃ powder with high magnetic permeability;

2) Prepare an ammonia solution with a mass fraction of 3%, then add 0.01mol CoCl ₂ ·6H ₂ O for every 300ml of the ammonia solution, and then add 100g Fe ₈₅ Si ₈ Al ₄ Ni ₃ for every 0.01mol CoCl ₂ ·6H ₂ O Powder, stir evenly, add the above materials into a hydrothermal reaction kettle, keep warm at 190°C for 2 hours, cool to room temperature naturally, filter with suction and wash with alcohol for 3 times, then dry in an oven at 70°C to obtain ₄ packets of inorganic oxide CoFe ₂ O Coated magnetic powder;

3) At room temperature, add silicone resin, xylene and alcohol to the reactor in turn, after stirring and dissolving, add the magnetic powder coated with inorganic oxide CoFe ₂ O ₄ , and finally, keep the above mixed material at a constant temperature of 60°C Until the solvent is completely evaporated, that is;

Wherein, 3 mL of xylene and 17 mL of alcohol are added for every 2-3 g of silicone resin, and 120 g of inorganic oxide CoFe ₂ O ₄ coated magnetic powder is added for every 3 g of silicone resin.

Example 3

A preparation method of a composite soft magnetic material: 1) Mix Fe powder, Si powder, Al powder and Ni powder according to the atomic ratio of 85:8:4:3 and add them into a vacuum atomization furnace, and set the temperature at 1800-2200 ℃, heat preservation for 2.5 hours, and then under the protection of Ar gas, use the gas atomization pulverization process to carry out spray pulverization, and prepare Fe ₈₅ Si ₈ Al ₄ Ni ₃ powder with high magnetic permeability;

2) Prepare an ammonia solution with a mass fraction of 2.5%, then add 0.01mol CoCl ₂ ·6H ₂ O for every 280ml of the ammonia solution, and then add 100g Fe ₈₅ Si ₈ Al ₄ Ni for every 0.01mol CoCl ₂ ·6H ₂ O ₃ powder, stir evenly, put the above materials into a hydrothermal reaction kettle, keep warm at 180°C for 1-2 hours, cool to room temperature naturally, filter with suction and wash with alcohol for 3 times, then dry in an oven at 60°C to obtain inorganic oxidized CoFe ₂ O ₄ coated magnetic powder;

3) At room temperature, add silicone resin, xylene and alcohol to the reactor in turn, after stirring and dissolving, add the magnetic powder coated with inorganic oxide CoFe ₂ O ₄ , and finally, keep the above mixed material at a constant temperature of 65°C Until the solvent is completely evaporated, that is;

Among them, 2.5 mL of xylene and 16 mL of alcohol were added per 2.5 g of silicone resin, and 110 g of inorganic oxide CoFe ₂ O ₄ coated magnetic powder was added per 2.5 g of silicone resin.

The prepared low core loss FeSiAlNi-based composite soft magnetic material was measured by laser particle size. The results are shown in Figure 1. The D50 of the Fe ₈₅ Si ₈ Al ₄ Ni ₃ powder obtained by gas atomization is about 36 microns.

The Fe ₈₅ Si ₈ Al ₄ Ni ₃ powder prepared in step 1) and the finally prepared low core loss FeSiAlNi-based composite soft magnetic material were subjected to scanning electron microscopy. The results are shown in Figures 2 and 3: Fe ₈₅ obtained by gas atomization The Si ₈ Al ₄ Ni ₃ powder is basically a spherical particle with a smooth surface and uniform particle size, but the surface of the coated powder is rough and the surface organic coating layer is clearly visible, and the spherical particle shape is still maintained.

As shown in Figure 4, X-ray photoelectron spectroscopy analysis can be obtained: the chemical valence states of the coating layer on the particle surface after oxidation are respectively +2 for Co, +3 for Fe, and -2 for O. It shows that the surface of Fe ₈₅ Si ₈ Al ₄ Ni ₃ particles is oxidized and a magnetic CoFe ₂ O ₄ inorganic coating layer is formed.

The test results of the vibrating sample magnetometer are shown in Figure 5: compared with the sample No. 130i-1P purchased by Hegnas, the coercive force of the present invention is small, sensitive and fast to the external magnetic field response, and is conducive to the miniaturization of the product change.

The product of the present invention and the two powders of 130i-1P were compression-molded by the compression molding method, the compression pressure was 1200MPa, the outer diameter of the sample was 45.18mm, the inner diameter was 34.08mm, and the heights were 4.68mm and 4.30mm respectively. In order to reduce the internal stress caused by molding, the ring-shaped sample after compression molding was annealed at 550°C under an argon protective atmosphere for 2 hours, and then the dynamic magnetic properties of the ring-shaped sample were tested by winding method. The test magnetic field strength was 50mT. The results are shown in Figure 6. The results show that: before 50KHz, the core loss of the two materials is not much different. As the frequency increases, the core loss of 130i-1P increases significantly, while the core loss of the FeSiAlNi-based composite soft magnetic material is the same as Compared with 130i-1P, the change is gentle and the core loss is lower at high frequency. At 100KHz, the core loss of 130i-1P is 250.61W/Kg, while the core loss of FeSiAlNi-based composite soft magnetic material is only 153.74W/Kg. Compared with it, the core loss is only 61% of 130i-1P. Therefore, the present invention has successfully prepared a FeSiAlNi-based composite soft magnetic material with low core loss at high frequency, which makes it more advantageous for application in the high frequency range.

Claims (2)

1. a kind of preparation method of compound soft magnetic material, it is characterised in that: 1) by Fe powder, Si powder, Al powder and Ni powder according to atom Than being uniformly mixed for 85:8:4:3, then in addition vacuum atomizing furnace, setting temperature is 1800-2200 DEG C, is heated 2-3 hours, Then it carries out making powder using gas-atomized powder method under Ar gas shielded, is prepared into the Fe with high magnetic permeability₈₅Si₈Al₄Ni₃Powder End；

2) ammonia spirit that mass fraction is 2-3% is prepared, is then added according to ammonia spirit described in every 250-300ml 0.01mol CoCl₂·6H₂O, later according to every 0.01molCoCl₂·6H₂100g Fe is added in O₈₅Si₈Al₄Ni₃Powder, stirring It is added in hydrothermal reaction kettle after uniformly, in 170-190 DEG C of cooled to room temperature after heat preservation 1-2 hours, suction filtration is simultaneously washed with alcohol It is put into 50-70 DEG C of drying of baking oven after washing 2 times or more, obtains CoFe₂O₄Magnaglo after cladding；

3) it at room temperature, sequentially adds silicone resin, dimethylbenzene and alcohol in the reactor, after the completion of stirring and dissolving, step is added 2) CoFe described in₂O₄Magnaglo after cladding, finally in 60-70 DEG C of constant temperature until solvent whole evaporation is answered to get described Close soft magnetic materials；

Wherein, dimethylbenzene 2-3mL and alcohol 15-17mL is added according to every 2-3g silicone resin, is added according to every 2-3g silicone resin 100-120g CoFe₂O₄Magnaglo after cladding.

2. a kind of compound soft magnetic material, it is characterised in that: by a kind of preparation method of compound soft magnetic material described in claim 1 The compound soft magnetic material of preparation.