High-frequency manganese-zinc ferrite material with low stress sensitivity and method for producing the same

Abstract

This article discloses a high-frequency manganese-zinc ferrite material with low stress sensitivity and a method for manufacturing the same. 【Means】The high-frequency manganese-zinc ferrite material with low stress sensitivity includes a main component and additives. The main component includes Fe2O3, ZnO, and MnO, and the additives include Co2O3, CaCO3, Nb2O5, and TiO2. In this application, by an appropriate main blending ratio, the magnetostriction constant of the material itself is reduced, the stress sensitivity performance of the material itself is decreased, and by an appropriate combination and addition amount of additives, the loss of the material is reduced to improve the temperature characteristics of the material. Moreover, by combining a low-temperature sintering process and a special temperature-lowering curve, the grain size of the material is reduced, the stress sensitivity and high-frequency loss of the material are decreased, and a high-frequency manganese-zinc ferrite material with low stress sensitivity and low loss is manufactured.

Description

Technical Field

[0001] Examples of the present application belong to the field of magnetic core material technology, for example, high-frequency manganese-zinc ferrite materials, and in particular, relate to low-stress-sensitive high-frequency manganese-zinc ferrite materials and manufacturing methods thereof.

Background Art

[0002] Manganese-zinc ferrite materials are widely applied as base materials for current electronic industries and information industries, and as energy storage and conversion materials in the fields of electronics and communications. With the development of electronic components towards being more user-friendly, miniaturized, and high-power, the operating frequency of MnZn ferrite cores gradually shifts from low frequency to high frequency.

[0003] Therefore, many scientists have studied high-frequency MnZn ferrites and discovered many manufacturing processes and formulations of high-frequency MnZn ferrites. However, many application problems have been discovered during the use process of high-frequency MnZn ferrite cores. For example, for the non-pressurized state, the permeability of high-frequency manganese-zinc ferrite cores after an external force is applied is different, which affects the stability of their application.

[0004] CN102503396A discloses a high-frequency low-loss MnZn ferrite and its manufacturing method. The high-frequency low-loss MnZn ferrite contains, as main raw materials, 50.2 - 54 mol% of Fe2O3, 36 - 42 mol% of MnO, and the balance ZnO, and as auxiliary materials, 0.25 - 0.35 wt% of CaCO3, 0.04 - 0.6 wt% of V2O5, and 0.02 - 0.03 wt% of Nb2O5. At the same time, it further discloses a manufacturing method of high-frequency low-loss MnZn ferrite including the manufacture of calcined materials, the manufacture of pellet materials, and a low-temperature sintering process. The high-frequency low-loss MnZn ferrite disclosed in this patent has a power consumption ≤ 200 mW / cm at 100 °C, 1 MHz, and 30 mT 3 is.

[0005] CN104108925A discloses a method for manufacturing a high-frequency manganese zinc ferrite material. The raw materials of the high-frequency manganese zinc ferrite material include Fe2O3, ZnO, MnO, SiO2, CaCO3, V2O5, TiO2, and ZrO2. The molar ratio of Fe2O3:MnO:ZnO is (53 - 56):(38 - 41):(5 - 8). Based on the total mass of Fe2O3, ZnO, and MnO, the mass fractions of SiO2, CaCO3, V2O5, TiO2, and ZrO2 are 20 - 70 ppm, 100 - 800 ppm, 100 - 500 ppm, 200 - 2400 ppm, and 100 - 500 ppm respectively. The high-frequency low-loss manganese zinc ferrite according to this patent has a power consumption ≤ 330 mW / cm at 100 °C, 1 MHz, and 50 mT 3 is.

[0006] CN113277840A discloses a high-frequency, high operating magnetic flux density, low-loss manganese zinc ferrite and its manufacturing method. The high-frequency, high operating magnetic flux density, low-loss manganese zinc ferrite is composed of a main component and a sub-component. The main component, as an oxide, is composed of 54.55 - 55.20 mol% of Fe2O3, 4.0 - 5.0 mol% of ZnO, and the balance of MnO. By weight of the main component, the sub-component I includes 0.01 - 0.06 wt% of Nb2O5, 0.15 - 0.30 wt% of Co2O3, 0.05 - 0.15 wt% of CaCO3, and 0.01 - 0.04 wt% of V2O5. The sub-component II is composed of at least two of 0.01 - 0.05 wt% of NiO, 0.005 - 0.015 wt% of SiO2, and 0.01 - 0.05 wt% of MoO3. The sintering temperature is 1060 - 1100 °C, and the pulverized particle size is 0.4 - 0.8 μm. The material according to this invention has a power consumption < 800 kW / m at 1 MHz and 100 mT from 25 °C to 100 °C 3 is less.

[0007] All of the manganese zinc ferrite materials according to the above invention have high-frequency characteristics, but none of them disclose the change in permeability after an external force is applied to the high-frequency manganese zinc ferrite material. However, this change affects the application of the high-frequency manganese zinc ferrite material. Therefore, the research and development of high-frequency manganese zinc ferrite materials with low stress sensitivity and low loss have very important theoretical and practical significance.

Summary of the Invention

Problems to be Solved by the Invention

[0008] The following is an overview of the main topics to be described in detail in the text. This overview does not limit the scope of the claims.

[0009] Embodiments of the present application provide a high-frequency manganese zinc ferrite material with low stress sensitivity and a manufacturing method thereof. The present application reduces the magnetostriction constant of the material itself and reduces the stress sensitivity performance of the material itself by an appropriate main component ratio, and reduces the loss of the material and improves the temperature characteristics of the material by an appropriate combination and addition amount of additives, and reduces the grain size of the material and reduces the stress sensitivity and high-frequency loss of the material by combining a low-temperature sintering process and a special cooling curve, thereby manufacturing a high-frequency manganese zinc ferrite material with low stress sensitivity and low loss.

Means for Solving the Problems

[0010] In Embodiment 1, the embodiments of the present application include a main component and additives, the main component includes Fe2O3, ZnO, and MnO, the additives include Co2O3, CaCO3, Nb2O5, and TiO2, and provide a high-frequency manganese zinc ferrite material with low stress sensitivity.

[0011] This application reduces the magnetostriction constant of the material itself and decreases the stress-sensing performance of the material itself by an appropriate main component ratio, and reduces the loss of the material and improves the temperature characteristics of the material by an appropriate combination and addition amount of additives.

[0012] The auxiliary additives selected in this application play the following roles. Co3+ in the Co2O3 has a positive K1 (crystalline magnetic anisotropy constant), compensates for the negative K1 value of manganese zinc ferrite, reduces the hysteresis loss, and improves the temperature performance of the material.

[0013] The CaCO3 has the role of increasing the grain boundary resistivity of the material and reducing the eddy current loss.

[0014] The Nb2O5 can promote the densification process during the sintering process, improve the uniformity of crystal grains, reduce pores, reduce the hysteresis loss, form a high-resistivity layer at the grain boundary, and reduce the eddy current loss of the material.

[0015] The TiO2 forms local Ti 4+ -Fe 2+ ion pairs with Fe 2+ and Fe 3+ to suppress the electron transfer between them, increase the room temperature resistance inside the crystal grains, reduce the room temperature eddy current loss, and provide additional cation vacancies for the diffusion of Nb2O5, further promoting the action of Nb2O5.

[0016] Preferably, the main component raw materials include, in terms of the percentage of the total mass, 52 to 53 mol% of Fe2O3 (for example, it may be 52 mol%, 52.2 mol%, 52.4 mol%, 52.6 mol%, 52.8 mol% or 53 mol%, but not limited to the listed values, and other unlisted values within the numerical range are similarly applicable), 6 to 7 mol% of ZnO (for example, it may be 6 mol%, 5.2 mol%, 6.4 mol%, 6.6 mol%, 6.8 mol% or 7 mol%, but not limited to the listed values, and other unlisted values within the numerical range are similarly applicable), and the balance of MnO.

[0017] Preferably, the additive is in terms of the percentage of the total mass of the main component, Co2O3 1500 - 3000 ppm CaCO3 600 - 1000 ppm Nb2O5 100 - 300 ppm contains TiO2 1000 - 3000 ppm.

[0018] The content of the Co2O3 is 1500 - 3000 ppm. For example, it may be 1500 ppm, 2000 ppm, 2500 ppm or 3000 ppm, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable. The content of the CaCO3 is 600 - 1000 ppm. For example, it may be 600 ppm, 700 ppm, 800 ppm, 900 ppm or 1000 ppm, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable. The content of the Nb2O5 is 100 - 300 ppm. For example, it may be 100 ppm, 150 ppm, 200 ppm, 250 ppm or 300 ppm, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable. The content of the TiO2 is 1000 - 3000 ppm. For example, it may be 1000 ppm, 1500 ppm, 2000 ppm, 2500 ppm or 3000 ppm, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0019] In Embodiment 2, the examples of the present application are mixing Fe2O3, ZnO and MnO of the main component according to the compounding amount, and then sequentially performing primary sand milling, drying and calcination to obtain a calcined material in step (1); mixing the additive and the calcined material obtained in step (1), performing secondary sand milling and drying, and then obtaining a sand-milled powder in step (2); Performing sieving, granulation, forming, and sintering on the sand-milled powder described in step (2) in sequence to obtain the low-stress-sensitivity high-frequency manganese-zinc ferrite material in step (3). Provided is a method for manufacturing a low-stress-sensitivity high-frequency manganese-zinc ferrite material according to Embodiment 1.

[0020] In the manufacturing process of the present application, first, the main components are mixed and uniformly mixed, then a calcination process is performed to grow a part of the spinel structure. After that, appropriate additives are added to the calcined product and secondary ball milling is performed so that the powder reaches an appropriate particle size range. In the present application, after the main components and additives are calcined, in order to prevent the crystal grains from becoming too large and difficult to finely pulverize, the main components and additives cannot be mixed at once. Also, if mixed at once, there is a problem that the additive content becomes inaccurate. By the method of the present application, the content of each component of the additive can be made accurate.

[0021] Preferably, the process of the first sand milling described in step (1) includes putting the main components and water into a sand mill for the first sand milling.

[0022] Preferably, the mass ratio of the main components to water is 1:(1.2 - 2.5). For example, it may be 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2, 1:2.2, or 1:2.5, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0023] Preferably, the time of the first sand milling described in step (1) is 1 - 3 h. For example, it may be 1 h, 1.4 h, 1.8 h, 2.2 h, 2.6 h, or 3 h, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0024] Preferably, the temperature of the preliminary firing described in step (1) is 750 to 850 °C. For example, it may be 750 °C, 760 °C, 770 °C, 780 °C, 790 °C, 800 °C, 810 °C, 820 °C, 830 °C, 840 °C or 850 °C. However, it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0025] Preferably, the time of the preliminary firing described in step (1) is 1 to 3 h. For example, it may be 1 h, 1.4 h, 1.8 h, 2.2 h, 2.6 h or 3 h. However, it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0026] Preferably, the atmosphere of the preliminary firing described in step (1) is an air atmosphere.

[0027] The preliminary firing temperature according to the present application needs to be within the range of 750 to 850 °C. If the preliminary firing temperature is too high, the crystal grains will grow too large, and it is difficult to obtain an appropriate particle size range by polishing within a specific time. If the preliminary firing temperature is too low, the powder activity is too high, the uniformity of the crystal grain size after sintering is poor, the product has many pores, and the product performance is poor.

[0028] Preferably, the additives described in step (2) include Co2O3, CaCO3, Nb2O5 and TiO2.

[0029] Preferably, the addition amount of Co2O3 in the additive is 1500 to 3000 ppm of the total mass of the main components. For example, it may be 1500 ppm, 2000 ppm, 2500 ppm or 3000 ppm. However, it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0030] Preferably, the addition amount of CaCO3 in the additive is 600 to 1000 ppm of the total mass of the main components. For example, it may be 600 ppm, 800 ppm or 1000 ppm. However, it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0031] Preferably, the addition amount of Nb2O5 in the additive is 100 - 300 ppm of the total mass of the main components. For example, it may be 100 ppm, 150 ppm, 200 ppm, 250 ppm or 300 ppm, but is not limited to the recited values, and other unrecited values within the numerical range are equally applicable.

[0032] Preferably, the addition amount of TiO2 in the additive is 1000 - 3000 ppm of the total mass of the main components. For example, it may be 1000 ppm, 1500 ppm, 2000 ppm, 2500 ppm or 3000 ppm, but is not limited to the recited values, and other unrecited values within the numerical range are equally applicable.

[0033] Preferably, the time of the secondary sand milling described in step (2) is 2 - 4 h. For example, it may be 2 h, 2.4 h, 2.8 h, 3.2 h, 3.6 h or 4 h, but is not limited to the recited values, and other unrecited values within the numerical range are equally applicable.

[0034] Preferably, the particle size X50 of the sand-milled powder described in step (2) is 0.8 - 1.2 μm. For example, it may be 0.8 μm, 0.9 μm, 1 μm, 1.1 μm or 1.2 μm, but is not limited to the recited values, and other unrecited values within the numerical range are equally applicable.

[0035] Preferably, the mesh number of the sieve used for sieving described in step (3) is 30 - 80 meshes. For example, it may be 30 meshes, 40 meshes, 50 meshes, 60 meshes, 70 meshes or 80 meshes, but is not limited to the recited values, and other unrecited values within the numerical range are equally applicable.

[0036] Preferably, a granulating agent is added in the granulation described in step (3).

[0037] Preferably, the granulating agent contains PVA and / or PVB.

[0038] Preferably, the addition amount of the granulating agent is 8-15% of the mass of the sand-milled powder described in step (2). For example, it may be 8%, 9%, 10%, 11%, 12%, 13%, 14% or 15%, but is not limited to the enumerated values, and other unenumerated values within the numerical range are equally applicable.

[0039] Preferably, the forming described in step (3) includes making the product obtained after granulation into a standard sample ring blank.

[0040] Preferably, the size of the standard sample ring blank is 12.5 mm × 7.5 mm × 7 mm.

[0041] Preferably, the sintering process described in step (3) includes heating the standard sample ring blank to a first temperature in an equilibrium oxygen partial pressure atmosphere, holding the temperature, then cooling to a second temperature at a first cooling rate, holding the temperature, and finally cooling to a third temperature at the second cooling rate.

[0042] Preferably, the heating rate of the heating is 1-3 °C / min. For example, it may be 1 °C / min, 1.5 °C / min, 2 °C / min, 2.5 °C / min or 3 °C / min, but is not limited to the enumerated values, and other unenumerated values within the numerical range are equally applicable.

[0043] Preferably, the first temperature is 950-1100 °C. For example, it may be 950 °C, 1000 °C, 1020 °C, 1040 °C, 1060 °C, 1080 °C or 1100 °C, but is not limited to the enumerated values, and other unenumerated values within the numerical range are equally applicable.

[0044] Preferably, the heat preservation time at the first temperature is 3 to 7 h. For example, it may be 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 h, 6 h, 6.5 h or 7 h, but is not limited to the enumerated values, and other unenumerated values within the numerical range are equally applicable.

[0045] Preferably, the first temperature reduction rate is 2.5 to 5 °C / min. For example, it may be 2.5 °C / min, 3 °C / min, 3.5 °C / min, 4 °C / min, 4.5 °C / min or 5 °C / min, but is not limited to the enumerated values, and other unenumerated values within the numerical range are equally applicable.

[0046] Preferably, the second temperature is 250 to 300 °C. For example, it may be 250 °C, 260 °C, 270 °C, 280 °C, 290 °C or 300 °C, but is not limited to the enumerated values, and other unenumerated values within the numerical range are equally applicable.

[0047] Preferably, the heat preservation time at the second temperature is 3 to 5 h. For example, it may be 3 h, 3.5 h, 4 h, 4.5 h or 5 h, but is not limited to the enumerated values, and other unenumerated values within the numerical range are equally applicable.

[0048] Preferably, the second temperature reduction rate is 0.1 to 0.5 °C / min. For example, it may be 0.1 °C / min, 0.2 °C / min, 0.3 °C / min, 0.4 °C / min or 0.5 °C / min, but is not limited to the enumerated values, and other unenumerated values within the numerical range are equally applicable.

[0049] Preferably, the third temperature is 40 to 80 °C. For example, it may be 40 °C, 50 °C, 60 °C, 70 °C or 80 °C, but is not limited to the enumerated values, and other unenumerated values within the numerical range are equally applicable. Preferably, it is 50 to 70 °C.

[0050] The sintering process according to the present application is as follows. During the heating process, at 800 °C, the reaction process in the system is Mn2O3 → MnMn2O4 + O2, The reaction process during the heating process from 850 °C to the first temperature is MnMn2O4 + Fe2O3 → MnFe2O4 + O2, The reaction process during the heat preservation process is Fe2O3 → FeFe2O4 + O2.

[0051] The oxygen gas content, FeFe2O4 content, material K1 (crystalline magnetic anisotropy constant), and performance are different during the sintering process. Regarding the stepwise cooling process, in the first cooling process, based on the equilibrium oxygen partial pressure formula, by setting the oxygen partial pressure at each stepwise temperature point, the FeFe2O4 in the manganese zinc ferrite is maintained at the required content. In the second cooling process, the Co 2+ ions in the ferrite change from the metastable state to the stability of the low energy level, reducing the loss of the material.

[0052] As a preferred technical solution of the present application, the manufacturing method of the low stress sensitivity high frequency manganese zinc ferrite material according to aspect 2 of the present application includes the following steps. Step (1): Mix the main components Fe2O3, ZnO, and MnO according to the blending amount, and then mix with water at a mass ratio of 1:(1.2 - 2.5) for primary sand milling for 1 - 3 h and drying. After that, perform calcination at a temperature of 750 - 850 °C in an air atmosphere for 1 - 3 h to obtain a calcined material. Step (2): Mix the additive with the calcined material obtained in step (1), perform secondary sand milling for 2 - 4 h, and after drying, obtain a sand milling powder with a particle size X50 of 0.8 - 1.2 μm. However, the additive contains 1500 - 3000 ppm of Co2O3, 600 - 1000 ppm of CaCO3, 100 - 300 ppm of Nb2O5, and 1000 - 3000 ppm of TiO2 based on the total mass of the main components. Step (3): Sieving the sand milling powder described in step (2) through a 30 - 80 mesh sieve, granulating and then molding to obtain a standard sample ring blank with a size of 12.5 mm×7.5 mm×7 mm, and obtaining the low stress - sensitivity high - frequency manganese zinc ferrite material after sintering. The sintering process includes: in an equilibrium oxygen partial pressure atmosphere, heating the standard sample ring blank from room temperature to 950 - 1100 °C at a heating rate of 1 - 3 °C / min, holding for 3 - 7 h, then cooling to 250 - 300 °C at a cooling rate of 2.5 - 5 °C / min, holding for 3 - 5 h, and finally cooling to 40 - 80 °C at a cooling rate of 0.1 - 0.5 °C / min.

[0053] The numerical ranges related to this application not only include the above - mentioned point values, but also any point values between the above - mentioned numerical ranges not listed. For the convenience of the paper layout and simplicity, the specific point values included in the above ranges are not comprehensively listed in this application.

Advantages of the Invention

[0054] Compared with the related art, the beneficial effects of the embodiments of this application are as follows.

[0055] (1) The embodiments of this application reduce the magnetostriction constant of the material itself and reduce the stress - sensitive performance of the material itself by an appropriate main compounding ratio.

[0056] (2) The embodiments of this application reduce the loss of the material and improve the temperature characteristics of the material by an appropriate combination and addition amount of additives.

[0057] (3) The low stress - sensitivity high - frequency manganese zinc ferrite material according to the embodiments of this application has a low stress - sensitive force. After applying a pressure of 10 MPa to the ferrite material, the change in its permeability is less than 5%.

[0058] Other aspects can be understood after reading and understanding the detailed description.

Modes for Carrying Out the Invention

[0059] The technical solution of the present application will be further described below with specific embodiments. Those skilled in the art should understand that the above embodiments are only for understanding the present application and should not be regarded as specific limitations of the present application.

[0060] [Example 1] This example provides a high-frequency manganese-zinc ferrite material with low stress sensitivity. The manufacturing method of the high-frequency manganese-zinc ferrite material with low stress sensitivity includes the following steps.

[0061] (1) 52.4 mol% of Fe2O3, 6.8 mol% of ZnO, and the balance MnO were mixed, and then mixed with water at a mass ratio of 1:1.5, followed by primary sand milling for 1 h and drying. After that, calcination was carried out at a temperature of 750 °C for 3 h in an air atmosphere to obtain a calcined material.

[0062] (2) The additive was mixed with the calcined material obtained in step (1), secondary sand milling was carried out for 2 h, and after drying, a sand-milled powder with a particle size X50 of 1 μm was obtained.

[0063] Here, the additive contained 3000 ppm of Co2O3, 1000 ppm of CaCO3, 100 ppm of Nb2O5, and 2000 ppm of TiO2 based on the total mass of the main components.

[0064] (3) The sand-milled powder described in step (2) was sieved through a 60-mesh sieve, granulated and then formed to obtain a standard sample ring blank with a size of 12.5 mm × 7.5 mm × 7 mm. After sintering, the high-frequency manganese-zinc ferrite material with low stress sensitivity was obtained.

[0065] The sintering process included heating the standard sample ring blank to 1060 °C at a heating rate of 1.5 °C / min in an equilibrium oxygen partial pressure atmosphere, holding for 7 h, then cooling to 280 °C at a cooling rate of 2.8 °C / min, holding for 3 h, and finally cooling to 50 °C at a cooling rate of 0.1 °C / min.

[0066] [Example 2] This example provides a high-frequency manganese zinc ferrite material with low stress sensitivity. The manufacturing method of the high-frequency manganese zinc ferrite material with low stress sensitivity includes the following steps.

[0067] (1) 52 mol% of Fe2O3, 6 mol% of ZnO, and the balance MnO were mixed, and then mixed with water at a mass ratio of 1:1.5, followed by primary sand milling for 3 h and drying. After that, calcination was carried out at a temperature of 750 °C in an air atmosphere for 2 h to obtain a calcined material.

[0068] (2) The additive was mixed with the calcined material obtained in step (1), secondary sand milling was carried out for 4 h, and after drying, a sand milling powder with a particle size X50 of 0.8 μm was obtained.

[0069] Here, the additive contained 1500 ppm of Co2O3, 600 ppm of CaCO3, 300 ppm of Nb2O5, and 3000 ppm of TiO2 based on the total mass of the main components.

[0070] (3) The sand milling powder described in step (2) was sieved through a 60-mesh sieve, granulated and then formed to obtain a standard sample ring blank with a size of 12.5 mm × 7.5 mm × 7 mm. After sintering, the high-frequency manganese zinc ferrite material with low stress sensitivity was obtained.

[0071] The sintering process included heating the standard sample ring blank to 950 °C at a heating rate of 1.5 °C / min in an equilibrium oxygen partial pressure atmosphere, holding for 7 h, then cooling to 300 °C at a cooling rate of 2.5 °C / min, holding for 3 h, and finally cooling to 80 °C at a cooling rate of 0.1 °C / min.

[0072] [Example 3] This example provides a high-frequency manganese zinc ferrite material with low stress sensitivity. The manufacturing method of the high-frequency manganese zinc ferrite material with low stress sensitivity includes the following steps.

[0073] (1) 53 mol% of Fe2O3, 7 mol% of ZnO, and the balance MnO were mixed, and then mixed with water at a mass ratio of 1:1.5, followed by primary sand milling for 1 h and drying. After that, calcination was carried out at a temperature of 850 °C for 1 h in an air atmosphere to obtain a calcined material.

[0074] (2) The additive and the calcined material obtained in step (1) were mixed, and secondary sand milling was carried out for 2 h and dried to obtain a sand-milled powder with a particle size X50 of 1 μm.

[0075] Here, the additive contained 3000 ppm of Co2O3, 1000 ppm of CaCO3, 100 ppm of Nb2O5, and 1000 ppm of TiO2 in terms of the total mass of the main components.

[0076] (3) The sand-milled powder described in step (2) was sieved through a 60-mesh sieve, granulated, and then formed to obtain a standard sample ring blank with a size of 12.5 mm × 7.5 mm × 7 mm. After sintering, the low-stress sensitivity high-frequency manganese zinc ferrite material was obtained.

[0077] The sintering process included heating the standard sample ring blank to 1100 °C at a heating rate of 1.5 °C / min in an equilibrium oxygen partial pressure atmosphere, holding for 7 h, then cooling to 250 °C at a cooling rate of 2.8 °C / min, holding for 3 h, and finally cooling to 40 °C at a cooling rate of 0.1 °C / min.

[0078] [Example 4] This example provides a low-stress sensitivity high-frequency manganese zinc ferrite material. The difference between the manufacturing method of the low-stress sensitivity high-frequency manganese zinc ferrite material and Example 1 is that only the first temperature of sintering described in step (3) of this example was changed to 1135 °C.

[0079] [Example 5] This example provides a high-frequency manganese-zinc ferrite material with low stress sensitivity. The difference between the manufacturing method of the high-frequency manganese-zinc ferrite material with low stress sensitivity and Example 1 is that only the first sintering temperature described in step (3) of this example is changed to 1100 °C.

[0080] [Example 6] This example provides a high-frequency manganese-zinc ferrite material with low stress sensitivity. The difference between the manufacturing method of the high-frequency manganese-zinc ferrite material with low stress sensitivity and Example 1 is that only the second cooling rate of sintering described in step (3) of this example is changed to 1 °C / min.

[0081] [Example 7] This example provides a high-frequency manganese-zinc ferrite material with low stress sensitivity. The difference between the manufacturing method of the high-frequency manganese-zinc ferrite material with low stress sensitivity and Example 1 is that only the content of the main components described in step (1) of this example is changed to 52.5 mol% of Fe2O3, 6.3 mol% of ZnO, and the balance of MnO.

[0082] [Example 8] This example provides a high-frequency manganese-zinc ferrite material with low stress sensitivity. The difference between the manufacturing method of the high-frequency manganese-zinc ferrite material with low stress sensitivity and Example 1 is that only the content of the additives described in step (2) of this example is changed to include 2000 ppm of Co2O3, 1000 ppm of CaCO3, 100 ppm of Nb2O5, and 1000 ppm of TiO2 based on the total mass of the main components.

[0083] [Comparative Example 1] This comparative example provides a high-frequency manganese-zinc ferrite material with low stress sensitivity. The difference between the manufacturing method of the high-frequency manganese-zinc ferrite material with low stress sensitivity and Example 1 is that only the content of ZnO described in step (1) of this comparative example is changed to 5 mol%.

[0084] [Comparative Example 2] This comparative example provides a high-frequency manganese-zinc ferrite material with low stress sensitivity. The difference between the manufacturing method of the high-frequency manganese-zinc ferrite material with low stress sensitivity and Example 1 is that only Co2O3 in the additive described in step (2) is omitted in this comparative example.

[0085] [Comparative Example 3] This comparative example provides a high-frequency manganese-zinc ferrite material with low stress sensitivity. The difference between the manufacturing method of the high-frequency manganese-zinc ferrite material with low stress sensitivity and Example 1 is that only TiO2 in the additive described in step (2) is omitted in this comparative example.

[0086] [Comparative Example 4] This comparative example provides a high-frequency manganese-zinc ferrite material with low stress sensitivity. The difference between the manufacturing method of the high-frequency manganese-zinc ferrite material with low stress sensitivity and Example 1 is that only the addition amount of Co2O3 in the additive described in step (2) is changed to 3500 ppm in this comparative example.

[0087] [Comparative Example 5] This comparative example provides a high-frequency manganese-zinc ferrite material with low stress sensitivity. The difference between the manufacturing method of the high-frequency manganese-zinc ferrite material with low stress sensitivity and Example 1 is that only the addition amount of TiO2 in the additive described in step (2) is changed to 3500 ppm in this comparative example.

[0088] Performance detection is carried out on the high-frequency manganese-zinc ferrite materials with low stress sensitivity according to Examples 1 to 8 and Comparative Examples 1 to 5. Specifically, it is as follows.

[0089] The high-frequency manganese-zinc ferrite material with low stress sensitivity is placed in a SY8218 test instrument, and its loss is tested under the conditions of 1 MHz 50 mT, T = 25 °C / 100 °C / 120 °C, and the magnetic permeability at 10 kHz, 0.25 V, 25 °C and the magnetic permeability under a uniform pressure of 10 Mpa are detected. The results are as shown in Table 1.

[0090]

Table 1

[0091] From Table 1, the following was found.

[0092] (1) By analyzing Example 1 and Comparative Example 1, it was found that when the ZnO content in the ferrite material is too low, the magnetic permeability as a whole decreases, and the influence of stress on the magnetic permeability increases.

[0093] (2) By analyzing Example 1 and Comparative Example 2, it was found that the lack of Co2O3 additive increases the overall power consumption of the material.

[0094] (3) By analyzing Example 1 and Comparative Example 3, it was found that the lack of TiO2 additive increases the power consumption of the material, especially the loss at room temperature.

[0095] (4) By analyzing Example 1 and Example 4, it was found that when the sintering temperature is too high, the overall magnetic permeability increases, the influence of stress on the magnetic permeability increases, and the overall power consumption of the material deteriorates.

[0096] (5) By analyzing Example 1 and Example 6, it was found that when the temperature drop in the cooling stage during the sintering process is fast, the overall power consumption of the material deteriorates.

[0097] (6) By analyzing Example 1 and Comparative Example 4, it was found that the addition of excessive Co2O3 deteriorates the overall power consumption of the material and decreases the magnetic permeability.

[0098] (7) By analyzing Example 1 and Comparative Example 5, it was found that the addition of excessive TiO2 deteriorates the high-temperature power consumption of the material, decreases the magnetic permeability, and deteriorates the stress performance.

[0099] To summarize the above, the high-frequency manganese-zinc ferrite material with low stress sensitivity according to the present application reduces the magnetostriction constant of the material itself and decreases the stress sensitivity performance of the material itself by an appropriate main blending ratio, and reduces the loss of the material and improves the temperature characteristics of the material by an appropriate combination and addition amount of additives. After applying a pressure of 10 MPa to the ferrite material, the change in its magnetic permeability is less than 5%.

[0100] It should be understood that the above specific embodiments further elaborate on the object, technical solution, and beneficial effects of the present application, and the above are only specific embodiments of the present application and do not limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present application should all be included within the protection scope of the present application.

Claims

1. A high-frequency manganese zinc ferrite material containing a main component and an additive, The main component is Fe ２ O ３ , and includes ZnO and MnO, The additive is Co ２ O ３ , CaCO ３ , Nb ２ O ５ and TiO ２ and contains with low stress sensitivity.

2. The raw material of the main component contains, in terms of percentage of the total mass, 52 to 53 mol% of Fe ２ O ３ , 6 to 7 mol% of ZnO, and MnO as the balance The high-frequency manganese zinc ferrite material with low stress sensitivity according to Claim 1.

3. The additive is included in the percentage of the total mass of the main component Co ２ O ３ 1500 - 3000 ppm CaCO ３ 600 - 1000 ppm Nb ２ O ５ 100 - 300 ppm TiO ２ 1000 to 3000 ppm, and contains The high-frequency manganese zinc ferrite material with low stress sensitivity according to Claim 1 or 2.

4. A method for manufacturing the high-frequency manganese zinc ferrite material with low stress sensitivity according to any one of Claims 1 to 3, Fe as the main component according to the compounding ratio ２ O ３ Step (1) of mixing Fe, ZnO, and MnO according to the compounding ratio, then sequentially performing primary sand milling, drying, and calcination to obtain a calcined material comprising the steps of: mixing the additive with the calcined material obtained in step (1), performing secondary sand milling and drying, and then obtaining sand-milled powder (step (2)); sequentially performing sieving, granulation, forming, and sintering on the sand-milled powder described in step (2) to obtain the high-frequency manganese zinc ferrite material with low stress sensitivity (step (3)). Manufacturing method.

5. The process of the primary sand milling described in step (1) includes putting the main component and water into a sand mill for primary sand milling. The manufacturing method according to Claim 4.

6. The mass ratio of the main component to water is 1:(1.2 - 2.5). The manufacturing method according to Claim 5.

7. The time of the primary sand milling described in step (1) is 1 - 3 h. The manufacturing method according to any one of Claims 4 to 6.

8. The temperature of the calcination described in step (1) is 750 - 850 °C. The manufacturing method according to any one of Claims 4 to 7.

9. The time of the calcination described in step (1) is 1 - 3 h, preferably, the atmosphere of the calcination described in step (1) is an air atmosphere. The manufacturing method according to any one of Claims 4 to 8.

10. The additive described in step (2) is Co ２ O ３ , CaCO ３ , Nb ２ O ５ and TiO ２ and includes Preferably, the addition amount of Co in the additive ２ O ３ is 1500 to 3000 ppm of the total mass of the main component, Preferably, the addition amount of CaCO in the additive ３ is 600 to 1000 ppm of the total mass of the main component, Preferably, the addition amount of Nb ２ O ５ in the additive is 100 to 300 ppm of the total mass of the main component, Preferably, the addition amount of TiO in the additive ２ is 1000 to 3000 ppm of the total mass of the main component. The manufacturing method according to any one of Claims 4 to 9.

11. The time of the secondary sand milling described in step (2) is 2 - 4 h, preferably, the particle size X50 of the sand-milled powder described in step (2) is 0.8 - 1.2 μm. The manufacturing method according to any one of Claims 4 to 10.

12. The mesh number of the sieve used for sieving described in step (3) is 30 - 80 meshes, preferably, a granulating agent is added in the granulation described in step (3), preferably, the granulating agent contains PVA and / or PVB, preferably, the addition amount of the granulating agent is 8 - 15% of the mass of the sand-milled powder described in step (2). Preferably, the molding described in step (3) includes preparing the product obtained after granulation into a standard sample ring blank. Preferably, the size of the standard sample ring blank is 12.5 mm × 7.5 mm × 7 mm. The manufacturing method according to any one of claims 4 to 11.

13. The sintering process described in step (3) includes heating the standard sample ring blank to a first temperature, passing a certain amount of oxygen gas during heat preservation, cooling to a second temperature at a first cooling rate in an equilibrium oxygen partial pressure atmosphere, holding the temperature, and finally cooling to a third temperature at a second cooling rate. Preferably, the heating rate of the heating is 1 to 3 °C / min. Preferably, the first temperature is 950 to 1100 °C. Preferably, the heat preservation time at the first temperature is 3 to 7 h. Preferably, the first cooling rate is 2.5 to 5 °C / min. Preferably, the second temperature is 250 to 300 °C. Preferably, the heat preservation time at the second temperature is 3 to 5 h. Preferably, the second cooling rate is 0.1 to 0.5 °C / min. Preferably, the third temperature is 40 to 80 °C, and preferably 50 to 70 °C. The manufacturing method according to any one of claims 4 to 12.

14. Step (1): According to the compounding amount, mix the main components Fe ２ O ３ with ZnO and MnO, then mix with water at a mass ratio of 1:(1.2 - 2.5), perform primary sand milling for 1 - 3 h and drying, then carry out calcination at a temperature of 750 - 850 °C for 1 - 3 h in an air atmosphere to obtain a calcined material, Step (2): Mix the additive with the calcined material obtained in step (1), perform secondary sand milling for 2 to 4 h, and after drying, obtain a sand-milled powder with a particle size X50 of 0.8 to 1.2 μm. The additive contains, in terms of the total mass of the main component, 1500 to 3000 ppm of Co ２ O ３ , 600 to 1000 ppm of CaCO ３ , 100 to 300 ppm of Nb ２ O ５ , and 1000 to 3000 ppm of TiO ２ and contains Step (3): Sieve the sand-milled powder described in step (2) through a 30-80 mesh sieve, form it after granulation to obtain a standard sample ring blank with a size of 12.5 mm × 7.5 mm × 7 mm, and obtain the low stress sensitivity high frequency manganese zinc ferrite material after sintering. The sintering process includes, in an equilibrium oxygen partial pressure atmosphere, heating the standard sample ring blank to 950 to 1100 °C at a heating rate of 1 to 3 °C / min, holding the temperature for 3 to 7 h, then cooling to 250 to 300 °C at a cooling rate of 2.5 to 5 °C / min, holding the temperature for 3 to 5 h, and finally cooling to 40 to 80 °C at a cooling rate of 0.1 to 0.5 °C / min. The manufacturing method according to any one of claims 4 to 13.

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