A high-frequency high-curie-temperature high-saturation-flux-density manganese-zinc soft magnetic ferrite, a preparation method and application thereof

Abstract

The application belongs to the field of soft magnetic materials, and provides a high-frequency high-Curie-temperature high-saturation-flux-density manganese-zinc soft magnetic ferrite and a preparation method and application thereof. The preparation method comprises the following steps: weighing main components Fe2O3, ZnO and Mn3O4 according to a proportion, performing sand grinding mixing to obtain a mixture, pre-sintering in air to obtain pre-sintered material, sand grinding, adding auxiliary components according to a proportion to perform sand grinding mixing to obtain a powder, adding metal FeNi powder according to a proportion, mixing to obtain mixed powder, granulating, pressing into shape, and sintering to obtain the soft magnetic ferrite. The preparation method adopts a high-iron formula and mixes metal iron nickel, greatly improves the Curie temperature and the saturation flux density of the material, and successfully obtains the high-frequency high-Curie-temperature high-saturation-flux-density manganese-zinc soft magnetic ferrite under MHz working conditions through component formula and process.

Description

Technical Field

[0001] This invention belongs to the field of soft magnetic materials, specifically relating to a high-frequency, high-Curie-temperature, high-saturation-flux-density manganese-zinc soft magnetic ferrite, its preparation method, and its application. Background Technology

[0002] With the rapid development of AI computing centers and high-density server clusters, the computing power and power consumption of single machines in data centers continue to soar. CPUs and GPUs are frequently subjected to instantaneous high current surges. Power supply systems are gradually iterating towards high-voltage DC architecture, high frequency, high power density, and modularization. The large-scale application of third-generation semiconductors GaN and SiC has increased the power switching frequency to hundreds of kHz to MHz levels. Magnetic components are operating under harsh conditions of high-frequency alternation, large DC bias superposition, and high current for a long time.

[0003] Meanwhile, data center equipment experiences rising internal temperatures and demanding heat dissipation environments. With the widespread adoption of liquid cooling and high-density cabinets, magnetic cores are constantly operating at high temperatures. Ordinary ferrite cores, with their relatively low Curie temperatures, suffer from rapid magnetic property decay, permeability drop, and soaring losses at high temperatures, making them highly susceptible to inductor failure, core overheating and saturation, decreased power efficiency, and even system crashes. Traditional ferrite cores also suffer from insufficient saturation flux density, poor DC superposition performance, and rapid inductance drop under large bias currents, failing to meet the long-term stable operation requirements of multi-phase VRM power supplies, high-voltage DC-DC converters, PFC circuits, and planar transformers. Furthermore, with increasingly stringent national and industry requirements for data center PUE energy efficiency control and low-carbon energy conservation, power supply systems must continuously reduce core losses, minimize heat generation, reduce cooling costs, and improve overall conversion efficiency.

[0004] High Curie temperature ensures stable magnetic performance without degradation under high temperature conditions, high saturation flux density effectively resists large current bias to avoid core saturation, reduces device size and increases power density, excellent DC superposition characteristics ensure inductor stability under heavy load and transient conditions, and high frequency and low loss significantly reduce high frequency hysteresis and eddy current losses and improve temperature control efficiency.

[0005] Therefore, ferrite cores, which combine high Curie temperature, high saturation flux density, high DC superposition, high frequency and low loss, have become the core essential material for AI data center server power supplies, high voltage DC-DC modules, GPU / CPU multiphase power supplies, UPS and HVDC power distribution, and network communication magnetic devices. They are key basic soft magnetic materials that support the high-density, high-frequency, high-temperature reliable and high-efficiency operation of data centers.

[0006] Patent No. 1 (CN 118812255 A) discloses a high-frequency, high-Bs, high-DC superposition, low-loss manganese-zinc ferrite and its preparation method. This invention improves the Curie temperature of the material by using a NiO quaternary main formulation, thereby increasing the Bs of the material and improving the DC superposition characteristics of the material. In terms of process, two batches of powders with different grinding particle sizes are mixed evenly in proportion to improve the particle size distribution of the powder, improve the microstructure of the material, increase the Bs of the material, and reduce the material loss.

[0007] Prior art 2 (publication number CN 119774994 A) discloses a high-saturation magnetic flux density, high-frequency, low-loss ferrite material and its preparation method. This invention introduces a fourth component, NiO, into the ferrite material, through Ni... 2+ The substitution effectively increases the saturation magnetic flux density of the prepared ferrite material to 490 mT at 100 °C.

[0008] The present invention aims to further improve the properties of magnetic materials, such as high Curie temperature, high saturation magnetic flux density, and high frequency and low loss, in order to meet the requirements of long-term stable operation. Summary of the Invention

[0009] To address the aforementioned technical problems, this invention provides a high-frequency, high-Curie-temperature, high-saturation-flux-density manganese-zinc soft magnetic ferrite, its preparation method, and its applications. This invention successfully obtains a high-frequency, high-Curie-temperature, high-saturation-flux-density manganese-zinc ferrite material under MHz operating conditions through component formulation, powder particle size distribution, and preparation process.

[0010] The purpose of this invention is to provide a method for preparing high-frequency, high-Curie-temperature, and high-saturation-magnetic-flux-density manganese-zinc soft magnetic ferrites, comprising the following steps: (1) Weigh Fe2O3, ZnO and Mn3O4 according to the proportion, and mix them by sand milling to obtain a mixture. The main components and their contents include Fe2O3: 57.8-60.5 mol%, ZnO: 3.5-5.5 mol%, and the remainder is Mn3O4. (2) The mixture obtained in step 1 is pre-fired in air to obtain pre-fired material; (3) The pre-calcined material obtained in step 2 is sand-milled, and auxiliary components are added in proportion for sand-milling and mixing to obtain powder; (4) Add metallic FeNi powder to the powder obtained in step 3 in a certain proportion and mix to obtain a mixed powder. The Fe content in the metallic FeNi powder is 50wt% and the Ni content is 50wt%. (5) Granulation, pressing and molding, sintering to obtain high frequency, high Curie temperature and high saturation magnetic flux density manganese zinc soft magnetic ferrite.

[0011] The preparation method of this invention, by using a high-iron formula and mixing metallic iron and nickel as the main components and doping components, significantly improves the Curie temperature and saturation magnetic flux density of the material. Through the above formula and process system, a high-frequency manganese-zinc soft magnetic ferrite with high Curie temperature and high saturation magnetic flux density under MHz operating conditions is successfully obtained.

[0012] Furthermore, in step (4), the particle size of the FeNi metal powder is D. 50 The particle size of the powder obtained in step (3) is 15-20 μm. 50 : 0.8~1.5μm. This invention utilizes a mixture of large-particle-size metallic iron-nickel powder (D... 50 (15-20 μm), forming ferrite powder (D 50 Metal powder (0.8-1.5μm) is coated to increase resistivity and reduce loss under MHz conditions.

[0013] Furthermore, in step (4), the particle size of the FeNi metal powder is D. 90 : 30~40μm, the particle size of the powder in step (3) is D 90 : 2.0~2.6μm.

[0014] Furthermore, in step (2), the preheating temperature is 800-1000℃ and the heating rate is 3-5℃ / min.

[0015] Furthermore, in step (5), the sintering temperature is 1130~1150℃.

[0016] Furthermore, in step (4), the amount of FeNi metal powder added is 8000-15000 ppm based on the total weight of the main components.

[0017] Further, in step (3), the auxiliary components include at least one of CaCO3, SiO2, ZrO2, Nb2O5, and Co2O3. Preferably, the amount of auxiliary components used is as follows, based on the total weight of the main components: CaCO3: 400-600ppm, SiO2: 100-200ppm, ZrO2: 100-300ppm, Nb2O5: 100-300ppm, and Co2O3: 2000-3500ppm.

[0018] Preferably, the main components include the following components and contents: Fe2O3: 57.8-60.2 mol%, ZnO: 3.8-5.0 mol%, with the remainder being Mn3O4.

[0019] The present invention also aims to provide a high-frequency, high Curie temperature, and high saturation magnetic flux density manganese-zinc soft magnetic ferrite prepared by the above preparation method.

[0020] The present invention also aims to provide an application of the above-mentioned high-frequency, high-Curie-temperature, high-saturation-flux-density manganese-zinc soft magnetic ferrite in AI data center server power supplies, high-voltage DC-DC modules, GPU / CPU multiphase power supplies, UPS and HVDC power distribution, and network communication magnetic devices.

[0021] Compared with the prior art 1, the present invention significantly optimizes Bs. The present invention employs a high-iron formulation, increasing Bs and reducing losses by mixing ferrite powder and metallic iron-nickel powder of different particle sizes. Prior art 2 has a slightly lower Bs (490 mT) at 100°C than the present invention (500 mT), and at 1 MHz, a loss of 50 mT (130 kW / m²). 3 Compared to the present invention (50 kW / m) 3 The situation has clearly deteriorated.

[0022] Compared with the prior art, the present invention has the following beneficial effects.

[0023] 1. This high-frequency material is suitable for MHz applications, meeting the market demand for MnZn ferrite materials with low power loss at higher frequencies for smaller, lighter, and thinner electronic devices.

[0024] 2. This material has a high Curie temperature and high saturation magnetic flux density, which can ensure that the magnetic properties are stable and do not deteriorate under high temperature environment, effectively resist large current bias to avoid core saturation, reduce device size and increase power density.

[0025] 3. The manganese-zinc soft magnetic ferrite of the present invention has the characteristics of high Curie temperature, high saturation flux density and low loss under MHz conditions, and achieves the following technical performance, indicators and parameters: initial permeability μ i ≥550(T=25℃, B<0.25mT); Curie temperature Tc ≥ 320℃ (10kHz, B < 0.25mT); Magnetic loss Pcv≤50kW / m 3 (T=25℃, f=1MHz, B=50mT); Pcv≤50kW / m 3 (T=100℃, f=1MHz, B=50mT); Saturation magnetic induction intensity Bs≥580mT (25℃, H=1194A / m); Bs≥500mT (100℃, H=1194A / m).

[0026] In summary, the high-frequency, high-Curie-temperature, and high-saturation-flux-density manganese-zinc soft magnetic ferrite of this invention combines the characteristics of high Curie temperature, high saturation-flux-density, high DC superposition, and high frequency with low loss. It can serve as a core material for AI data center server power supplies, high-voltage DC-DC modules, GPU / CPU multiphase power supplies, UPS and HVDC power distribution, and network communication magnetic devices. It is a key basic soft magnetic material supporting the high-density, high-frequency, high-temperature, reliable, and high-energy-efficiency operation of data centers. Attached Figure Description

[0027] Figure 1 The initial magnetic permeability μ of the material prepared in Example 1 i -Temperature T curve. Detailed Implementation

[0028] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] The purpose of this invention is to provide a high-frequency, high-Curie-temperature, high-saturation-flux-density manganese-zinc soft magnetic ferrite and its preparation method. The MnZn ferrite material of this invention: 1. By using appropriate main components and doping, and employing a high-iron formulation and mixing with metallic iron and nickel, the Curie temperature and saturation-flux-density of the material are significantly improved; 2. By mixing large-particle metallic iron-nickel powder (D... 50 (15-20 μm), forming ferrite powder (D 50 A 0.8–1.5 μm (0.8–1.5 μm) coated metal powder is used to increase resistivity and reduce losses under MHz conditions. Using the above formulation and process system, a high-frequency, high-Curie-temperature, high-saturation-flux-density manganese-zinc soft magnetic ferrite was successfully achieved under MHz operating conditions.

[0030] To achieve the above objectives, the technical solution adopted by the present invention is as follows.

[0031] A high-frequency, high Curie temperature, high saturation magnetic flux density manganese-zinc soft magnetic ferrite comprises a main component and auxiliary components. The main component includes Fe₂O₃: 57.8–60.5 mol%, ZnO: 3.5–5.5 mol%, with the remainder being Mn₃O₄. The auxiliary components, by weight of the main component, include: CaCO₃: 400–600 ppm, SiO₂: 100–200 ppm, ZrO₂: 100–300 ppm, Nb₂O₅: 100–300 ppm, and Co₂O₃: 2000–3500 ppm.

[0032] The preparation method includes the following steps: Step 1: Ingredients: Weigh Fe2O3, ZnO, and Mn3O4 according to the proportion, and then mix them by wet sand milling for 10-20 minutes; Step 2: Pre-firing: After drying the mixture obtained in Step 1, pre-firing is carried out in air at a temperature of 800-1000℃ and a heating rate of 3-5℃ / min.

[0033] Step 3: Sand milling: Vibrate mill the pre-calcined material obtained in Step 2, and then add auxiliary components according to the proportion: CaCO3, SiO2, ZrO2, Nb2O5, Co2O3. The sand milling time is 40-60 min. Step 4: Mixing: Add metallic FeNi powder to the powder obtained in step 3 in proportion, mix for 10-30 minutes, and then dry the powder. Step 5: Granulation: The powder from Step 4 is sieved and granulated; Step 6: Pressing and molding: Pressing into a ring-shaped green body with dimensions of Φ12.5mm*Φ7.5mm*7mm; Step 7: Sintering: Sinter the blank at a temperature of 1130-1150℃; hold for 5-7 hours.

[0034] Preferably, the main components include Fe2O3: 57.8–60.2 mol%, ZnO: 3.8–5.0 mol%, and the remainder is Mn3O4.

[0035] Preferably, the particle size D of the powder in step 3 is... 50 : 0.8~1.5μm, D 90 : 2.0~2.6μm.

[0036] Preferably, the particle size D of the FeNi metal powder in step 4 is... 50 15~20μm, D 90 30~40μm.

[0037] Preferably, the amount of FeNi powder added in step 4 is 8000-15000 ppm. The FeNi powder contains 50 wt% Fe and 50 wt% Ni.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This high-frequency material is suitable for MHz application scenarios, meeting the market demand for MnZn ferrite materials with low power loss at higher frequencies for smaller, lighter and thinner electronic devices.

[0039] (2) This material has a high Curie temperature and a high saturation magnetic flux density, which can ensure that the magnetic properties are stable and do not deteriorate under high temperature conditions, effectively resist large current bias to avoid core saturation, reduce device size and increase power density.

[0040] (3) The manganese-zinc soft magnetic ferrite of the present invention has the characteristics of high Curie temperature, high saturation flux density and low loss under MHz conditions, and achieves the following technical performance, indicators and parameters: initial permeability μ i ≥550(T=25℃, B<0.25mT); Curie temperature Tc ≥ 320℃ (10kHz, B < 0.25mT); Magnetic loss Pcv≤50kW / m 3 (T=25℃, f=1MHz, B=50mT); Pcv≤50kW / m 3 (T=100℃, f=1MHz, B=50mT); Saturation magnetic induction intensity Bs≥580mT (25℃, H=1194A / m); Bs≥500mT (100℃, H=1194A / m).

[0041] This invention relates to a high-frequency, high-Curie-temperature, high-saturation-flux-density manganese-zinc soft magnetic ferrite material. This material combines the characteristics of high Curie temperature, high saturation-flux-density, high DC superposition, and high frequency with low loss. It has become a core material required for AI data center server power supplies, high-voltage DC-DC modules, GPU / CPU multiphase power supplies, UPS and HVDC power distribution, and network communication magnetic devices. It is a key basic soft magnetic material that supports the high-density, high-frequency, high-temperature, reliable, and high-energy-efficiency operation of data centers.

[0042] Example 1 A high-frequency, high-Curie-temperature, high-saturation-flux-density manganese-zinc soft magnetic ferrite is composed of a main component and auxiliary components, and its preparation method is as follows.

[0043] Step 1, Ingredients: Weigh the following ingredients according to the proportions: Fe2O3: 58.3 mol%, ZnO: 4.1 mol%, with the remainder being Mn3O4. Then, perform wet sand milling for 10 minutes.

[0044] Step 2, Pre-firing: After drying the mixture obtained in Step 1, pre-firing is carried out in air at a temperature of 900℃ and a heating rate of 3℃ / min.

[0045] Step 3, Sand Milling: Vibrate the pre-calcined material obtained in Step 2, then add auxiliary components according to the following proportions: CaCO3: 500ppm, SiO2: 140ppm, ZrO2: 150ppm, Nb2O5: 200ppm, Co2O3: 3000ppm. The sand milling time is 50 minutes, and the sand milling particle size D is... 50 1.1μm, D 90 : 2.2μm.

[0046] Step 4, Mixing: Add 10,000 ppm of metallic FeNi powder to the powder obtained in Step 3, D 50 17μm, D 90 The powder was 33 μm thick and mixed for 15 min. Then the powder was dried. The FeNi powder was a commercially available soft magnetic nickel alloy powder with an oxygen content of less than 300 ppm, an Fe content of 50 wt%, and a Ni content of 50 wt%.

[0047] Step 5, Granulation: The powder from step 4 is sieved and granulated.

[0048] Step 6, Pressing and molding: Press into a ring-shaped green body with dimensions of Φ12.5mm*Φ7.5mm*7mm.

[0049] Step 7, Sintering: Sinter the blank at a temperature of 1130℃ for 5 hours.

[0050] Example 2 A high-frequency, high Curie temperature, and high saturation magnetic flux density manganese-zinc soft magnetic ferrite is composed of a main component and auxiliary components. Compared with Example 1, the difference is that in the preparation of step 1, the main component Fe2O3 is 59.5 mol%, ZnO is 4.6 mol%, and the remainder is Mn3O4.

[0051] Example 3 A high-frequency, high Curie temperature, high saturation magnetic flux density manganese-zinc soft magnetic ferrite is composed of main components and auxiliary components. The difference from Example 1 is that in step 4, 12,000 ppm of metallic FeNi powder is added during mixing.

[0052] Comparative Example 1 A high-frequency, high Curie temperature, and high saturation magnetic flux density manganese-zinc soft magnetic ferrite is composed of a main component and auxiliary components. Compared with Example 1, the difference is that in the preparation of step 1, the main component Fe2O3 is 56.8 mol%, ZnO is 3.3 mol%, and the remainder is Mn3O4.

[0053] Comparative Example 2 A high-frequency, high Curie temperature, high saturation magnetic flux density manganese-zinc soft magnetic ferrite is composed of main components and auxiliary components. The difference from Example 1 is that in step 4, 5000 ppm of metallic FeNi powder is added during mixing.

[0054] Comparative Example 3 A high-frequency, high-Curie-temperature, high-saturation-flux-density manganese-zinc soft magnetic ferrite, composed of main and auxiliary components, differs from Example 1 in that the mixing in step 4 involves adding FeNi powder with a particle size D. 50 12μm, D 90 : 23μm.

[0055] Performance testing 1. Saturation magnetic induction intensity Bs and magnetic loss performance test The power consumption Pcv of the sample rings prepared in Examples 1-3 and Comparative Examples 1-3 was tested. The test method refers to SJ 20966, with the number of turns N1 of the Pcv winding being 3 Ts and the number of turns N1 of the Bs winding being 20 Ts.

[0056] The test conditions were as follows: Pcv was tested at 1MHz and 50mT, and Bs was tested at 1kHz and 1194A / m. The performance data are recorded in Table 1 below.

[0057] Table 1. Power consumption performance test data of the materials in the examples and comparative examples.

[0058] As can be seen from the data in the table, the saturation magnetic induction intensity Bs of the materials prepared in Examples 1-3 are all greater than 580mT at 25℃ and 1194A / m, and are all greater than 500mT at 100℃ and 1194A / m, which are all higher than the saturation magnetic induction intensity Bs of the materials prepared in Comparative Examples 1-3.

[0059] The materials prepared in Examples 1-3 exhibit magnetic losses as low as 45 kW / m under conditions of 25 °C, f = 1 MHz, and B = 50 mT. 3 The magnetic loss is as low as 50 kW / m under the conditions of 100℃, f = 1 MHz, and B = 50 mT. 3 The following values ​​are all lower than the magnetic losses in Comparative Examples 1-3.

[0060] 2. Initial permeability test The initial magnetic permeability of the material prepared in Example 1 was tested, and the test results are as follows: Figure 1 As shown.

[0061] As shown in the figure, the initial magnetic permeability μ of this material i≥550 (T=25℃, B<0.25mT). Curie temperature Tc≥320℃ (10kHz, B<0.25mT).

[0062] This invention, through formulation system, powder particle size distribution, and preparation process, successfully obtained a manganese-zinc ferrite material that exhibits high-frequency, high-saturation magnetic flux density, high superposition, and low-loss performance under conditions of 1MHz to 3MHz and working magnetic flux density of 30mT to 50mT.

[0063] The above embodiments are for illustrative purposes only and are not intended to limit the invention. Those skilled in the art can make various changes or modifications without departing from the spirit and scope of the invention. Therefore, all equivalent technical solutions should also fall within the scope of the invention and should be defined by the claims.

Claims

1. A method for preparing a high-frequency, high-Curie-temperature, high-saturation-magnetic-flux-density manganese-zinc soft magnetic ferrite, characterized in that, Includes the following steps, (1) Weigh the main components Fe2O3, ZnO and Mn3O4 according to the proportion, and mix them by sand milling to obtain a mixture. The composition and content of the main components include Fe2O3: 57.8~60.5 mol%, ZnO: 3.5~5.5 mol%, and the remainder is Mn3O4; (2) The mixture obtained in step 1 is pre-fired in air to obtain pre-fired material; (3) The pre-calcined material obtained in step 2 is sand-milled, and auxiliary components are added in proportion for sand-milling and mixing to obtain powder; (4) Add metallic FeNi powder to the powder obtained in step 3 in a certain proportion and mix to obtain a mixed powder. The Fe content in the metallic FeNi powder is 50wt% and the Ni content is 50wt%. (5) Granulation, pressing and molding, sintering to obtain high frequency, high Curie temperature and high saturation magnetic flux density manganese zinc soft magnetic ferrite.

2. The preparation method according to claim 1, characterized in that, In step (4), the particle size of the FeNi metal powder is D. 50 : 15~20μm, the particle size of the powder obtained in step (3) is D 50 : 0.8~1.5μm.

3. The preparation method according to claim 2, characterized in that, In step (4), the particle size of the FeNi metal powder is D. 90 The particle size of the powder obtained in step (3) is 30-40 μm. 90 : 2.0~2.6μm.

4. The preparation method according to claim 1, characterized in that, In step (2), the pre-firing temperature is 800-1000℃ and the heating rate is 3-5℃ / min; in step (5), the sintering temperature is 1130-1150℃.

5. The preparation method according to claim 1, characterized in that, In step (4), the amount of FeNi metal powder added is 8000-15000 ppm based on the total weight of the main components.

6. The preparation method according to claim 1, characterized in that, In step (3), the auxiliary components include at least one of CaCO3, SiO2, ZrO2, Nb2O5, and Co2O3.

7. The preparation method according to claim 6, characterized in that, The amounts of the auxiliary components are as follows, based on the total weight of the main components: CaCO3: 400-600ppm, SiO2: 100-200ppm, ZrO2: 100-300ppm, Nb2O5: 100-300ppm, Co2O3: 2000-3500ppm.

8. The preparation method according to claim 1, characterized in that, The main components and their contents include Fe2O3: 57.8–60.2 mol%, ZnO: 3.8–5.0 mol%, and the remainder is Mn3O4.

9. A high-frequency, high Curie temperature, high saturation magnetic flux density manganese-zinc soft magnetic ferrite prepared by the preparation method described in claims 1-8.

10. The application of the manganese-zinc soft magnetic ferrite as described in claim 9 in AI data center server power supplies, high-voltage DC-DC modules, GPU / CPU multiphase power supplies, UPS and HVDC power distribution, and network communication magnetic devices.

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