NiCuZn-MgO composite material and preparation method thereof

Abstract

The application relates to the technical field of soft magnetic ferrite material, and particularly discloses a NiCuZn-MgO composite material and a preparation method thereof. The NiCuZn-MgO composite material comprises a main component and an additive, and the main component comprises the following components in percentage by weight: Fe2O3 66-72 wt%, ZnO 13-16 wt%, NiO 6-9 wt%, MgO 3-6 wt%, and the balance is CuO; and the additive comprises the following components in percentage by weight based on the total weight of the main component: Bi2O3 0.5-1.5 wt%, SiO2 0.3-1.5 wt%, and CaO 0.3-1.5 wt%. The prepared NiCuZn-MgO composite material can reduce the cost of the soft magnetic ferrite, and has high magnetic permeability and high Bs.

Description

Technical Field

[0001] The present application relates to the technical field of soft ferrite materials, and in particular to a NiCuZn-MgO composite material and a preparation method thereof. Background Art

[0002] With the rapid development and accelerated penetration of the global new energy vehicle industry, new energy vehicles are replacing traditional fuel vehicles at an unprecedented rate. This trend is not only driving the transformation of the entire automotive industry but also significantly contributing to the continued expansion of the automotive electronics market. Compared to traditional fuel vehicles, new energy vehicles, due to their higher degree of electrification, are more dependent on onboard electronic systems, resulting in a significant increase in the number and complexity of electronic components used within them. In particular, the per-vehicle value of magnetic components has increased exponentially.

[0003] Automotive electronics, the cornerstone of modern automotive intelligence and electrification, encompass numerous key components, among which passive electronic components such as inductors play an indispensable role. The inductor core, a core component of an inductor, plays a crucial role in automotive power management systems, inverters, DC / DC converters, and various filtering and power amplifier circuits. It processes high-frequency signals, suppresses noise, stabilizes voltage and current, and ensures efficient operation of the power system.

[0004] Traditionally, inductor cores are made of nickel-zinc ferrite, a material favored for its excellent magnetic properties, high resistivity, and wide operating frequency band. However, the price of nickel oxide (NiO), the primary component of nickel-zinc ferrite, remains high and volatile, placing significant cost pressure on the automotive electronics industry chain and hindering the large-scale production and market adoption of related products. Summary of the Invention

[0005] In order to solve at least one of the above technical problems, a low-cost nickel-zinc ferrite material with high magnetic permeability and high Bs is developed. The present application provides a NiCuZn-MgO composite material and a preparation method thereof.

[0006] On the one hand, the present application provides a NiCuZn-MgO composite material, including a main component and an additive, wherein the main component includes the following components in weight percentage: Fe2O3 66-76wt%, ZnO 13-16wt%, NiO 6-9wt%, MgO 3-6wt%, and the balance is CuO.

[0007] Based on the total weight of the main components, the additive includes the following components in weight percentage: Bi2O3 0.5-1.5wt%, SiO2 0.3-1.5wt%, and CaO 0.3-1.5wt%.

[0008] By adopting the above-mentioned technical solution, the use of MgO to replace part of NiO in this application can reduce the overall cost of nickel-zinc ferrite materials. An appropriate amount of MgO can act as a grain growth inhibitor, which helps to form a fine and uniform grain structure, thereby improving the high-frequency performance and mechanical strength of the material. It can also improve the sintering activity of the ferrite, which is conducive to obtaining better phase purity and higher density, thereby optimizing the magnetic properties; the addition of MgO can improve the sintering behavior of the ferrite, reduce the sintering temperature or shorten the sintering time, and facilitate industrial large-scale production; the presence of MgO helps to increase the resistivity of the ferrite material, thereby reducing eddy current losses and improving device efficiency.

[0009] This application uses Bi2O3, SiO2 and CaO as additives. Bi2O3 acts as a grain growth inhibitor, which can effectively refine ferrite particles, thereby improving the high-frequency performance of the material; the addition of Bi2O3 can help reduce the sintering temperature of ferrite, and bismuth ions can promote the formation of liquid phase during the sintering process, thereby accelerating the sintering rate and improving the sintering activity; SiO2 can affect the sintering density and microstructure of ferrite, and by adjusting its content, the dielectric properties and mechanical properties of the material can be improved; CaO can inhibit the oxidation of grain boundaries and enhance the oxidation resistance and stability of the material.

[0010] Optionally, the main component includes the following components in weight percentage: Fe2O3 66-76wt%, ZnO 13-16wt%, NiO 6.5-8wt%, MgO 4-5.5wt%, and the balance is CuO;

[0011] Optionally, in the main component, the weight ratio of NiO to MgO is 1.2 to 2:1.

[0012] Optionally, in the main component, the weight ratio of NiO to MgO is 1.5:1.

[0013] In a second aspect, the present application provides a method for preparing the above-mentioned NiCuZn-MgO composite material, comprising the following steps:

[0014] S1. Main components Fe2O3, ZnO, NiO, MgO, CuO and part of Bi2O3 in the additive are mixed by wet sand grinding to obtain a mixture A;

[0015] S2, pre-calcining the mixed material A obtained in step S1 to obtain a pre-calcined material;

[0016] S3, adding additives SiO2, CaO and the remaining Bi2O3 to the pre-burned material obtained in step S2, and performing secondary sand grinding to obtain a mixture B;

[0017] S4, adding a binder and a defoamer to the mixed material B obtained in step S3, stirring and mixing, and then spray granulating to obtain granular material;

[0018] S5, pressing the granular material obtained in step S4 into a mold to prepare a green body;

[0019] S6. Sintering the green body obtained in step S5. After sintering, rapidly cooling the green body to obtain the NiCuZn-MgO composite material.

[0020] By adopting the above technical solution, the present application sand-mills the main component and part of Bi2O3 for pre-sintering, sand-mills for the second time, and then adds all the additives including the remaining Bi2O3. Adding Bi2O3 twice can significantly optimize the structure of high nickel-zinc ferrite, make the grains more uniform, and significantly improve the density of nickel-zinc ferrite, thereby enabling nickel-zinc ferrite to obtain high strength.

[0021] The preparation method of the NiCuZn-MgO composite material of the present application is simple and suitable for industrial production.

[0022] Optionally, in step S1, the amount of Bi2O3 added is 0.3-0.5 wt%, and the sanding time is 1-2 h.

[0023] Optionally, the pre-firing temperature in step S2 is 800-900° C., and the pre-firing time is 3-4 hours.

[0024] Optionally, in step S3, a dispersant is further added in an amount of 0.5 to 1.2% by weight of the total weight of the main components.

[0025] Optionally, the dispersant comprises mannitol, light calcium carbonate and sodium lauryl sulfate in a weight ratio of (1-3):(5-7):(1-3).

[0026] By adopting the above technical solution, the present application adds a dispersant during sand milling. Through the combined action of mannitol, light calcium carbonate, and sodium lauryl sulfate, the dispersion and sand milling effect of the ferrite raw material can be significantly improved, resulting in a more uniform particle distribution. Mannitol and light calcium carbonate promote particle refinement through steric hindrance and adsorption, while sodium lauryl sulfate further improves dispersibility through electrostatic repulsion.

[0027] Optionally, after the secondary sand grinding in step S3, the particle size D50 of the mixture B is 0.9±0.1 μm.

[0028] Optionally, in step S4, the binder is a PVA binder, and the amount of the PVA binder added is 0.1-0.3 wt% of the solid content of the mixture B; the defoaming agent is polydimethylsiloxane, and the amount of the polydimethylsiloxane added is 0.05-0.15 wt% of the solid content of the mixture B.

[0029] Optionally, in step S6, the sintering temperature is 1050-1100° C., and the sintering time is 5-6 hours.

[0030] In summary, the present invention includes at least one of the following beneficial technical effects:

[0031] 1. The use of MgO to replace part of NiO in this application can reduce the overall cost of nickel-zinc ferrite materials. An appropriate amount of MgO can act as a grain growth inhibitor, helping to form a fine and uniform grain structure, thereby improving the high-frequency performance and mechanical strength of the material. It can also increase the sintering activity of the ferrite, which is conducive to obtaining better phase purity and higher density, thereby optimizing the magnetic properties; the addition of MgO can improve the sintering behavior of the ferrite, reduce the sintering temperature or shorten the sintering time, and facilitate industrial large-scale production; the presence of MgO helps to increase the resistivity of the ferrite material, thereby reducing eddy current losses and improving device efficiency.

[0032] 2. This application uses Bi2O3, SiO2 and CaO as additives. Bi2O3, as a grain growth inhibitor, can effectively refine ferrite particles, thereby improving the high-frequency performance of the material; the addition of Bi2O3 can help reduce the sintering temperature of ferrite, and bismuth ions can promote the formation of liquid phase during the sintering process, thereby accelerating the sintering rate and improving the sintering activity; SiO2 can affect the sintering density and microstructure of ferrite, and by adjusting its content, the dielectric properties and mechanical properties of the material can be improved; CaO can reduce grain boundary resistance and improve magnetic permeability, and can also inhibit the oxidation of grain boundaries, enhancing the oxidation resistance and stability of the material.

[0033] 3. In this application, the main component and part of Bi2O3 are mixed and sand-milled for pre-sintering, and then all the additives including the remaining Bi2O3 are added after a second sand-milling. Adding Bi2O3 twice can significantly optimize the structure of high nickel-zinc ferrite, make the grains more uniform, and significantly improve the density of nickel-zinc ferrite, thereby enabling nickel-zinc ferrite to obtain high strength.

[0034] 4. The preparation method of the NiCuZn-MgO composite material of the present application is simple, the product has good stability, and is suitable for industrial production. DETAILED DESCRIPTION

[0035] The present application is further described in detail below with reference to the embodiments.

[0036] The present application designs a NiCuZn-MgO composite material, comprising a main component and an additive, wherein the main component comprises the following components in weight percentage: Fe2O3 66-76wt%, ZnO 13-16wt%, NiO 6-9wt%, MgO 3-6wt%, and the balance is CuO;

[0037] The additive is calculated based on the total weight of the main component, and includes the following weight percentage components: Bi2O3 0.5-1.5wt%, SiO2 0.3-1.5wt%, and CaO 0.3-1.5wt%.

[0038] The NiCuZn-MgO composite material of the present application is prepared by the following method, comprising the following steps:

[0039] S1. Main components Fe2O3, ZnO, NiO, MgO, CuO and part of Bi2O3 in the additive are mixed by wet sand grinding to obtain a mixture A;

[0040] S2, pre-calcining the mixed material A obtained in step S1 to obtain a pre-calcined material;

[0041] S3, adding additives SiO2, CaO and the remaining Bi2O3 to the pre-burned material obtained in step S2, and performing secondary sand grinding to obtain a mixture B;

[0042] S4, adding a binder and a defoamer to the mixed material B obtained in step S3, stirring and mixing, and then spray granulating to obtain granular material;

[0043] S5, pressing the granular material obtained in step S4 into a mold to prepare a green body;

[0044] S6. Sintering the green body obtained in step S5. After sintering, rapidly cooling the green body to obtain the NiCuZn-MgO composite material.

[0045] The NiCuZn-MgO composite material of the present application can be used in the field of soft magnetic ferrite materials.

[0046] The use of MgO to replace part of NiO in this application can reduce the overall cost of nickel-zinc ferrite materials. An appropriate amount of MgO can act as a grain growth inhibitor, helping to form a fine and uniform grain structure, thereby improving the high-frequency performance and mechanical strength of the material. It can also increase the sintering activity of the ferrite, which is conducive to obtaining better phase purity and higher density, thereby optimizing the magnetic properties; the addition of MgO can improve the sintering behavior of the ferrite, reduce the sintering temperature or shorten the sintering time, and facilitate industrial large-scale production; the presence of MgO helps to increase the resistivity of the ferrite material, thereby reducing eddy current losses and improving device efficiency.

[0047] This application uses Bi2O3, SiO2 and CaO as additives. Bi2O3 acts as a grain growth inhibitor, which can effectively refine ferrite particles, thereby improving the high-frequency performance of the material; the addition of Bi2O3 can help reduce the sintering temperature of ferrite, and bismuth ions can promote the formation of liquid phase during the sintering process, thereby accelerating the sintering rate and improving the sintering activity; SiO2 can affect the sintering density and microstructure of ferrite, and by adjusting its content, the dielectric properties and mechanical properties of the material can be improved; CaO can reduce grain boundary resistance and improve magnetic permeability, and can also inhibit grain boundary oxidation, enhancing the material's oxidation resistance and stability. Specific embodiments

[0049] Example 1

[0050] This embodiment provides a NiCuZn-MgO composite material, including a main component and an additive, wherein the main component includes the following components in weight percentage: 70wt% Fe2O3, 14wt% ZnO, 8wt% NiO, 4wt% MgO, and the balance is CuO;

[0051] Based on the total weight of the main components, the additives include the following weight percentage components: 1.0 wt% Bi2O3, 0.8 wt% SiO2, and 0.8 wt% CaO.

[0052] The preparation method of the NiCuZn-MgO composite material in this embodiment includes the following steps:

[0053] S1. The main components Fe2O3, ZnO, NiO, MgO, CuO and part of the Bi2O3 in the additive were mixed by wet sand grinding for 1.5 h to obtain a mixture A;

[0054] S2. The mixed material A is transferred into a sintering furnace for pre-calcination at a temperature of 850° C. for 3.5 h to obtain a pre-calcined material;

[0055] S3. Adding additives SiO2, CaO and the remaining Bi2O3 to the pre-burned material, performing secondary sand grinding to obtain a mixture B. The particle size of the mixture B is: D50 = 0.9 ± 0.1 μm;

[0056] S4, adding a PVA binder having a solid content of 0.2 wt% of the mixture B and a polydimethylsiloxane having a solid content of 0.1 wt% of the mixture B to the mixture B, and performing spray granulation to obtain granules;

[0057] S5. The granular material is pressed into a powder forming machine through a mold to obtain a circular green body with a specification of φ25×15×7.5 mm;

[0058] S6. Transferring the green body into a sintering furnace for sintering at a temperature of 1080° C. for 5.5 h. After sintering, rapidly cooling is performed to obtain the NiCuZn-MgO composite material.

[0059] Example 2-3

[0060] Example 2

[0061] The difference between this embodiment and embodiment 1 is that, when preparing the NiCuZn-MgO composite material, the sum of the weights of NiO and MgO accounts for 12 wt % of the main component, and the weight ratio of NiO to MgO is 1.2:1.

[0062] Example 3

[0063] The difference between this embodiment and embodiment 1 is that, when preparing the NiCuZn-MgO composite material, the sum of the weights of NiO and MgO accounts for 12 wt % of the main component, and the weight ratio of NiO to MgO is 1.5:1.

[0064] Comparative Examples 1-5

[0065] Comparative Example 1

[0066] The difference between this comparative example and Example 3 is that, when preparing the NiCuZn-MgO composite material, the sum of the weights of NiO and MgO accounts for 12 wt % of the main component, and the weight ratio of NiO to MgO is 1:1.

[0067] Comparative Example 2

[0068] The difference between this comparative example and Example 3 is that, when preparing the NiCuZn-MgO composite material, the sum of the weights of NiO and MgO accounts for 12 wt % of the main component, and the weight ratio of NiO to MgO is 2.5:1.

[0069] Comparative Example 3

[0070] The difference between this comparative example and Example 3 is that when preparing the NiCuZn-MgO composite material, an equal amount of NiO is used to replace MgO.

[0071] Comparative Example 4

[0072] The difference between this comparative example and Example 3 is that when preparing the NiCuZn-MgO composite material, all of the Bi2O3 is added in step S1.

[0073] Comparative Example 5

[0074] The difference between this comparative example and Example 3 is that, when preparing the NiCuZn-MgO composite material, no Bi2O3 is added in step S1, and all of the Bi2O3 is added in step S3.

[0075] The specific compositions of the NiCuZn-MgO composite materials prepared in Examples 1 to 3 of the present invention and Comparative Examples 1 to 5 are shown in Table 1.

[0076] Table 1

[0077]

[0078] Examples 4-5

[0079] The difference between Example 4-5 and Example 3 is that the amounts of some components were changed when preparing the NiCuZn-MgO composite material. See Table 2 for the differences.

[0080] Table 2

[0081]

[0082] Example 6

[0083] The difference between Example 6 and Example 3 is that in step S3 of this embodiment, a dispersant is further added in an amount of 0.8% by weight of the total weight of the main components, and the dispersant is mannitol, light calcium carbonate and sodium lauryl sulfate in a weight ratio of 1:5:1.

[0084] Step S3 is: S3, adding additives SiO2, CaO, dispersant and the remaining part of Bi2O3 to the pre-burned material, performing secondary sand grinding to obtain a mixture B, the particle size of the mixture B is: D50 = 0.9 ± 0.1 μm.

[0085] Example 7

[0086] The difference between Example 7 and Example 3 is that in step S3 of this embodiment, a dispersant is further added in an amount of 0.8% by weight of the total weight of the main components, and the dispersant is mannitol, light calcium carbonate and sodium lauryl sulfate in a weight ratio of 2:6:3.

[0087] Step S3 is: S3, adding additives SiO2, CaO, dispersant and the remaining part of Bi2O3 to the pre-burned material, performing secondary sand grinding to obtain a mixture B, the particle size of the mixture B is: D50 = 0.9 ± 0.1 μm.

[0088] Example 8

[0089] The difference between Example 8 and Example 3 is that in step S3 of this embodiment, a dispersant is further added in an amount of 0.8% by weight of the total weight of the main components, and the dispersant is mannitol, light calcium carbonate and sodium lauryl sulfate in a weight ratio of 3:7:2.

[0090] Step S3 is: S3, adding additives SiO2, CaO, dispersant and the remaining part of Bi2O3 to the pre-burned material, performing secondary sand grinding to obtain a mixture B, the particle size of the mixture B is: D50 = 0.9 ± 0.1 μm.

[0091] Experimental testing

[0092] The following performance tests were performed on the NiCuZn-MgO composite materials obtained in Examples 1-8 and Comparative Examples 1-5:

[0093] Initial magnetic permeability μ i :Under the condition of number of turns N=20Ts, the initial magnetic permeability of the sample ring is tested using HP-4284A LCR meter;

[0094] Saturation magnetic induction intensity Bs: Under the condition of number of turns N=20Ts, the saturation magnetic induction intensity Bs of the nickel-zinc ferrite core is tested using SY-8258 BH analyzer.

[0095] Test results

[0096] The test results are shown in Table 3.

[0097] Table 3

[0098]

[0099] Result Analysis

[0100] From the data in Examples 1-3, Comparative Examples 1-3 and Table 3, it can be seen that the use of MgO to replace part of NiO in the present application can not only reduce the production cost, but also an appropriate amount of MgO can serve as a grain growth inhibitor, which is conducive to obtaining better phase purity and higher density, thereby ensuring the magnetic properties of the ferrite. The presence of MgO helps to increase the resistivity of the ferrite material, thereby reducing eddy current losses and improving device efficiency.

[0101] Combining Example 3, Comparative Examples 4-5 and the data in Table 3, it can be seen that the present application mixes the main component and part of Bi2O3 and sand-mills them for pre-sintering, sand-mills them for the second time, and then adds all the additive parts including the remaining Bi2O3. Adding Bi2O3 twice can significantly optimize the structure of high nickel zinc ferrite, make the grains more uniform, and significantly improve the density of nickel zinc ferrite, thereby enabling nickel zinc ferrite to obtain high strength.

[0102] Combining Examples 3-5 and the data in Table 3, it can be seen that when the weight ratio of NiO and MgO is 1.2 to 2:1, the comprehensive performance of the obtained NiCuZn-MgO composite material is better. When the weight ratio of NiO and MgO is 1.5:1, the comprehensive performance of the obtained NiCuZn-MgO composite material is even better.

[0103] Combined with the data in Example 3, Examples 6-8 and Table 3, it can be seen that when 0.8% of the total weight of the dispersant is added as the main component during the secondary sand grinding, the dispersant is mannitol, light calcium carbonate and sodium lauryl sulfate in a weight ratio of (1-3): (5-7): (1-3), and the obtained NiCuZn-MgO composite material has better comprehensive performance.

[0104] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A NiCuZn-MgO composite material comprising a main component and an additive, characterized in that: The main components include the following weight percentage components: Fe2O3 66-72wt%, ZnO 13-16wt%, NiO 6-9wt%, MgO 3-6wt%, and the balance is CuO; Based on the total weight of the main components, the additive is composed of the following components in weight percentage: Bi2O3 0.5-1.5wt%, SiO2 0.3-1.5wt%, and CaO 0.3-1.5wt%; in the main components, the weight ratio of NiO to MgO is 1.2-2:

1.

2. The NiCuZn-MgO composite material according to claim 1, characterized in that Among the main components, the weight ratio of NiO to MgO is 1.5:

1.

3. A method for preparing the NiCuZn-MgO composite material according to claim 1 or 2, characterized in that: The following steps are involved: S1. Main components Fe2O3, ZnO, NiO, MgO, CuO and part of Bi2O3 in the additive are mixed by wet sand grinding to obtain a mixture A; S2, pre-calcining the mixed material A obtained in step S1 to obtain a pre-calcined material; S3, adding additives SiO2, CaO and the remaining Bi2O3 to the pre-burned material obtained in step S2, and performing secondary sand grinding to obtain a mixture B; S4, adding a binder and a defoamer to the mixed material B obtained in step S3, stirring and mixing, and then spray granulating to obtain granular material; S5, pressing the granular material obtained in step S4 into a mold to prepare a green body; S6. Sintering the green body obtained in step S5. After sintering, rapidly cooling the green body to obtain the NiCuZn-MgO composite material.

4. The method for preparing the NiCuZn-MgO composite material according to claim 3, characterized in that: Based on the total weight of the main components, the amount of Bi2O3 added in step S1 is 0.3-0.5 wt%, and the sanding time is 1-2 h.

5. The method for preparing the NiCuZn-MgO composite material according to claim 3, characterized in that: In step S2, the pre-firing temperature is 800-900° C., and the pre-firing time is 3-4 hours.

6. The method for preparing the NiCuZn-MgO composite material according to claim 3, characterized in that: In step S3, a dispersant is added in an amount of 0.5-1.2% by weight of the total weight of the main components.

7. The method for preparing the NiCuZn-MgO composite material according to claim 6, characterized in that: The dispersant comprises mannitol, light calcium carbonate and sodium lauryl sulfate in a weight ratio of (1-3): (5-7): (1-3).

8. The method for preparing the NiCuZn-MgO composite material according to claim 3, characterized in that: After the secondary sand grinding in step S3, the particle size D50 of the mixture B is 0.9±0.1 μm.

9. The method for preparing the NiCuZn-MgO composite material according to claim 3, characterized in that: In step S6, the sintering temperature is 1050-1100° C., and the sintering time is 5-6 hours.

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