阅读说明：本技术 一种超高频高磁导率低损耗锰锌软磁铁氧体及制备方法 (Ultrahigh-frequency high-permeability low-loss manganese-zinc soft magnetic ferrite and preparation method thereof ) 是由 张志新 张强原 邢冰冰 王鸿健 徐涛 缪思敏 于 2021-09-24 设计创作，主要内容包括：本发明属于磁性材料技术领域,公开了一种超高频高磁导率低损耗锰锌软磁铁氧体及制备方法。本发明材料包含主成分和辅助成分,主成分包括Fe-(2)O-(3)、ZnO、MoO-(3)、Mn-(3)O-(4),辅助成分包括CaCO-(3)、ZrO-(2)、TiO-(2)、Co-(2)O-(3)、CuO。本发明通过合适的主成分与掺杂,采用低Zn主配方,ZnO含量为0～3.0 wt%,提高截至频率；在主配方中掺杂低熔点物质MoO-(3),降低烧结温度；将其在600～900℃进行退火处理,提高磁导率。通过以上方式,成功制作出在6MHz、30mT和8MHz、10mT,及25℃和40℃条件下具有超高频高磁导率低损耗的锰锌软磁铁氧体材料。(The invention belongs to the technical field of magnetic materials, and discloses an ultrahigh frequency high magnetic conductivity low loss manganese zinc soft magnetic ferrite and a preparation method thereof. The material of the invention comprises a main component and an auxiliary component, wherein the main component comprises Fe 2 O 3 、ZnO、MoO 3 、Mn 3 O 4 The auxiliary component comprises CaCO 3 、ZrO 2 、TiO 2 、Co 2 O 3 And CuO. According to the invention, through proper main components and doping, a low-Zn main formula is adopted, the ZnO content is 0-3.0 wt%, and the cut-off frequency is improved; the main formula is doped with a low-melting-point material MoO 3 Reducing the sintering temperature; annealing treatment is carried out on the magnetic material at 600-900 ℃, and the magnetic conductivity is improved. By the method, the ultrahigh-temperature-resistant aluminum alloy with ultrahigh temperature at the temperature of 25 ℃ and 40 ℃ and ultrahigh temperature at 6MHz, 30mT, 8MHz and 10mTThe manganese-zinc soft magnetic ferrite material has high frequency, high magnetic conductivity and low loss.)

1. The ultrahigh-frequency high-permeability low-loss manganese-zinc soft magnetic ferrite is characterized in that the ultrahigh-frequency high-permeability low-loss manganese-zinc soft magnetic ferrite material comprises a main component andan auxiliary component, wherein the main component comprises Fe₂O₃：73.5～76.5wt%，ZnO：0～3.0 wt%，MoO₃: 0.01 to 0.04 wt%, and the balance Mn₃O₄The auxiliary components comprise the following components in percentage by weight based on the total weight of the main components: CaCO₃：400～600ppm、ZrO₂：100～300ppm、TiO₂：500～800ppm、Co₂O₃：1500～4000ppm、CuO:50～200ppm，

The preparation method of the ultrahigh frequency high magnetic conductivity low loss manganese-zinc soft magnetic ferrite comprises the following steps:

step 1: preparing materials: weighing Fe in proportion₂O₃、ZnO、MoO₃、Mn₃O₄Then, carrying out wet sanding mixing for 10-20 min;

step 2: pre-burning: pre-burning the mixture obtained in the step 1 after drying, and pre-burning in air, wherein the pre-burning temperature is 800-1000 ℃, and the heating rate is 3-5 ℃/min;

and step 3: sanding: and (3) vibrating and grinding the pre-sintered material obtained in the step (2), and then adding auxiliary components in proportion: CaCO₃、ZrO₂、TiO₂、Co₂O₃And CuO, sanding for 30-90 min;

and 4, step 4: and (3) granulation: drying and granulating the ground slurry;

and 5: and (3) pressing and forming: pressing into annular green body with size of phi 12.5mm phi 7.5mm phi 7 mm;

step 6: sintering, wherein the sintering temperature is 1000-1200 ℃, the heat preservation time is 4-8 h, and the equilibrium oxygen content is 1.5-3.0%;

and 7: annealing, namely annealing the fired product under a vacuum condition, namely heating to 600-900 ℃ under the vacuum condition, and preserving heat for 2-4 h.

2. The uhp high permeability low loss mn-zn soft magnetic ferrite according to claim 1, wherein the main component comprises Fe₂O₃：74.0～75.5wt%，ZnO：1.4～3.0 wt%，MoO₃: 0.03-0.04 wt%, and the balance of Mn₃O₄(ii) a Auxiliary components: CaCO₃：400～600ppm、ZrO₂：100～300ppm、TiO₂：500～800ppm、Co₂O₃：1500～2000ppm、CuO:50～200ppm。

3. The ultrahigh-frequency high-permeability low-loss manganese-zinc soft magnetic ferrite according to any one of claims 1 to 2 is characterized in that the sintering temperature in the step 6 is 1050-1150 ℃, and the grain size after sintering is 2-4 μm.

4. The ultrahigh-frequency high-permeability low-loss manganese-zinc soft magnetic ferrite according to any one of claims 1 to 2, characterized in that in the step 7, in the annealing process, the temperature is raised to 250 to 400 ℃ at a rate of 3 to 5 ℃/min, the temperature is preserved for 30 to 60min, then the temperature is raised to 600 to 900 ℃ at a rate of 1 to 3 ℃/min, the temperature is preserved for 2 to 4h, then the temperature is lowered to 300 to 500 ℃ at a rate of 1 to 3 ℃/min, and finally the temperature is lowered to room temperature at a rate of 5 to 8 ℃/min.

Technical Field

The invention relates to an ultrahigh frequency high magnetic conductivity low loss manganese zinc soft magnetic ferrite and a preparation method thereof, belonging to the technical field of magnetic materials.

Background

With the development of microelectronic technology, the performance of traditional Si and GaAs semiconductor devices has approached the theoretical limit determined by their materials themselves. The third generation semiconductor, i.e., wide bandgap semiconductor material, represented by silicon carbide (SiC) and gallium nitride (GaN) has the outstanding advantages of wide bandgap, high saturation drift velocity, high critical breakdown electric field, etc., and thus becomes an ideal substitute material for manufacturing high-power, high-frequency and anti-radiation electronic devices. The working frequency of the current high-frequency transformer is higher than 1MHz, and with the development of science and technology, the future development trend is over 5 MHz. At present, the common material with the use frequency of more than 5MHz is NiZn ferrite, but the cost of the material is much higher than that of MnZn ferrite. Therefore, in order to meet the requirement of a magnetic device on high frequency and further save cost, a new generation of high-performance soft magnetic material with ultrahigh frequency, low loss, high magnetic permeability and high direct current bias capability in a frequency range of 6MHz to 8MHz is to be developed.

The Chinese patent with the publication number of CN106830913B discloses a method for manufacturing MnZn ferrite with high frequency, high saturation magnetic flux density and low loss, the formula and the process of the MnZn ferrite are greatly different from the invention,and isNo permeability is involved and the applicable frequency does not break through 6 MHz. Chinese patent publication No. CN112759379A discloses a tempering process for reducing loss of a high-frequency MnZn ferrite sintered core, which improves loss after treating the core at Tc ± 150 ℃ in a nitrogen atmosphere, but does not describe changes in other magnetic properties. The annealing mode of the invention is greatly different from the annealing mode of the invention, the invention not only can improve the loss, but also can improve the magnetic conductivity, so that the magnetic conductivity of the magnetic core is not deteriorated under the ultrahigh frequency.

Disclosure of Invention

In order to solve the problems, the invention provides a manganese-zinc soft magnetic ferrite with ultrahigh frequency and high magnetic permeability and a preparation method thereof. According to the invention, through proper main components and doping and the adoption of a low-Zn main formula, the cut-off frequency of the material is improved, so that the material has lower loss under the frequency characteristic of 6-8 MHz. The main formula is doped with a low-melting-point material MoO₃The method has the effects of dissolving aid, reducing sintering temperature, accelerating reaction speed and the like, reduces the grain size and reduces high-frequency loss. Due to the low Zn formulation and the doping of the cosolvent, the materialThe magnetic permeability of the material is reduced, and in order to further reduce loss and improve the magnetic permeability, the material is subjected to annealing treatment at 600-900 ℃. Through annealing, the internal stress of the magnetic core can be eliminated, the magnetic conductivity is improved, the liquid phase distribution is more uniform, the resistivity is improved, and the loss is reduced. Finally obtaining the ultrahigh frequency high magnetic conductivity manganese-zinc soft magnetic ferrite.

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

step 1: preparing materials: weighing Fe in proportion₂O₃：73.5～76.5wt%，ZnO：0～3.0 wt%，MoO₃: 0.01 to 0.04 wt%, and the balance Mn₃O₄Then, carrying out wet sanding mixing for 10-20 min;

step 2: pre-burning: pre-burning the mixture obtained in the step 1 after drying, and pre-burning in air, wherein the pre-burning temperature is 800-1000 ℃, and the heating rate is 3-5 ℃/min;

and step 3: sanding: and (3) vibrating and grinding the pre-sintered material obtained in the step (2), and then adding auxiliary components in proportion: CaCO₃：400～600ppm、ZrO₂：100～300ppm、TiO₂：500～800ppm、Co₂O₃: 1500-4000 ppm of CuO, 50-200 ppm of CuO, and the sanding time is 30-90 min;

and 4, step 4: and (3) granulation: adding 15 wt% of polyvinyl alcohol according to the total weight of the ground powder, grinding and sieving the powder into particles with a certain size, drying the ground slurry and granulating;

and 5: and (3) pressing and forming: pressing into annular green body with size of phi 12.5mm phi 7.5mm phi 7 mm;

step 6: sintering, wherein the sintering temperature is 1000-1200 ℃, the heat preservation time is 4-8 h, and the equilibrium oxygen content is 1.5-3.0%;

and 7: annealing, and annealing the sintered product under a vacuum condition. In the heating process, the temperature is increased to 250-400 ℃ at a speed of 3-5 ℃/min, the temperature is maintained for 30-60 min, then the temperature is increased to 600-900 ℃ at a speed of 1-3 ℃, the temperature is maintained for 2-4 h, then the temperature is gradually reduced, the temperature reduction rate is reduced to 300-500 ℃ at a speed of 1-3 ℃/min, and then the temperature is reduced to the room temperature at a speed of 5-8 ℃.

Further excellenceOptionally, the main component of the manganese-zinc ferrite with ultrahigh frequency, high magnetic permeability and low loss comprises Fe₂O₃：74.0～75.5wt%，ZnO：1.4～3.0 wt%，MoO₃: 0.03-0.04 wt%, and the balance of Mn₃O₄(ii) a Auxiliary components: CaCO₃：400～600ppm、ZrO₂：100～300ppm、TiO₂：500～800ppm、Co₂O₃：1500～2000ppm、CuO:50～200ppm。

Further preferably, the sintering temperature in the step 6 is 1050-1150 ℃, and the grain size after sintering is 2-4 mu m.

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

the manganese-zinc soft magnetic ferrite has lower loss and high magnetic conductivity under the frequency characteristic of 6-8 MHz, and achieves the following technical performance, indexes and parameters:

(1) the initial magnetic conductivity mu i is more than or equal to 850(T is 25 ℃, B is less than 0.25 mT);

(2) the magnetic loss Pcv is less than or equal to 1150kW/m³(T＝25℃，f＝6MHz，B＝30mT)；Pcv≤1250kW/m³(T＝40℃，f＝6MHz，B＝30mT)；Pcv≤600kW/m³(T＝25℃，f＝8MHz，B＝10mT)；Pcv≤730kW/m³(T＝40℃，f＝8MHz，B＝10mT)；

(3) The saturation magnetic induction intensity Bs is more than or equal to 530mT (25 ℃, H is 1194A/m); bs is more than or equal to 440mT (100 ℃, H is 1194A/m);

the ultrahigh frequency high magnetic conductivity low loss manganese zinc soft magnetic ferrite of the invention not only can replace partial NiZn ferrite, meet the use requirement of magnetic devices on ultrahigh frequency, greatly reduce the material cost, but also is beneficial to reducing the volume and the number of turns of winding, reducing the line loss and reducing the temperature rise of the device, can be widely applied to miniaturized devices, and can make material storage for further miniaturization of the devices in the future.

Detailed Description

The ultrahigh frequency, high magnetic permeability and low loss manganese-zinc soft magnetic ferrite material prepared by the invention and the preparation process thereof are further specifically explained by specific implementation examples. Two kinds of MnZn soft magnetic ferrite materials of example 1 and example 2 and four kinds of MnZn soft magnetic ferrite materials of comparative example 1, comparative example 2, comparative example 3, and comparative example 4 were prepared according to the following preparation methods.

Example 1: the preparation method of the manganese-zinc soft magnetic ferrite with ultrahigh frequency, high magnetic conductivity and low loss comprises the following steps:

step 1: preparing materials: fe₂O₃：74.3wt%，ZnO：1.8 wt%，MoO₃: 0.04 wt% and the balance Mn₃O₄Burdening, and then performing wet ball milling mixing for 15 min;

step 2: pre-burning: after drying the mixture obtained in the step 1, presintering the mixture, wherein the presintering temperature is 900 ℃, and the heating rate is 5 ℃/min;

and step 3: sanding: and (3) carrying out vibration grinding on the obtained pre-sintering material, and then adding auxiliary components: CaCO₃：600ppm、ZrO₂：200ppm、TiO₂：800ppm、Co₂O₃: 1800ppm of CuO and 50-200 ppm of sand milling for 70 min;

and 4, step 4: and (3) granulation: adding 15 wt% of polyvinyl alcohol according to the total weight of the powder obtained after grinding, and grinding and sieving the mixture into particles with a certain size;

and 5: and (3) pressing and forming: pressing into annular green body with size of phi 12.5mm phi 7.5mm phi 7 mm;

step 6: and (3) sintering: the sintering temperature is 1120 ℃, the heat preservation time is 6 hours, and the equilibrium oxygen content is 1.6 percent;

and 7: annealing: raising the temperature to 700 ℃ at a certain heating rate under the vacuum condition, preserving the temperature for 2 hours, and then gradually reducing the temperature to room temperature at a certain rate.

Example 2: the manganese-zinc soft magnetic ferrite material with ultrahigh frequency, high magnetic conductivity and low loss consists of main components and auxiliary components, and the preparation method comprises the following steps:

step 1: preparing materials: fe₂O₃：74.8wt%，ZnO：2.4 wt%，MoO₃: 0.04 wt% and the balance Mn₃O₄Burdening, and then performing wet ball milling mixing for 15 min;

step 2: pre-burning: after drying the mixture obtained in the step 1, presintering the mixture, wherein the presintering temperature is 900 ℃, and the heating rate is 5 ℃/min;

and step 3: sanding: to the obtainedPre-sintering materials are subjected to vibration milling, and then auxiliary components are added: CaCO₃：600ppm、ZrO₂：200ppm、TiO₂：800ppm、Co₂O₃: 1800ppm of CuO and 80ppm of CuO, and sanding for 70 min;

and 4, step 4: and (3) granulation: adding 15 wt% of polyvinyl alcohol according to the total weight of the powder obtained after grinding, and grinding and sieving the mixture into particles with a certain size;

and 5: and (3) pressing and forming: pressing into annular green body with size of phi 12.5mm phi 7.5mm phi 7 mm;

step 6: and (3) sintering: the sintering temperature is 1120 ℃, the heat preservation time is 6 hours, and the equilibrium oxygen content is 1.6 percent;

and 7: annealing: raising the temperature to 700 ℃ at a certain heating rate under the vacuum condition, preserving the temperature for 2 hours, and then gradually reducing the temperature to room temperature at a certain rate.

Example 3: the manganese-zinc soft magnetic ferrite material with ultrahigh frequency, high magnetic conductivity and low loss consists of main components and auxiliary components, and the preparation method comprises the following steps:

step 1: preparing materials: fe₂O₃：75.2wt%，ZnO：2.8 wt%，MoO₃: 0.03 wt% and the balance Mn₃O₄Burdening, and then performing wet ball milling mixing for 15 min;

step 2: pre-burning: after drying the mixture obtained in the step 1, presintering the mixture, wherein the presintering temperature is 900 ℃, and the heating rate is 5 ℃/min;

and step 3: sanding: and (3) carrying out vibration grinding on the obtained pre-sintering material, and then adding auxiliary components: CaCO₃：600ppm、ZrO₂：200ppm、TiO₂：800ppm、Co₂O₃: 1800ppm, 80ppm CuO, sanding for 70 min.

And 4, step 4: and (3) granulation: adding 15 wt% of polyvinyl alcohol according to the total weight of the powder obtained after grinding, and grinding and sieving the mixture into particles with a certain size;

and 5: and (3) pressing and forming: pressing into annular green body with size of phi 12.5mm phi 7.5mm phi 7 mm;

step 6: and (3) sintering: the sintering temperature is 1120 ℃, the heat preservation time is 6 hours, and the equilibrium oxygen content is 1.6 percent;

and 7: annealing: raising the temperature to 800 ℃ at a certain heating rate under the vacuum condition, preserving the temperature for 2 hours, and then gradually reducing the temperature to room temperature at a certain rate.

Comparative example 1: a manganese-zinc soft magnetic ferrite material comprises a main component and an auxiliary component, and the preparation method comprises the following steps:

step 1: preparing materials: fe₂O₃：74.3wt%，ZnO：2.2 wt%，MoO₃: 0.04 wt% and the balance Mn₃O₄Burdening, and then performing wet ball milling mixing for 15 min;

step 2: pre-burning: after drying the mixture obtained in the step 1, presintering the mixture, wherein the presintering temperature is 900 ℃, and the heating rate is 5 ℃/min;

and step 3: sanding: and (3) carrying out vibration grinding on the obtained pre-sintering material, and then adding auxiliary components: CaCO₃：600ppm、ZrO₂：200ppm、TiO₂：800ppm、Co₂O₃: 1800ppm of CuO and 50-200 ppm of sand milling for 70 min;

and 4, step 4: and (3) granulation: adding 15 wt% of polyvinyl alcohol according to the total weight of the powder obtained after grinding, and grinding and sieving the mixture into particles with a certain size;

and 5: and (3) pressing and forming: pressing into annular green body with size of phi 12.5mm phi 7.5mm phi 7 mm;

step 6: and (3) sintering: the sintering temperature is 1120 ℃, the heat preservation time is 6 hours, and the equilibrium oxygen content is 1.6 percent.

Comparative example 2: a manganese-zinc soft magnetic ferrite material comprises a main component and an auxiliary component, and the preparation method comprises the following steps:

step 1: preparing materials: fe₂O₃：74.6wt%，ZnO：3.4wt%，MoO₃: 0.04 wt% and the balance Mn₃O₄Burdening, and then performing wet ball milling mixing for 15 min;

step 2: pre-burning: after drying the mixture obtained in the step 1, presintering the mixture, wherein the presintering temperature is 900 ℃, and the heating rate is 5 ℃/min;

and step 3: sanding: and (3) carrying out vibration grinding on the obtained pre-sintering material, and then adding auxiliary components: CaCO₃：600ppm、ZrO₂：200ppm、TiO₂：800ppm、Co₂O₃: 1800ppm of CuO and 50-200 ppm of sand milling for 70 min;

and 4, step 4: and (3) granulation: adding 15 wt% of polyvinyl alcohol according to the total weight of the powder obtained after grinding, and grinding and sieving the mixture into particles with a certain size;

and 5: and (3) pressing and forming: pressing into annular green body with size of phi 12.5mm phi 7.5mm phi 7 mm;

step 6: and (3) sintering: the sintering temperature is 1120 ℃, the heat preservation time is 6 hours, and the equilibrium oxygen content is 1.6 percent;

and 7: annealing: raising the temperature to 700 ℃ at a certain heating rate under the vacuum condition, preserving the temperature for 2 hours, and then gradually reducing the temperature to room temperature at a certain rate.

Comparative example 3: a manganese-zinc soft magnetic ferrite material comprises a main component and an auxiliary component, and the preparation method comprises the following steps:

step 1: preparing materials: fe₂O₃: 74.3wt%, ZnO: 1.8wt%, the balance being Mn₃O₄Burdening, and then performing wet ball milling mixing for 15 min;

step 2: pre-burning: after drying the mixture obtained in the step 1, presintering the mixture, wherein the presintering temperature is 900 ℃, and the heating rate is 5 ℃/min;

and step 3: sanding: and (3) carrying out vibration grinding on the obtained pre-sintering material, and then adding auxiliary components: CaCO₃：600ppm、ZrO₂：200ppm、TiO₂：800ppm、Co₂O₃: 1800ppm of CuO and 50-200 ppm of sand milling for 70 min;

and 4, step 4: and (3) granulation: adding 15 wt% of polyvinyl alcohol according to the total weight of the powder obtained after grinding, and grinding and sieving the mixture into particles with a certain size;

and 5: and (3) pressing and forming: pressing into annular green body with size of phi 12.5mm phi 7.5mm phi 7 mm;

step 6: and (3) sintering: the sintering temperature is 1120 ℃, the heat preservation time is 6 hours, and the equilibrium oxygen content is 1.6 percent;

and 7: annealing: raising the temperature to 700 ℃ at a certain heating rate under the vacuum condition, preserving the temperature for 2 hours, and then gradually reducing the temperature to room temperature at a certain rate.

Comparative example 4: a manganese-zinc soft magnetic ferrite material comprises a main component and an auxiliary component, and the preparation method comprises the following steps:

step 1: preparing materials: fe₂O₃：74.6wt%，ZnO：3.4wt%，MoO₃: 0.04 wt% and the balance Mn₃O₄Burdening, and then performing wet ball milling mixing for 15 min;

step 2: pre-burning: after drying the mixture obtained in the step 1, presintering the mixture, wherein the presintering temperature is 900 ℃, and the heating rate is 5 ℃/min;

and step 3: sanding: and (3) carrying out vibration grinding on the obtained pre-sintering material, and then adding auxiliary components: CaCO₃：600ppm、ZrO₂：200ppm、TiO₂：800ppm、Co₂O₃: 1800ppm of CuO and 50-200 ppm of sand milling for 70 min;

and 4, step 4: and (3) granulation: adding 15 wt% of polyvinyl alcohol according to the total weight of the powder obtained after grinding, and grinding and sieving the mixture into particles with a certain size;

and 5: and (3) pressing and forming: pressing into annular green body with size of 12.5mm phi 7.5mm phi 7mm and density of 3.2g/cm³；

Step 6: and (3) sintering: the sintering temperature is 1120 ℃, the heat preservation time is 6 hours, and the equilibrium oxygen content is 1.6 percent.

The examples and comparative examples were tested for magnetic properties as follows:

from the table, one can see: examples 1, 2 and 3 the best magnetic properties were obtained according to the fabrication of the present invention. Comparing comparative example 1 with the embodiment, or comparing comparative example 2 with comparative example 4, the magnetic permeability is obviously increased and the loss is also reduced after the annealing treatment. Comparison of comparative example 2 with the examples shows that the high frequency losses are significantly reduced when the main formulation has a lower Zn content. Comparison of comparative example 3 with the examples shows that MoO is added to the main formulation when₃When the magnetic permeability is increased, the high-frequency loss is reduced.