Nickel-zinc ferrite material as well as preparation method and application thereof

Abstract

The invention provides a nickel-zinc ferrite material as well as a preparation method and application thereof. The nickel-zinc ferrite material is prepared from main components and auxiliary components, according to the total weight of the main components, the main components comprise the following components in percentage by weight: 65.5 to 67 percent of Fe2O3, 21 to 23.5 percent of ZnO, 6.5 to 8 percent of NiO and 3.6 to 5.7 percent of CuO; according to the total weight of the main components, the auxiliary components comprise the following components in parts by weight: 600 to 2000 ppm of Bi2O3, 300 to 800 ppm of Nb2O5 and 250 to 500 ppm of MoO3. The nickel-zinc ferrite material provided by the invention has both high magnetic conductivity and high saturation flux density, meanwhile, the stability of the material is improved, the service life of the material is prolonged, the application limitation of a soft magnetic ferrite material under extreme conditions is solved, and large-scale popularization and application are facilitated.

Description

Technical Field

[0001] The invention belongs to the technical field of soft ferrite materials, and relates to a nickel-zinc ferrite material, and in particular to a nickel-zinc ferrite material and a preparation method and application thereof. Background Art

[0002] In recent years, ferrite materials have been increasingly widely used in various industries such as communications, IT, automobiles, aerospace, ships, and defense weapon systems, and surface mount components must meet conditions such as being suitable for surface mounting and welding and having good strength. As surface mount components continue to develop in the direction of miniaturization and thinness, the ferrite market has put forward higher requirements for the thermal shock resistance and electromagnetic properties of NiZn materials.

[0003] Outdoor facilities, satellites and other devices of modern communication equipment, whether in hot tropical areas or cold frigid areas, require not only high temperature resistance but also severe cold resistance. This requires the components used to have excellent characteristics such as high magnetic permeability, high stability and long life.

[0004] At present, the high magnetic permeability of soft magnetic nickel-zinc ferrite materials on the market is generally below 2000, and the magnetic core generally uses MnZn ferrite material. Inductors made of this material are prone to cracking during tinning, which leads to products made of NiZn materials having disadvantages such as low energy conversion efficiency and limited operating temperature during use.

[0005] CN101169996A discloses a low-power Mn-Zn ferrite magnetic material for use under ultra-high temperature conditions and a preparation method thereof. The invention adds numerous impurities such as ZrO2, CaCO3, Nb2O5 and Co2O3 to the main components of ferrite Fe2O3, NiO, ZnO and CuO at the same time, thereby achieving the effects of high Bs and high Tc. However, its magnetic permeability after sintering is relatively low, less than 2500, and there is still much room for improvement.

[0006] CN110357610A discloses a nickel-zinc ferrite material and its preparation method and use. The invention adds ZrO2, CaCO3, Nb2O5 and Co2O3 and other trace elements to the main components of ferrite Fe2O3, Ni2O3, ZnO and CuO, achieving the effect of high magnetic permeability and high temperature impact resistance. Although the invention solves the problem that traditional power materials cannot meet the requirements of automotive electronic products, the saturation magnetic induction intensity of the above materials does not meet the required requirements.

[0007] CN114262221A discloses a high temperature stability nickel-zinc ferrite material, its preparation method and application. The invention adds numerous impurities such as BaCO3, LiCO3, MnCO3 and Co2O3 to the main components of ferrite Fe2O3, NiO and ZnO at the same time, thereby achieving the effect of high temperature stability. However, there is also a large room for improvement in its saturation magnetic induction intensity.

[0008] It can be seen that how to provide a nickel-zinc ferrite material and a preparation method thereof, improve the magnetic permeability and saturation magnetic induction intensity of the soft magnetic material, while improving the stability of the material, extending its service life, and solving the application limitations of the soft magnetic ferrite material under extreme conditions has become an urgent problem that technical personnel in this field need to solve. Summary of the invention

[0009] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a nickel-zinc ferrite material and a preparation method and application thereof. The nickel-zinc ferrite material has both high magnetic permeability and high saturation magnetic induction intensity, while improving the material stability and extending its service life, thus solving the application limitations of soft ferrite materials under extreme conditions and facilitating large-scale promotion and application.

[0010] To achieve this object, the present invention adopts the following technical solutions:

[0011] In a first aspect, the present invention provides a nickel-zinc ferrite material, wherein the nickel-zinc ferrite material is made of a main component and an auxiliary component.

[0012] Based on the total weight of the main components, the main components include: 65.5-67wt% Fe2O3, 21-23.5wt% ZnO, 6.5-8wt% NiO and 3.6-5.7wt% CuO.

[0013] Based on the total weight of the main components, the auxiliary components include: 600-2000 ppm Bi2O3, 300-800 ppm Nb2O5 and 250-500 ppm MoO3.

[0014] The present invention optimizes and controls the ratio of main components and the types and contents of auxiliary components on the basis of traditional nickel-zinc ferrite materials. The initial magnetic permeability μi of the obtained nickel-zinc ferrite material is as high as 3000±25% (f=100kHz, u=0.1V), the magnetic permeability at a high frequency of 300kHz is close to 2000, the Q value exceeds 80, the saturation magnetic induction intensity Bs is as high as 300A / m, the material has good stability and long service life, solves the application limitation of soft magnetic ferrite materials under extreme conditions, and is conducive to large-scale promotion and application.

[0015] In the present invention, the proportion of Fe2O3 is 65.5-67wt%, for example, it can be 65.5wt%, 65.6wt%, 65.7wt%, 65.8wt%, 65.9wt%, 66wt%, 66.1wt%, 66.2wt%, 66.3wt%, 66.4wt%, 66.5wt%, 66.6wt%, 66.7wt%, 66.8wt%, 66.9wt% or 67wt%, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0016] In the present invention, the proportion of ZnO is 21-23.5wt%, for example, it can be 21wt%, 21.2wt%, 21.4wt%, 21.6wt%, 21.8wt%, 22wt%, 22.2wt%, 22.4wt%, 22.6wt%, 22.8wt%, 23wt%, 23.2wt%, 23.4wt% or 23.5wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0017] In the present invention, the proportion of NiO is 6.5-8wt%, for example, it can be 6.5wt%, 6.6wt%, 6.7wt%, 6.8wt%, 6.9wt%, 7wt%, 7.1wt%, 7.2wt%, 7.3wt%, 7.4wt%, 7.5wt%, 7.6wt%, 7.7wt%, 7.8wt%, 7.9wt% or 8wt%, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] In the present invention, the proportion of CuO is 3.6-5.7wt%, for example, it can be 3.6wt%, 3.8wt%, 4wt%, 4.2wt%, 4.4wt%, 4.6wt%, 4.8wt%, 5wt%, 5.2wt%, 5.4wt%, 5.6wt% or 5.7wt%, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0019] In the present invention, the proportion of Bi2O3 is 600-2000ppm, for example, it can be 600ppm, 700ppm, 800ppm, 900ppm, 1000ppm, 1100ppm, 1200ppm, 1300ppm, 1400ppm, 1500ppm, 1600ppm, 1700ppm, 1800ppm, 1900ppm or 2000ppm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0020] In the present invention, the proportion of Nb2O5 is 300-800ppm, for example, it can be 300ppm, 350ppm, 400ppm, 450ppm, 500ppm, 550ppm, 600ppm, 650ppm, 700ppm, 750ppm or 800ppm, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0021] In the present invention, the proportion of MoO3 is 250-500ppm, for example, it can be 250ppm, 260ppm, 280ppm, 300ppm, 320ppm, 340ppm, 360ppm, 380ppm, 400ppm, 420ppm, 440ppm, 460ppm, 480ppm or 500ppm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0022] In a second aspect, the present invention provides a method for preparing the nickel-zinc ferrite material as described in the first aspect, wherein the preparation method comprises batching, pre-sintering, ball milling, granulation, molding and sintering performed in sequence.

[0023] Preferably, the batching comprises: weighing the main components according to the weight ratio and sequentially performing wet ball milling and spray granulation.

[0024] Preferably, the mass ratio of the main component, the grinding medium and the water in the wet ball milling process is 1:(6-10):(0.3-1.2), for example, it can be 1:6:0.3, 1:6.5:0.4, 1:7:0.5, 1:7.5:0.6, 1:8:0.8, 1:8.5:0.9, 1:9:1, 1:9.5:1.1 or 1:10:1.2, but it is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0025] Preferably, the wet ball milling time is 20-60 min, for example, it can be 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min or 60 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0026] Preferably, the particle size distribution of the slurry obtained by wet ball milling satisfies D50 of 0.6-1.2 μm, for example, it can be 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 1.1 μm or 1.2 μm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0027] Preferably, the particle size distribution of the slurry obtained by wet ball milling satisfies D99 of 1.5-3μm, for example, it can be 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm, 2μm, 2.1μm, 2.2μm, 2.3μm, 2.4μm, 2.5μm, 2.6μm, 2.7μm, 2.8μm, 2.9μm or 3μm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0028] Preferably, the pre-firing is carried out in a rotary kiln.

[0029] Preferably, the pre-firing temperature is 800-950°C, for example, it can be 800°C, 810°C, 820°C, 830°C, 840°C, 850°C, 860°C, 870°C, 880°C, 890°C, 900°C, 910°C, 920°C, 930°C, 940°C or 950°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0030] Preferably, the pre-burning time is 2-4h, for example, it can be 2h, 2.2h, 2.4h, 2.6h, 2.8h, 3h, 3.2h, 3.4h, 3.6h, 3.8h or 4h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0031] Preferably, the ball milling includes: pouring the pre-burned main component into a ball mill, and adding auxiliary components, water, adhesive, dispersant and defoamer, and first performing low-speed ball milling and then high-speed ball milling during the feeding process; after the ball milling is completed, the slurry is transferred to a stirring tank.

[0032] In the present invention, the binder, dispersant and defoamer are all ball milling additives conventionally used in the art. As long as they can achieve the corresponding functions, the specific type of each additive is not particularly limited. For example, the binder can be polyvinyl alcohol or polyvinyl acetate, the dispersant can be any one of methyl cellulose, ethyl cellulose or hydroxymethyl cellulose, and the defoamer can be methyl silicone oil or dimethyl silicone oil.

[0033] Preferably, the mixing mass ratio of the main component, water, adhesive, dispersant and defoamer is 100:(40-150):(4-20):(0.1-2):(0.001-0.0025), for example, it can be 100:40:4:0.1:0.001, 100:50:5:0.2:0.001, 100:60:6:0.4:0.001, 100:70:8:0.6:0.001, 100:80:10:0.8:0.001 , 100:90:12:1:0.002, 100:100:14:1.2:0.002, 100:110:15:1.4:0.002, 100:120:16:1.6:0.002, 100:130:17:1.8:0.002, 100:140:18:2:0.002 or 100:150:20:2:0.0025, but are not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0034] Preferably, the rotation speed of the low-speed ball mill is 30-60 rpm, for example, it can be 30 rpm, 35 rpm, 40 rpm, 45 rpm, 50 rpm, 55 rpm or 60 rpm, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0035] Preferably, the low-speed ball milling time is 5-10 min, for example, it can be 5 min, 5.5 min, 6 min, 6.5 min, 7 min, 7.5 min, 8 min, 8.5 min, 9 min, 9.5 min or 10 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0036] Preferably, the rotation speed of the high-speed ball mill is 80-100rpm, for example, it can be 80rpm, 82rpm, 84rpm, 86rpm, 88rpm, 90rpm, 92rpm, 94rpm, 96rpm, 98rpm or 100rpm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0037] Preferably, the high-speed ball milling time is 0.5-2h, for example, it can be 0.5h, 0.6h, 0.7h, 0.8h, 0.9h, 1h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h or 2h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0038] Preferably, the granulation comprises spray granulation.

[0039] Preferably, the average particle size of the particles obtained by spray granulation is 30-200 μm, for example, it can be 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm or 200 μm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0040] Preferably, the forming comprises press forming.

[0041] Preferably, the press molding obtains an annular blank with a size of H(20-30)mm×(10-20)mm×(8-12)mm, for example, it can be H20mm×10mm×8mm, H22mm×12mm×9mm, H24mm×14mm×10mm, H26mm×16mm×11mm, H28mm×18mm×12mm or H30mm×20mm×12mm, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0042] In the present invention, the size of the annular blank is H (20-30) mm × (10-20) mm × (8-12) mm, which specifically means that the outer diameter of the annular blank is 20-30 mm, the inner diameter is 10-20 mm, and the height is 8-12 mm.

[0043] Preferably, the density of the annular blank is 3.10-3.25 g / cm 3 , for example, it can be 3.10 g / cm 3 、3.11g / cm 3 、3.12g / cm 3 、3.13g / cm 3 、3.14g / cm 3 、3.15g / cm 3 、3.16g / cm 3 、3.17g / cm 3 、3.18g / cm 3 、3.19g / cm 3 、3.20g / cm 3 、3.21g / cm 3 、3.22g / cm 3 、3.23g / cm 3 、3.24g / cm 3 or 3.25g / cm 3 , but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0044] Preferably, the sintering is performed in a box furnace.

[0045] Preferably, the sintering includes: heating to a first temperature at a first rate and keeping it at that temperature for a first time, heating to a second temperature at a second rate and keeping it at that temperature for a second time, cooling to a third temperature at a third rate, and finally cooling to a fourth temperature at a fourth rate in an air atmosphere.

[0046] Preferably, the first rate is 0.5-2.5℃ / min, for example, it can be 0.5℃ / min, 0.6℃ / min, 0.8℃ / min, 1℃ / min, 1.2℃ / min, 1.4℃ / min, 1.6℃ / min, 1.8℃ / min, 2℃ / min, 2.2℃ / min, 2.4℃ / min or 2.5℃ / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0047] Preferably, the first temperature is 550-750°C, for example, it can be 550°C, 560°C, 580°C, 600°C, 620°C, 640°C, 660°C, 680°C, 700°C, 720°C, 740°C or 750°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0048] Preferably, the first time is 2-7h, for example, it can be 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h or 7h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0049] Preferably, the second rate is 1-3°C / min, for example, it can be 1°C / min, 1.2°C / min, 1.4°C / min, 1.6°C / min, 1.8°C / min, 2°C / min, 2.2°C / min, 2.4°C / min, 2.6°C / min, 2.8°C / min or 3°C / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0050] Preferably, the second temperature is 1100-1200°C, for example, it can be 1100°C, 1110°C, 1120°C, 1130°C, 1140°C, 1150°C, 1160°C, 1170°C, 1180°C, 1190°C or 1200°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0051] Preferably, the second time is 2-5 hours, for example, it can be 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours or 5 hours, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0052] Preferably, the third rate is 4-7°C / min, for example, it can be 4°C / min, 4.5°C / min, 5°C / min, 5.5°C / min, 6°C / min, 6.5°C / min or 7°C / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0053] Preferably, the third temperature is 500-700°C, for example, it can be 500°C, 520°C, 540°C, 560°C, 580°C, 600°C, 620°C, 640°C, 660°C, 680°C or 700°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0054] Preferably, the fourth rate is 6-10℃ / min, for example, it can be 6℃ / min, 6.5℃ / min, 7℃ / min, 7.5℃ / min, 8℃ / min, 8.5℃ / min, 9℃ / min, 9.5℃ / min or 10℃ / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0055] Preferably, the fourth temperature is 40-60°C, for example, it can be 40°C, 42°C, 44°C, 46°C, 48°C, 50°C, 52°C, 54°C, 56°C, 58°C or 60°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0056] As a preferred technical solution of the second aspect of the present invention, the preparation method comprises the following steps:

[0057] (1) Ingredients: Weigh the main components according to the weight ratio and perform wet ball milling and spray granulation in sequence; wherein, during the wet ball milling, the mixing mass ratio of the main component, the grinding medium and water is 1:(6-10):(0.3-1.2), the ball milling time is 20-60 min, and the particle size distribution of the obtained slurry satisfies D50 of 0.6-1.2 μm and D99 of 1.5-3 μm;

[0058] (2) Pre-burning: The material obtained by spray granulation is placed in a rotary kiln for pre-burning at a temperature of 800-950°C for 2-4 hours;

[0059] (3) ball milling: pour the pre-calcined main component into a ball mill, and add auxiliary components, water, adhesive, dispersant and defoamer, and the mixing mass ratio of the main component, water, adhesive, dispersant and defoamer is 100:(40-150):(4-20):(0.1-2):(0.001-0.0025); during the feeding process, first perform low-speed ball milling at 30-60rpm for 5-10min, and then perform high-speed ball milling at 80-100rpm for 0.5-2h; after the ball milling is completed, transfer the slurry to a stirring tank;

[0060] (4) Granulation: The slurry obtained by ball milling is sprayed and granulated into material particles with an average particle size of 30-200 μm in a spray tower;

[0061] (5) Molding: The material particles are pressed and molded to obtain a density of 3.10-3.25g / cm 3 H(20-30)mm×(10-20)mm×(8-12)mm annular blank;

[0062] (6) Sintering: Place the annular blank in a box furnace, first heat it to 550-750°C at 0.5-2.5°C / min in an air atmosphere and keep it at that temperature for 2-7h, then heat it to 1100-1200°C at 1-3°C / min and keep it at that temperature for 2-5h, then cool it to 500-700°C at 4-7°C / min, and finally cool it to 40-60°C at 6-10°C / min.

[0063] In a third aspect, the present invention provides an application of the nickel-zinc ferrite material as described in the first aspect, wherein the nickel-zinc ferrite material is used to prepare a broadband transformer, a filter inductor or a laminated magnetic bead for an electronic circuit.

[0064] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0065] Compared with the prior art, the present invention has the following beneficial effects:

[0066] The present invention optimizes and controls the ratio of main components and the types and contents of auxiliary components on the basis of traditional nickel-zinc ferrite materials. The initial magnetic permeability μi of the obtained nickel-zinc ferrite material is as high as 3000±25% (f=100kHz, u=0.1V), the magnetic permeability at a high frequency of 300kHz is close to 2000, the Q value exceeds 80, the saturation magnetic induction intensity Bs is as high as 300A / m, the material has good stability and long service life, solves the application limitation of soft magnetic ferrite materials under extreme conditions, and is conducive to large-scale promotion and application. DETAILED DESCRIPTION

[0067] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0068] Example 1

[0069] This embodiment provides a nickel-zinc ferrite material and a preparation method thereof, the preparation method comprising the following steps:

[0070] (1) Ingredients: The main components were weighed according to the components and weight ratios shown in Table 1 and wet ball milled and spray granulated in sequence; wherein, during the wet ball milling, the mixing mass ratio of the main component, the grinding medium (a steel ball with a diameter of 5 mm) and water was 1:6:1, the ball milling time was 40 min, and the particle size distribution of the obtained slurry satisfied D50 of 1 μm and D99 of 2.5 μm;

[0071] (2) Pre-calcination: The material obtained by spray granulation is fed into a rotary kiln at a rate of 150 kg / h for pre-calcination at a temperature of 890 ± 20 °C for 3 h;

[0072] (3) Ball milling: Pour the pre-calcined main component into a ball mill, and add auxiliary components (specific components and weight ratios are shown in Table 1), water, polyvinyl alcohol, methyl cellulose and methyl silicone oil, and the mixing mass ratio of the main component, water, binder, dispersant and defoamer is 100:60:10:1:0.0015; during the feeding process, first perform low-speed ball milling at 45 rpm for 10 minutes, and then perform high-speed ball milling at 90 rpm for 1 hour; after the ball milling is completed, transfer the slurry to a stirring tank;

[0073] (4) Granulation: The slurry obtained by ball milling is sprayed and granulated into material particles with an average particle size of 100±50 μm in a spray tower;

[0074] (5) Molding: The material particles are pressed and molded to obtain a density of 3.20±0.05g / cm 3 H25mm×15mm×10mm annular blank;

[0075] (6) Sintering: Place the annular blank in a box furnace, first heat it to 650°C at 2°C / min in an air atmosphere and keep it at that temperature for 5 h, then heat it to 1120°C at 2°C / min and keep it at that temperature for 3 h, then cool it to 500°C at 6°C / min, and finally cool it to 50°C at 8°C / min.

[0076] Example 2

[0077] This embodiment provides a nickel-zinc ferrite material and a preparation method thereof, the preparation method comprising the following steps:

[0078] (1) Ingredients: The main components were weighed according to the components and weight ratios shown in Table 1 and wet ball milled and spray granulated in sequence; wherein, during the wet ball milling, the mixing mass ratio of the main component, the grinding medium (a steel ball with a diameter of 5 mm) and water was 1:6.5:0.5, the ball milling time was 40 min, and the particle size distribution of the obtained slurry satisfied D50 of 1 μm and D99 of 2.5 μm;

[0079] (2) Pre-calcination: The material obtained by spray granulation is fed into a rotary kiln at a rate of 150 kg / h for pre-calcination at a temperature of 850 ± 20 °C for 3 h;

[0080] (3) Ball milling: Pour the pre-calcined main component into a ball mill, and add auxiliary components (specific components and weight ratios are shown in Table 1), water, methyl silicone oil, methyl silicone oil and dimethyl silicone oil, and the mixing mass ratio of the main component, water, binder, dispersant and defoamer is 100:60:10:0.6:0.001; during the feeding process, first perform low-speed ball milling at 30 rpm for 10 minutes, and then perform high-speed ball milling at 80 rpm for 2 hours; after the ball milling is completed, transfer the slurry to a stirring tank;

[0081] (4) Granulation: The slurry obtained by ball milling is sprayed and granulated into material particles with an average particle size of 100±50 μm in a spray tower;

[0082] (5) Molding: The material particles are pressed and molded to obtain a density of 3.20±0.05g / cm 3 H25mm×15mm×10mm annular blank;

[0083] (6) Sintering: Place the annular blank in a box furnace, heat it to 650°C at a rate of 2.5°C / min in an air atmosphere and keep it at that temperature for 4 h, then heat it to 1150°C at a rate of 1.3°C / min and keep it at that temperature for 2.5 h, then cool it to 600°C at a rate of 6°C / min, and finally cool it to 50°C at a rate of 6°C / min.

[0084] Example 3

[0085] This embodiment provides a nickel-zinc ferrite material and a preparation method thereof, the preparation method comprising the following steps:

[0086] (1) Ingredients: The main components were weighed according to the components and weight ratios shown in Table 1 and wet ball milled and spray granulated in sequence; wherein, during the wet ball milling, the mixing mass ratio of the main component, the grinding medium (a steel ball with a diameter of 5 mm) and water was 1:6.5:0.8, the ball milling time was 40 min, and the particle size distribution of the obtained slurry satisfied D50 of 1 μm and D99 of 2.5 μm;

[0087] (2) Pre-calcination: The material obtained by spray granulation is fed into a rotary kiln at a rate of 150 kg / h for pre-calcination at a temperature of 890 ± 20 °C for 3 h;

[0088] (3) Ball milling: Pour the pre-calcined main component into a ball mill, and add auxiliary components (specific components and weight ratios are shown in Table 1), water, polyvinyl alcohol, hydroxymethyl cellulose and methyl silicone oil, and the mixing mass ratio of the main component, water, binder, dispersant and defoamer is 100:60:12:1.2:0.002; during the feeding process, first perform low-speed ball milling at 60 rpm for 5 minutes, and then perform high-speed ball milling at 100 rpm for 0.5 hours; after the ball milling is completed, transfer the slurry to a stirring tank;

[0089] (4) Granulation: The slurry obtained by ball milling is sprayed and granulated into material particles with an average particle size of 100±50 μm in a spray tower;

[0090] (5) Molding: The material particles are pressed and molded to obtain a density of 3.20±0.05g / cm 3 H25mm×15mm×10mm annular blank;

[0091] (6) Sintering: Place the annular blank in a box furnace, first heat it to 750°C at 2°C / min and keep it at that temperature for 5 h in an air atmosphere, then heat it to 1130°C at 3°C / min and keep it at that temperature for 5 h, then cool it to 600°C at 4°C / min, and finally cool it to 50°C at 6.5°C / min.

[0092] Example 4

[0093] This embodiment provides a nickel-zinc ferrite material and a preparation method thereof, the preparation method comprising the following steps:

[0094] (1) Ingredients: The main components were weighed according to the components and weight ratios shown in Table 1 and wet ball milled and spray granulated in sequence; wherein, during the wet ball milling, the mixing mass ratio of the main component, the grinding medium (a steel ball with a diameter of 5 mm) and water was 1:6.5:0.6, the ball milling time was 40 min, and the particle size distribution of the obtained slurry satisfied D50 of 1 μm and D99 of 2.5 μm;

[0095] (2) Pre-calcination: The material obtained by spray granulation is fed into a rotary kiln at a rate of 150 kg / h for pre-calcination at a temperature of 930 ± 20 °C for 3 h;

[0096] (3) Ball milling: Pour the pre-calcined main component into a ball mill, and add auxiliary components (specific components and weight ratios are shown in Table 1), water, polyvinyl acetate, methyl cellulose and methyl silicone oil, and the mixing mass ratio of the main component, water, binder, dispersant and defoamer is 100:60:10:1:0.0015; during the feeding process, first perform low-speed ball milling at 60 rpm for 5 minutes, and then perform high-speed ball milling at 80 rpm for 2 hours; after the ball milling is completed, transfer the slurry to a stirring tank;

[0097] (4) Granulation: The slurry obtained by ball milling is sprayed and granulated into material particles with an average particle size of 100±50 μm in a spray tower;

[0098] (5) Molding: The material particles are pressed and molded to obtain a density of 3.20±0.05g / cm 3 H25mm×15mm×10mm annular blank;

[0099] (6) Sintering: Place the annular blank in a box furnace, heat it to 625°C at a rate of 1.5°C / min in an air atmosphere and keep it at that temperature for 5 h, then heat it to 1200°C at a rate of 2°C / min and keep it at that temperature for 3.5 h, then cool it to 600°C at a rate of 5°C / min, and finally cool it to 50°C at a rate of 7°C / min.

[0100] Example 5

[0101] This embodiment provides a nickel-zinc ferrite material and a preparation method thereof, the preparation method comprising the following steps:

[0102] (1) Ingredients: The main components were weighed according to the components and weight ratios shown in Table 1 and wet ball milled and spray granulated in sequence; wherein, during the wet ball milling, the mixing mass ratio of the main component, the grinding medium (a steel ball with a diameter of 5 mm) and water was 1:7:1.2, the ball milling time was 60 min, and the particle size distribution of the obtained slurry satisfied D50 of 1 μm and D99 of 2.5 μm;

[0103] (2) Pre-calcination: The material obtained by spray granulation is fed into a rotary kiln at a rate of 150 kg / h for pre-calcination at a temperature of 930 ± 20 °C for 3 h;

[0104] (3) Ball milling: Pour the pre-calcined main component into a ball mill, and add auxiliary components (specific components and weight ratios are shown in Table 1), water, polyvinyl acetate, ethyl cellulose and dimethyl silicone oil, and the mixing mass ratio of the main component, water, binder, dispersant and defoamer is 100:50:10:1:0.0025; during the feeding process, first perform low-speed ball milling at 30 rpm for 10 minutes, and then perform high-speed ball milling at 80 rpm for 2 hours; after the ball milling is completed, transfer the slurry to a stirring tank;

[0105] (4) Granulation: The slurry obtained by ball milling is sprayed and granulated into material particles with an average particle size of 100±50 μm in a spray tower;

[0106] (5) Molding: The material particles are pressed and molded to obtain a density of 3.20±0.05g / cm 3 H25mm×15mm×10mm annular blank;

[0107] (6) Sintering: Place the annular blank in a box furnace, heat it to 750°C at a rate of 2.5°C / min in an air atmosphere and keep it at that temperature for 3 h, then heat it to 1150°C at a rate of 3°C / min and keep it at that temperature for 2.5 h, then cool it to 600°C at a rate of 5.7°C / min, and finally cool it to 50°C at a rate of 8°C / min.

[0108] Example 6

[0109] This embodiment provides a nickel-zinc ferrite material and a preparation method thereof, the preparation method comprising the following steps:

[0110] (1) Ingredients: The main components were weighed according to the components and weight ratios shown in Table 1 and wet ball milled and spray granulated in sequence; wherein, during the wet ball milling, the mixing mass ratio of the main component, the grinding medium (a steel ball with a diameter of 5 mm) and water was 1:10:1.1, the ball milling time was 30 min, and the particle size distribution of the obtained slurry satisfied D50 of 1 μm and D99 of 2.5 μm;

[0111] (2) Pre-calcination: The material obtained by spray granulation is fed into a rotary kiln at a rate of 150 kg / h for pre-calcination at a temperature of 910 ± 20 °C for 3 h;

[0112] (3) Ball milling: Pour the pre-calcined main component into a ball mill, and add auxiliary components (specific components and weight ratios are shown in Table 1), water, polyvinyl alcohol, hydroxymethyl cellulose and methyl silicone oil, and the mixing mass ratio of the main component, water, binder, dispersant and defoamer is 100:60:10:0.1:0.0015; during the feeding process, first perform low-speed ball milling at 30 rpm for 10 minutes, and then perform high-speed ball milling at 95 rpm for 1.2 hours; after the ball milling is completed, transfer the slurry to a stirring tank;

[0113] (4) Granulation: The slurry obtained by ball milling is sprayed and granulated into material particles with an average particle size of 100±50 μm in a spray tower;

[0114] (5) Molding: The material particles are pressed and molded to obtain a density of 3.20±0.05g / cm 3 H25mm×15mm×10mm annular blank;

[0115] (6) Sintering: Place the annular blank in a box furnace, heat it to 600°C at a rate of 1.5°C / min in an air atmosphere and keep it at that temperature for 3 h, then heat it to 1100°C at a rate of 1.5°C / min and keep it at that temperature for 5 h, then cool it to 600°C at a rate of 4°C / min, and finally cool it to 50°C at a rate of 10°C / min.

[0116] Comparative Examples 1-14

[0117] Comparative Examples 1-14 respectively adopt the same preparation method as Example 1, the only difference is the specific proportion of the main component and the auxiliary component, see Table 1 below for details.

[0118] Table 1

[0119]

[0120]

[0121] The magnetic permeability μi, saturation magnetic induction intensity Bs, quality factor Q, appearance test results and usability determination results of the nickel-zinc ferrite materials obtained in Examples 1-6 and Comparative Examples 1-14 are shown in Table 2 below.

[0122] Table 2

[0123]

[0124] In Table 2 above, the present invention uses Agilent E4991 to test the inductance of the sintered magnetic ring, calculates the magnetic permeability μi according to the size factor, uses Mt-2000 magnetic material tester to test the saturation magnetic induction intensity Bs, reflows 50 DR core products, and observes the cracking with an optical microscope.

[0125] Combining Table 1 and Table 2, it can be seen that: compared with Comparative Examples 1-14, when the specific proportions of the main components and the auxiliary components in Example 1-6 are controlled within a specific range, the initial magnetic permeability μi of the obtained nickel-zinc ferrite material is as high as 3000±25% (f=100kHz, u=0.1V), and the magnetic permeability at a high frequency of 300kHz is close to 2000, the Q value exceeds 80, and the saturation magnetic induction intensity Bs is as high as 300A / m. The material has good stability and a long service life, which solves the application limitations of soft magnetic ferrite materials under extreme conditions and is conducive to large-scale promotion and application.

[0126] In addition, the present invention can generate BiFe2O4 with a large K1 value by adding Bi2O3. Since this K1 value is large, the amount of BiFe2O4 in the composition largely determines the material's ability to obtain a greater magnetic permeability, while also taking into account high Bs performance at various temperatures.

[0127] Furthermore, Bi-Mo and nickel-zinc ferrite mainly undergo solid-phase reaction at the grain boundaries, and when the Bi2O3 content exceeds 2000ppm, it will cause crystallization on the magnet surface, thereby causing the Q value to decrease; Nb can refine the grains of nickel-zinc ferrite, and adding an appropriate amount of Nb2O5 can significantly improve the magnetic permeability and quality factor Q.

[0128] It can be seen that the present invention optimizes and controls the ratio of the main components and the types and contents of the auxiliary components on the basis of the traditional nickel-zinc ferrite material, and the initial magnetic permeability μi of the obtained nickel-zinc ferrite material is as high as 3000±25% (f=100kHz, u=0.1V), and the magnetic permeability at a high frequency of 300kHz is close to 2000, the Q value exceeds 80, the saturation magnetic induction intensity Bs is as high as 300A / m, the material has good stability and long service life, which solves the application limitations of soft magnetic ferrite materials under extreme conditions and is conducive to large-scale promotion and application.

[0129] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A nickel-zinc ferrite material, characterized in that: The nickel-zinc ferrite material is made of a main component and an auxiliary component; Based on the total weight of the main components, the main components include: 65.5-67wt% Fe2O3, 21-23.5wt% ZnO, 6.5-8wt% NiO and 3.6-5.7wt% CuO; Based on the total weight of the main components, the auxiliary components include: 600-2000 ppm Bi2O3, 300-800 ppm Nb2O5 and 250-500 ppm MoO3.

2. A method for preparing the nickel-zinc ferrite material as claimed in claim 1, characterized in that: The preparation method comprises batching, pre-sintering, ball milling, granulation, molding and sintering in sequence.

3. The preparation method according to claim 2, characterized in that: The preparation comprises: weighing the main components according to the weight ratio and sequentially performing wet ball milling and spray granulation; Preferably, the mixing mass ratio of the main component, the grinding medium and the water during the wet ball milling process is 1:(6-10):(0.3-1.2); Preferably, the wet ball milling time is 20-60 min; Preferably, the particle size distribution of the slurry obtained by wet ball milling satisfies D50 of 0.6-1.2 μm and D99 of 1.5-3 μm.

4. The preparation method according to claim 2 or 3, characterized in that: The pre-firing is carried out in a rotary kiln; Preferably, the pre-burning temperature is 800-950°C; Preferably, the pre-burning time is 2-4 hours.

5. The preparation method according to any one of claims 2 to 4, characterized in that: The ball milling comprises: pouring the pre-burned main component into a ball mill, and adding auxiliary components, water, adhesive, dispersant and defoamer, and firstly performing low-speed ball milling and then high-speed ball milling during the feeding process; after the ball milling is completed, transferring the slurry to a stirring tank.

6. The preparation method according to claim 5, characterized in that: The mixing mass ratio of the main component, water, adhesive, dispersant and defoamer is 100:(40-150):(4-20):(0.1-2):(0.001-0.0025); Preferably, the rotation speed of the low-speed ball mill is 30-60 rpm; Preferably, the low-speed ball milling time is 5-10 min; Preferably, the speed of the high-speed ball mill is 80-100 rpm; Preferably, the high-speed ball milling time is 0.5-2h.

7. The preparation method according to any one of claims 2 to 6, characterized in that: The granulation comprises spray granulation; Preferably, the average particle size of the particles obtained by the spray granulation is 30-200 μm; Preferably, the forming comprises press forming; Preferably, the press forming obtains an annular blank having a size of H (20-30) mm × (10-20) mm × (8-12) mm; Preferably, the density of the annular blank is 3.10-3.25 g / cm 3 .

8. The preparation method according to any one of claims 2 to 7, characterized in that: The sintering is carried out in a box furnace; Preferably, the sintering comprises: firstly heating the temperature to a first temperature at a first rate and keeping the temperature for a first time, then heating the temperature to a second temperature at a second rate and keeping the temperature for a second time, then cooling the temperature to a third temperature at a third rate, and finally cooling the temperature to a fourth temperature at a fourth rate in an air atmosphere; Preferably, the first rate is 0.5-2.5°C / min; Preferably, the first temperature is 550-750°C; Preferably, the first time is 2-7h; Preferably, the second rate is 1-3°C / min; Preferably, the second temperature is 1100-1200°C; Preferably, the second time is 2-5h; Preferably, the third rate is 4-7°C / min; Preferably, the third temperature is 500-700°C; Preferably, the fourth rate is 6-10°C / min; Preferably, the fourth temperature is 40-60°C.

9. The preparation method according to any one of claims 2 to 8, characterized in that: The preparation method comprises the following steps: (1) Ingredients: Weigh the main components according to the weight ratio and perform wet ball milling and spray granulation in sequence; wherein, during the wet ball milling, the mixing mass ratio of the main component, the grinding medium and water is 1:(6-10):(0.3-1.2), the ball milling time is 20-60 min, and the particle size distribution of the obtained slurry satisfies D50 of 0.6-1.2 μm and D99 of 1.5-3 μm; (2) Pre-burning: The material obtained by spray granulation is placed in a rotary kiln for pre-burning at a temperature of 800-950°C for 2-4 hours; (3) ball milling: pour the pre-calcined main component into a ball mill, and add auxiliary components, water, adhesive, dispersant and defoamer, and the mixing mass ratio of the main component, water, adhesive, dispersant and defoamer is 100:(40-150):(4-20):(0.1-2):(0.001-0.0025); during the feeding process, first perform low-speed ball milling at 30-60rpm for 5-10min, and then perform high-speed ball milling at 80-100rpm for 0.5-2h; after the ball milling is completed, transfer the slurry to a stirring tank; (4) Granulation: The slurry obtained by ball milling is sprayed and granulated into material particles with an average particle size of 30-200 μm in a spray tower; (5) Molding: The material particles are pressed and molded to obtain a density of 3.10-3.25g / cm 3 H(20-30)mm×(10-20)mm×(8-12)mm annular blank; (6) Sintering: Place the annular blank in a box furnace, first heat it to 550-750°C at 0.5-2.5°C / min in an air atmosphere and keep it at that temperature for 2-7h, then heat it to 1100-1200°C at 1-3°C / min and keep it at that temperature for 2-5h, then cool it to 500-700°C at 4-7°C / min, and finally cool it to 40-60°C at 6-10°C / min.

10. An application of the nickel-zinc ferrite material as claimed in claim 1, characterized in that: The nickel-zinc ferrite material is used for preparing broadband transformers, filter inductors or laminated magnetic beads for electronic circuits.

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