Nickel-zinc copper ferrite material, and preparation method and application thereof

Abstract

The present application relates to a kind of nickel-zinc copper ferrite material and its preparation method and application, the nickel-zinc copper ferrite material provided by the present application, by controlling main component and its content range, can obtain higher saturation magnetic induction intensity, mechanical strength and excellent heat shock resistance characteristics;Through the joint substitution of auxiliary component Ca 2+ And Bi 3+ Can improve magnet density, optimize mechanical strength and heat shock resistance performance;Through the small amount of substitution of Ca 2+ , Sn 4+ Can improve magnetic permeability, reduce loss;Through the combined substitution of Ca 2+ , Sn 4+ And Bi 3+ Can control saturation magnetic induction intensity to meet the applicability of device in each environment;The nickel-zinc copper ferrite material prepared can meet the requirement as high-performance magnetic core material.

Description

Technical Field

[0001] This invention relates to the field of soft magnetic ferrite technology, specifically to a nickel-zinc-copper ferrite material, its preparation method, and its application. Background Technology

[0002] With the rapid development and iteration of electronic product technology in recent years, ferrite cores have been widely used in medical devices, wireless charging, new energy vehicle charging piles, LED lighting, smart homes, and high-performance computers. The trend towards miniaturization and thinning of components has placed higher demands on the thermal shock resistance, mechanical strength, and magnetoelectric properties of nickel-zinc materials, the mainstream ferrite material.

[0003] Currently, nickel-zinc soft magnetic ferrite materials in existing technologies have high permeability, but low Curie temperature and saturation magnetic induction intensity. This results in products made from nickel-zinc materials exhibiting disadvantages such as low inductance after superimposed current, low energy conversion efficiency, and poor thermal shock resistance during use.

[0004] CN 113636838A discloses a nickel-zinc ferrite material, its preparation method, and its application. The nickel-zinc ferrite material includes a main component and additives. The main component includes Fe2O3, NiO, ZnO, and CuO, and the additives include Co2O3, Nb2O5, and Bi2O3. In the main component, the content of Fe2O3 is 47.8-49.8 mol%, the content of NiO is 13.5-15 mol%, the content of ZnO is 29-31 mol%, the content of CuO is 5-7 mol%, the content of Co2O3 is 0.15-0.3 wt%, the content of Nb2O5 is 0.04-0.075 wt%, and the content of Bi2O3 is 0.05-0.15 wt%. This invention adds numerous trace elements to the main component of the ferrite, achieving wide-temperature high permeability and high-temperature impact resistance. However, the mechanical strength of the magnet still needs further improvement.

[0005] CN 101169996A discloses a Mn-Zn ferrite magnetic material and its preparation method. The main components and contents of the Mn-Zn ferrite magnetic material, calculated as oxides, are: Fe2O3 52-56 mol%; ZnO 2-10 mol%; MnO 38-42 mol%; auxiliary components are: CaO: 400-800 ppm, Nb2O5: 100-400 ppm, ZrO2: 100-800 ppm, Co2O3: 1000-5000 ppm, or a combination thereof. This invention simultaneously dops numerous substances such as ZrO2, Nb2O5, and Co2O3 into the main ferrite components to achieve high saturation magnetic induction and high Curie temperature. However, its magnetic permeability after sintering is relatively low, and the thermal shock resistance and mechanical strength of the material still need further investigation.

[0006] Therefore, in view of the shortcomings of the existing technology, there is an urgent need to provide a nickel-zinc-copper ferrite material with high saturation magnetic induction intensity, high mechanical strength and excellent thermal shock resistance. Summary of the Invention

[0007] The purpose of this invention is to provide a nickel-zinc-copper ferrite material, its preparation method and application. By limiting the reasonable ratio of raw materials, the nickel-zinc-copper ferrite material obtained has high saturation magnetic induction intensity, high magnetic permeability, high mechanical strength and excellent thermal shock resistance.

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

[0009] In a first aspect, the present invention provides a nickel-zinc-copper ferrite material, the nickel-zinc-copper ferrite material comprising a main component and auxiliary components; the main component, based on a total molar percentage of 100 mol%, comprises: Fe2O3 46.5-49.5 mol%, NiO 16.5-19 mol%, ZnO 23-26 mol%, CuO 7.5-12.5 mol%; the auxiliary components, based on the total mass percentage of the main component, comprise: Bi2O3 0.3-1.5 wt%, SnO2 0.1-0.3 wt%, CaCO3 0.03-0.1 wt%.

[0010] The nickel-zinc-copper ferrite material provided by this invention can achieve high magnetic permeability and Curie temperature by controlling the contents of Fe2O3, ZnO, and CuO. To ensure high saturation magnetic induction, high strength, and high thermal shock resistance, the contents of Fe2O3, ZnO, NiO, and CuO need to be adjusted accordingly. The auxiliary component Ca... 2+ and Bi 3 + The combined substitution of [agents] can increase magnet density and achieve high strength and thermal shock resistance; through Ca [substituents]...2+ Sn 4+ A small amount of substitution can improve magnetic permeability and reduce losses; through Ca... 2+ Sn 4+ and Bi 3+ The combination of substitutions can adjust the saturation magnetic induction intensity to meet the applicability of devices in various environments. SnO2 can refine the grain size and improve the saturation magnetic induction intensity; Ca... 2+ High-resistivity grain boundaries can be formed at grain boundaries, and Zn can be avoided. 2+ The volatilization of Bi2O3 prevents the formation of defects and increases internal stress; while the addition of Bi2O3 can uniformly grow FeBi2O4 with a spinel structure, thus ensuring the comprehensive performance of the matrix. The nickel-zinc-copper ferrite material prepared by this invention has high saturation magnetic induction intensity, high magnetic permeability, high mechanical strength and excellent thermal shock resistance, and can be better applied in power inductors or common-mode inductors.

[0011] The molar percentage of Fe2O3 in the main component is 46.5-49.5 mol%, for example, it can be 46.5 mol%, 47 mol%, 47.5 mol%, 48.5 mol%, or 49.5 mol%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0012] The molar percentage of NiO in the main component is 16.5-19 mol%, for example, it can be 16.5 mol%, 17 mol%, 17.5 mol%, 18 mol%, or 19 mol%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0013] The molar percentage of ZnO in the main component is 23-26 mol%, for example, it can be 23 mol%, 23.5 mol%, 24 mol%, 25 mol%, or 26 mol%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0014] The molar percentage of CuO in the main component is 7.5-12.5 mol%, for example, it can be 7.5 mol%, 8.5 mol%, 9.5 mol%, 10.5 mol%, or 12.5 mol%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0015] The mass percentage of Bi2O3 in the auxiliary component is 0.3-1.5 wt% of the total mass percentage of the main component, for example, it can be 0.3 wt%, 0.5 wt%, 0.8 wt%, 1.2 wt% or 1.5 wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0016] The mass percentage of SnO2 in the auxiliary component is 0.1-0.3 wt% of the total mass percentage of the main component, for example, it can be 0.1 wt%, 0.15 wt%, 0.2 wt%, 0.25 wt% or 0.3 wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0017] The mass percentage of CaCO3 in the auxiliary component is 0.03-0.1 wt% of the total mass percentage of the main component, for example, it can be 0.03 wt%, 0.05 wt%, 0.06 wt%, 0.08 wt% or 0.1 wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0018] Preferably, the total molar percentage of Fe2O3+ZnO+CuO in the main component is 81.5-83 mol%, for example, it can be 81.5 mol%, 81.8 mol%, 82 mol%, 82.5 mol%, or 83 mol%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0019] In this invention, the total amount of Fe2O3, ZnO, and CuO needs to be controlled within a reasonable range. If the amount exceeds the limit, even if the content of each main component is within the required range, the magnetic permeability of the prepared nickel-zinc-copper ferrite material will be reduced.

[0020] Preferably, the total mass percentage of Bi2O3+CaCO3 in the auxiliary component is 0.4-1.5 wt% of the total mass percentage of the main component, for example, it can be 0.4 wt%, 0.7 wt%, 1 wt%, 1.2 wt% or 1.5 wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0021] In this invention, the total amount of Bi2O3 and CaCO3 needs to be controlled within a reasonable range. If the amount exceeds the limit, even if the content of each auxiliary component is within the required range, the magnetic permeability and saturation magnetic induction intensity Bs of the prepared nickel-zinc-copper ferrite material will be reduced.

[0022] Secondly, the present invention provides a method for preparing a nickel-zinc-copper ferrite material as described in the first aspect, the method comprising the following steps:

[0023] (1) The main components of the formula are mixed with liquid medium by ball milling. The resulting ball milled material is pre-calcined after first spray granulation to obtain pre-calcined material.

[0024] (2) The auxiliary components, additives, liquid medium and the pre-burned material obtained in step (1) are subjected to first grinding and second grinding in sequence. The resulting grinding material is granulated by second spraying and then shaped and sintered to obtain the nickel-zinc-copper ferrite material.

[0025] The method for preparing nickel-zinc-copper ferrite materials provided by the present invention, through the setting of the first grinding and the second grinding, is conducive to the refinement of magnetic domains of the nickel-zinc-copper ferrite materials obtained by subsequent sintering, thereby improving the magnet strength and ensuring that the product has high saturation magnetic induction intensity, high magnetic permeability, high mechanical strength and excellent thermal shock resistance.

[0026] Preferably, the mass ratio of the main component, the ball milling medium and the liquid medium in the ball milling mixture in step (1) is 1:(4-8):(0.5-1.2), for example, it can be 1:4:0.5, 1:5:0.6, 1:6:0.8, 1:7:1 or 1:8:1.2, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0027] Preferably, the milling media comprises zirconium balls.

[0028] Preferably, the ball milling time in step (1) is 20-60 min, for example, it can be 20 min, 30 min, 40 min, 50 min or 60 min, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0029] Preferably, the preheating temperature in step (1) is 720-900℃, for example, it can be 720℃, 750℃, 800℃, 850℃ or 900℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0030] Preferably, the preheating time in step (1) is 2-4 hours, for example, 2 hours, 2.5 hours, 3 hours, 3.5 hours or 4 hours, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0031] Preferably, the additive in step (2) includes any one or a combination of at least two of the following: adhesive, dispersant or defoamer. Typical but non-limiting combinations include a combination of adhesive and dispersant, a combination of dispersant and defoamer, or a combination of adhesive, dispersant and defoamer, preferably a combination of adhesive, dispersant and defoamer.

[0032] Preferably, when the additive in step (2) is a combination of binder, dispersant and defoamer, the mass ratio of the pre-burned material, liquid medium, binder, dispersant and defoamer is 100:(60-140):(6-14):(0.1-2):(0.001-0.0025), for example, it can be 100:60:6:0.1:0.001, 100:80:8:0.5:0.0012, 100:100:10:1:0.0015, 100:120:12:1.5:0.002 or 100:140:14:2:0.0025, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0033] Preferably, the liquid medium in step (1) and the liquid medium in step (2) each independently comprise deionized water.

[0034] Preferably, the adhesive comprises any one or a combination of at least two of polyvinyl alcohol, polyvinyl butyral, hydroxycellulose, or polyacrylate. Typical but non-limiting combinations include a combination of polyvinyl alcohol and polyvinyl butyral, a combination of polyvinyl butyral, hydroxycellulose, and polyacrylate, or a combination of polyvinyl alcohol, polyvinyl butyral, hydroxycellulose, and polyacrylate.

[0035] Preferably, the dispersant comprises any one or a combination of at least two of citrate, sodium stearate, polyacrylic acid, or triethanolamine. Typical but non-limiting combinations include a combination of citrate and sodium stearate, a combination of sodium stearate and polyacrylic acid, or a combination of citrate, sodium stearate, polyacrylic acid, and triethanolamine.

[0036] Preferably, the defoamer comprises any one or a combination of at least two of n-octanol, tributyl phosphate, hard fatty acid, or polyethylene glycol. Typical but non-limiting combinations include a combination of n-octanol and tributyl phosphate, a combination of hard fatty acid and polyethylene glycol, or a combination of n-octanol, tributyl phosphate, hard fatty acid, and polyethylene glycol.

[0037] Preferably, the rotation speed of the first grinding in step (2) is 200-260 rpm, for example, it can be 200 rpm, 220 rpm, 240 rpm or 260 rpm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0038] Preferably, the grinding time in step (2) is 4-6 min, for example, it can be 4 min, 4.5 min, 5 min, 5.5 min or 6 min, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0039] Preferably, the rotation speed of the second grinding in step (2) is 280-360 rpm, for example, it can be 280 rpm, 300 rpm, 320 rpm, 340 rpm or 360 rpm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0040] Preferably, the second grinding time in step (2) is 0.5-2h, for example, it can be 0.5h, 0.8h, 1h, 1.5h or 2h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0041] Preferably, the median particle size X50 of the abrasive in step (2) is 0.5-0.9 μm, and the cumulative percentage of particle size X90 is 1.25-1.8 μm.

[0042] The median particle size X50 of the abrasive is 0.5-0.9μm, for example, it can be 0.5μm, 0.6μm, 0.7μm, 0.8μm or 0.9μm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0043] The lower median particle size X50 of the abrasive material is beneficial for refining the magnetic domains of the nickel-zinc-copper ferrite material obtained by subsequent sintering, thereby improving the magnet strength.

[0044] The cumulative percentage of the abrasive is 90% with a particle size of 1.25-1.8 μm x 90, for example, it can be 1.25 μm, 1.5 μm, 1.6 μm, 1.7 μm or 1.8 μm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0045] Preferably, the average particle size of the particles obtained by the second spray granulation in step (2) is 30-200μm, for example, it can be 30μm, 60μm, 100μm, 150μm or 200μm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0046] Preferably, the molding process in step (2) includes standard sample ring blank molding and strip blank molding.

[0047] The density of the standard sample ring blank is 3.1-3.25 g / cm³. 3 The dimensions are H25*15*10mm; the dimensions of the strip-shaped blank are T90*20*2mm, and it is formed under the conditions of 20MPa and holding time of 30s, and is used to test the bending strength and thermal shock resistance.

[0048] Preferably, the sintering in step (2) is carried out in a pusher kiln.

[0049] Preferably, the sintering in step (2) includes a first heating, a second heating, a first cooling and a second cooling in sequence.

[0050] Preferably, the specific steps of the first heating include: heating from room temperature to 550-750°C in an air atmosphere at a heating rate of 0.5-2°C / min, and holding at that temperature for 2-7 hours.

[0051] The heating rate of the first heating is 0.5-2℃ / min, for example, it can be 0.5℃ / min, 0.8℃ / min, 1℃ / min, 1.5℃ / min or 2℃ / min, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0052] The so-called normal temperature refers to a temperature of 20-25℃.

[0053] The endpoint of the first temperature rise is 550-750℃, for example, it can be 550℃, 600℃, 650℃, 700℃ or 750℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0054] The holding time for the first heating is 2-7 hours, for example, it can be 2 hours, 3 hours, 5 hours, 6 hours or 7 hours, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0055] Preferably, the specific steps of the second heating include: continuing to heat to 950-1050℃ at a heating rate of 1-3℃ / min, and holding at that temperature for 2-5 hours.

[0056] The second heating rate is 1-3℃ / min, for example, it can be 1℃ / min, 1.5℃ / min, 2℃ / min, 2.5℃ / min or 3℃ / min, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0057] The second temperature rise endpoint is 950-1050℃, for example, it can be 950℃, 980℃, 1000℃, 1020℃ or 1050℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0058] The second heating and holding time is 2-5 hours, for example, it can be 2 hours, 2.5 hours, 3 hours, 4 hours or 5 hours, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0059] Preferably, the specific steps of the first cooling include: cooling to 590-610°C in an air atmosphere at a cooling rate of 2-6°C / min.

[0060] The cooling rate of the first cooling is 2-6℃ / min, for example, it can be 2℃ / min, 3℃ / min, 4℃ / min, 5℃ / min or 6℃ / min, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0061] The first cooling temperature endpoint is 590-610℃, for example, it can be 590℃, 595℃, 600℃, 605℃ or 610℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0062] Preferably, the specific steps of the second cooling include: continuing to cool down to 45-55°C at a cooling rate of 1-5°C / min.

[0063] The second cooling rate is 1-5℃ / min, for example, it can be 1℃ / min, 2℃ / min, 3℃ / min, 4℃ / min or 5℃ / min, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0064] The second cooling temperature endpoint is 45-55℃, for example, it can be 45℃, 48℃, 50℃, 52℃ or 55℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0065] The sintering process employs an air atmosphere sintering method in a pusher kiln, which enables large-scale production of magnetic core samples and achieves low-cost production. Simultaneously, by using a two-stage heating and two-stage cooling method, the magnetic permeability can be improved, the magnet densification can be enhanced, and thus the saturation magnetic induction intensity Bs of the magnetic core can be increased.

[0066] Thirdly, the present invention provides an application of the nickel-zinc-copper ferrite material as described in the first aspect, wherein the nickel-zinc-copper ferrite material is used in power inductors or common-mode inductors.

[0067] The nickel-zinc-copper ferrite material provided by this invention solves the problems of stable magnetic permeability and low saturation magnetic induction intensity under thermal shock, thereby improving the applicability of power magnetic products such as common mode inductors and multilayer magnetic beads / inductors, and can be better applied to industries such as aerospace electronics, automotive electronics, and communication electronics.

[0068] Compared with the prior art, the present invention has the following beneficial effects:

[0069] The nickel-zinc-copper ferrite material provided by this invention, by controlling the main components and their content range, can achieve high saturation magnetic induction intensity, mechanical strength, and excellent thermal shock resistance; through the auxiliary component Ca... 2+ and Bi 3+The combined substitution of [components] can improve magnet density and optimize mechanical strength and thermal shock resistance; through Ca [substituents]... 2+ Sn 4+ A small amount of substitution can improve magnetic permeability and reduce losses; through Ca... 2+ Sn 4+ and Bi 3+ The combination of substitutions can adjust the saturation magnetic induction intensity to meet the applicability of devices in various environments; the prepared nickel-zinc-copper ferrite material can meet the requirements as a high-performance magnetic core material. Attached Figure Description

[0070] Figure 1 This is a SEM image of the nickel-zinc-copper ferrite material provided in Embodiment 1 of the present invention. Detailed Implementation

[0071] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0072] Example 1

[0073] This embodiment provides a nickel-zinc-copper ferrite material, which includes a main component and auxiliary components. Based on a total molar percentage of 100 mol%, the main component includes: Fe₂O₃ 49.26 mol%, NiO 18 mol%, ZnO 25 mol%, and CuO 7.74 mol%. Based on the total mass percentage of the main component, the auxiliary components include: Bi₂O₃ 1 wt%, SnO₂ 0.2 wt%, and CaCO₃ 0.075 wt%.

[0074] The total molar percentage of Fe2O3+ZnO+CuO in the main component is 82 mol%; the total mass percentage of Bi2O3+CaCO3 in the auxiliary component is 1.075 wt% of the total mass percentage of the main component.

[0075] The preparation method of the nickel-zinc-copper ferrite material includes the following steps:

[0076] (1) The main component and deionized water were ball-milled and mixed for 40 min. The mass ratio of the main component, zirconium balls and deionized water in the ball-milling mixture was 1:6:0.8. The resulting ball-milled material was pre-calcined at 800℃ for 3 h after the first spray granulation to obtain the pre-calcined material.

[0077] (2) The auxiliary ingredients, polyvinyl alcohol, amine citrate, tributyl phosphate, deionized water and the pre-calcined material obtained in step (1) are successively ground at 240 rpm for 5 min and at 320 rpm for 1.5 h to obtain abrasive material with a median particle size X50 of 0.7 μm and a cumulative percentage of 90% of the particles with a particle size X90 of 1.5 μm; the abrasive material is then subjected to a second spray granulation to obtain particles with an average particle size of 100 μm, and then shaped and sintered in a pusher kiln to obtain the nickel-zinc-copper ferrite material;

[0078] The mass ratio of the pre-burned material, deionized water, polyvinyl alcohol, ammonium citrate, and tributyl phosphate is 100:100:10:1:0.002.

[0079] The sintering process includes a first heating, a second heating, a first cooling, and a second cooling, performed sequentially. The first heating step includes heating from room temperature to 650°C in an air atmosphere at a heating rate of 1°C / min and holding at that temperature for 5 hours. The second heating step includes heating to 1000°C at a heating rate of 2°C / min and holding at that temperature for 3 hours. The first cooling step includes cooling to 600°C in an air atmosphere at a cooling rate of 4°C / min. The second cooling step includes cooling to 50°C at a cooling rate of 3°C / min.

[0080] The molding process includes standard sample ring blank molding and strip-shaped blank molding; the density of the standard sample ring blank is 3.2 g / cm³. 3 The dimensions are H25*15*10mm; the dimensions of the strip-shaped blank are T90*20*2mm, and it is formed under the conditions of 20MPa and a holding time of 30s.

[0081] The SEM image of the nickel-zinc-copper ferrite material prepared in this embodiment is shown below. Figure 1 As shown in the figure, the nickel-zinc-copper ferrite has a uniform size and is relatively dense.

[0082] Example 2

[0083] This embodiment provides a nickel-zinc-copper ferrite material, which includes a main component and auxiliary components. Based on a total molar percentage of 100 mol%, the main component includes: Fe₂O₃ 47.6 mol%, NiO 18.5 mol%, ZnO 23 mol%, and CuO 10.9 mol%. Based on the total mass percentage of the main component, the auxiliary components include: Bi₂O₃ 1.45 wt%, SnO₂ 0.17 wt%, and CaCO₃ 0.05 wt%.

[0084] The total molar percentage of Fe2O3+ZnO+CuO in the main component is 81.5 mol%; the total mass percentage of Bi2O3+CaCO3 in the auxiliary component is 1.5 wt% of the total mass percentage of the main component.

[0085] The preparation method of the nickel-zinc-copper ferrite material includes the following steps:

[0086] (1) The main component and deionized water were mixed by ball milling for 20 min. The mass ratio of the main component, zirconium balls and deionized water in the ball milling mixture was 1:4:0.5. The resulting ball milled material was pre-calcined at 720℃ for 4 h after the first spray granulation to obtain the pre-calcined material.

[0087] (2) The auxiliary components, polyacrylate, triethanolamine, tributyl phosphate, deionized water and the pre-calcined material obtained in step (1) are successively ground at 200 rpm for 6 min and at 280 rpm for 2 h to obtain abrasive material with a median particle size X50 of 0.5 μm and a cumulative percentage of 90% of the particle size X90 of 1.25 μm; the abrasive material is then spray-granulated to obtain particles with an average particle size of 30 μm, and then shaped and sintered in a pusher kiln to obtain the nickel-zinc-copper ferrite material;

[0088] The mass ratio of the pre-burned material, deionized water, polyacrylate, triethanolamine, and tributyl phosphate is 100:60:6:0.1:0.001.

[0089] The sintering process includes a first heating, a second heating, a first cooling, and a second cooling, performed sequentially. The first heating step includes heating from room temperature to 550°C at a heating rate of 0.5°C / min in an air atmosphere and holding at that temperature for 7 hours. The second heating step includes heating to 950°C at a heating rate of 1°C / min and holding at that temperature for 5 hours. The first cooling step includes cooling to 610°C at a cooling rate of 2°C / min in an air atmosphere. The second cooling step includes cooling to 55°C at a cooling rate of 1°C / min.

[0090] The molding process includes standard sample ring blank molding and strip-shaped blank molding; the density of the standard sample ring blank is 3.2 g / cm³. 3 The dimensions are H25*15*10mm; the dimensions of the strip-shaped blank are T90*20*2mm, and it is formed under the conditions of 20MPa and a holding time of 30s.

[0091] Example 3

[0092] This embodiment provides a nickel-zinc-copper ferrite material, which includes a main component and auxiliary components. Based on a total molar percentage of 100 mol%, the main component includes: Fe₂O₃ 49.5 mol%, NiO 17 mol%, ZnO 26 mol%, and CuO 7.5 mol%. Based on the total mass percentage of the main component, the auxiliary components include: Bi₂O₃ 0.35 wt%, SnO₂ 0.25 wt%, and CaCO₃ 0.05 wt%.

[0093] The total molar percentage of Fe2O3+ZnO+CuO in the main component is 83 mol%; the total mass percentage of Bi2O3+CaCO3 in the auxiliary component is 0.4 wt% of the total mass percentage of the main component.

[0094] The preparation method of the nickel-zinc-copper ferrite material includes the following steps:

[0095] (1) The main component and deionized water were ball-milled and mixed for 60 min. The mass ratio of the main component, zirconium balls and deionized water in the ball-milling mixture was 1:8:1.2. The resulting ball-milled material was pre-calcined at 900℃ for 2 h after the first spray granulation to obtain the pre-calcined material.

[0096] (2) The auxiliary ingredients, polyvinyl butyral, polyacrylic acid, n-octanol, deionized water and the pre-calcined material obtained in step (1) are successively ground at 260 rpm for 4 min and at 360 rpm for 0.5 h to obtain abrasive material with a median particle size X50 of 0.9 μm and a cumulative percentage of 90% of the particles with a particle size X90 of 1.8 μm; the abrasive material is then spray-granulated to obtain particles with an average particle size of 200 μm, and then shaped and sintered in a pusher kiln to obtain the nickel-zinc-copper ferrite material;

[0097] The mass ratio of the pre-burned material, deionized water, polyvinyl butyral, polyacrylic acid, and n-octanol is 100:140:14:2:0.0025.

[0098] The sintering process includes a first heating, a second heating, a first cooling, and a second cooling, performed sequentially. The first heating step includes heating from room temperature to 750°C in air at a heating rate of 2°C / min and holding for 2 hours. The second heating step includes heating to 1050°C at a heating rate of 3°C / min and holding for 2 hours. The first cooling step includes cooling to 590°C in air at a cooling rate of 6°C / min. The second cooling step includes cooling to 45°C at a cooling rate of 5°C / min.

[0099] The molding process includes standard sample ring blank molding and strip-shaped blank molding; the density of the standard sample ring blank is 3.2 g / cm³. 3 The dimensions are H25*15*10mm; the dimensions of the strip-shaped blank are T90*20*2mm, and it is formed under the conditions of 20MPa and a holding time of 30s.

[0100] Example 4

[0101] This embodiment provides a nickel-zinc-copper ferrite material, which differs from Embodiment 1 in that, based on a total molar percentage of 100 mol%, the main components are adjusted to: Fe2O3 48.65 mol%, NiO 19 mol%, ZnO 24 mol%, CuO 8.35 mol%, resulting in a total molar percentage of Fe2O3+ZnO+CuO of 81 mol%, with the remainder being the same as in Embodiment 1.

[0102] Example 5

[0103] This embodiment provides a nickel-zinc-copper ferrite material, which differs from Example 1 in that, based on a total molar percentage of 100 mol%, the main components are adjusted to: Fe2O3 48.2 mol%, NiO 16.8 mol%, ZnO 24.8 mol%, CuO 10.2 mol%, resulting in a total molar percentage of Fe2O3+ZnO+CuO of 83.2 mol%. The rest are the same as in Example 1.

[0104] Example 6

[0105] This embodiment provides a nickel-zinc-copper ferrite material. The difference from Embodiment 1 is that, based on the total mass percentage of the main component, the auxiliary components are adjusted to: Bi2O3 0.3wt%, SnO2 0.2wt%, CaCO3 0.05wt%, and the total mass percentage of Bi2O3+CaCO3 is adapted to be 0.35wt% of the total mass percentage of the main component. The rest are the same as in Embodiment 1.

[0106] Example 7

[0107] This embodiment provides a nickel-zinc-copper ferrite material. The difference from Embodiment 1 is that, based on the total mass percentage of the main component, the auxiliary components are adjusted to: Bi2O3 1.5wt%, SnO2 0.2wt%, CaCO3 0.1wt%, adapting to obtain a total mass percentage of Bi2O3+CaCO3 of 1.6wt% of the total mass percentage of the main component. The rest are the same as in Embodiment 1.

[0108] Example 8

[0109] This embodiment provides a nickel-zinc-copper ferrite material. The difference between the preparation method of the nickel-zinc-copper ferrite material and that of Embodiment 1 is that the median particle size X50 of the abrasive in step (2) is adjusted to 0.4 μm, and the particle size X90 of the cumulative percentage of 90% is adjusted to 1.2 μm. The rest are the same as in Embodiment 1.

[0110] Example 9

[0111] This embodiment provides a nickel-zinc-copper ferrite material. The preparation method of the nickel-zinc-copper ferrite material differs from that of Embodiment 1 in that the median particle size X50 of the abrasive in step (2) is adjusted to 1 μm, and the particle size X90 of the cumulative percentage of 90% is adjusted to 2 μm. The rest are the same as in Embodiment 1.

[0112] Example 10

[0113] This embodiment provides a nickel-zinc-copper ferrite material. The difference between the preparation method of the nickel-zinc-copper ferrite material and that of Embodiment 1 is that the sintering in step (2) is adjusted to be a sequential heating and cooling process. The specific steps of the heating process include: heating from room temperature to 1000℃ in an air atmosphere at a heating rate of 1.5℃ / min and holding at that temperature for 8 hours; the specific steps of the cooling process include: cooling to 50℃ in an air atmosphere at a cooling rate of 3.5℃ / min. The rest are the same as in Embodiment 1.

[0114] Comparative Example 1

[0115] This comparative example provides a nickel-zinc-copper ferrite material. The difference from Example 1 is that, based on a total molar percentage of 100 mol%, the main components are adjusted to: Fe2O3 45.9 mol%, NiO 16.9 mol%, ZnO 24.7 mol%, CuO 12.5 mol%, resulting in a total molar percentage of Fe2O3+ZnO+CuO of 83.1 mol%. The rest are the same as in Example 1.

[0116] Comparative Example 2

[0117] This comparative example provides a nickel-zinc-copper ferrite material. The difference from Example 1 is that, based on a total molar percentage of 100 mol%, the main components are adjusted to: Fe2O3 49.8 mol%, NiO 16.8 mol%, ZnO 23 mol%, CuO 10.4 mol%, resulting in a total molar percentage of Fe2O3+ZnO+CuO of 83.2 mol%. The rest are the same as in Example 1.

[0118] Comparative Example 3

[0119] This comparative example provides a nickel-zinc-copper ferrite material, which differs from Example 1 in that, based on a total molar percentage of 100 mol%, the main components are adjusted to: Fe2O3 48.65 mol%, NiO 15.8 mol%, ZnO 24.5 mol%, CuO 11.05 mol%, resulting in a total molar percentage of Fe2O3+ZnO+CuO of 84.2 mol%. The rest are the same as in Example 1.

[0120] Comparative Example 4

[0121] This comparative example provides a nickel-zinc-copper ferrite material, which differs from Example 1 in that, based on a total molar percentage of 100 mol%, the main components are adjusted to: Fe2O3 48.65 mol%, NiO 19.2 mol%, ZnO 21.35 mol%, CuO 10.8 mol%, resulting in a total molar percentage of Fe2O3+ZnO+CuO of 80.8 mol%. The rest are the same as in Example 1.

[0122] Comparative Example 5

[0123] This comparative example provides a nickel-zinc-copper ferrite material, which differs from Example 1 in that, based on a total molar percentage of 100 mol%, the main components are adjusted to: Fe2O3 47.75 mol%, NiO 19 mol%, ZnO 22.9 mol%, CuO 10.35 mol%, resulting in a total molar percentage of Fe2O3+ZnO+CuO of 81 mol%, while the rest are the same as in Example 1.

[0124] Comparative Example 6

[0125] This comparative example provides a nickel-zinc-copper ferrite material. The difference from Example 1 is that, based on a total molar percentage of 100 mol%, the main components are adjusted to: Fe2O3 48 mol%, NiO 16.5 mol%, ZnO 26.2 mol%, CuO 9.3 mol%, resulting in a total molar percentage of Fe2O3+ZnO+CuO of 83.5 mol%. The rest are the same as in Example 1.

[0126] Comparative Example 7

[0127] This comparative example provides a nickel-zinc-copper ferrite material. The difference from Example 1 is that, based on a total molar percentage of 100 mol%, the main components are adjusted to: Fe2O3 48.1 mol%, NiO 18.6 mol%, ZnO 25.9 mol%, CuO 7.4 mol%, resulting in a total molar percentage of Fe2O3+ZnO+CuO of 81.4 mol%. The rest are the same as in Example 1.

[0128] Comparative Example 8

[0129] This comparative example provides a nickel-zinc-copper ferrite material. The difference from Example 1 is that, based on a total molar percentage of 100 mol%, the main components are adjusted to: Fe2O3 47.75 mol%, NiO 16.6 mol%, ZnO 23 mol%, CuO 12.65 mol%, resulting in a total molar percentage of Fe2O3+ZnO+CuO of 83.4 mol%. The rest are the same as in Example 1.

[0130] Comparative Example 9

[0131] This comparative example provides a nickel-zinc-copper ferrite material. The difference from Example 1 is that, based on the total mass percentage of the main component, the auxiliary components are adjusted to: Bi2O3 1.5wt%, SnO2 0.2wt%, CaCO3 0.025wt%, adapting to obtain a total mass percentage of Bi2O3+CaCO3 of 1.525wt% of the total mass percentage of the main component. All other components are the same as in Example 1.

[0132] Comparative Example 10

[0133] This comparative example provides a nickel-zinc-copper ferrite material. The difference from Example 1 is that, based on the total mass percentage of the main component, the auxiliary components are adjusted to: Bi2O3 0.25wt%, SnO2 0.2wt%, CaCO3 0.1wt%, adapting to obtain a total mass percentage of Bi2O3+CaCO3 of 0.35wt% of the total mass percentage of the main component. All other components are the same as in Example 1.

[0134] Comparative Example 11

[0135] This comparative example provides a nickel-zinc-copper ferrite material. The difference from Example 1 is that, based on the total mass percentage of the main components, the auxiliary components are adjusted to: Bi2O3 1.5wt%, SnO2 0.35wt%, CaCO3 0.1wt%, adapting to obtain a total mass percentage of Bi2O3+CaCO3 of 1.6wt% of the total mass percentage of the main components. The rest are the same as in Example 1.

[0136] Comparative Example 12

[0137] This comparative example provides a nickel-zinc-copper ferrite material. The difference from Example 1 is that, based on the total mass percentage of the main components, the auxiliary components are adjusted to: Bi2O3 1.6wt%, SnO2 0.35wt%, CaCO3 0.1wt%, adapting to obtain a total mass percentage of Bi2O3+CaCO3 of 1.7wt% of the total mass percentage of the main components. All other components are the same as in Example 1.

[0138] Performance testing

[0139] The nickel-zinc-copper ferrite materials provided in Examples 1-10 and Comparative Examples 1-12 were tested for inductance using an Agilent E4991, and the real part of the permeability μi was calculated based on the size factor. The results are shown in Table 1.

[0140] The saturation magnetic induction intensity Bs was measured using the SY8218 instrument from Iwasaki Corporation, Japan. The results are shown in Table 1.

[0141] The mechanical bending strength (three-point bending method) was tested using a DPX-20TR instrument, and the results are shown in Table 1.

[0142] Thermal shock test: 1) Heat the laboratory tin furnace to 400℃; 2) Use tweezers to hold the test sample and immerse it in the tin furnace for 3 seconds; 3) Observe the sample after thermal shock; 4) Record the number of intact samples out of 50 samples and calculate the integrity rate. If the number of intact samples is less than 49, it is considered NG, otherwise it is OK. The results are shown in Table 1.

[0143] Table 1

[0144]

[0145]

[0146] As can be seen from Table 1, the nickel-zinc-copper ferrite material provided by the present invention has the characteristics of high saturation magnetic induction intensity, high mechanical strength, and excellent thermal shock resistance, and can be better applied to power inductors or common-mode inductors.

[0147] A comparison of Examples 1 and 4-7 shows that when the content of each main component and auxiliary component is within a limited range, but the total amount of some components exceeds the limited range, the magnetic permeability or mechanical strength will decrease. A comparison of Examples 1 and 8 and 9 shows that if the particle size of the abrasive after the second grinding is too small or too large, it is not conducive to sintering densification and will reduce the magnetic permeability and saturation magnetic induction intensity Bs. A comparison of Examples 1 and 10 shows that sintering is a single heating and cooling process, which, compared to two heating and two cooling processes, will result in a less dense core morphology, leading to a lower magnetic permeability and saturation magnetic induction intensity Bs.

[0148] As can be seen from the comparison between Example 1 and Comparative Examples 1-11, when the content of the main component or auxiliary component exceeds the limit range, and the total amount of some components also exceeds the limit range, the saturation magnetic induction intensity, mechanical strength and thermal shock resistance of the nickel-zinc-copper ferrite material will be greatly reduced. As can be seen from the comparison between Example 1 and Comparative Example 12, when the Bi2O3 content exceeds 1.5wt%, it will cause crystallization on the magnet surface, resulting in a decrease in magnetic permeability, a decrease in saturation magnetic induction intensity and a significant decrease in magnet strength.

[0149] In summary, the nickel-zinc-copper ferrite material provided by this invention, by controlling the main components and their content range, can achieve high saturation magnetic induction intensity, mechanical strength, and excellent thermal shock resistance; and by controlling the auxiliary component Ca... 2+ and Bi 3+ The combined substitution of [components] can improve magnet density and optimize mechanical strength and thermal shock resistance; through Ca [substituents]... 2+ Sn 4+ A small amount of substitution can improve magnetic permeability and reduce losses; through Ca... 2+ Sn 4+ and Bi 3+ The combination of substitutions can adjust the saturation magnetic induction intensity to meet the applicability of devices in various environments; the prepared nickel-zinc-copper ferrite material can meet the requirements as a high-performance magnetic core material.

[0150] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A nickel-zinc-copper ferrite material, characterized in that, The nickel-zinc-copper ferrite material includes main components and auxiliary components; Based on a total molar percentage of 100 mol%, the main components include: Fe2O3 46.5-49.5 mol%, NiO 16.5-19 mol%, ZnO 23-26 mol%, CuO 7.5-12.5 mol%; based on the total mass percentage of the main components, the auxiliary components include: Bi2O3 0.3-1.5 wt%, SnO2 0.1-0.3 wt%, CaCO3 0.03-0.1 wt%. The total molar percentage of Fe2O3+ZnO+CuO in the main components is 81.5-83 mol%. The total mass percentage of Bi2O3+CaCO3 in the auxiliary components is 0.4-1.5 wt% of the total mass percentage of the main components. The nickel-zinc-copper ferrite material is prepared by the following method, which includes the following steps: (1) The main components of the ball milling formula are mixed with liquid medium, and the resulting ball milled material is pre-calcined after first spray granulation to obtain pre-calcined material; (2) The auxiliary ingredients, additives, liquid medium and the pre-burned material obtained in step (1) are subjected to first grinding and second grinding in sequence. The resulting grinding material is granulated by second spraying and then shaped and sintered to obtain the nickel-zinc-copper ferrite material. The additive mentioned in step (2) is a combination of binder, dispersant and defoamer; The median particle size X50 of the abrasive in step (2) is 0.5-0.9 μm, and the cumulative percentage of particle size X90 is 1.25-1.8 μm.

2. A method for preparing the nickel-zinc-copper ferrite material as described in claim 1, characterized in that, The preparation method includes the following steps: (1) The main components of the ball milling formula are mixed with liquid medium, and the resulting ball milled material is pre-calcined after first spray granulation to obtain pre-calcined material; (2) The auxiliary ingredients, additives, liquid medium and the pre-burned material obtained in step (1) are subjected to first grinding and second grinding in sequence. The resulting grinding material is granulated by second spraying and then shaped and sintered to obtain the nickel-zinc-copper ferrite material. The additive mentioned in step (2) is a combination of binder, dispersant and defoamer; The median particle size X50 of the abrasive in step (2) is 0.5-0.9 μm, and the cumulative percentage of particle size X90 is 1.25-1.8 μm.

3. The preparation method according to claim 2, characterized in that, In step (1), the mass ratio of the main component, the ball milling medium, and the liquid medium in the ball milling mixture is 1:(4-8):(0.5-1.2).

4. The preparation method according to claim 2, characterized in that, The ball milling mixing time in step (1) is 20-60 min.

5. The preparation method according to claim 2, characterized in that, The preheating temperature in step (1) is 720-900℃.

6. The preparation method according to claim 2, characterized in that, The pre-burning time in step (1) is 2-4 hours.

7. The preparation method according to claim 2, characterized in that, When the additive in step (2) is a combination of binder, dispersant and defoamer, the mass ratio of the pre-burned material, liquid medium, binder, dispersant and defoamer is 100:(60-140):(6-14):(0.1-2):(0.001-0.0025).

8. The preparation method according to claim 2, characterized in that, The liquid medium in step (1) and the liquid medium in step (2) each independently include deionized water.

9. The preparation method according to claim 2, characterized in that, Step (2) The rotation speed of the first grinding is 200-260 rpm.

10. The preparation method according to claim 2, characterized in that, Step (2) The first grinding time is 4-6 minutes.

11. The preparation method according to claim 2, characterized in that, In step (2), the rotation speed of the second grinding is 280-360 rpm.

12. The preparation method according to claim 2, characterized in that, Step (2) The second grinding time is 0.5-2h.

13. The preparation method according to claim 2, characterized in that, In step (2), the average particle size of the particles obtained by the second spray granulation is 30-200 μm.

14. The preparation method according to claim 2, characterized in that, The sintering in step (2) is carried out in a pusher kiln.

15. The preparation method according to claim 2, characterized in that, The sintering in step (2) includes a first heating, a second heating, a first cooling and a second cooling in sequence.

16. The preparation method according to claim 15, characterized in that, The specific steps of the first heating process include: heating to 550-750°C in an air atmosphere at a heating rate of 0.5-2°C / min, and holding at that temperature for 2-7 hours.

17. The preparation method according to claim 15, characterized in that, The specific steps of the second heating process include: continuing to heat to 950-1050℃ at a heating rate of 1-3℃ / min, and holding at that temperature for 2-5 hours.

18. The preparation method according to claim 15, characterized in that, The specific steps of the first cooling process include: cooling to 590-610°C in an air atmosphere at a cooling rate of 2-6°C / min.

19. The preparation method according to claim 15, characterized in that, The specific steps of the second cooling process include: continuing to cool down to 45-55℃ at a cooling rate of 1-5℃ / min.

20. An application of the nickel-zinc-copper ferrite material as described in claim 1, characterized in that, The nickel-zinc-copper ferrite material is used in power inductors or common-mode inductors.

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