High-frequency low-loss magnesium-zinc ferrite material and preparation method thereof
The preparation of high-frequency, low-loss magnesium-zinc ferrite materials by the oxide method solves the problems of high loss and temperature stability of traditional MgZn ferrites in high-frequency environments. It achieves low loss and stable magnetic properties over a wide temperature range, making it suitable for high-frequency transformers, radio frequency inductors and microwave devices, reducing production costs and improving production efficiency.
Patent Information
- Application Number
- CN202511448531.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-11
- Publication Date
- 2026-01-20
AI Technical Summary
Traditional MgZn ferrite exhibits a sharp increase in high-frequency loss, insufficient temperature stability, and decreased mechanical strength under high-frequency conditions, making it difficult to maintain reliability under extreme environments. Existing technologies have failed to effectively solve the material failure problem under multi-field coupling conditions of high-frequency and high-temperature loads.
High-frequency, low-loss magnesium-zinc ferrite materials were prepared using the oxide method. By optimizing the microstructure and magnetocrystalline anisotropy of the materials through specific formulation design and ion doping technology, and combined with appropriate sintering processes, magnesium-zinc ferrite materials suitable for high-frequency, low-loss applications were prepared.
Achieving low loss under high-frequency conditions and maintaining excellent magnetic performance stability over a wide temperature range, it is suitable for high-frequency transformers, RF inductors, and microwave devices, reducing production costs and improving production efficiency and product consistency.
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Figure CN121362037A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to a kind of magnesium zinc ferrite material and its preparation method, especially to a kind of high-frequency low-loss magnesium zinc MgZn Ferrite material and its preparation method. BACKGROUND
[0002] Soft magnetic ferrite material is widely used in communication, new energy, aerospace and other fields as the core basic material of high-frequency electronic devices. Among them, magnesium zinc ferrite becomes the preferred material of high-frequency transformer, radio frequency inductor and microwave device due to its high resistivity, low eddy current loss and adjustable permeability. However, with the extension of 5G / 6G communication to millimeter wave frequency band and the development of new energy vehicle electric drive system to high power density, the traditional MgZn ferrite has exposed significant technical bottlenecks in high-frequency environment: high-frequency loss increases dramatically, temperature stability is insufficient and mechanical strength decreases, which seriously restricts its reliability in extreme environment.
[0003] In the prior art, the improvement of material performance mainly depends on the following ways: adjusting the magnetic crystal anisotropy by ion doping to add Co, Mn, Cu and other elements to reduce hysteresis loss; using sintering process optimization, high-temperature solid-phase sintering or hot isostatic pressing post-processing to improve density; using sol-gel method to synthesize nano powder to reduce sintering activation energy. However, the high surface energy of nano powder easily leads to impurity segregation at grain boundaries, which worsens the high-frequency power loss and other characteristics, and still has the following limitations: poor performance balance, difficult to simultaneously consider high-frequency low-loss, high-temperature stability and mechanical strength; high process complexity, insufficient material reliability, Zn 2+ Migration aggravates grain boundary oxidation, affecting device life.
[0004] However, the existing technology has not completely solved the material failure problem under the multi-field coupling working condition of high-frequency-high-temperature load. Therefore, developing a MgZn ferrite material with high-frequency low-loss has become the key to breaking through the technical barriers of new generation high-frequency power devices. Compared with MnZn ferrite, MgZn ferrite material is not sensitive to atmosphere during sintering and can be sintered directly in air. This completely eliminates the expensive and complex nitrogen protection kiln system, greatly simplifies the production process, reduces the harsh requirements on production equipment, thereby significantly reducing equipment investment cost and production cost, improving production efficiency and product consistency. Existing researches mainly focus on the electromagnetic shielding of MgZn ferrite in weak electric applications, while the power loss characteristics of MgZn ferrite in high-frequency power inductor, transformer and other strong electric applications, especially its loss mechanism, temperature characteristics and frequency characteristics lack systematic and in-depth research.
[0005] In summary, it is of great application value and value to develop a high-frequency low-loss magnesium zinc ferrite material. SUMMARY
[0006] To solve the above technical problems, the application provides a high-frequency low-loss magnesium-zinc ferrite material and a preparation method thereof.
[0007] The technical scheme adopted by the application is as follows: a high-frequency low-loss magnesium-zinc ferrite material, the magnesium-zinc ferrite material being composed of main components and auxiliary components; The main components, in terms of mole percentage, are 100% and include 48.10%-50.00% of diiron trioxide, 15.00%-15.25% of zinc oxide, 0.00%-10.00% of nickel oxide, and the rest is magnesium oxide. The auxiliary components include at least one of the following raw materials: SiO2, CaCO3 and CaO.
[0008] Preferably, the auxiliary components, in terms of total weight of the main components, are composed of the following raw materials: SiO2 60-160 ppm, CaCO3 800-1800 ppm and CaO 1500 ppm. 1500 ppm.
[0009] Preferably, the main components include 48.10% of diiron trioxide, 15.25% of zinc oxide and 35.00% of magnesium oxide; and the auxiliary components include SiO2 80 ppm, CaCO3 1600 ppm and CaO 1500 ppm.
[0010] A preparation method of the high-frequency low-loss magnesium-zinc ferrite material includes the following steps. Step one, batching and mixing: the main component raw materials of the magnesium-zinc ferrite material are mixed and ball milled; Step two, pre-sintering: the material after ball milling is pre-sintered; Step three, secondary ball milling: the auxiliary component raw materials are added to the pre-sintered material in proportion and secondary ball milling is performed; Step four, granulation and forming: the material after ball milling is granulated and formed; the granular material prepared in step four is pressed into a magnetic ring; the size of the magnetic ring is Ф20mm*Ф10mm*5mm; Step five, sintering: the formed material is sintered at a temperature of 1200-1300℃ to obtain the high-frequency low-loss magnesium-zinc ferrite material.
[0011] Preferably, the specific process of step one is as follows: the main components are mixed with deionized water in a formula amount, fully ball milled and the obtained slurry is dried to obtain a powder; the amount of deionized water is 45-55% of the total weight of the main components, preferably 50%.
[0012] Preferably, the specific process of step two is that the powder obtained in step one is subjected to pre-sintering treatment, the pre-sintering temperature is 750-1050℃, and the pre-sintered material is obtained by natural cooling.
[0013] Preferably, the specific process of step three is that the auxiliary components are added to the pre-sintered material of step two according to the formula amount, and the powder with a particle size of 0.1-1.5 μm is obtained by secondary ball milling for 16-24 h and drying; the amount of deionized water is 45-55% based on the total weight of the main components, preferably 50%.
[0014] Preferably, the specific process of step four is that the polyvinyl alcohol aqueous solution with a mass concentration of 6%-12% is added to the ball-milled powder obtained in step three, the mixture is uniformly mixed and granulated to obtain the granular material; the weight ratio of the polyvinyl alcohol aqueous solution to the ball-milled powder is 8-15:1, preferably 10:1.
[0015] Preferably, the specific process of step four is that the polyvinyl alcohol aqueous solution with a mass concentration of 6%-12% is added to the ball-milled powder obtained in step three, the mixture is uniformly mixed and granulated to obtain the granular material; the weight ratio of the polyvinyl alcohol aqueous solution to the ball-milled powder is 8-15:1, preferably 10:1.
[0016] Preferably, the specific process of step five is that the magnetic ring prepared in step five is sintered at a temperature of 1200-1300℃, and then cooled to below 120℃ to be taken out of the furnace, and the reduction oxygen partial pressure is adopted in the cooling process to obtain the magnesium-zinc ferrite.
[0017] Compared with the prior art, the high-frequency low-loss magnesium-zinc ferrite material has the following beneficial effects: 1. Through a large number of systematic doping test research, a high-frequency low-loss magnesium-zinc ferrite material with a lowest loss of 516KW / m 3 under the conditions of 3000 kHz and 10 mT and in the temperature range of -25℃-140℃ is obtained, and the material is suitable for scenes with large temperature changes, and ensures the normal use of electronic devices. 3
[0018] 2. In the main formula of the present application, by adjusting the content of NiO, the material can have a lower valley temperature under high-frequency conditions, which ensures the normal use of the material. In the auxiliary components of the present application, the addition of CaCO3-SiO2 reduces the ferrite eddy current loss and optimizes the overall loss ratio, so that the material can also maintain a lower loss under high frequency.
[0019] 3、The sintering process of the application is beneficial to miniaturization and light weight of electronic components, and has great significance in energy saving and environmental protection. The working temperature of the magnesium-zinc ferrite material of the application can be as low as -20 DEG C and as high as 140 DEG C, and has a super wide working temperature range, and the loss is low between 0 DEG C and 100 DEG C.
[0020] The application protects a magnesium-zinc ferrite material with low loss under different frequency bands and a preparation method thereof. The prepared magnesium-zinc ferrite has a minimum loss of 516 KW / m under the condition of 3000 kHz and 10 mT and in the temperature range of -20 DEG C to 140 DEG C. 3 The prepared magnesium-zinc ferrite has a minimum loss of 378.9 KW / m under the condition of 5000 kHz and 5 mT and in the temperature range of -20 DEG C to 140 DEG C. 3 The electronic components have very low loss in different frequency bands and low cost. BRIEF DESCRIPTION OF DRAWINGS
[0021] Fig. 1 A typical curve graph of power loss temperature characteristics of the magnesium-zinc ferrite obtained in Example 6 of the application under the condition of 1000 kHz and 10 mT is shown in the figure. Fig. 2 A typical curve graph of power loss temperature characteristics of the magnesium-zinc ferrite obtained in Example 6 of the application under the condition of 3000 kHz and 10 mT is shown in the figure. Fig. 3 A typical curve graph of power loss temperature characteristics of the magnesium-zinc ferrite obtained in Example 6 of the application under the condition of 5000 kHz and 10 mT is shown in the figure. DETAILED DESCRIPTION
[0022] The application optimizes the microstructure and magnetocrystalline anisotropy of the material by unique formula design and ion doping technology, systematically studies and reduces the power loss (Pcv) in the MHz frequency band. The application first discloses the loss model and application boundary of MgZn ferrite in high-frequency high-power applications in detail in China, which provides key theoretical basis and data support for the large-scale application of the material in high-efficiency switching power supply (SMPS), radio frequency power amplifier and other fields. The MgZn ferrite material prepared by the application has extremely high resistivity, which fundamentally suppresses the high-frequency eddy current loss. Therefore, the application frequency of the MgZn ferrite material is much higher than that of the traditional MnZn ferrite. The effective application frequency of the MnZn ferrite is usually limited to below 1-2 MHz, while the MgZn ferrite material of the application can still maintain extremely low power loss and excellent magnetic property stability at a frequency of 3 MHz or even higher. This characteristic makes it very suitable for power magnetic elements in the next generation of ultra-high frequency switching power supply, vehicle wireless charging module, 5G communication base station and various radio frequency energy transmission systems, providing an ideal magnetic material solution for the miniaturization and light weight of equipment, which helps to reduce the device size and the number of windings, reduce the line loss and reduce the temperature rise, and can be widely used in miniaturized devices, and provides material reserves for the future miniaturization of devices.
[0023] The application will be further described in detail below in combination with examples.
[0024] Example 1 Step one, batching and mixing: the main ingredients (Fe2O3, MgO, ZnO, NiO) are weighed according to the formula amount in Table 1, then 50% of the total weight of the main ingredients of deionized water is added in the ball mill tank, and ball milling is carried out until the average particle size is 0.8-1.2 μm, then the slurry is dried to obtain the powder; Step two, pre-sintering: the obtained powder is pre-sintered at a temperature of 850℃ for 3 hours, and the pre-sintered material is obtained by natural cooling; Step three, secondary ball milling: the auxiliary ingredient raw material is added to the pre-sintered material in the above step according to the proportion, and the auxiliary ingredient is SiO2 80 ppm, CaCO3 1600 ppm and CaO 1500 ppm based on the total weight of the main ingredient, then 50% of the total weight of the main ingredient of deionized water is added in the ball mill tank, and secondary ball milling and drying are carried out to obtain a powder with an average particle size of about 0.9 μm; Step four, granulation: a PVA aqueous solution with a weight ratio of 10:1 and a concentration of 10 wt% is added to the powder obtained in step three, mixed uniformly and granulated to obtain granular material for molding; Step five, molding: the granulated granular material is pressed into a magnetic ring with a size of Ф20 mm*Ф10 mm*5 mm; Step six, sintering: the magnetic ring after step five is placed in a precision atmosphere control sintering furnace, sintered at a temperature of 1250℃, and kept at the sintering temperature for 4 hours, then cooled to below 120℃ and taken out of the furnace, air cooling is adopted, and ferrite is obtained.
[0025] Examples 2-6 are to adjust the amount of main components (Fe2O3, MgO, NiO, ZnO) in Example 1 according to Table 1, and other operations are the same as in Example 1, and the results are listed in Table 1.
[0026] Table 1 In addition, the magnetic performance data related to Examples 1-6 at room temperature are also tested, as shown in Table 2.
[0027] Table 2 From the data in Table 1: 1) Comparing Examples 1-6, by adjusting the content of NiO, the material maintains an overall loss of 100 KW / m at a frequency of 1 MHz and a condition of 10mT in the temperature range of -25℃-140℃ 3 The lowest loss of Example 1 under the condition of 1M is 78.9 KW / m 3 ; the overall loss range is 516-562.4 KW / m at 3MHz 10mT 3 , the lowest loss of Example 4 is 516.0 KW / m 3 ; the loss range is 378.9-410.3 KW / m at 5MHz 5mT 3 , the lowest loss of Example 4 is 378.9 KW / m 3 , and the sample can ensure normal use of the material at high temperature environment under the condition of low loss.
[0028] From the data in Table 2: 2) Comparing Examples 1-6, it can be found that with the increase of the amount of NiO doping, the Bm of the material first increases and then decreases, reaching a maximum of 0.313 T in Example 5, and the square ratio (Br / Bm) is also the largest, reaching 0.7833, and the coercive force Hc significantly increases with the increase of the amount of NiO doping, showing that the sample can maintain good magnetic performance while maintaining low loss.
[0029] 3) Comparing Figs. 1-3Pcv-T curve, it can be found that with the increase of the amount of NiO doping, the wide temperature performance of the sample also shows more and more stable, in the range of-20℃~140℃, the degree of Pcv affected by temperature is lower and lower, and with the increase of the amount of NiO doping, the valley temperature moves to the right, the possible reason is that because Ni 2+ The K1 value is negative, which reduces the overall magnetocrystalline anisotropy constant, and finally causes the valley temperature to move to the right. With the increase of NiO doping, it is more suitable for the scene with larger temperature change, which is beneficial to the miniaturization and light weight of electronic components.
[0030] Example 7 Step one, batching and mixing: according to the formula amount of 48.10% of ferric oxide, 15.25% of zinc oxide, 5% of nickel oxide, and the rest of magnesium oxide, the main components (Fe2O3, MgO, ZnO, NiO) are weighed, then 55% of the total weight of the main components of deionized water is added in the ball mill tank, and ball milling is carried out until the average particle size is 0.8-1.2 μm, the slurry is obtained and dried to obtain the powder; Step two, pre-sintering: the obtained powder is pre-sintered, the pre-sintering temperature is 750℃, the pre-sintering time is 3 hours, and the pre-sintered material is obtained by natural cooling; Step three, secondary ball milling: the auxiliary component raw materials are added to the above pre-sintered material according to the proportion, the auxiliary component is SiO2 60 ppm, CaCO3 800 ppm, CaO 1500 ppm based on the total weight of the main component, then 45% of the total weight of the main component of deionized water is added in the ball mill tank, and secondary ball milling is carried out to obtain a powder with an average particle size of about 0.9 μm after drying; Step four, granulation: add PVA aqueous solution with a weight ratio of 8:1 and a concentration of 12 wt% to the powder obtained in step three, mix uniformly to granulate to obtain granules for molding; Step five, molding: the granulated granules are pressed into a magnetic ring with Ф20 mm*Ф10 mm*5 mm; Step six, sintering: the magnetic ring after molding in the above step five is placed in a precision atmosphere control sintering furnace and sintered at a temperature of 1200℃, and then cooled to below 120℃ and taken out of the furnace, and air cooling is adopted to obtain a ferrite.
[0031] Through testing, the working temperature of the magnesium-zinc ferrite material can be as low as-20℃ and as high as 140℃, and it has a super wide working temperature range, and the loss is low between 0℃-100℃.
[0032] Example 8 Step one, ingredients, mixing: according to the formula amount of 49.00% of Fe2O3, 15.10% of ZnO, 6% of NiO, the rest of MgO, the main ingredients (Fe2O3, MgO, ZnO, NiO) are weighed, then 45% of the total weight of the main ingredients of deionized water is added in the ball mill tank, and the average particle size is 0.8-1.2 μm after ball milling, the slurry is obtained and dried to obtain the powder; Step two, pre-burning: the obtained powder is pre-burned, the pre-burning temperature is 1050℃, the pre-burning time is 3 hours, and the pre-burned material is obtained by natural cooling; Step three, secondary ball milling: the auxiliary ingredient raw material is added to the pre-burned material according to the proportion, the auxiliary ingredient is SiO2 160 ppm, CaCO3 1800 ppm, CaO 1500 ppm, and the total weight of the main ingredients, then 55% of the total weight of the main ingredients of deionized water is added in the ball mill tank, and the powder with an average particle size of about 0.9 μm is obtained after secondary ball milling and drying; Step four, granulation: the powder obtained in step three is added with PVA aqueous solution with a weight ratio of 15:1 and a concentration of 6 wt%, mixed uniformly and granulated to obtain granular material for molding; Step five, molding: the granulated granular material is pressed into a magnetic ring with Ф20 mm*Ф10 mm*5 mm; Step six, sintering: the magnetic ring after molding in step five is placed in a precision atmosphere control sintering furnace and sintered at a temperature of 1300℃, and the sintering temperature is maintained for 3 hours, then cooled to below 120℃ and discharged, and air cooling is adopted to obtain the ferrite.
[0033] Test results show that the working temperature of the Mg-Zn ferrite material can be as low as-20℃ and as high as 140℃, and has a super-wide working temperature range, and the loss is low between 0℃ and 100℃.
[0034] The above embodiments are not a limitation of the present application, and the present application is not limited to the above examples, and the changes, modifications, additions or replacements made by the person skilled in the art within the scope of the technical solutions of the present application also belong to the protection scope of the present application.
Claims
1. A high frequency low loss magnesium-zinc ferrite material, characterized in that, The magnesium-zinc ferrite material is made of main components and auxiliary components; The main components include, in terms of molar percentage, 48.10%-50.00% of Fe2O3, 15.00%-15.25% of ZnO, 1%-10.00% of NiO, and the rest of MgO; The auxiliary components include at least one of the following raw materials: SiO2, CaCO3, and CaO.
2. The high frequency low loss Mg-Zn ferrite material according to claim 1, characterized in that, The auxiliary components, in terms of the total weight of the main components, are composed of the following raw materials: SiO2 60-160 ppm, CaCO3 800-1800 ppm, and CaO 1500 ppm.
3. A method of producing the high-frequency low-loss magnesium-zinc ferrite material according to any one of claims 1 to 2, characterized by, The method comprises the following steps: Step one, mixing and ball-milling the main component raw materials of the magnesium-zinc ferrite material; Step two, pre-sintering the ball-milled material; Step three, adding the auxiliary component raw materials weighed in proportion to the pre-sintered material and performing secondary ball-milling; Step four, granulating and forming the ball-milled material; Step five, sintering the formed material at a temperature of 1200-1300℃ to obtain the high-frequency low-loss magnesium-zinc ferrite material.
4. The method of producing a high-frequency low-loss magnesium-zinc ferrite material according to claim 3, characterized by: The specific process of step one is: mixing the main components with deionized water according to the formula amount, fully ball-milling, and drying the obtained slurry to obtain a powder; the deionized water amount is 45-55% of the total weight of the main components.
5. The method of producing a high-frequency low-loss magnesium-zinc ferrite material according to claim 3, characterized by: The specific process of step two is: pre-sintering the powder obtained in step one at a temperature of 750-1050℃, and naturally cooling to obtain a pre-sintered material.
6. The method of producing a high-frequency low-loss magnesium-zinc ferrite material according to claim 3, characterized by: The specific process of step three is: adding auxiliary components to the pre-sintered material of step two according to the formula amount, and performing secondary ball-milling for 16-24 hours to obtain a powder with a particle size of 0.1-1.5 μm after drying; the deionized water amount is 45-55% of the total weight of the main components.
7. The method of producing a high-frequency low-loss magnesium-zinc ferrite material according to claim 3, characterized by: The specific process of step four is: adding a polyvinyl alcohol aqueous solution with a mass concentration of 6%-12% to the ball-milled powder obtained in step three, mixing uniformly, and granulating to obtain a granular material; the weight ratio of the polyvinyl alcohol aqueous solution to the ball-milled powder is 8-15:
1.
8. The method of producing a high-frequency low-loss magnesium-zinc ferrite material according to claim 7, characterized by: The specific process of step four is: pressing the prepared granular material into a magnetic ring; the size of the magnetic ring is Ф20mm*Ф10mm*5mm.
9. The method of producing a high-frequency low-loss magnesium-zinc ferrite material according to claim 3, characterized by: The specific process of step five is: sintering the formed material at a temperature of 1200-1300℃, maintaining the sintering temperature for 3-6 hours, and then cooling to below 120℃ before discharging to obtain a magnesium-zinc ferrite.
10. The method of producing a high-frequency low-loss magnesium-zinc ferrite material according to claim 9, characterized by: The cooling process uses reducing air.