A manganese-zinc ferrite material, its preparation method and application

Abstract

This invention provides a manganese-zinc ferrite material, its preparation method, and its applications. The manganese-zinc ferrite material comprises a main material and additives. The main material includes Fe2O3, ZnO, and MnO, and the additives include SnO2, SiO2, CaO, Nb2O5, ZrO2, and Co2O3. The manganese-zinc ferrite material of this invention exhibits low overall loss in the temperature range of 100–160°C, which can improve the energy conversion efficiency of electronic devices under ultra-high temperature and high current conditions.

Description

Technical Field

[0001] This invention belongs to the field of magnetic materials technology, and relates to a manganese-zinc ferrite material, its preparation method and application. Background Technology

[0002] As a functional material, soft magnetic ferrites have played a significant role in promoting national economic development and have been widely applied in various fields. With the rapid development of digital technology, automotive electronics, network communications, energy, biotechnology, and defense technology, higher demands are being placed on electronic devices. The miniaturization, intelligence, efficiency, and integration of electronic devices are also driving the continuous development of transformers.

[0003] Power-type manganese-zinc ferrites are mainly used in switching power supplies for various electronic devices such as computers and flat-screen TVs, as well as in on-board chargers (OBCs). The trend towards lightweighting, miniaturization, and planarization of these devices has placed higher demands on reducing the size of the components.

[0004] With the increasing popularity of electric vehicles, on-board chargers (OBCs) and charging stations are widely used. The growing demand for fast charging of electric vehicles inevitably leads to a significant increase in the power requirements for OBCs and charging stations. Furthermore, as new energy vehicle platforms operate at high voltages, the temperature of OBCs and charging stations must be maintained at least above 100°C during operation. To achieve efficient energy conversion, higher requirements are placed on the power consumption of power-type manganese-zinc ferrite batteries at high temperatures.

[0005] CN101169996A discloses a low-power Mn-Zn ferrite magnetic material for use under ultra-high temperature conditions and its preparation method. The main components of the ferrite magnetic material include: Fe2O3: 52-56 mol%, ZnO: 2-10 mol%, MnO: 38-42 mol%. Additives include one or a combination of CaCO3: 400-800 ppm, Nb2O5: 100-400 ppm, ZrO2: 100-800 ppm, and Co2O3: 1000-5000 ppm. The volumetric power loss (Pcv) at 140℃, 100 kHz, and 200 mT is less than or equal to 350 kW / m. 3 Its losses are relatively high, and it only focuses on the temperature point of 140℃, so its application range is not wide.

[0006] CN102219486A discloses a high-temperature, low-loss manganese-zinc ferrite material. The high-temperature, low-loss manganese-zinc ferrite material comprises the following main components: Fe₂O₃: 52–53.5 mol%, ZnO: 6–9 mol%, MnO: 37.5–42 mol%, and additives selected from at least one of SiO₂, CaCO₃, Nb₂O₅, V₂O₅, ZrO₂, Co₂O₃, NiO, and Li₂CO₃. Although the unit volume loss P is within the temperature range of 120–150 °C at 100 kHz and 200 mT. cv All less than 450kW / m 3 However, its losses are still relatively high.

[0007] CN112125655A discloses a method for preparing high-temperature, high-frequency, low-loss ferrite. The ferrite comprises the following main materials: Fe₂O₃: 52–58 mol%, ZnO: 9–13 mol%, MnCO₃: 31–38 mol%, NiO: 0.5–5 mol%, and additives including: SnO₂: 0.02–0.3 wt%, TiO₂: 0.02–0.3 wt%, and V₂O₅: 0.02–0.3 wt%. Although the power loss is low at relatively high operating temperatures of 120–180 °C within the 100–1000 kHz frequency range, its overall power loss is still relatively high.

[0008] In summary, providing a high-temperature, low-loss manganese-zinc ferrite with low overall loss in the temperature range of 100–160℃, its preparation method, and its application is of great significance in meeting the high efficiency requirements of devices such as OBCs and charging piles under ultra-high temperature and high current conditions. Summary of the Invention

[0009] The purpose of this invention is to provide a manganese-zinc ferrite material, its preparation method, and its application. The manganese-zinc ferrite material of this invention has low overall loss in the temperature range of 100-160℃, which can improve the energy conversion efficiency of electronic devices under ultra-high temperature and high current conditions.

[0010] To achieve this objective, the present invention adopts the following technical solution:

[0011] In a first aspect, the present invention provides a manganese-zinc ferrite material, the manganese-zinc ferrite material comprising a main material and additives, the main material comprising Fe2O3, ZnO and MnO, and the additives comprising SnO2, SiO2, CaO, Nb2O5, ZrO2 and Co2O3.

[0012] This invention incorporates SnO2, SiO2, CaO, Nb2O5, ZrO2, and Co2O3 as additives into manganese-zinc ferrite materials. The synergistic effect of these additives not only reduces eddy current and hysteresis losses but also achieves a wide-temperature range and low-loss effect. The resulting manganese-zinc power ferrite material achieves low losses (power consumption P at 100kHz and 200mT) over a relatively wide high-temperature range (100–160℃). cv ≤360kW / m 3 )performance.

[0013] Preferably, based on the total molar amount of the main material as 100%, the molar fraction of Fe2O3 is 52.4% to 52.8%, for example: 52.4%, 52.5%, 52.6%, 52.7% or 52.8%, etc., not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0014] In the prior art, the iron oxide content in the main material of manganese zinc ferrite is about 54%. This invention improves the resistivity of manganese zinc ferrite material by appropriately reducing the Fe2O3 content, thereby reducing eddy current loss; however, too low Fe2O3 content is also not conducive to reducing hysteresis loss.

[0015] Preferably, based on the total molar amount of the main material as 100%, the molar fraction of ZnO is 7-10%, for example: 7%, 7.5%, 8%, 9% or 10%, etc., not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0016] Controlling the ZnO content within the aforementioned range is beneficial for controlling the valley point and hysteresis loss (BS). Specifically, a ZnO content below 7% is detrimental to reducing hysteresis loss; a ZnO content above 10% is detrimental to increasing BS and will also cause the valley point to shift towards lower temperatures, which is not conducive to reducing high-temperature losses.

[0017] Preferably, based on the total molar amount of the main material as 100%, the molar fraction of MnO is 36-42%, for example: 36%, 37%, 37.2%, 38%, 39%, 40% or 42%, etc., not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0018] Preferably, the amount of SnO2 added is 0.12 to 0.18 wt% of the total mass of the main material, for example: 0.12 wt%, 0.13 wt%, 0.14 wt%, 0.16 wt%, or 0.18 wt%, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0019] Preferably, the amount of SiO2 added is 0.02 to 0.04 wt% of the total mass of the main material, for example: 0.02 wt%, 0.025 wt%, 0.03 wt%, 0.035 wt%, or 0.04 wt%, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0020] Preferably, the amount of CaO added is 0.08 to 0.15 wt% of the total mass of the main material, for example: 0.08 wt%, 0.1 wt%, 0.11 wt%, 0.13 wt%, or 0.15 wt%, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0021] Preferably, the amount of Nb2O5 added is 0.02 to 0.04 wt% of the total mass of the main material, for example: 0.02 wt%, 0.025 wt%, 0.03 wt%, 0.035 wt%, or 0.04 wt%, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0022] Preferably, the amount of ZrO2 added is 0.02 to 0.04 wt% of the total mass of the main material, for example: 0.02 wt%, 0.025 wt%, 0.03 wt%, 0.035 wt%, or 0.04 wt%, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0023] The combined addition of SiO2, CaCO3, Nb2O5 and ZrO2 forms a high-resistivity layer at the grain boundaries to improve the grain boundary resistivity, while also improving grain uniformity and reducing porosity, thereby reducing eddy current loss and hysteresis loss.

[0024] Preferably, the amount of Co2O3 added is 0.2 to 0.4 wt% of the total mass of the main material, for example: 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.35 wt%, or 0.4 wt%, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0025] Co2O3 and Fe 2+ It forms a synergistic effect. Because it has a positive K1 (magnetic anisotropy constant), it compensates for the negative K1 value of manganese zinc ferrite, reduces hysteresis loss, and achieves the effect of wide temperature range and reduced loss.

[0026] In a second aspect, the present invention provides a method for preparing the manganese-zinc ferrite material as described in the first aspect, the method comprising the following steps:

[0027] (1) After mixing and grinding the main material and the first additive, a pre-calcined material is obtained by pre-calcination treatment;

[0028] (2) The pre-burned material is mixed and ground with the second additive and then granulated. The granulated material is then sintered to obtain the manganese-zinc ferrite material.

[0029] The first additive includes SnO2, and the second additive includes SiO2, CaCO3, Nb2O5, ZrO2, and Co2O3.

[0030] This invention involves pre-firing SnO2 mixed with the main material, allowing SnO2 to penetrate the grains and suppress Fe. 2+ with Fe 3+ Electron transitions between grains increase the resistivity within the grains, reducing eddy current losses. The pre-sintered material is then mixed with other additives and sintered. Furthermore, some SnO2 that doesn't enter the ferrite lattice segregates at the grain boundary layer. Since the melting point of SnO2 (1127℃) is lower than the sintering temperature, a liquid phase forms during sintering, promoting solid-phase reactions and accelerating ion diffusion. When the ion diffusion rate is too fast, some pores cannot be eliminated in time and remain inside the grains. Compared to adding SnO2 in step (2), the more beneficial effect of adding SnO2 in step (1) is that Sn... 4+ Easier to penetrate the crystal lattice, enhancing Fe 2+ with Fe 3+ It inhibits electronic transitions between grains and increases grain resistivity, reduces SnO2 segregation at grain boundaries, weakens solid-phase reactions, and reduces porosity.

[0031] Preferably, the mixing and grinding in step (1) includes sand milling.

[0032] Preferably, the mixing and grinding time in step (1) is 2 to 4 hours, for example: 2 hours, 2.5 hours, 3 hours, 3.5 hours or 4 hours, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0033] Preferably, the temperature of the pre-firing treatment in step (1) is 700 to 800°C, for example: 700°C, 720°C, 750°C, 780°C or 800°C, etc., not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0034] Preferably, the pre-burning time in step (1) is 2 to 4 hours, for example: 2 hours, 2.5 hours, 3 hours, 3.5 hours or 4 hours, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0035] Preferably, the atmosphere for the pre-firing treatment in step (1) includes air and / or oxygen.

[0036] Preferably, the mixing and grinding in step (2) includes sand milling, and is not limited to the listed values; other unlisted values ​​within the range are also applicable.

[0037] Preferably, the mixing and grinding time in step (2) is 2 to 4 hours, for example: 2 hours, 2.5 hours, 3 hours, 3.5 hours or 4 hours.

[0038] Preferably, after mixing and grinding in step (2) and before granulation, a drying process is performed. This is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0039] Preferably, the median particle size D50 of the powder obtained by the drying process is 0.9 to 1.2 μm, for example: 0.9 μm, 0.95 μm, 1 μm, 1.1 μm or 1.2 μm, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0040] Preferably, the granulating agent in step (2) includes PVA and / or PVB.

[0041] Preferably, the mass ratio of the granulating agent to the powder obtained by drying is 0.05 to 0.1:1, for example: 0.05:1, 0.06:1, 0.08:1, 0.09:1 or 0.1:1, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0042] Preferably, the sintering process in step (2) includes heat preservation and cooling processes.

[0043] Preferably, the insulation temperature is 1240-1280℃, for example: 1240℃, 1250℃, 1260℃, 1270℃ or 1280℃, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0044] Preferably, the heat preservation time is 150 to 250 minutes, for example: 150 minutes, 180 minutes, 200 minutes, 220 minutes or 250 minutes, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0045] Preferably, the oxygen volume percentage in the insulating atmosphere is 4-6%, for example: 4%, 4.5%, 5%, 5.5% or 6%, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0046] Preferably, the cooling process includes one-step cooling and two-step cooling.

[0047] Preferably, the final temperature of the one-step cooling is ≥1100℃.

[0048] Preferably, the oxygen volume percentage in the atmosphere during the one-step cooling process is 1.5% to 3.5%, for example: 1.5%, 2%, 2.5%, 3% or 3.5%, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0049] Preferably, the endpoint temperature of the two-step cooling is 900-1100℃, for example: 900℃, 950℃, 1000℃, 1050℃ or 1100℃, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0050] Preferably, the oxygen volume percentage in the atmosphere during the two-step cooling process is 0.3% to 0.8%, for example: 0.3%, 0.4%, 0.5%, 0.6%, or 0.8%, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0051] Thirdly, the present invention provides an electronic device comprising the manganese-zinc ferrite material as described in the first aspect.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] (1) In this invention, SnO2, SiO2, CaO, Nb2O5, ZrO2 and Co2O3 are added to manganese zinc ferrite material as additives. The synergistic effect of various additives can not only reduce eddy current loss and hysteresis loss, but also achieve the effect of wide temperature range and reduced loss.

[0054] (2) By adjusting the preparation process and the ratio of raw materials, this invention enables the manganese-zinc power ferrite material to achieve a power consumption P of 100kHz and 200mT within a temperature range of 100-160℃. cv ≤360kW / m 3 Furthermore, at 140°C, under conditions of 100kHz and 200mT, the power consumption P of the manganese-zinc ferrite... cv ≤320kW / m 3 . Detailed Implementation

[0055] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0056] The materials mentioned in the embodiments of the present invention are the mixed materials obtained after mixing the materials in each step. For example, the material mentioned in step (1) of embodiment 1 is the mixture of the main material and SnO2, and the material mentioned in step (2) is the mixture of the remaining additives and pre-burned materials.

[0057] Example 1

[0058] This embodiment provides a manganese-zinc ferrite material, which is composed of a main material and additives. The main material consists of 52.4 mol% Fe₂O₃ and 10 mol% ZnO, with the remainder being MnO. The additives, based on the total mass of the main material, include 1500 ppm (0.15%) SnO₂, 300 ppm (0.03%) SiO₂, 1000 ppm (0.1%) CaO, 300 ppm (0.03%) Nb₂O₅, 200 ppm (0.02%) ZrO₂, and 3900 ppm (0.39%) Co₂O₃.

[0059] The preparation method of the manganese-zinc ferrite material is as follows:

[0060] (1) Mix the main material and SnO2, and perform a sand milling for 3 hours. During the process, the mass ratio of material, zirconium balls and water is 1:6:1.5. After drying, pre-calcine at 750°C for 3 hours in an air atmosphere to obtain pre-calcined material.

[0061] (2) Mix the remaining additives and the obtained pre-calcined material, and perform secondary sand milling for 3 hours. During the process, the mass ratio of material, zirconium balls and water is 1:6:1.5. The median particle size D50 of the sand milling material is 1 μm. Mix the secondary sand milling and dry the powder with 8 wt% PVA for granulation and molding. Finally, sintering is carried out. The sintering includes a heat preservation section of 1260℃ for 180 min and a cooling section. The oxygen content in the heat preservation section is 5 vol%. The oxygen content in the cooling section is 1.5 vol% in the process of cooling down to 1100℃. The oxygen content in the temperature range of 1100℃-900℃ is 0.3 vol%. The manganese zinc power ferrite material is obtained.

[0062] Example 2

[0063] This embodiment provides a manganese-zinc ferrite material, which is composed of a main material and additives. The main material consists of 52.8 mol% Fe₂O₃ and 7 mol% ZnO, with the remainder being MnO. The additives, based on the total mass of the main material, include 1200 ppm SnO₂, 200 ppm SiO₂, 1000 ppm CaO, 400 ppm Nb₂O₅, 300 ppm ZrO₂, and 2400 ppm Co₂O₃. The preparation method of the manganese-zinc ferrite material is as follows:

[0064] (1) Mix the main material and SnO2, and perform a sand milling for 2 hours. During the process, the mass ratio of material, zircon balls and water is 1:5:2. After drying, pre-calcine at 700°C for 4 hours in an air atmosphere to obtain pre-calcined material.

[0065] (2) Mix the remaining additives and the obtained pre-calcined material, and perform secondary sand milling for 4 hours. During the process, the mass ratio of material, zirconium balls and water is 1:5:2. The median particle size D50 of the sand milling material is 0.9μm. After secondary sand milling, mix 5wt% of PVA powder and dry it for granulation and molding. Finally, sintering is carried out. The sintering includes a heat preservation section of 1240℃ for 180 minutes and a cooling section. The oxygen content in the heat preservation section is 5vol%, the oxygen content in the cooling process to 1100℃ is 3.4vol%, and the oxygen content in the 1100℃-900℃ range is 0.6vol%. The manganese zinc power ferrite material is obtained.

[0066] Example 3

[0067] This embodiment provides a manganese-zinc ferrite material, which is composed of a main material and additives. The main material consists of 52.5 mol% Fe₂O₃ and 9.5 mol% ZnO, with the remainder being MnO. The additives, based on the total mass of the main material, include 1400 ppm SnO₂, 200 ppm SiO₂, 800 ppm CaO, 400 ppm Nb₂O₅, 400 ppm ZrO₂, and 2400 ppm Co₂O₃. The preparation method of the manganese-zinc ferrite material is as follows:

[0068] (1) Mix the main material and SnO2, and perform a sand milling for 4 hours. During the process, the mass ratio of material, zircon balls and water is 1:7:1. Then, pre-calcine at 800℃ for 2 hours in an air atmosphere to obtain pre-calcined material.

[0069] (2) Mix the remaining additives and the obtained pre-calcined material, and perform secondary sand milling for 2 hours. During the process, the mass ratio of material, zirconium balls and water is 1:7:1. The median particle size D50 of the sand milling material is 1.2 μm. Mix the secondary sand milling and dry the powder with 10 wt% PVA for granulation and molding. Finally, sintering is carried out. The sintering includes a heat preservation section of 1280℃ for 150 min and a cooling section. The oxygen content in the heat preservation section is 5 vol%. The oxygen content in the cooling process to 1100℃ is 1.6 vol%. The oxygen content in the temperature range of 1100℃-900℃ is 0.5 vol%. The manganese zinc power ferrite material is obtained.

[0070] Example 4

[0071] This embodiment provides a manganese-zinc ferrite material, which is composed of a main material and additives. The main material consists of 52.6 mol% Fe₂O₃ and 9 mol% ZnO, with the remainder being MnO. The additives, based on the total mass of the main material, are 1600 ppm SnO₂, 300 ppm SiO₂, 1300 ppm CaO, 200 ppm Nb₂O₅, 400 ppm ZrO₂, and 2800 ppm Co₂O₃. The preparation method of the manganese-zinc ferrite material is as follows:

[0072] (1) Mix the main material and SnO2, and perform a sand milling for 3 hours. During the process, the mass ratio of material, zirconium balls and water is 1:6:1.5. Then, pre-calcine at 750°C for 3 hours in an air atmosphere to obtain pre-calcined material.

[0073] (2) Mix the remaining additives and the obtained pre-burned material, and perform secondary sand milling for 3 hours. During the process, the mass ratio of material, zirconium balls and water is 1:6:1.5. The median particle size D50 of the sand milling material is 1 μm. Then mix 8 wt% PVA for granulation and molding, and finally sinter. The sintering includes a heat preservation section of 1270℃ for 200 min and a cooling section. The oxygen content in the heat preservation section is 5 vol%, the oxygen content in the cooling process to 1100℃ is 1.8 vol%, and the oxygen content in the 1100℃-900℃ range is 0.6 vol%, thus obtaining the manganese-zinc power ferrite material.

[0074] Example 5

[0075] The only difference between this embodiment and Example 1 is that the molar percentage of Fe2O3 is 52 mol% (the total amount is adjusted with MnO). All other conditions and parameters are exactly the same as in Example 1.

[0076] Example 6

[0077] The only difference between this embodiment and Example 1 is that the molar percentage of Fe2O3 is 53 mol% (the total amount is adjusted with MnO). All other conditions and parameters are exactly the same as in Example 1.

[0078] Example 7

[0079] The only difference between this embodiment and Example 1 is that the molar percentage of ZnO is 11 mol% (the total amount is adjusted with MnO). All other conditions and parameters are exactly the same as in Example 1.

[0080] Example 8

[0081] The only difference between this embodiment and Example 1 is that the molar percentage of ZnO is 6 mol% (the total amount is adjusted with MnO). All other conditions and parameters are exactly the same as in Example 1.

[0082] Example 9

[0083] The only difference between this embodiment and Embodiment 1 is that the mass of SnO2 is 800 ppm of the total mass of the main material; all other conditions and parameters are exactly the same as in Embodiment 1.

[0084] Example 10

[0085] The only difference between this embodiment and Embodiment 1 is that the mass of SnO2 is 2000 ppm of the total mass of the main material; all other conditions and parameters are exactly the same as in Embodiment 1.

[0086] Example 11

[0087] The only difference between this embodiment and Embodiment 1 is that the mass of SiO2 is 500 ppm of the total mass of the main material; all other conditions and parameters are exactly the same as in Embodiment 1.

[0088] Example 12

[0089] The only difference between this embodiment and Embodiment 1 is that the mass of SiO2 is 100 ppm of the total mass of the main material; all other conditions and parameters are exactly the same as in Embodiment 1.

[0090] Example 13

[0091] The only difference between this embodiment and Embodiment 1 is that the mass of CaO is 400 ppm of the total mass of the main material; all other conditions and parameters are exactly the same as in Embodiment 1.

[0092] Example 14

[0093] The only difference between this embodiment and Embodiment 1 is that the mass of CaO is 2000 ppm of the total mass of the main material; all other conditions and parameters are exactly the same as in Embodiment 1.

[0094] Example 15

[0095] The only difference between this embodiment and Embodiment 1 is that the mass of Nb2O5 is 100 ppm of the total mass of the main material; all other conditions and parameters are exactly the same as in Embodiment 1.

[0096] Example 16

[0097] The only difference between this embodiment and Embodiment 1 is that the mass of Nb2O5 is 500 ppm of the total mass of the main material; all other conditions and parameters are exactly the same as in Embodiment 1.

[0098] Example 17

[0099] The only difference between this embodiment and Embodiment 1 is that the mass of ZrO2 is 500 ppm of the total mass of the main material; all other conditions and parameters are exactly the same as in Embodiment 1.

[0100] Example 18

[0101] The only difference between this embodiment and Embodiment 1 is that the mass of ZrO2 is 100 ppm of the total mass of the main material; all other conditions and parameters are exactly the same as in Embodiment 1.

[0102] Example 19

[0103] The only difference between this embodiment and Embodiment 1 is that the mass of Co2O3 is 1500 ppm of the total mass of the main material; all other conditions and parameters are exactly the same as in Embodiment 1.

[0104] Example 20

[0105] The only difference between this embodiment and Embodiment 1 is that the mass of Co2O3 is 4500 ppm of the total mass of the main material; all other conditions and parameters are exactly the same as in Embodiment 1.

[0106] Example 21

[0107] The only difference between this embodiment and Embodiment 1 is that the mass of Co2O3 is 4500 ppm of the total mass of the main material; all other conditions and parameters are exactly the same as in Embodiment 1.

[0108] The only difference between this embodiment and embodiment 1 is that in step (2), the oxygen content is controlled at 4 vol% during the cooling process when the temperature drops to 1100℃, and the oxygen content is controlled at 1 vol% during the 1100-900℃ period. Other conditions and parameters are exactly the same as in embodiment 1.

[0109] Example 22

[0110] The only difference between this embodiment and embodiment 1 is that in step (2), the oxygen content is controlled at 1 vol% during the cooling process when the temperature drops to 1100℃, and the oxygen content is controlled at 0.2 vol% during the 1100-900℃ period. Other conditions and parameters are exactly the same as in embodiment 1.

[0111] Comparative Example 1

[0112] The only difference between this comparative example and Example 1 is that SnO2 is not added; all other conditions and parameters are exactly the same as in Example 1.

[0113] Comparative Example 2

[0114] The only difference between this comparative example and Example 1 is that SnO2 is added together with other additives in step (2), while the other conditions and parameters are exactly the same as in Example 1.

[0115] Comparative Example 3

[0116] The only difference between this comparative example and Example 1 is that CaCO3 is not added; all other conditions and parameters are exactly the same as in Example 1.

[0117] Comparative Example 4

[0118] The only difference between this comparative example and Example 1 is that Nb2O5 is not added; all other conditions and parameters are exactly the same as in Example 1.

[0119] Comparative Example 5

[0120] The only difference between this comparative example and Example 1 is that ZrO2 is not added; all other conditions and parameters are exactly the same as in Example 1.

[0121] Comparative Example 6

[0122] The only difference between this comparative example and Example 1 is that Co2O3 is not added; all other conditions and parameters are exactly the same as in Example 1.

[0123] Comparative Example 7

[0124] The only difference between this comparative example and Example 1 is that SiO2 is not added; all other conditions and parameters are exactly the same as in Example 1.

[0125] Performance testing:

[0126] The manganese-zinc power ferrite materials obtained in the above embodiments and comparative examples were placed on the SY8219 test equipment, and their losses were tested under the conditions of 100kHz 200mT and T = 100℃ / 120℃ / 140℃ / 160℃. The test results are shown in Table 1.

[0127] Table 1

[0128]

[0129]

[0130]

[0131] As shown in Table 1, and based on Examples 1-4, the manganese-zinc ferrite material prepared by the method of the present invention can achieve a loss of 345 kW / m at 100℃, 100 kHz, and 200 mT. 3 Below this, at 120℃, 100kHz, and 200mT, the loss can reach 320kW / m. 3 Below this, at 140℃, 100kHz, and 200mT, the loss can reach 320kW / m. 3 Below, at 160℃, 100kHz, and 200mT, the loss can reach 355kW / m. 3 the following.

[0132] A comparison of Examples 1 and 5-6 shows that the molar percentage of Fe2O3 in the main material affects the performance of the manganese-zinc ferrite material of the present invention during preparation. When the molar percentage of Fe2O3 in the main material is controlled at 52.4-52.8%, the manganese-zinc ferrite has better performance. If the molar percentage of Fe2O3 in the main material is too high, the high-temperature performance of the material will decrease more quickly. If the molar percentage of Fe2O3 in the main material is too low, the overall performance of the material will decrease.

[0133] A comparison of Examples 1 and 7-8 shows that the molar percentage of ZnO in the main material affects the performance of the manganese-zinc ferrite material prepared according to the present invention. Controlling the molar percentage of ZnO in the main material to 7-10% results in better performance of the manganese-zinc ferrite. If the molar percentage of ZnO in the main material is too high, the high-temperature performance of the material will decrease more rapidly. If the molar percentage of ZnO in the main material is too low, the overall performance of the material will decrease.

[0134] A comparison of Examples 1 and 9-10 shows that the amount of SnO2 added during the preparation of the manganese-zinc ferrite material of the present invention affects its performance. When the mass of SnO2 is controlled at 0.12-0.18% of the total mass of the main material, the manganese-zinc ferrite has better performance. If the amount of SnO2 added is too high or too low, the performance of the material will decrease to varying degrees.

[0135] A comparison of Examples 1 and 11-20 shows that the amount of other additives added during the preparation of the manganese-zinc ferrite material of the present invention also affects its performance. The material exhibits better performance when the mass of SiO2 is controlled at 0.02-0.04% of the total mass of the main material, the mass of CaCO3 at 0.08-0.15% of the total mass of the main material, the mass of Nb2O5 at 0.02-0.04% of the total mass of the main material, the mass of ZrO2 at 0.02-0.04% of the total mass of the main material, and the mass of Co2O3 at 0.2-0.4% of the total mass of the main material. If these ranges are exceeded, the material's performance will decrease to varying degrees.

[0136] A comparison of Examples 1 and 21-22 shows that the oxygen content in the atmosphere during the cooling process of the manganese-zinc ferrite material prepared according to the present invention also affects its performance. During the cooling process with an end temperature ≥1100℃, the oxygen volume ratio in the atmosphere is controlled at 1.5-3.5%, and during the cooling process with an end temperature of 900-1100℃, the oxygen volume ratio in the atmosphere is controlled at 0.3-0.8%. The manganese-zinc ferrite material prepared has better performance. If it exceeds the above range, the performance of the material will decrease to varying degrees.

[0137] As can be seen from the comparison between Example 1 and Comparative Example 1, the present invention adds SnO2 as an additive to manganese-zinc ferrite. SnO2 enters the grains and inhibits Fe 2+ with Fe 3+ Electron transitions between grains increase the resistivity within the grain, thereby reducing eddy current losses.

[0138] As can be seen from the comparison between Example 1 and Comparative Example 2, SnO2 adds properties that are beneficial to the overall material in step (1).

[0139] A comparison of Example 1 and Comparative Examples 3-7 shows that the combined addition of SiO2, CaCO3, Nb2O5, and ZrO2 forms a high-resistivity layer at the grain boundaries to improve grain boundary resistivity. Simultaneously, it improves grain uniformity and reduces porosity, thereby lowering eddy current loss and hysteresis loss. Co2O3 and Fe... 2+ It forms a synergistic effect. Because it has a positive K1 (magnetic anisotropy constant), it compensates for the negative K1 value of manganese zinc ferrite, reduces hysteresis loss, and achieves the effect of wide temperature range and reduced loss.

[0140] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a manganese-zinc ferrite material, characterized in that, The preparation method includes the following steps: (1) After mixing and grinding the main material and the first additive, the pre-calcined material is obtained by pre-calcination treatment; (2) The pre-burned material is mixed and ground with the second additive and then granulated. The granulated material is then sintered to obtain the manganese-zinc ferrite material. Wherein, the first additive is SnO2, and the second additive includes SiO2, CaO, Nb2O5, ZrO2 and Co2O3; The main materials include Fe2O3, ZnO, and MnO; Based on the total molar amount of the main material being 100%, the molar fraction of Fe2O3 is 52.4% to 52.8%. Based on the total molar amount of the main material being 100%, the molar fraction of ZnO is 7-10%; Based on the total molar amount of the main material being 100%, the molar fraction of MnO is 36-42%. The amount of SnO2 added is 0.12~0.18 wt% of the total mass of the main material; The SiO2 added is 0.02~0.04 wt% of the total mass of the main material; The amount of CaO added is 0.08~0.15 wt% of the total mass of the main material; The amount of Nb2O5 added is 0.02~0.04 wt% of the total mass of the main material; The amount of ZrO2 added is 0.02~0.04 wt% of the total mass of the main material; The amount of Co2O3 added is 0.2~0.4 wt% of the total mass of the main material; The sintering process in step (2) includes heat preservation and cooling processes; The insulation temperature is 1240~1280℃; The heat preservation time is 150~250 minutes; The oxygen volume percentage in the insulating atmosphere is 4-6%; The cooling process includes one-step cooling and two-step cooling; The final temperature of the one-step cooling process is ≥1100℃; The oxygen volume percentage in the atmosphere during the one-step cooling process is 1.5% to 3.5%. The final temperature of the two-step cooling process is 900~1100℃; The oxygen volume percentage in the atmosphere during the two-step cooling process is 0.3-0.8%.

2. The preparation method according to claim 1, characterized in that, The mixing and grinding in step (1) includes sand milling.

3. The preparation method according to claim 1, characterized in that, The mixing and grinding time in step (1) is 2 to 4 hours.

4. The preparation method according to claim 1, characterized in that, The temperature of the pre-firing treatment in step (1) is 700~800℃.

5. The preparation method according to claim 1, characterized in that, The pre-burning treatment in step (1) takes 2 to 4 hours.

6. The preparation method according to claim 1, characterized in that, The atmosphere for the pre-firing treatment in step (1) includes an oxygen-containing atmosphere.

7. The preparation method according to claim 6, characterized in that, The oxygen-containing atmosphere includes oxygen and / or air.

8. The preparation method according to claim 1, characterized in that, The mixing and grinding in step (2) includes sand milling.

9. The preparation method according to claim 1, characterized in that, The mixing and grinding time in step (2) is 2 to 4 hours.

10. The preparation method according to claim 1, characterized in that, After mixing and grinding in step (2) and before granulation, the mixture is dried.

11. The preparation method according to claim 10, characterized in that, The median particle size D50 of the powder obtained by the drying process is 0.9~1.2μm.

12. The preparation method according to claim 11, characterized in that, The granulating agent in the granulation process includes PVA and / or PVB.

13. The preparation method according to claim 12, characterized in that, The mass ratio of the granulating agent to the powder obtained by drying is 0.05~0.1:

1.

14. A manganese-zinc ferrite material, characterized in that, The manganese-zinc ferrite material is obtained by the preparation method described in any one of claims 1-13.

15. An electronic device, characterized in that, The electronic device comprises the manganese-zinc ferrite material as described in claim 14.

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