A broadband high-impedance high-curie-temperature manganese-zinc ferrite material, a preparation method and application thereof

Abstract

The application provides a wideband high-impedance high-Curie-temperature manganese-zinc ferrite material which is prepared from main components, auxiliary components and additives; the main components are composed of Fe2O3 51.8-52.5 mol%, ZnO 19.4-20.2 mol% and the rest is Mn3O4 in terms of mole percentage; the auxiliary components include CaCO3 400-600 ppm, SiO2 100-200 ppm, V2O5 500-700 ppm, SnO2 300-400 ppm and WO3 100-200 ppm in terms of the total mass of the main components; and the additives include LiCl 100-200 ppm in terms of the total mass of the main components. The formula of the manganese-zinc ferrite and the preparation process thereof are reasonably limited, and finally the manganese-zinc ferrite material with excellent comprehensive performance is prepared.

Description

Technical Field

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

[0002] Manganese-zinc ferrite materials are widely used in inductors, communications, and power industries, such as common-mode inductors, transformers, high-conductivity filters for electromagnetic interference suppression, microwave devices, antennas, isolators, and power switches. With the rapid development and advancement of technology, the miniaturization, thinning, and high-frequency application of equipment necessitate that manganese-zinc ferrite materials not only possess higher permeability, impedance, and Curie temperature performance, but also excellent broadband characteristics.

[0003] Materials such as H5C3 from TDK in Japan, T66 and T46 from EPCOS, JPH-15 from Jiangmen Magnetic Powder, TL15 from Haining Tiantong, and 3E7 and 3E12 from Ferroxcube all have at least one of the following problems: initial permeability less than 15000, low Curie temperature, low impedance performance, and frequency characteristics that need further improvement.

[0004] CN112723873A discloses a broadband, high-impedance, high-permeability MnZn soft magnetic ferrite and its preparation method. The main components are Fe2O3: 52.5-53.9 mol%, ZnO: 21.3.5-23.3 mol%, and the remainder is Mn3O4. It is doped with nanoscale auxiliary materials CaCO3, Bi2O3, Nb2O5, SiO2, and MoO3. The process used is oxygen-enriched sintering, and the sintering temperature is 1300-1400℃.

[0005] CN107324794A discloses a broadband, high impedance, and high Curie temperature manganese-zinc ferrite and its preparation method. The main components are Fe2O3: 51-53 mol%, ZnO: 20-22 mol%, and the remainder is MnO. The auxiliary components, based on the total mass of the main components, are CaCO3, Bi2O3, MoO3, TiO2, and Nb2O5. The sintering temperature is 1300-1400℃.

[0006] However, all of the above-mentioned existing technologies suffer from the problem of high sintering temperatures, and the overall performance of ferrite materials still needs to be further improved. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a wideband, high impedance, and high Curie temperature manganese-zinc ferrite material. By rationally limiting the formulation and preparation process of manganese-zinc ferrite, a manganese-zinc ferrite material with excellent comprehensive performance is finally obtained.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a wideband, high impedance, and high Curie temperature manganese-zinc ferrite material, wherein the manganese-zinc ferrite material is prepared from a main component, an auxiliary component, and additives.

[0010] The composition of the principal component, in mole percentage, is as follows:

[0011] The Fe2O3 content is 51.8-52.5 mol%, for example, it can be 51.8 mol%, 51.9 mol%, 52.0 mol%, 52.1 mol%, 52.2 mol%, 52.3 mol%, 52.4 mol%, or 52.5 mol%, more preferably 52.0-52.4 mol%, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0012] The ZnO content is 19.4-20.2 mol%, for example, it can be 19.4 mol%, 19.5 mol%, 19.6 mol%, 19.7 mol%, 19.8 mol%, 19.9 mol%, 20.0 mol%, 20.1 mol%, or 20.2 mol%, more preferably 19.4-20.0 mol%, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0013] The rest are Mn3O4.

[0014] Preferably, the total mass of the principal component is used as the calculation basis, and the auxiliary components include:

[0015] The CaCO3 concentration is 400-600 ppm, for example, it can be 400 ppm, 420 ppm, 440 ppm, 460 ppm, 480 ppm, 500 ppm, 520 ppm, 540 ppm, 560 ppm, 580 ppm or 600 ppm, more preferably 500-600 ppm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0016] The SiO2 content is 100-200 ppm, for example, it can be 100 ppm, 110 ppm, 120 ppm, 130 ppm, 140 ppm, 150 ppm, 160 ppm, 170 ppm, 180 ppm, 190 ppm or 200 ppm, more preferably 150-200 ppm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0017] The V2O5 is 500-700 ppm, for example, it can be 500 ppm, 520 ppm, 540 ppm, 560 ppm, 580 ppm, 600 ppm, 620 ppm, 640 ppm, 660 ppm, 680 ppm or 700 ppm, more preferably 600-700 ppm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0018] SnO2 is 300-400ppm, for example, it can be 300ppm, 310ppm, 320ppm, 330ppm, 340ppm, 350ppm, 360ppm, 370ppm, 380ppm, 390ppm or 400ppm, more preferably 300-350ppm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0019] WO3 is 100-200 ppm, for example, it can be 100 ppm, 110 ppm, 120 ppm, 130 ppm, 140 ppm, 150 ppm, 160 ppm, 170 ppm, 180 ppm, 190 ppm or 200 ppm, more preferably 150-200 ppm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0020] Preferably, the additives are calculated based on the total mass of the main components, and include:

[0021] The LiCl concentration is 100-200 ppm, for example, it can be 100 ppm, 110 ppm, 120 ppm, 130 ppm, 140 ppm, 150 ppm, 160 ppm, 170 ppm, 180 ppm, 190 ppm or 200 ppm, more preferably 150-200 ppm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0022] This invention, by rationally limiting the composition and ratio of manganese-zinc ferrite, appropriately reduces the ZnO content in the main component based on the traditional formula, thereby lowering the sintering temperature. Simultaneously, it increases the Mn3O4 content, thus improving the resistivity of the ferrite. The auxiliary components, CaCO3 and SiO2, are abundant at the grain boundaries, refining the grains and improving grain uniformity, reducing porosity, and increasing the magnetic permeability and resistivity of the ferrite. V2O5, with its low melting point (690℃), forms a liquid phase in the early stages of sintering, accelerating the solid-state reaction, promoting the formation of a spinel structure, further lowering the sintering temperature. Furthermore, as its content increases, grain uniformity continuously improves, grain boundaries and intra-grain porosity significantly decrease, and the magnetic permeability of the ferrite significantly increases. 5+ Entering the B site of spinel ferrite increases the Fe content in the ferrite. 2+ Compensation was applied to K1, causing it to move closer to 0. This explains why the magnetic permeability increases with the increase of V2O5 content. In addition, the addition of SnO2, WO3 auxiliary components and LiCl additives further reduced the sintering temperature and increased the magnetic permeability and Curie temperature, ultimately resulting in a manganese-zinc ferrite material with excellent comprehensive performance.

[0023] The manganese-zinc ferrite material provided by this invention has the following properties: permeability μi≥16000 at 10kHz; permeability μi≥11000 at 200kHz; μi≥9000 at 300kHz; impedance coefficient ZN≥25.0Ω / mm at 200kHz; impedance coefficient ZN≥35.0Ω / mm at 0.5-1MHz; and Curie temperature Tc≥140℃.

[0024] Secondly, 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:

[0025] (1) Weigh the main components and perform wet ball milling and spray drying in sequence to obtain the first powder;

[0026] (2) The first powder obtained in step (1) is pre-fired in a nitrogen atmosphere to obtain pre-fired material;

[0027] (3) Add auxiliary components to the pre-calcined material obtained in step (2), and ball mill to obtain intermediate material;

[0028] (4) Add additives to the intermediate material obtained in step (3), and then spray granulate to obtain the second powder;

[0029] (5) The second powder obtained in step (4) is pressed and sintered in sequence to obtain manganese zinc ferrite material.

[0030] Preferably, the wet ball milling time in step (1) is 20-40 min, for example, it can be 20 min, 22 min, 24 min, 26 min, 28 min, 30 min, 32 min, 34 min, 36 min, 38 min or 40 min, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0031] Preferably, the pre-firing in step (2) is carried out in a box-type resistance furnace, and the pre-firing temperature is 800-1000℃, for example, it can be 800℃, 820℃, 840℃, 860℃, 880℃, 900℃, 920℃, 940℃, 960℃, 980℃ or 1000℃, and the holding time is 1-3h, for example, it can be 1h, 1.2h, 1.4h, 1.6h, 1.8h, 2h, 2.2h, 2.4h, 2.6h, 2.8h or 3h, but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0032] This invention involves pre-firing in a nitrogen atmosphere, which generates a large amount of spinel structure in the powder during the pre-firing stage, thereby reducing the subsequent sintering temperature. The pre-firing temperature needs to be limited to a reasonable range: when the pre-firing temperature is below 800℃, only a small amount of spinel structure can be generated; when the sintering temperature is above 1000℃, the material strength becomes too high, increasing the difficulty of subsequent ball milling, failing to effectively reduce the particle size of the powder, and also affecting the reduction of the sintering temperature and the improvement of the overall performance of the ferrite.

[0033] Preferably, the average particle size D50 of the auxiliary component in step (3) is 10-20 μm, for example, it can be 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm or 20 μm, but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0034] Preferably, the ball milling time in step (3) is 1-1.5h, for example, it can be 1h, 1.1h, 1.2h, 1.3h, 1.4h or 1.5h, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0035] Preferably, the pressing pressure in step (5) is 10-12 MPa, for example, it can be 10 MPa, 10.2 MPa, 10.4 MPa, 10.6 MPa, 10.8 MPa, 11 MPa, 11.2 MPa, 11.4 MPa, 11.6 MPa, 11.8 MPa or 12 MPa, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0036] Preferably, the sintering process in step (5) includes: first heating to a first temperature at a first rate, holding at the temperature for a first time period at a first oxygen content; then heating to a second temperature at a second rate, holding at the temperature for a second time period at a second oxygen content, and then holding at the temperature for a third time period at a third oxygen content; then naturally cooling to a third temperature, holding at the temperature for a fourth time period at a fourth oxygen content; and finally cooling to room temperature at a third rate.

[0037] Preferably, the first rate is 2-3℃ / min, for example, it can be 2℃ / min, 2.1℃ / min, 2.2℃ / min, 2.3℃ / min, 2.4℃ / min, 2.5℃ / min, 2.6℃ / min, 2.7℃ / min, 2.8℃ / min, 2.9℃ / min or 3℃ / min, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0038] Preferably, the first temperature is 860-880℃, for example, it can be 860℃, 862℃, 864℃, 866℃, 868℃, 870℃, 872℃, 874℃, 876℃, 878℃ ​​or 880℃, but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0039] Preferably, the first oxygen content is 0-0.5%, for example, it can be 0%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45% or 0.5%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0040] Preferably, the first time period is 0.5-1h, for example, it can be 0.5h, 0.55h, 0.6h, 0.65h, 0.7h, 0.75h, 0.8h, 0.85h, 0.9h, 0.95h or 1h, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0041] Preferably, the second rate is 2-3℃ / min, for example, it can be 2℃ / min, 2.1℃ / min, 2.2℃ / min, 2.3℃ / min, 2.4℃ / min, 2.5℃ / min, 2.6℃ / min, 2.7℃ / min, 2.8℃ / min, 2.9℃ / min or 3℃ / min, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0042] Preferably, the second temperature is 1240-1260℃, for example, it can be 1240℃, 1242℃, 1244℃, 1246℃, 1248℃, 1250℃, 1252℃, 1254℃, 1256℃, 1258℃ or 1260℃, but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0043] Preferably, the second oxygen content is 18-20%, for example, it can be 18%, 18.2%, 18.4%, 18.6%, 18.8%, 19%, 19.2%, 19.4%, 19.6%, 19.8% or 20%, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0044] Preferably, the second time period is 3-5 hours, for example, it can be 3 hours, 3.2 hours, 3.4 hours, 3.6 hours, 3.8 hours, 4 hours, 4.2 hours, 4.4 hours, 4.6 hours, 4.8 hours or 5 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0045] Preferably, the third oxygen content is 2-2.5%, for example, it can be 2%, 2.05%, 2.1%, 2.15%, 2.2%, 2.25%, 2.3%, 2.35%, 2.4%, 2.45% or 2.5%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0046] Preferably, the third time period is 2-4 hours, for example, it can be 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours, 3 hours, 3.2 hours, 3.4 hours, 3.6 hours, 3.8 hours or 4 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0047] Preferably, the third temperature is 990-1010℃, for example, it can be 990℃, 992℃, 994℃, 996℃, 998℃, 1000℃, 1002℃, 1004℃, 1006℃, 1008℃ or 1010℃, but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0048] Preferably, the fourth oxygen content is 1.5-2%, for example, it can be 1.5%, 1.55%, 1.6%, 1.65%, 1.7%, 1.75%, 1.8%, 1.85%, 1.9%, 1.95% or 2%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0049] Preferably, the fourth time period is 1-2 hours, for example, it can be 1 hour, 1.1 hours, 1.2 hours, 1.3 hours, 1.4 hours, 1.5 hours, 1.6 hours, 1.7 hours, 1.8 hours, 1.9 hours or 2 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0050] Preferably, the third rate is 3-4℃ / min, for example, it can be 3℃ / min, 3.1℃ / min, 3.2℃ / min, 3.3℃ / min, 3.4℃ / min, 3.5℃ / min, 3.6℃ / min, 3.7℃ / min, 3.8℃ / min, 3.9℃ / min or 4℃ / min, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0051] As a preferred embodiment of the second aspect of the present invention, the preparation method includes the following steps:

[0052] (1) Weigh the main components and wet ball mill them for 20-40 minutes, then spray dry them to obtain the first powder.

[0053] (2) In a box-type resistance furnace under nitrogen atmosphere, the first powder obtained in step (1) is pre-fired, and the pre-fired temperature is controlled at 800-1000℃ and the holding time is 1-3h to obtain pre-fired material;

[0054] (3) Add auxiliary components with an average particle size D50 of 10-20 μm to the pre-calcined material obtained in step (2), and ball mill for 1-1.5 h to obtain intermediate material;

[0055] (4) Add additives to the intermediate material obtained in step (3), and then spray granulate to obtain the second powder;

[0056] (5) The second powder obtained in step (4) is pressed into shape at 10-12 MPa and then sintered. Specifically, the temperature is first raised to 860-880℃ at 2-3℃ / min and held at 0-0.5% oxygen content for 0.5-1h; then the temperature is raised to 1240-1260℃ at 2-3℃ / min and held at 18-20% oxygen content for 3-5h; then held at 2-2.5% oxygen content for 2-4h; then the temperature is naturally cooled to 990-1010℃ and held at 1.5-2% oxygen content for 1-2h; finally, the temperature is lowered to room temperature at 3-4℃ / min to obtain manganese zinc ferrite material.

[0057] Thirdly, the present invention provides an application of the manganese-zinc ferrite material as described in the first aspect, wherein the manganese-zinc ferrite material is used to manufacture common-mode inductors, transformers, high-conductivity filters for electromagnetic interference suppression, microwave devices, antennas, isolators, or power switches.

[0058] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0059] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0060] (1) By reasonably limiting the composition and ratio of manganese zinc ferrite, the present invention appropriately reduces the ZnO content in the main component on the basis of the traditional formula, thereby reducing the sintering temperature, while increasing the Mn3O4 content, thereby increasing the resistivity of the ferrite.

[0061] (2) The auxiliary components CaCO3 and SiO2 are enriched in large quantities at the grain boundaries, which plays a role in refining the grains, thereby improving the grain uniformity, reducing the porosity of the material, and improving the magnetic permeability and resistivity of the ferrite.

[0062] (3) V₂O₅ has a low melting point (690℃), forming a liquid phase in the early stages of sintering, thus accelerating the solid-state reaction, promoting the formation of spinel structure, further reducing the sintering temperature, and with the increase of its content, the grain uniformity is continuously improved, the porosity of grain boundaries and within grain boundaries is significantly reduced, and the magnetic permeability of ferrite is significantly increased, while V 5+ Entering the B site of spinel ferrite increases the Fe content in the ferrite. 2+ Compensation is applied to K1 to bring it closer to 0, which is why the magnetic permeability increases with the increase of V2O5 content.

[0063] (4) With the addition of SnO2, WO3 auxiliary components and LiCl additives, the sintering temperature was further reduced, the magnetic permeability and Curie temperature were increased, and finally a manganese zinc ferrite material with excellent comprehensive performance was obtained.

[0064] (5) The manganese zinc ferrite material provided by the present invention has a permeability μi≥16000 at a frequency of 10kHz; a permeability μi≥11000 at 200kHz; a permeability μi≥9000 at 300kHz; an impedance coefficient ZN≥25.0Ω / mm at a frequency of 200KHz; an impedance coefficient ZN≥35.0Ω / mm at 0.5-1MHz; and a Curie temperature Tc≥140℃. Detailed Implementation

[0065] The technical solution of the present invention will be further illustrated below through specific embodiments.

[0066] Example 1

[0067] This embodiment provides a broadband, high-impedance, high-Curie-temperature manganese-zinc ferrite material and its preparation method. The manganese-zinc ferrite material is prepared from a main component, auxiliary components, and additives. The main component, in molar percentage, consists of: Fe₂O₃ 52.2 mol%, ZnO 19.4 mol%, with the remainder being Mn₃O₄. Using the total mass of the main component as the calculation basis, the auxiliary components are: CaCO₃ 500 ppm, SiO₂ 150 ppm, V₂O₅ 600 ppm, SnO₂ 300 ppm, and WO₃ 200 ppm. Using the total mass of the main component as the calculation basis, the additive is: LiCl 200 ppm.

[0068] The preparation method provided in this embodiment includes the following steps:

[0069] (1) Weigh the main components and wet ball mill for 30 min, then spray dry to obtain the first powder;

[0070] (2) In a box-type resistance furnace under nitrogen atmosphere, the first powder obtained in step (1) is pre-burned, and the pre-burning temperature is controlled at 900℃ and the holding time is 2h to obtain pre-burned material;

[0071] (3) Add auxiliary components with an average particle size D50 of 15 μm to the pre-calcined material obtained in step (2), and ball mill for 1 hour to obtain intermediate material;

[0072] (4) Add additives to the intermediate material obtained in step (3), and then spray granulate to obtain the second powder;

[0073] (5) The second powder obtained in step (4) is pressed and shaped at 11 MPa, and then sintered. Specifically, the temperature is raised to 870°C at 3°C / min and held at 0% oxygen content for 1 hour; then the temperature is raised to 1240°C at 3°C / min and held at 19% oxygen content for 5 hours, and then held at 2.5% oxygen content for 2 hours; then the temperature is naturally lowered to 1010°C and held at 1.5% oxygen content for 2 hours; finally, the temperature is lowered to room temperature at 3°C / min to obtain manganese zinc ferrite material.

[0074] Example 2

[0075] This embodiment provides a wideband, high impedance, and high Curie temperature manganese-zinc ferrite material and its preparation method. Except for changing the molar percentage of ZnO in the main component to 20.2 mol% and adaptively adjusting the content of Mn3O4, the other steps and conditions are the same as in Example 1, so they will not be described in detail here.

[0076] Example 3

[0077] This embodiment provides a wideband, high impedance, and high Curie temperature manganese-zinc ferrite material and its preparation method. Except for changing the SnO2 content in the auxiliary component to 400 ppm, the other steps and conditions are the same as in Example 1, so they will not be described in detail here.

[0078] Example 4

[0079] This embodiment provides a wideband, high impedance, high Curie temperature manganese-zinc ferrite material and its preparation method. Except for changing the content of WO3 in the auxiliary component to 100 ppm, the other steps and conditions are the same as in Example 1, so they will not be described in detail here.

[0080] Example 5

[0081] This embodiment provides a wideband, high impedance, and high Curie temperature manganese-zinc ferrite material and its preparation method. Except for changing the content of the additive LiCl to 100 ppm, the other steps and conditions are the same as in Example 1, so they will not be described in detail here.

[0082] Example 6

[0083] This embodiment provides a wideband, high impedance, high Curie temperature manganese-zinc ferrite material and its preparation method. Except for changing "heating to 1240°C at 3°C / min and holding at 19% oxygen content for 5h" in step (5) to "heating to 1260°C at 3°C / min and holding at 19% oxygen content for 3h", the other steps and conditions are the same as in Example 1, so they will not be repeated here.

[0084] Example 7

[0085] This embodiment provides a wideband, high impedance, high Curie temperature manganese-zinc ferrite material and its preparation method. Except for changing "holding at 2.5% oxygen content for 2 hours" in step (5) to "holding at 2% oxygen content for 4 hours", the other steps and conditions are the same as in embodiment 1, so they will not be repeated here.

[0086] Example 8

[0087] This embodiment provides a wideband, high impedance, high Curie temperature manganese-zinc ferrite material and its preparation method. Except for changing "naturally cooling to 1010℃ and holding at 1.5% oxygen content for 2h" in step (5) to "naturally cooling to 990℃ and holding at 2% oxygen content for 2h", the other steps and conditions are the same as in embodiment 1, so they will not be repeated here.

[0088] Comparative Example 1

[0089] This comparative example provides a manganese-zinc ferrite material and its preparation method. Except for changing the molar percentage of ZnO in the main component to 20.5 mol% and adaptively adjusting the content of Mn3O4, the other steps and conditions are the same as in Example 1, so they will not be described in detail here.

[0090] Comparative Example 2

[0091] This comparative example provides a manganese-zinc ferrite material and its preparation method. Except for changing the molar percentage of ZnO in the main component to 19 mol% and adaptively adjusting the content of Mn3O4, the other steps and conditions are the same as in Example 1, so they will not be described in detail here.

[0092] Comparative Example 3

[0093] This comparative example provides a manganese-zinc ferrite material and its preparation method. Except for changing the SnO2 content in the auxiliary component to 200 ppm, the other steps and conditions are the same as in Example 1, so they will not be described in detail here.

[0094] Comparative Example 4

[0095] This comparative example provides a manganese-zinc ferrite material and its preparation method. Except for changing the SnO2 content in the auxiliary component to 500 ppm, the other steps and conditions are the same as in Example 1, so they will not be described in detail here.

[0096] Comparative Example 5

[0097] This comparative example provides a manganese-zinc ferrite material and its preparation method. Except for the absence of WO3 in the auxiliary components, the other steps and conditions are the same as in Example 1, so they will not be described in detail here.

[0098] Comparative Example 6

[0099] This comparative example provides a manganese-zinc ferrite material and its preparation method. Except for changing the content of WO3 in the auxiliary component to 300 ppm, the other steps and conditions are the same as in Example 1, so they will not be described in detail here.

[0100] Comparative Example 7

[0101] This comparative example provides a manganese-zinc ferrite material and its preparation method. Except for the absence of the additive LiCl, the other steps and conditions are the same as in Example 1, so they will not be described in detail here.

[0102] Comparative Example 8

[0103] This comparative example provides a manganese-zinc ferrite material and its preparation method. Except for changing the content of the additive LiCl to 300 ppm, the other steps and conditions are the same as in Example 1, so they will not be described in detail here.

[0104] Comparative Example 9

[0105] This comparative example provides a manganese-zinc ferrite material and its preparation method. Except for changing "heating to 1240°C at 3°C / min and holding at 19% oxygen content for 5h" in step (5) to "heating to 1220°C at 3°C / min and holding at 19% oxygen content for 5h", the other steps and conditions are the same as in Example 1, so they will not be repeated here.

[0106] Comparative Example 10

[0107] This comparative example provides a manganese-zinc ferrite material and its preparation method. Except for changing "heating to 1240°C at 3°C / min and holding at 19% oxygen content for 5h" in step (5) to "heating to 1280°C at 3°C / min and holding at 19% oxygen content for 3h", the other steps and conditions are the same as in Example 1, so they will not be repeated here.

[0108] Comparative Example 11

[0109] This comparative example provides a manganese-zinc ferrite material and its preparation method. Except for changing "holding at 2.5% oxygen content for 2 hours" in step (5) to "holding at 2.5% oxygen content for 1 hour", the other steps and conditions are the same as in Example 1, so they will not be repeated here.

[0110] Comparative Example 12

[0111] This comparative example provides a manganese-zinc ferrite material and its preparation method. Except for changing "holding at 2.5% oxygen content for 2 hours" in step (5) to "holding at 2.5% oxygen content for 5 hours", the other steps and conditions are the same as in Example 1, so they will not be repeated here.

[0112] Comparative Example 13

[0113] This comparative example provides a manganese-zinc ferrite material and its preparation method. Except for changing "holding at 2.5% oxygen content for 2 hours" in step (5) to "holding at 1.5% oxygen content for 2 hours", the other steps and conditions are the same as in Example 1, so they will not be repeated here.

[0114] Comparative Example 14

[0115] This comparative example provides a manganese-zinc ferrite material and its preparation method. Except for changing "holding at 2.5% oxygen content for 2 hours" in step (5) to "holding at 3% oxygen content for 2 hours", the other steps and conditions are the same as in Example 1, so they will not be repeated here.

[0116] Comparative Example 15

[0117] This comparative example provides a manganese-zinc ferrite material and its preparation method. Except for changing "naturally cooling to 1010℃ and holding at 1.5% oxygen content for 2h" in step (5) to "naturally cooling to 970℃ and holding at 2.5% oxygen content for 2h", the other steps and conditions are the same as in Example 1, so they will not be repeated here.

[0118] Comparative Example 16

[0119] This comparative example provides a manganese-zinc ferrite material and its preparation method. Except for changing "naturally cooling to 1010℃ and holding at 1.5% oxygen content for 2h" in step (5) to "naturally cooling to 1030℃ and holding at 1% oxygen content for 2h", the other steps and conditions are the same as in Example 1, so they will not be repeated here.

[0120] The permeability, impedance coefficient and Curie temperature of the manganese-zinc ferrite materials obtained in Examples 1-8 and Comparative Examples 1-16 at different frequencies are shown in Table 1 below.

[0121] Table 1

[0122]

[0123]

[0124] As shown in Table 1, the manganese-zinc ferrite material provided by this invention has the following properties: permeability μi ≥ 16000 at 10kHz; permeability μi ≥ 11000 at 200kHz; μi ≥ 9000 at 300kHz; impedance coefficient ZN ≥ 25.0Ω / mm at 200kHz; impedance coefficient ZN ≥ 35.0Ω / mm at 0.5-1MHz; and Curie temperature Tc ≥ 140℃.

[0125] Therefore, this invention, by rationally limiting the composition and ratio of manganese-zinc ferrite, appropriately reduces the ZnO content in the main component based on the traditional formula, thereby lowering the sintering temperature. Simultaneously, it increases the Mn3O4 content, thus improving the resistivity of the ferrite. The auxiliary components, CaCO3 and SiO2, are abundant at the grain boundaries, refining the grains and improving grain uniformity, reducing porosity, and increasing the magnetic permeability and resistivity of the ferrite. V2O5, with its low melting point (690℃), forms a liquid phase in the early stages of sintering, accelerating the solid-state reaction, promoting the formation of spinel structures, further lowering the sintering temperature. Furthermore, as its content increases, grain uniformity continuously improves, grain boundaries and intra-grain porosity significantly decrease, and the magnetic permeability of the ferrite significantly increases. 5+ Entering the B site of spinel ferrite increases the Fe content in the ferrite. 2+Compensation was applied to K1, causing it to move closer to 0. This explains why the magnetic permeability increases with the increase of V2O5 content. In addition, the addition of SnO2, WO3 auxiliary components and LiCl additives further reduced the sintering temperature and increased the magnetic permeability and Curie temperature, ultimately resulting in a manganese-zinc ferrite material with excellent comprehensive performance.

[0126] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A broadband, high-impedance, high-Curie-temperature manganese-zinc ferrite material, characterized in that, The manganese-zinc ferrite material is prepared from main components, auxiliary components, and additives; The composition of the principal component, in mole percentage, is as follows: Fe2O3 51.8-52.5 mol% ZnO 19.4-20.2 mol% The rest are Mn3O4; The auxiliary components include the following, calculated based on the total mass of the principal components: CaCO3 400-600ppm; SiO2 100-200ppm; V2O5 500-700ppm; SnO2 300-400ppm; WO3 100-200ppm; The additives, calculated based on the total mass of the main components, include: LiCl 100-200ppm; The broadband, high-impedance, high-Curie-temperature manganese-zinc ferrite material is prepared by the following method, which includes the following steps: (1) Weigh the main components and perform wet ball milling and spray drying in sequence to obtain the first powder; (2) The first powder obtained in step (1) is pre-fired in a nitrogen atmosphere to obtain pre-fired material; (3) Add auxiliary components to the pre-calcined material obtained in step (2), and ball mill to obtain intermediate material; (4) Add additives to the intermediate material obtained in step (3), and then spray granulate to obtain the second powder; (5) The second powder obtained in step (4) is pressed and sintered in sequence to obtain manganese zinc ferrite material; The pre-firing in step (2) is carried out in a box-type resistance furnace, and the pre-firing temperature is 800-1000℃, and the holding time is 1-3h; The sintering process in step (5) includes: first heating to a first temperature at a first rate, holding at a first oxygen content for a first time period; then heating to a second temperature at a second rate, holding at a second oxygen content for a second time period, and then holding at a third oxygen content for a third time period; then naturally cooling to a third temperature, holding at a fourth oxygen content for a fourth time period; and finally cooling to room temperature at a third rate.

2. The manganese-zinc ferrite material according to claim 1, characterized in that, The composition of the principal component, in mole percentage, is as follows: Fe2O3 52.0-52.4 mol% ZnO 19.4-20.0 mol% The rest are Mn3O4; The auxiliary components include the following, calculated based on the total mass of the principal components: CaCO3 500-600ppm; SiO2 150-200ppm; V2O5 600-700ppm; SnO2 300-350ppm; WO3 150-200ppm; The additives, calculated based on the total mass of the main components, include: LiCl 150-200ppm.

3. A method for preparing the manganese-zinc ferrite material as described in claim 1 or 2, characterized in that, The preparation method includes the following steps: (1) Weigh the main components and perform wet ball milling and spray drying in sequence to obtain the first powder; (2) The first powder obtained in step (1) is pre-fired in a nitrogen atmosphere to obtain pre-fired material; (3) Add auxiliary components to the pre-calcined material obtained in step (2), and ball mill to obtain intermediate material; (4) Add additives to the intermediate material obtained in step (3), and then spray granulate to obtain the second powder; (5) The second powder obtained in step (4) is pressed and sintered in sequence to obtain manganese zinc ferrite material; The pre-firing in step (2) is carried out in a box-type resistance furnace, and the pre-firing temperature is 800-1000℃, and the holding time is 1-3h; The sintering process in step (5) includes: first heating to a first temperature at a first rate, holding at a first oxygen content for a first time period; then heating to a second temperature at a second rate, holding at a second oxygen content for a second time period, then holding at a third oxygen content for a third time period; then naturally cooling to a third temperature, holding at a fourth oxygen content for a fourth time period; and finally cooling to room temperature at a third rate.

4. The preparation method according to claim 3, characterized in that, The wet ball milling time in step (1) is 20-40 min.

5. The preparation method according to claim 3, characterized in that, The average particle size D50 of the auxiliary component in step (3) is 10-20 μm.

6. The preparation method according to claim 3, characterized in that, The ball milling time in step (3) is 1-1.5 hours.

7. The preparation method according to claim 3, characterized in that, The pressing pressure in step (5) is 10-12 MPa.

8. The preparation method according to claim 3, characterized in that, The first rate is 2-3 °C / min.

9. The preparation method according to claim 3, characterized in that, The first temperature is 860-880℃.

10. The preparation method according to claim 3, characterized in that, The first oxygen content is 0-0.5%.

11. The preparation method according to claim 3, characterized in that, The first time period is 0.5-1 hour.

12. The preparation method according to claim 3, characterized in that, The second rate is 2-3 °C / min.

13. The preparation method according to claim 3, characterized in that, The second temperature is 1240-1260℃.

14. The preparation method according to claim 3, characterized in that, The second oxygen content is 18-20%.

15. The preparation method according to claim 3, characterized in that, The second time period is 3-5 hours.

16. The preparation method according to claim 3, characterized in that, The third oxygen content is 2-2.5%.

17. The preparation method according to claim 3, characterized in that, The third time period is 2-4 hours.

18. The preparation method according to claim 3, characterized in that, The third temperature is 990-1010℃.

19. The preparation method according to claim 3, characterized in that, The fourth oxygen content is 1.5-2%.

20. The preparation method according to claim 3, characterized in that, The fourth time period is 1-2 hours.

21. The preparation method according to claim 3, characterized in that, The third rate is 3-4℃ / min.

22. The preparation method according to claim 3, characterized in that, The preparation method includes the following steps: (1) Weigh the main components and wet ball mill for 20-40 min, then spray dry to obtain the first powder; (2) In a box-type resistance furnace under nitrogen atmosphere, the first powder obtained in step (1) is pre-burned, and the pre-burning temperature is controlled at 800-1000℃ and the holding time is 1-3h to obtain pre-burned material; (3) Add auxiliary components with an average particle size D50 of 10-20 μm to the pre-calcined material obtained in step (2), and ball mill for 1-1.5 h to obtain intermediate material; (4) Add additives to the intermediate material obtained in step (3), and then spray granulate to obtain the second powder; (5) The second powder obtained in step (4) is pressed into shape at 10-12 MPa and then sintered. Specifically, the temperature is raised to 860-880℃ at 2-3℃ / min and held at 0-0.5% oxygen content for 0.5-1h; then the temperature is raised to 1240-1260℃ at 2-3℃ / min and held at 18-20% oxygen content for 3-5h; then held at 2-2.5% oxygen content for 2-4h; then the temperature is naturally cooled to 990-1010℃ and held at 1.5-2% oxygen content for 1-2h; finally, the temperature is lowered to room temperature at 3-4℃ / min to obtain manganese zinc ferrite material.

23. An application of the manganese-zinc ferrite material as described in claim 1 or 2, characterized in that, The manganese-zinc ferrite material is used to manufacture common-mode inductors, transformers, high-conductivity filters for electromagnetic interference suppression, microwave devices, antennas, isolators, or power switches.

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