High-frequency wide-temperature low-power-consumption soft magnetic manganese zinc ferrite material and preparation method thereof

Abstract

The invention discloses a high-frequency wide-temperature low-power-consumption soft magnetic manganese-zinc ferrite material and a preparation method, and belongs to the technical field of manganese-zinc ferrites.The soft magnetic manganese-zinc ferrite material comprises main materials and auxiliary materials, the main materials comprise, by mole, 53-55 mol% of Fe2O3, 9-10 mol% of ZnO and the balance MnO; the auxiliary materials comprise the following raw materials in parts by million: 3500 to 5000 ppm of Co3O4, 500 to 2000 ppm of SnO2, 300 to 800 ppm of CaCO3, 20 to 100 ppm of SiO2, 500 to 2000 ppm of TiO2 and 200 to 500 ppm of Nb2O5. According to the invention, the problem of high power consumption at 25 DEG C to 140 DEG C under 300KHz and 100mT in the prior art is solved. The invention has excellent loss characteristics and temperature characteristics.

Description

Technical Field

[0001] The invention relates to the technical field of manganese-zinc ferrite, in particular to a high-frequency, wide-temperature, low-power consumption soft magnetic manganese-zinc ferrite material and a preparation method thereof. Background Art

[0002] The rapid development of electronic technology has put forward higher and higher requirements for high frequency, wide temperature range, low power consumption, etc. for MnZn power ferrite materials used in the main transformer of switching power supplies. Switching power supplies have gradually replaced traditional linear power supplies due to their small size, light weight, and high efficiency. They are used in various fields, from civilian communication digital equipment to industrial production and even military electronic equipment. They are an indispensable part of modern electronic equipment. The rapid development of modern electronic science and technology has forced switching power supplies to evolve towards miniaturization, integration, and lightweight. In switching power supplies, the weight and volume of magnetic material components are very large, accounting for almost 30% of the weight and volume of the entire switching power supply circuit. Reducing the volume and weight of magnetic material components is equivalent to reducing the volume and weight of switching power supplies, which is conducive to the miniaturization and lightweight of switching power supplies.

[0003] From the working principle of the transformer, we know that the output voltage V = kfB m A e N, where k is the waveform factor, f is the operating frequency of the switching power supply, B m is the magnetic induction intensity, A e is the effective area of ​​the core, and N is the number of turns of the coil. From this formula, we can see that under the same output voltage, increasing the operating frequency can reduce the volume of the switching power supply, which is conducive to the miniaturization and lightweight of the device. However, for ferrite cores, increasing the operating frequency often leads to increased core loss. According to the core loss formula: PL = kh*B 3 *f+ke*B 2 *f 2 +pr, where PL is the total core loss, kh is the hysteresis loss coefficient, ke is the eddy current loss coefficient, B is the applied magnetic field, f is the applied frequency, and pr is the residual loss. The residual loss is still small under 300kHz and can be ignored. The core loss increases exponentially with the increase of the operating frequency. High core loss will reduce the efficiency of the switching power supply. In severe cases, it will cause the electronic components to heat up or even burn out. In addition to the operating frequency, the operating temperature of the device will also affect the core loss. Since electronic devices inevitably generate energy loss and dissipate heat when working, the operating temperature of the ferrite core is usually higher than room temperature, and the core loss will also change. Therefore, under the premise of increasing the operating frequency to meet the miniaturization and integration of the device, the core loss of the ferrite core at high frequency should be reduced as much as possible, and the temperature characteristics of the core should also be taken into account to ensure that the switching power supply can maintain high transmission and conversion efficiency in different application environments.

[0004] The high-frequency, wide-temperature, low-power consumption materials reported so far are generally used under conditions below 100KHz or above 500KHz. The Chinese patent with publication number CN102161585B discloses high-frequency, wide-temperature, low-power consumption soft magnetic manganese-zinc ferrite and its preparation method. The test scenario is 100KHz, 200mT, the frequency is relatively low and the overall loss is relatively high. The Chinese patent with publication number CN108863339A discloses a wide-temperature, low-loss MnZn ferrite material used in high-frequency, large-magnetic-field transformers. The test scenario is 500KHz, 70mT. Although its loss is relatively low, its magnetic permeability and applied magnetic field are relatively low. Therefore, high-frequency, wide-temperature, low-power consumption soft magnetic manganese-zinc ferrite materials are urgently needed to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material and a preparation method, which is applied to 300KHz, 100mT, and has the application of high frequency and large magnetic field, and has excellent loss characteristics and temperature characteristics, solving the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material includes a main material and auxiliary materials. The main material includes the following raw materials calculated in molar percentage: 53-55mol% Fe2O3, 9-10mol% ZnO, and the rest is MnO; the auxiliary materials include the following raw materials calculated in parts per million: 3500-5000ppm Co3O4, 500-2000ppm SnO2, 300-800ppm CaCO3, 20-100ppm SiO2, 500-2000ppm TiO2 and 200-500ppm Nb2O5.

[0008] According to another aspect of the present invention, a method for preparing a high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material is provided, which is used to prepare the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material as described above, comprising the following steps:

[0009] S1. Ingredients: weigh the main ingredients and auxiliary materials according to the above ratio, add deionized water to the main ingredients for sand grinding, and spray dry to obtain the spray material;

[0010] S2, pre-burning: pre-burning the sprayed material to obtain pre-burned material;

[0011] S3, secondary sand grinding: after adding auxiliary materials to the pre-burned material, add deionized water for secondary sand grinding to obtain secondary sand abrasive;

[0012] S4, spray granulation and molding: spray granulation and molding of the secondary abrasive to obtain a ring blank;

[0013] S5. Sintering: Sinter the ring blank to obtain a high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material.

[0014] Preferably, in S2, the pre-firing temperature is 800-950° C., and the pre-firing time is 2-5 hours.

[0015] Preferably, in S3, the secondary sanding time is 30-90 min, and the particle size distribution is controlled at D50: 1.0-1.6 um.

[0016] Preferably, in S5, the sintering temperature change curve is: heating from room temperature to 400-600°C at a heating rate of 2-4°C / min, and keeping warm for 2-4h; continuing to heat to 900-1100°C at a heating rate of 2-5°C / min; continuing to heat to 1220-1260°C at a heating rate of 1-3°C / min.

[0017] Preferably, in S5, the temperature is kept at 1220-1260° C. for 4-8 hours, and the oxygen content of the atmosphere is controlled at 3%-5%; after the temperature is kept, the temperature is cooled to room temperature at a speed of 2-5° C. / min.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite prepared by the present invention has a power consumption of less than 300kW / m in a wide temperature range of 300kHz, 100mT, and 25 to 140°C. 3 , 25℃ power consumption is 190kW / m 3 , 140℃ power consumption is 277kW / m 3 The difference between the maximum and minimum power loss in the temperature range of 25 to 140°C is 100kW / m 3 Below, and magnetic permeability>3000, Bs>530, can be applied to 300KHz, 100mT, and has high frequency and large magnetic field applications, and has excellent loss characteristics and temperature characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The present invention is a flow chart for preparing the high-frequency, wide-temperature, low-power-consumption soft magnetic manganese-zinc ferrite material. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] To solve the existing problem of high power consumption at 300KHz and 100mT, 25℃ to 140℃, please refer to Figure 1 , this embodiment provides the following technical solutions:

[0023] Example 1

[0024] A high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material, comprising a main material and auxiliary materials, wherein the main material comprises raw materials calculated in the following molar percentages: 53 mol% of Fe2O3, 37.9 mol% of MnO and 9.1 mol% of ZnO;

[0025] The auxiliary materials include the following raw materials calculated in parts per million: 3800 ppm Co3O4, 1500 ppm SnO2, 600 ppm CaCO3, 50 ppm SiO2, 1000 ppm TiO2 and 300 ppm Nb2O5.

[0026] In order to better demonstrate the preparation process of high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite materials, this embodiment provides a method for preparing high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite materials, which is used to prepare the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite materials as described above, including the following steps:

[0027] S1. Ingredients: weigh the main ingredients and auxiliary materials according to the above ratio, add deionized water to the main ingredients for sand grinding, and spray dry to obtain the spray material;

[0028] S2, pre-burning: pre-burn the sprayed material to obtain a pre-burned material, the pre-burning temperature is 800-950°C, and the pre-burning time is 2-5 hours;

[0029] S3, secondary sand grinding: after adding auxiliary materials to the pre-burned material, add deionized water for secondary sand grinding to obtain secondary sand abrasives. The secondary sand abrasive time is 30-90min, and the particle size distribution is controlled at D50: 1.0-1.6um;

[0030] S4, spray granulation and molding: spray granulation and molding of the secondary abrasive to obtain a ring blank;

[0031] S5. Sintering: The ring blank is sintered to obtain a high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material. The sintering temperature change curve is: heating from room temperature to 400-600°C at a heating rate of 2-4°C / min, and keeping warm for 2-4h; heating to 900-1100°C at a heating rate of 2-5°C / min; heating to 1250°C at a heating rate of 1-3°C / min, and keeping warm at 1250°C for 4-8h, with the oxygen content of the atmosphere controlled at 4.8%; cooling to room temperature at a rate of 2-5°C / min after the insulation is completed.

[0032] Preparation principle: The material has the characteristics of low power consumption in a wide temperature range by adjusting the magnetocrystalline anisotropy constant K1 through Co3O4. From the above formula, it can be seen that under high-frequency conditions, eddy current loss dominates. Therefore, when SiO2 and CaCO3 are added during the sintering process, SiO2 and CaCO3 will generate high-resistivity CaSiO3, which accumulates at the grain boundary in high concentration, thereby increasing the grain boundary resistivity and reducing the eddy current loss Pe. When TiO2 and SnO2 are added, due to Ti 4+ and Sn 4+ Some of them will enter the grains, which will largely bind Fe 2+ , so that it is combined with Fe 3+ The electron exchange becomes difficult, thereby increasing the resistivity inside the grains. The increase in the resistivity of the grain boundaries and grains effectively reduces the Pe of the material. The sintering is carried out at a low temperature, and the oxygen atmosphere can not only reduce the number of domain walls and freeze them to reduce the residual loss, but also reduce Fe 2+ The content reduces eddy current loss and achieves satisfactory results. The combination of low-temperature sintering and Nb2O5 makes the grains small and uniform.

[0033] Example 2

[0034] The difference from Example 1 is that the main material used in the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material is different;

[0035] The high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material includes a main material and an auxiliary material, wherein the main material includes the following raw materials calculated in molar percentage: 53 mol% of Fe2O3, 37 mol% of MnO and 10 mol% of ZnO;

[0036] The auxiliary materials include the following raw materials calculated in parts per million: 3800 ppm Co3O4, 1500 ppm SnO2, 600 ppm CaCO3, 50 ppm SiO2, 1000 ppm TiO2 and 300 ppm Nb2O5.

[0037] Example 3

[0038] The difference from Example 1 is that the main material used in the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material is different;

[0039] Among them, the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material includes a main material and an auxiliary material, and the main material includes the following raw materials calculated by molar percentage: 53.2 mol% of Fe2O3, 37.3 mol% of MnO and 9.5 mol% of ZnO;

[0040] The auxiliary materials include the following raw materials calculated in parts per million: 3800 ppm Co3O4, 1500 ppm SnO2, 600 ppm CaCO3, 50 ppm SiO2, 1000 ppm TiO2 and 300 ppm Nb2O5.

[0041] Example 4

[0042] The difference from Example 1 is that the auxiliary materials used in the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material are different, the sintering temperature is raised to 1280° C., and the oxygen content of the atmosphere is controlled at 4.0%;

[0043] Among them, the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material includes a main material and an auxiliary material, and the main material includes the following raw materials calculated by molar percentage: 53 mol% of Fe2O3, 37.9 mol% of MnO and 9.1 mol% of ZnO;

[0044] The auxiliary materials include the following raw materials calculated in parts per million: 4000ppm Co3O4, 1000ppm SnO2, 500ppm CaCO3 and 250ppm Nb2O5.

[0045] Comparative Example 1

[0046] The difference from Example 1 is that the main material used in the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material is different;

[0047] Among them, the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material includes a main material and an auxiliary material, and the main material includes the following raw materials calculated by molar percentage: 53 mol% of Fe2O3, 36 mol% of MnO and 11 mol% of ZnO;

[0048] The auxiliary materials include the following raw materials calculated in parts per million: 3800 ppm Co3O4, 1500 ppm SnO2, 600 ppm CaCO3, 50 ppm SiO2, 1000 ppm TiO2 and 300 ppm Nb2O5.

[0049] Comparative Example 2

[0050] The difference from Example 1 is that the auxiliary materials used in the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material are different;

[0051] Among them, the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material includes a main material and an auxiliary material, and the main material includes the following raw materials calculated by molar percentage: 53 mol% of Fe2O3, 37.9 mol% of MnO and 9.1 mol% of ZnO;

[0052] The auxiliary materials include the following raw materials calculated in parts per million: 3000 ppm Co3O4, 1500 ppm SnO2, 600 ppm CaCO3, 50 ppm SiO2, 1000 ppm TiO2 and 300 ppm Nb2O5.

[0053] Comparative Example 3

[0054] The difference from Example 1 is that the sintering temperature and atmosphere oxygen content used in the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material are different, wherein the sintering temperature is raised to 1280° C., and the atmosphere oxygen content is controlled at 4.0%;

[0055] Among them, the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material includes a main material and an auxiliary material, and the main material includes the following raw materials calculated by molar percentage: 53 mol% of Fe2O3, 37.9 mol% of MnO and 9.1 mol% of ZnO;

[0056] The auxiliary materials include the following raw materials calculated in parts per million: 3800 ppm Co3O4, 1500 ppm SnO2, 600 ppm CaCO3, 50 ppm SiO2, 1000 ppm TiO2 and 300 ppm Nb2O5.

[0057] Comparative Example 4

[0058] The difference from Example 1 is that the auxiliary materials used in the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material are different;

[0059] Among them, the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material includes a main material and an auxiliary material, and the main material includes the following raw materials calculated by molar percentage: 53 mol% of Fe2O3, 37.9 mol% of MnO and 9.1 mol% of ZnO;

[0060] The auxiliary materials include the following raw materials calculated in parts per million: 3800 ppm Co3O4, 600 ppm CaCO3, 50 ppm SiO2 and 300 ppm Nb2O5.

[0061] Comparative Example 5

[0062] The difference from Example 1 is that the auxiliary materials used in the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material are different;

[0063] Among them, the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material includes a main material and an auxiliary material, and the main material includes the following raw materials calculated by molar percentage: 53 mol% of Fe2O3, 37.9 mol% of MnO and 9.1 mol% of ZnO;

[0064] The auxiliary materials include the following raw materials calculated in parts per million: 3800 ppm of Co3O4, 1500 ppm of SnO2, 1000 ppm of TiO2 and 300 ppm of Nb2O5.

[0065] Comparative Example 6

[0066] The difference from Example 1 is that the auxiliary materials used in the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material are different;

[0067] Among them, the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material includes a main material and an auxiliary material, and the main material includes the following raw materials calculated by molar percentage: 53 mol% of Fe2O3, 37.9 mol% of MnO and 9.1 mol% of ZnO;

[0068] The auxiliary materials include the following raw materials calculated in parts per million: 3800 ppm Co3O4, 1500 ppm SnO2, 600 ppm CaCO3, 50 ppm SiO2 and 1000 ppm TiO2.

[0069] The high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite materials prepared in Examples 1-4 and Comparative Examples 1-6 are summarized, wherein the composition, sintering temperature and oxygen content of the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite materials are shown in Table 1:

[0070] Table 1: Composition, sintering temperature and oxygen content of high frequency, wide temperature and low power consumption soft magnetic manganese zinc ferrite materials

[0071]

[0072]

[0073] The soft magnetic manganese-zinc ferrite materials prepared in Examples 1-4 and Comparative Examples 1-6 were tested for loss along with the temperature change trend. The loss test results along with the temperature change trend are shown in Table 2:

[0074] Table 2: Loss test results with temperature variation trend

[0075]

[0076]

[0077] It can be seen from Tables 1 and 2 above that the prepared high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite has a power consumption of less than 300kW / m in a wide temperature range of 300kHz, 100mT, and 25 to 140°C. 3 , 25℃ power consumption is 190kW / m 3 , 140℃ power consumption is 277kW / m 3 The difference between the maximum and minimum power loss in the temperature range of 25 to 140°C is 100kW / m 3 Below, and magnetic permeability>3000, Bs>530.

[0078] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0079] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material, comprising a main material and auxiliary materials, characterized in that: The main material includes the following raw materials calculated in molar percentage: 53-55 mol% of Fe2O3, 9-10 mol% of ZnO, and the rest of MnO; The auxiliary materials include the following raw materials calculated in parts per million: 3500-5000ppm Co3O4, 500-2000ppm SnO2, 300-800ppm CaCO3, 20-100ppm SiO2, 500-2000ppm TiO2 and 200-500ppm Nb2O5.

2. A method for preparing a high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material, which is used to prepare the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material as claimed in claim 1, characterized in that: The steps include: S1. Ingredients: weigh the main ingredients and auxiliary materials according to the above ratio, add deionized water to the main ingredients for sand grinding, and spray dry to obtain the spray material; S2, pre-burning: pre-burning the sprayed material to obtain pre-burned material; S3, secondary sand grinding: after adding auxiliary materials to the pre-burned material, add deionized water for secondary sand grinding to obtain secondary sand abrasive; S4, spray granulation and molding: spray granulation and molding of the secondary abrasive to obtain a ring blank; S5. Sintering: Sinter the ring blank to obtain a high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material.

3. The method for preparing the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material according to claim 2, characterized in that: In the step S2, the pre-firing temperature is 800-950°C, and the pre-firing time is 2-5 hours.

4. The method for preparing the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material according to claim 3, characterized in that: In S3, the secondary sanding time is 30-90 min, and the particle size distribution is controlled at D50: 1.0-1.6 um.

5. The method for preparing the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material according to claim 4, characterized in that: In S5, the sintering temperature change curve is: heating from room temperature to 400-600°C at a heating rate of 2-4°C / min, and keeping warm for 2-4h; heating to 900-1100°C at a heating rate of 2-5°C / min; and heating to 1220-1260°C at a heating rate of 1-3°C / min.

6. The method for preparing the high-frequency, wide-temperature, low-power soft magnetic manganese-zinc ferrite material according to claim 5, characterized in that: In S5, the temperature is kept at 1220-1260° C. for 4-8 hours, and the oxygen content of the atmosphere is controlled at 3%-5%; after the heat preservation, the temperature is cooled to room temperature at a speed of 2-5° C. / min.

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