阅读说明：本技术 一种软磁镍锌铁氧体材料及其制备方法和应用 (Soft magnetic nickel-zinc ferrite material and preparation method and application thereof ) 是由 陈军林 张利康 于 2020-12-11 设计创作，主要内容包括：本发明提供了一种软磁镍锌铁氧体材料及其制备方法和应用,所述的软磁镍锌铁氧体材料通过在副成分中加入纳米CaO、纳米MgO来改善材料在不同温度下的抗应力特性；在副成分中加入纳米Bi-2O-3降低烧结温度促进致密化来改善材料的饱和磁通密度特性；纳米Co-2O-3改善材料的频率特性与磁导率特性；在副成分中加入纳米TiO-2来改善材料的磁导率温度因数；通过副成分的组合添加增加晶界的厚度,降低高频段相对损耗因子和磁导率的温度因数；再通过生产工艺进一步调整材料晶体结构和晶界分布,从而得到较低的磁导率温度因数和良好的抗应力性能。该材料具有在应力作用下磁导率变化较小的特点,适应需要树脂封装的功率电感对铁氧体材料的抗应力的要求。(The invention provides a soft magnetic nickel zinc ferrite material and a preparation method and application thereof, wherein the soft magnetic nickel zinc ferrite material improves the stress resistance of the material at different temperatures by adding nano CaO and nano MgO into the subcomponents; adding nano Bi into the accessory components 2 O 3 Reducing the sintering temperature to promote densification to improve the saturation magnetic flux density characteristics of the material; nano Co 2 O 3 The frequency characteristic and the magnetic permeability characteristic of the material are improved; adding nanometer TiO into the accessory component 2 To improve the permeability temperature factor of the material; the thickness of a grain boundary is increased by the combined addition of the accessory components, and the temperature factors of the relative loss factor and the magnetic permeability of a high-frequency band are reduced; regeneration by regenerationThe production process further adjusts the crystal structure and the grain boundary distribution of the material, thereby obtaining a lower magnetic permeability temperature factor and good stress resistance. The material has the characteristic of small change of magnetic conductivity under the action of stress, and meets the requirement of power inductance needing resin encapsulation on stress resistance of ferrite materials.)

1. The soft magnetic nickel zinc ferrite material is characterized by comprising a main component and an auxiliary component;

the main components comprise iron oxide, nickel oxide, zinc oxide and copper oxide;

the auxiliary components comprise nano calcium oxide, nano bismuth oxide, nano cobalt oxide, nano titanium oxide and nano magnesium oxide.

2. The soft magnetic nickel zinc ferrite material according to claim 1, wherein the molar content fraction of the iron oxide is 38.8 to 40.2 mol% based on 100% of the total molar content of the main component;

preferably, the mole content fraction of the nickel oxide is 5.0-40.0 mol%;

preferably, the mole content fraction of the zinc oxide is 8.8-11.2 mol%;

preferably, the mole content fraction of the copper oxide is 9.0-12 mol%.

3. The soft magnetic nickel zinc ferrite material according to claim 1 or 2, wherein the mass fraction of the nano calcium oxide is 1.0 to 5.0 wt%, preferably 1.25 wt%, based on 100% of the total mass of the main component;

preferably, the mass fraction of the nano bismuth oxide is 0.5-0.8 wt%, preferably 0.55 wt%;

preferably, the nano Co₂O₃The mass fraction of (A) is 0.1-0.2 wt%, preferably 0.15 wt%;

preferably, the mass fraction of the nano titanium oxide is 0.35-0.65 wt%, preferably 0.4 wt%;

preferably, the mass fraction of the nano magnesium oxide is 1.0-1.60 wt%, preferably 1.34 wt%.

4. A method for preparing a soft magnetic nickel zinc ferrite material as claimed in any of claims 1 to 3, characterized in that said method comprises the steps of:

(1) mixing the main component ingredients, pelletizing, presintering and coarsely crushing to obtain powder I;

(2) and (2) adding auxiliary components into the powder I in the step (1), dispersing and emulsifying, finely crushing, granulating, pressing, sintering, and cooling to room temperature to obtain the soft magnetic nickel-zinc ferrite material.

5. The method according to claim 4, wherein the apparatus for the mixed pelletization in the step (1) comprises a ZQ-1 pelletizer;

preferably, the time for mixing and pelletizing is 80-100 min;

preferably, the pre-burning equipment comprises a rotary kiln;

preferably, the rotary kiln is of an integrated structure;

preferably, the temperature of the pre-sintering is 1090-1110 ℃;

preferably, the pre-sintering time is 300-480 min.

Preferably, the pre-sintering amount is 130-170 kg/Hr;

preferably, said coarse comminution apparatus comprises a bucket shaker;

preferably, the coarse crushing time is 80-100 min.

6. The preparation method according to claim 4 or 5, wherein the equipment for dispersion and emulsification in the step (2) comprises a GP-290 three-stage emulsifying machine and/or a GF-240 dispersing agent stirring machine;

preferably, the time for dispersing and emulsifying is 50-60 min;

preferably, the fine crushing equipment comprises a horizontal sand mill;

preferably, the time for fine crushing is 120-180 min;

preferably, the average particle size of the slurry obtained after the fine grinding is 0.2 to 1.0 μm.

7. The method according to any one of claims 4 to 6, wherein the granulation in step (2) is centrifugal spray drying granulation;

preferably, a PVA solution is added in the granulation process;

preferably, the concentration of the PVA solution is 5-10%;

preferably, the mass of the PVA solution is 10-18% of that of the slurry.

8. The method according to any one of claims 4 to 7, wherein the pressing apparatus of step (2) comprises a powder molding machine;

preferably, the pressed blank obtained by pressing has a pressing density of 3.2-3.4 g/cm³；

Preferably, the sintering equipment comprises a resistance furnace;

preferably, the sintering temperature is 1160-1200 ℃;

preferably, the sintering time is 300-480 min;

preferably, the sintering atmosphere is an oxygen-nitrogen equilibrium atmosphere.

9. The method of any one of claims 4 to 8, comprising the steps of:

(1') putting the main component ingredients into a mixing pelletizing device for mixing and pelletizing, wherein the pelletizing time is 60-120 min;

(2 ') pre-burning the mixed and pelletized material obtained in the step (1') in a rotary kiln with an integrated structure at 1090-1110 ℃, wherein the pre-burning amount is 130-170 kg/Hr;

(3 ') coarsely grinding the pre-sintered material in the step (2') by adopting a bucket vibration grinder, wherein the coarsely grinding time is 80-100 min;

(4 ') adding auxiliary ingredient into the material obtained after coarse crushing in the step (3'), and dispersing and emulsifying by adopting dispersing and emulsifying equipment for 50-60 min;

(5 ') carrying out wet fine grinding on the slurry obtained by dispersing and emulsifying in the step (4') by using a horizontal sand mill for 120-180 min, wherein the average particle size of the ground slurry is 0.2-1.0 mu m;

(6 ') adding the slurry finely ground by the wet method in the step (5') into a PVA solution which accounts for 10-18% of the weight of the slurry, and performing centrifugal spray drying granulation;

(7 ') pressing the granulated material in the step (6') by using a powder forming machine to obtain a blank, wherein the pressing density of the blank is 3.2-3.4 g/cm³；

(8 ') sintering the blank in the step (7') in a resistance furnace, wherein the sintering temperature is 1160-1200 ℃, the sintering time is 300-480 minutes, the sintering atmosphere is an oxygen-nitrogen balanced atmosphere, and the soft magnetic nickel-zinc ferrite material is obtained after the sintering is finished and is cooled to the room temperature along with the furnace.

10. A nickel zinc ferrite, characterized in that it comprises a soft magnetic nickel zinc ferrite material according to any of claims 1-3.

Technical Field

The invention belongs to the technical field of magnetic materials, and relates to a soft magnetic nickel-zinc ferrite material, and a preparation method and application thereof.

Background

With the technological improvement and development of high-tech products such as portable computers, digital products, liquid crystal televisions, micro communication and the like, the nickel-zinc ferrite material is widely applied to the fields of communication, networks, power supplies, consumer electronic products and the like by virtue of the characteristics of high resistivity, good high-frequency characteristic, low loss tangent value and the like, and is an important basic functional material in the electronic information industry.

CN105985103A discloses a nickel-zinc soft magnetic ferrite material, a NiZn ferrite, a preparation method thereof and an inductor, wherein Fe in a main material is adjusted₂O₃The molar content proportion of ZnO, NiO and CuO and the types and the amount of the added and controlled auxiliary materials are used for realizing the regulation and control of the performance of the nickel-zinc soft magnetic ferrite material, so that the nickel-zinc soft magnetic ferrite material has excellent strength and thermal shock resistance, but the magnetic conductivity temperature factor is large, the magnetic conductivity change is large under the action of stress, and the requirements of large temperature change or resin encapsulation power inductance on the temperature stability and stress resistance of the ferrite material cannot be met.

CN106587977A discloses a power type nickel-zinc ferrite material, which contains iron oxide, nickel oxide, zinc oxide, and copper oxide as main components, and tungsten oxide, cobalt oxide, bismuth oxide, silicon oxide, manganese oxide, and titanium oxide as auxiliary components within a predetermined range, and under appropriate process conditions, can ensure that high magnetic permeability, ultrahigh saturation magnetic induction, and ultralow power loss can be obtained, and can also increase the high-temperature-resistant solder temperature, thereby increasing the application range of the nickel-zinc ferrite material.

The above schemes all have the disadvantages of large temperature factor of magnetic permeability, large change of magnetic permeability under stress action and the like, but the globalization of the market requires that various electronic components can normally work all over the world, and the temperature difference all over the world is very large, so that the raw materials for forming various devices have good temperature characteristics in a wide temperature range, and the heating phenomenon caused by eddy current loss and the like during the operation of the ferrite can cause the change of magnetic performance.

Disclosure of Invention

The invention aims to provide a soft magnetic nickel-zinc ferrite material and a preparation method and application thereof, and the soft magnetic nickel-zinc ferrite material mainly meets the requirements of temperature stability and stress resistance of the ferrite material for large temperature change or resin packaging power inductance by adding compounds comprising nano calcium oxide, nano bismuth oxide, nano cobaltous oxide, nano titanium oxide, nano magnesium oxide and the like.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the invention provides a soft magnetic nickel zinc ferrite material, which comprises a main component and an auxiliary component, wherein the main component comprises iron oxide, nickel oxide, zinc oxide and copper oxide, and the auxiliary component comprises nano calcium oxide, nano bismuth oxide, nano cobalt oxide, nano titanium oxide and nano magnesium oxide.

The invention adopts a reasonable main formula and adopts the Fe₂O₃Adjusting the content of NiO to optimize the saturation magnetic flux density, the initial permeability, the permeability temperature factor and the Curie temperature of the material; adjusting the use frequency of the material by adjusting the content of ZnO; the sintering temperature of the material is adjusted by adjusting the CuO content. Nano CaO and nano MgO are added into the accessory components to improve the stress resistance of the material at different temperatures; adding nano Bi into the accessory components₂O₃Reducing the sintering temperature to promote densification to improve the saturation magnetic flux density characteristics of the material; nano Co₂O₃The frequency characteristic and the magnetic permeability characteristic of the material are improved; adding nanometer TiO into the accessory component₂To improve the permeability temperature factor of the material; the thickness of a grain boundary is increased by the combined addition of the accessory components, and the temperature factors of the relative loss factor and the magnetic permeability of a high-frequency band are reduced; further adjusting the crystal structure and the grain boundary distribution of the material by the production process, therebyThe low magnetic permeability temperature factor and the good stress resistance are obtained. The material has the characteristic of small change of magnetic conductivity under the action of stress, and meets the requirement of power inductance needing resin encapsulation on stress resistance of ferrite materials.

Preferably, the mole content fraction of the iron oxide is 38.8-40.2 mol% based on the total mole content of the main component as 100%, for example: 38.8 mol%, 38.9 mol%, 39 mol%, 39.1 mol%, 39.2 mol%, 39.3 mol%, 39.4 mol%, 39.5 mol%, 39.6 mol%, 39.7 mol%, 39.8 mol%, 39.9 mol%, 40 mol%, 40.1 mol%, or 40.2 mol%.

Preferably, the mole content fraction of the nickel oxide is 5.0-40.0 mol%, for example: 5 mol%, 6 mol%, 7 mol%, 8 mol%, 9 mol%, 10 mol%, 12 mol%, 15 mol%, 20 mol%, 25 mol%, 30 mol%, 35 mol%, 40 mol%, or the like.

Preferably, the mole content fraction of the zinc oxide is 8.8-11.2 mol%, for example: 8.8 mol%, 8.9 mol%, 9 mol%, 9.1 mol%, 9.3 mol%, 9.5 mol%, 9.8 mol%, 10 mol%, 10.3 mol%, 10.6 mol%, 10.8 mol%, 11 mol%, 11.2 mol%, and the like.

Preferably, the mole content fraction of the copper oxide is 9.0-12 mol%, for example: 9 mol%, 9.2 mol%, 9.4 mol%, 9.6 mol%, 9.8 mol%, 10 mol%, 10.3 mol%, 10.6 mol%, 10.8 mol%, 11 mol%, 11.4 mol%, 11.6 mol%, 11.8 mol%, or 12 mol%.

By the invention to Fe₂O₃Adjusting the content of NiO to optimize the saturation magnetic flux density, the initial permeability, the permeability temperature factor and the Curie temperature of the material; adjusting the use frequency of the material by adjusting the content of ZnO; the sintering temperature of the material is adjusted by adjusting the CuO content.

Preferably, the mass fraction of the nano calcium oxide is 1.0-5.0 wt% based on 100% of the total mass of the main components, such as: 1.0 wt%, 1.1 wt%, 1.25 wt%, 1.3 wt%, 1.55 wt%, 1.6 wt%, 2.0 wt%, 2.5 wt%, 2.85 wt%, 3.0 wt%, 3.45 wt%, 4.0 wt%, 4.75 wt%, or 5.0 wt%, etc., preferably 1.25 wt%.

Preferably, the mass fraction of the nano bismuth oxide is 0.5-0.8 wt%, for example: 0.5 wt%, 0.55 wt%, 0.6 wt%, 0.65 wt%, 0.7 wt%, 0.75 wt%, 0.8 wt%, etc., preferably 0.55 wt%.

Preferably, the nano Co₂O₃Is 0.1 to 0.2 wt%, for example: 0.1 wt%, 0.11 wt%, 0.12 wt%, 0.13 wt%, 0.14 wt%, 0.15 wt%, 0.16 wt%, 0.17 wt%, 0.18 wt%, 0.19 wt%, or 0.2 wt%, etc., preferably 0.15 wt%.

Preferably, the mass fraction of the nano titanium oxide is 0.35-0.65 wt%, for example: 0.35 wt%, 0.4 wt%, 0.45 wt%, 0.5 wt%, 0.55 wt%, 0.6 wt%, 0.65 wt%, etc., preferably 0.4 wt%.

Preferably, the mass fraction of the nano magnesium oxide is 1.0-1.6 wt%, for example: 1.0 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, 1.5 wt%, 1.6 wt%, etc., preferably 1.34 wt%.

The invention adds nano Bi into the accessory component₂O₃Reducing the sintering temperature to promote densification to improve the saturation magnetic flux density characteristics of the material; nano Co₂O₃The frequency characteristic and the magnetic permeability characteristic of the material are improved; adding nanometer TiO into the accessory component₂To improve the permeability temperature factor of the material.

In a second aspect, the present invention provides a method for preparing the soft magnetic nickel zinc ferrite material according to the first aspect, wherein the method comprises the following steps:

(1) mixing the main component ingredients, pelletizing, presintering and coarsely crushing to obtain powder I;

(2) and (2) adding auxiliary components into the powder I in the step (1), dispersing and emulsifying, finely crushing, granulating, pressing, sintering, and cooling to room temperature to obtain the soft magnetic nickel-zinc ferrite material.

The average size of crystal grains of the sintered product prepared by the method is 5-20 mu m, the crystal grains are uniform and have obvious crystal boundaries, the thickness of the crystal boundaries is increased by adding the auxiliary components in a combined manner, and the temperature factors of high-frequency-band relative loss factors and magnetic permeability are reduced; and the crystal structure and the grain boundary distribution of the material are further adjusted through a production process, so that a low magnetic permeability temperature factor and good stress resistance are obtained. The material has the characteristic of small change of magnetic conductivity under the action of stress, and meets the requirement of power inductance needing resin encapsulation on stress resistance of ferrite materials.

Preferably, the equipment for mixing and pelletizing in the step (1) comprises a ZQ-1 pelletizer.

Preferably, the time for mixing and pelletizing is 80-100 min, for example: 80min, 85min, 90min, 95min or 100min and the like.

Preferably, the pre-firing apparatus comprises a rotary kiln.

Preferably, the rotary kiln is of an integrated structure.

Preferably, the temperature of the pre-sintering is 1090-1110 ℃, for example: 1090. 1095, 1100, 1105, 1110, etc.

Preferably, the pre-burning time is 300-480 min, for example: 300min, 320min, 350min, 380min, 400min, 450min or 480min and the like.

Preferably, the pre-burning amount of the pre-burning is 130 to 170kg/Hr, for example: 130kg/Hr, 135kg/Hr, 140kg/Hr, 145kg/Hr, 150kg/Hr, 160kg/Hr, 170kg/Hr, or the like.

Preferably, said coarse comminution apparatus comprises a bucket shaker.

Preferably, the coarse crushing time is 80-100 min, for example: 80min, 85min, 90min, 95min or 100min and the like.

Preferably, the equipment for dispersing and emulsifying in the step (2) comprises a GP-290 three-stage emulsifying machine and/or a GF-240 dispersing agent stirring machine.

Preferably, the time for dispersing and emulsifying is 50-60 min, for example: 50min, 51min, 52min, 53min, 54min, 55min, 56min, 57min, 58min, 59min or 60min and the like

Preferably, the fine crushing apparatus comprises a horizontal sand mill.

Preferably, the time for fine crushing is 120-180 min, for example: 120min, 125min, 130min, 135min, 140min, 150min, 160min, 170min or 180min and the like.

Preferably, the slurry obtained after the fine pulverization has an average particle diameter of 0.2 to 1.0 μm, for example: 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1.0 μm, or the like.

Preferably, the granulation in step (2) is centrifugal spray drying granulation.

Preferably, a PVA solution is added during the granulation process.

Preferably, the concentration of the PVA solution is 5 to 10%, for example: 5%, 6%, 7%, 8%, 9%, 10%, etc.

Preferably, the PVA solution accounts for 10-18% of the slurry by mass, such as: 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, or the like.

Preferably, the pressing apparatus of step (2) comprises a powder forming machine.

Preferably, the pressed blank obtained by pressing has a pressing density of 3.2-3.4 g/cm³For example: 3.2g/cm³、3.22g/cm³、3.25g/cm³、3.28g/cm³、3.3g/cm³、3.35g/cm³Or 3.4g/cm³And the like.

Preferably, the sintering equipment comprises a resistance furnace.

Preferably, the sintering temperature is 1160-1200 ℃, for example: 1160 deg.C, 1165 deg.C, 1170 deg.C, 1175 deg.C, 1180 deg.C, 1185 deg.C, 1190 deg.C, or 1200 deg.C.

Preferably, the sintering time is 300-480 min, for example: 300min, 320min, 360min, 380min, 400min, 420min, 450min, 460min, 480min, etc.

Preferably, the sintering atmosphere is an oxygen-nitrogen equilibrium atmosphere.

As a preferred technical scheme, the preparation method comprises the following steps:

(1') putting the main component ingredients into a mixing pelletizing device for mixing and pelletizing, wherein the pelletizing time is 60-120 min;

(2 ') pre-burning the mixed and pelletized material obtained in the step (1') in a rotary kiln with an integrated structure at 1090-1110 ℃, wherein the pre-burning amount is 130-170 kg/Hr;

(3 ') coarsely grinding the pre-sintered material in the step (2') by adopting a bucket vibration grinder, wherein the coarsely grinding time is 80-100 min;

(4 ') adding auxiliary ingredient into the material obtained after coarse crushing in the step (3'), and dispersing and emulsifying by adopting dispersing and emulsifying equipment for 50-60 min;

(5 ') carrying out wet fine grinding on the slurry obtained by dispersing and emulsifying in the step (4') by using a horizontal sand mill for 120-180 min, wherein the average particle size of the ground slurry is 0.2-1.0 mu m;

(6 ') adding the slurry finely ground by the wet method in the step (5') into a PVA solution which accounts for 10-18% of the weight of the slurry, and performing centrifugal spray drying granulation;

(7 ') pressing the granulated material in the step (6') by using a powder forming machine to obtain a blank, wherein the pressing density of the blank is 3.2-3.4 g/cm³；

And (8 ') sintering the blank in the step (7') in a resistance furnace, wherein the sintering temperature is 1160-1200 ℃, the sintering time is 300-480 minutes, the sintering atmosphere is an oxygen-nitrogen balanced atmosphere, and the soft magnetic nickel-zinc ferrite material is obtained after the sintering is finished and is cooled to room temperature along with the furnace.

In a third aspect, the present invention also provides a nickel zinc ferrite comprising the soft magnetic nickel zinc ferrite material according to the first aspect.

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

(a) the invention adds nano CaO and nano MgO into the accessory components to improve the stress resistance of the material at different temperatures; adding nano Bi into the accessory components₂O₃Reducing the sintering temperature to promote densification to improve the saturation magnetic flux density characteristics of the material; nano Co₂O₃The frequency characteristic and the magnetic permeability characteristic of the material are improved; in thatNanometer TiO is added into the accessory ingredients₂To improve the permeability temperature factor of the material.

(b) According to the invention, the thickness of the crystal boundary is increased by combining and adding the auxiliary components, the temperature factors of the relative loss factor and the magnetic conductivity of the high-frequency band are reduced, and the crystal structure and the crystal boundary distribution of the material are further adjusted by the production process, so that the temperature factor of the magnetic conductivity of the material is effectively reduced to 0-2, and the stress resistance of the material is improved by less than or equal to 5%.

(c) The soft magnetic nickel-zinc ferrite material has the characteristic of small change of magnetic conductivity under the action of stress, and can meet the requirement of power inductance needing resin encapsulation on stress resistance of the ferrite material.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1

The embodiment provides a soft magnetic nickel zinc ferrite material, and the preparation method of the soft magnetic nickel zinc ferrite material comprises the following steps:

(1) putting 39.5 mol% of iron oxide, 39 mol% of nickel oxide, 11 mol% of zinc oxide and 10.5 mol% of copper oxide into a mixing pelletizing device for mixing and pelletizing, wherein the pelletizing time is 80min, pre-burning the pelletized material in a rotary kiln with an integrated structure, the pre-burning temperature is 1100 ℃, the pre-burning amount is 150kg/Hr, and coarsely pulverizing the pre-burned material by a bucket type vibration mill for 90 min;

(2) adding 2.07 wt% of calcium oxide, 0.58 wt% of nano bismuth oxide, 0.16 wt% of nano cobalt oxide, 0.49 wt% of nano titanium oxide and 1.33 wt% of nano magnesium oxide into the coarsely crushed material in the step (1) by taking the mass of the coarsely crushed material as 100%, dispersing and emulsifying by adopting a dispersing and emulsifying device for 50min, finely crushing the slurry obtained by dispersing and emulsifying for 150min by adopting a horizontal sand mill, and controlling the average particle size of the crushed slurry to be 0.5 mu m;

(3) adding PVA solution 15 wt% of the slurry into the finely crushed slurry, centrifugal spray drying to granulate, and pressing the obtained granules with a powder forming machine to obtain the product with density of 3.3g/cm²The blank is sintered for 400min in a resistance furnace at the temperature of 1180 ℃, and is cooled to room temperature along with the furnace after the sintering is finished, so that the soft magnetic nickel-zinc ferrite material is obtained.

Example 2

This example differs from example 1 only in that the composition of the subcomponents is: the mass fraction of calcium oxide is 1.8 wt%, nano bismuth oxide is 0.53 wt%, nano cobalt oxide is 0.15 wt%, nano titanium oxide is 0.4 wt% and nano magnesium oxide is 1.2 wt%, and other conditions and parameters are completely the same as those of example 1.

Example 3

This example differs from example 1 only in that the composition of the subcomponents is: the mass fraction of calcium oxide is 2.2 wt%, nano bismuth oxide is 0.65 wt%, nano cobalt oxide is 0.18 wt%, nano titanium oxide is 0.55 wt% and nano magnesium oxide is 1.46 wt%, and other conditions and parameters are completely the same as those of example 1.

Example 4

This example differs from example 1 only in that the composition of the subcomponents is: the mass fraction of calcium oxide is 1.94 wt%, nano bismuth oxide is 0.62 wt%, nano cobalt oxide is 0.16 wt%, nano titanium oxide is 0.48 wt% and nano magnesium oxide is 1.33 wt%, and other conditions and parameters are completely the same as those of example 1.

Example 5

This example differs from example 1 only in that the composition of the subcomponents is: the mass fraction of calcium oxide is 2.07 wt%, nano bismuth oxide is 0.55 wt%, nano cobalt oxide is 0.16 wt%, nano titanium oxide is 0.48 wt% and nano magnesium oxide is 1.33 wt%, and other conditions and parameters are completely the same as those of example 1.

Comparative example 1

The comparative example is different from example 4 only in that no nano calcium oxide is added to the accessory ingredients, and other conditions and parameters are completely the same as example 4.

Comparative example 2

The comparative example is different from example 4 only in that nano bismuth oxide is not added to the subcomponents, and other conditions and parameters are completely the same as those of example 4.

Comparative example 3

The comparative example is different from example 4 only in that no nano cobalt oxide is added to the accessory components, and other conditions and parameters are completely the same as example 4.

Comparative example 4

The comparative example is different from example 4 only in that no nano titanium oxide is added to the subcomponents, and other conditions and parameters are completely the same as those of example 4.

Comparative example 5

The comparative example is different from example 4 only in that no nano-magnesia is added to the subcomponents, and other conditions and parameters are completely the same as example 4.

The soft magnetic nickel zinc ferrite materials prepared in examples 1 to 5 and comparative examples 1 to 5 were prepared into nickel zinc ferrite magnetic ring samples having a size of (Φ 25mm × Φ 15mm × 8mm), the inductance of the samples at 25 ℃ was measured at f 10kHz, 10mV and 10mV using an LCR tester model HP-4284A, and the initial permeability μ was calculated according to the formula (1)_i(ii) a Magnetic permeability temperature factor alpha of samples tested by matching MC-711 small-sized ultralow temperature test box and PHH-101 high temperature test box_FAnd a Curie temperature Tc; testing the saturation magnetic flux density Bs of the sample by using a SY-8218 type B-H analyzer; applying 200N pressure to the wound magnetic ring by using a CMT6203 microcomputer controlled electronic universal tester, measuring the inductance of the sample at f-10 kHz, 10mV and 25 ℃ by using HP-4284A, and calculating the initial permeability mu according to the formula (1)_iAnd then the magnetic permeability change rate | Δ μ/μ by the formula (2)_i| to characterize the stress resistance characteristics of the ferrite material, the temperature factor α of permeability according to equations (3) and (4)_FTo show the temperature stability of the ferrite material:

wherein: mu.s_iIs the magnetic permeability (initial magnetic permeability) at a pressure of 0N; mu.s_NIs the permeability at a pressure of 200N; mu.s_refPermeability at a reference temperature of 20 ℃; mu.s_TTo test the permeability at temperature T; l is the product inductance (H); n is the number of winding turns; d is the sample outer diameter (mm); d is the sample inner diameter (mm); h is the sample thickness (mm) and the results are shown in Table 1:

as can be seen from Table 1, by comparing examples 1-5 with comparative examples 1-5, the invention effectively reduces the magnetic permeability temperature factor of the material to 0-2, improves the stress resistance of the material by less than or equal to 5%, and can maintain the corresponding initial magnetic permeability, higher saturation magnetic induction intensity and higher Curie temperature. Comparing the microstructures of the examples and the comparative examples, wherein the comparative example material is coarse in crystallization, and the grain size is 80-120 mu m; the crystal of the embodiment is small, the grain boundary is obvious, and the grain size is 10-20 mu m. Grain refinement and grain boundary thickening should be the important reason why the stress resistance of the materials of examples is greatly improved relative to the comparative examples. The material of the invention can meet the performance requirement of the small power inductor on the nickel-zinc material.

The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope and disclosure of the present invention.