CN115947594A - High-frequency-band ferrite material and preparation method thereof - Google Patents
High-frequency-band ferrite material and preparation method thereof Download PDFInfo
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Abstract
The invention relates to a high-frequency-band ferrite material and a preparation method thereof, wherein the high-frequency-band ferrite material comprises a main component and an auxiliary component, wherein the main component comprises the following components in molar content: 49-50mol% of Fe 2 O 3 4-8mol% ZnO, 40-43mol% NiO and 6-8.5mol% CuO; the subcomponent comprises 0.15wt% Bi based on the total mass of the main component 2 O 3 、0.12wt％CaO、0.1wt％BaTiO 3 Also discloses a preparation method for preparing the ferrite material. The ferrite of the invention has the characteristics of high frequency band, stable performance, low production process cost and stable process.
Description
Technical Field
The invention relates to the field of magnetic materials, in particular to a high-frequency-band ferrite material and a preparation method thereof.
Background
Ferrite is a novel non-metallic magnetic material developed in the 40 s of the 20 th century. With the development of electronic devices and communication technologies, high-frequency ferrites are widely applied to various communication and electronic fields, the demand for materials is higher and higher, and higher requirements are also put forward on the performance of the materials. The existing high-frequency ferrite has unstable performance and high loss and cannot meet the requirements of the market on the comprehensive properties of materials.
Disclosure of Invention
Aiming at the existing defects, the invention provides the high-frequency-band ferrite material which can be rapidly cooled, effectively remove stress and reduce the deformation degree and the preparation method thereof.
The technical scheme adopted by the invention for solving the technical problems is as follows: a high-band ferrite material: the beverage comprises a main component and an auxiliary component, wherein the main component comprises the following components in molar content: 49-50mol% of Fe 2 O 3 4-8mol% ZnO, 40-43mol% NiO and 6-8.5mol% CuO; the subcomponent comprises 0.15wt% Bi based on the total mass of the main component 2 O 3 、0.12wt％CaO、0.1wt％BaTiO 3 。
A preparation method of a high-frequency-band ferrite material comprises the following steps:
s1, mixing the main component ingredients and performing primary ball milling;
s2, drying the ball-milled mixture;
s3, pre-burning the dried mixture for a certain time, and naturally cooling to room temperature to obtain an intermediate product;
s4, doping the auxiliary components into the intermediate product;
s5, carrying out secondary ball milling on the intermediate product doped with the auxiliary components;
s6, drying and sieving the product subjected to secondary ball milling, and then adding 15wt% of PVA into the product subjected to sieving to mix;
s7, forming the mixture mixed with the PVA on a mould;
and S8, sintering the formed product at a certain temperature for a certain time.
Preferably, in the step S1, the first ball milling is performed by using steel balls, the steel balls include steel balls with a diameter of 8mm and steel balls with a diameter of 6mm, and when performing the ball milling, the steel balls are, by weight: the main components are as follows: 3.3 of water, ball milling speed 241rpm and ball milling time 3h.
Preferably, the step S2 is baking in an oven at 80 ℃ for 8h.
Preferably, the pre-firing of step S3 is performed at a temperature of 900 ℃, and includes the following steps:
s3a, heating, namely heating from the room temperature of 20 ℃ to 900 ℃ at the speed of 2.0 ℃/min for 440min;
s3b, preserving heat, and preserving heat for 150min at the temperature of 900 ℃;
and S3c, cooling, and naturally cooling from 900 ℃ to room temperature to obtain an intermediate product.
Preferably, the secondary spheroidal graphite in step S5 is ball-milled by using zirconium balls with a diameter of 5mm, and during ball-milling, the weight percentage of the zirconium balls is as follows: intermediate product (2): 3.3 of water, 241rpm of ball milling speed and 6h of ball milling time.
Preferably, the step S6 is to bake in an oven at 80 ℃ for 8 hours, and after baking, the mixture is sequentially sieved by a 40-mesh sieve and a 200-mesh sieve.
Preferably, the step S7 is performed by pressing the mold for 8MPa for 10 seconds.
Preferably, the step S8 is performed by sintering,
s8a, heating from room temperature to 300 ℃ at the heating rate of 1.5 ℃/min;
s8b, heating up from 300 ℃ to 550 ℃ at a heating rate of 0.8 ℃/min;
s8c, increasing the temperature from 550 ℃ to 750 ℃ at the temperature increase rate of 2 ℃/min;
s8d, increasing the temperature from 750 ℃ to 900 ℃ at the temperature increase rate of 1.5 ℃/min;
s8e, heating from 900 ℃ to 1080-1100 ℃ at the heating rate of 1.0 ℃/min;
s8f, preserving heat for 3-5h at the temperature of 1080-1100 ℃;
s8g, cooling from 1080-1100 ℃ to 1000 ℃ at a cooling rate of 1.0 ℃/min;
s8h, reducing the temperature from 1000 ℃ to 300 ℃ at the cooling rate of 2.0 ℃/min;
and S8i, naturally cooling to the room temperature from the temperature of 300 ℃.
Preferably, in the step S8f, the temperature is kept for 5h at 1080 ℃ and kept for 3-5h at 1100 ℃.
The invention has the beneficial effects that: the material has the characteristic of low loss in a high-frequency band, optimizes the performance of the ferrite, ensures that the ferrite has better comprehensive performance and more stable performance, and meets the comprehensive performance requirement of the market on the material. The preparation process is low in cost, and the process is stable by changing the components and the content of the components, the sintering temperature, the heat preservation time and the temperature rise and fall curve.
Detailed Description
To more clearly illustrate the objects, technical solutions and advantages of the embodiments of the present invention, the present invention will be further described in conjunction with the embodiments for clear and complete description, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without inventive step, are within the scope of the present invention.
The embodiment of the invention discloses a high-frequency-band ferrite material which comprises the following components in parts by weight: the adhesive comprises a main component and an auxiliary component, wherein the main component comprises the following components in molar content: 49-50mol% of Fe 2 O 3 4-8mol% ZnO, 40-43mol% NiO and 6-8.5mol% CuO; the subcomponent comprises 0.15wt% Bi based on the total mass of the main component 2 O 3 、0.12wt％CaO、0.1wt％BaTiO 3 . By the pair of Fe 2 O 3 Adjusting the content of NiO to optimize the saturation magnetic flux density, the initial permeability, the permeability temperature factor and the Curie temperature of the material; adjusting the use frequency of the material by adjusting the content of ZnO; the sintering temperature of the material is adjusted by adjusting the CuO content. Nano CaO is added into the accessory ingredients to improve the stress resistance of the material at different temperatures; adding nano Bi into the accessory ingredients 2 O 3 The sintering temperature is reduced to promote densification so as to improve the saturation magnetic flux density characteristic of the material, and the material has a cubic fluorite structure, wherein 1/4 of oxygen ion positions in crystal lattices are vacant, so that the material has very high oxygen ion conductivity; baTiO 2 3 Can attenuate the incident electromagnetic wave in the form of absorption, mainly by heat effect, when the angular frequency generated by magnetocrystalline anisotropy of ferrite is in phase with the angular frequency generated by the incident electromagnetic fieldIn the near future, resonance will occur, and BaTiO at this time 3 The energy can be absorbed from the outside, the attenuation of electromagnetic energy is reduced, the thickness of a crystal boundary is increased by adding the combination of the accessory components, and the temperature factors of relative loss factors and magnetic permeability of a high-frequency band are reduced; and then the crystal structure and the grain boundary distribution of the material are further adjusted through a production process, so that a lower magnetic conductivity temperature factor and good stress resistance are obtained, the material has the characteristic of high frequency band and low loss, the performance of the ferrite is optimized, the ferrite has better comprehensive performance and more stable performance, and the requirement of the market on the comprehensive performance of the material is met.
A preparation method of a high-frequency-band ferrite material comprises the following steps:
s1, mixing the main component ingredients, and performing primary ball milling, namely mixing the following components in molar content: 49-50mol% of Fe 2 O 3 4-8mol% ZnO, 40-43mol% NiO and 6-8.5mol% CuO, mixing them, and then remixing them with an abrasive for primary ball milling, wherein the abrasive is a steel ball comprising a steel ball having a diameter of 8mm and a steel ball having a diameter of 6mm, and the steel ball, the main component and water are in a ratio by weight at the time of ball milling, as follows: the main components are as follows: 3.3 of water, ball milling speed of 241rpm, ball milling time of 3h, wherein 335g of each of 8mm steel balls and 6mm steel balls is selected in the embodiment, 200g of main component and 300g of water are selected for ball milling;
s2, drying the ball-milled mixture, namely drying the ball-milled mixture in an oven at 80 ℃ for 8 hours;
s3, pre-burning the dried mixture for a certain time, and naturally cooling to room temperature to obtain an intermediate product, wherein the pre-burning is performed at the temperature of 900 ℃, and specifically, firstly, the temperature is increased from the room temperature of 20 ℃ to 900 ℃ at the speed of 2.0 ℃/min, and the temperature is increased for 440min; then preserving the heat for 150min at the temperature of 900 ℃; then naturally cooling the mixture from the temperature of 900 ℃ to room temperature to obtain an intermediate product;
s4, doping the intermediate product with the above-mentioned subcomponents, that is, doping the intermediate product formed after the calcination with Bi in an amount of 0.15wt% 2 O 3 、0.12wt％CaO、0.1wt％BaTiO 3 The specific doping ratios in the examples are shown below, wherein 200 refers to the total mass of the main component and the subcomponents, and the units are sample numbers represented by g,1, 2 and 3, that is, parallel samples conducted simultaneously, table 1 is a calculated value of the addition amount, table 2 is an actual weighed value of the addition amount, and similarly, the value after each sample number in table 2 is the total mass of the main component and the subcomponents actually weighed;
| 1(200.0) | 2(200.0) | 3(200.0) | 4(200.0) | ||
| Bi 2 O 3 | 0.15wt％ | 0.31 | 0.31 | 0.31 | 0.31 |
| CaO | 0.12wt％ | 0.25 | 0.25 | 0.25 | 0.25 |
| BaTiO 3 | 0.10wt％ | 0.21 | 0.21 | 0.21 | 0.21 |
TABLE 1
| 1(198.1) | 2(200.1) | 3(200.6) | 4(199.0) | ||
| Bi 2 O 3 | 0.15wt％ | 0.31 | 0.31 | 0.31 | 0.31 |
| CaO | 0.12wt％ | 0.25 | 0.25 | 0.25 | 0.25 |
| BaTiO 3 | 0.10wt％ | 0.20 | 0.20 | 0.20 | 0.20 |
TABLE 2
S5, carrying out secondary ball milling on the intermediate product doped with the auxiliary components, wherein the grinding material is zirconium balls with the diameter of 5mm, and the zirconium balls, the intermediate product and water are in the following proportion in percentage by weight during ball milling: intermediate product (2): 3.3 of water, ball milling speed of 241rpm, ball milling time of 6h, wherein 660g of 5mm zirconium balls are selected in the example, 200g of intermediate product and 300g of water are selected for ball milling;
s6, drying the product subjected to secondary ball milling, sieving the product by a sieve, adding 15wt% of PVA into the product subjected to sieving, and mixing, wherein the drying is carried out in an oven at 80 ℃ for 8 hours, then sequentially sieving the dried material by 40-mesh and 200-mesh sieves, adding 15wt% of PVA into the product subjected to sieving, mixing and granulating, and the 15% is calculated by 100% of the weight of the product subjected to sieving;
s7, forming the mixture mixed with PVA on a mould, namely putting the material granulated in the previous step into the mould, then loading the mould on a press, and pressurizing for 8MPa for 10 seconds to form the material;
s8, sintering the formed product at a certain temperature for a certain time, wherein the sintering step is as follows: firstly, heating from room temperature to 300 ℃ at the heating rate of 1.5 ℃/min; then raising the temperature from 300 ℃ to 550 ℃ at a temperature raising rate of 0.8 ℃/min; then heating up to 750 ℃ from 550 ℃ at the heating rate of 2 ℃/min; then heating from 750 ℃ to 900 ℃ at the heating rate of 1.5 ℃/min; finally, the temperature is increased from 900 ℃ to 1080-1100 ℃ at the temperature increase rate of 1.0 ℃/min; then preserving heat for 3-5h at the temperature of 1080-1100 ℃, and adopting final sintering temperature and heat preservation time according to different weight ingredients, such as preserving heat for 5h at the temperature of 1080 and preserving heat for 3-5h at the temperature of 1100 ℃; the cooling stage is carried out after the heat preservation is finished, and when the temperature is reduced, the temperature is reduced from 1080 ℃ to 1100 ℃ to 1000 ℃ at the cooling rate of 1.0 ℃/min; then reducing the temperature from 1000 ℃ to 300 ℃ at the cooling rate of 2.0 ℃/min; and finally, naturally cooling the mixture from the temperature of 300 ℃ to room temperature to obtain the final high-frequency-band ferrite. The following tables show the performance parameters of the ferrites prepared at different sintering temperatures for the above samples, table 3 shows the product test parameters of sintering at 1080 ℃ for 5h, table 4 shows the product test parameters of sintering at 1100 ℃ for 3h, and Table 5 shows the product test parameters of sintering at 1100 ℃ for 5h.
TABLE 3
TABLE 4
TABLE 5
It will be understood that modifications and variations can be made by persons skilled in the art in light of the above teachings and all such modifications and variations are intended to be included within the scope of the invention as defined in the appended claims.
Claims (10)
1. A high-band ferrite material, characterized by: the adhesive comprises a main component and an auxiliary component, wherein the main component comprises the following components in molar content: 49-50mol% of Fe 2 O 3 4-8mol% ZnO, 40-43mol% NiO and 6-8.5mol% CuO; the subcomponent comprises 0.15wt% Bi based on the total mass of the main component 2 O 3 、0.12wt％CaO、0.1wt％BaTiO 3 。
2. A preparation method of a high-frequency-band ferrite material is characterized by comprising the following steps:
s1, mixing the main component ingredients of claim 1 and carrying out primary ball milling;
s2, drying the ball-milled mixture;
s3, pre-burning the dried mixture for a certain time, and naturally cooling to room temperature to obtain an intermediate product;
s4, doping the accessory ingredient in the claim 1 into the intermediate product;
s5, carrying out secondary ball milling on the intermediate product doped with the auxiliary components;
s6, drying and sieving the product subjected to secondary ball milling, and then adding 15wt% of PVA into the product subjected to sieving to mix;
s7, forming the mixture mixed with the PVA on a mould;
and S8, sintering the formed product at a certain temperature for a certain time.
3. The preparation method of the high-frequency ferrite material according to claim 2, wherein the first ball milling in step S1 is performed by using steel balls, the steel balls comprise steel balls with a diameter of 8mm and steel balls with a diameter of 6mm, and the steel balls are, in terms of weight percentage during ball milling, as follows: the main components are as follows: water 3.3.
4. The method for preparing the high-frequency-band ferrite material according to claim 2, wherein the step S2 is baking in an oven at 80 ℃ for 8h.
5. The method for preparing a high-frequency ferrite material according to claim 2, wherein the pre-sintering in the step S3 is performed at a temperature of 900 ℃, and comprises the following steps:
s3a, heating, namely heating from the room temperature of 20 ℃ to 900 ℃ at the speed of 2.0 ℃/min for 440min;
s3b, preserving heat, and preserving heat for 150min at the temperature of 900 ℃;
and S3c, cooling, and naturally cooling from 900 ℃ to room temperature to obtain an intermediate product.
6. The method for preparing the high-frequency ferrite material according to claim 2, wherein the secondary ball milling in the step S5 is performed by using zirconium balls with the diameter of 5mm, and the weight percentage of the zirconium balls is as follows: intermediate product (2): 3.3 of water, 241rpm of ball milling speed and 6h of ball milling time.
7. The preparation method of the high-frequency-band ferrite material according to claim 2, wherein the step S6 is to bake in an oven at 80 ℃ for 8 hours, and then to sequentially pass through a 40-mesh sieve and a 200-mesh sieve.
8. The method for preparing a high-frequency ferrite material according to claim 2, wherein the step S7 is performed by pressing the ferrite material on a mold for 10 seconds under a pressure of 8 MPa.
9. The method according to claim 2, wherein the step S8 comprises sintering the ferrite material,
s8a, heating from room temperature to 300 ℃ at the heating rate of 1.5 ℃/min;
s8b, heating up from 300 ℃ to 550 ℃ at a heating rate of 0.8 ℃/min;
s8c, increasing the temperature from 550 ℃ to 750 ℃ at the temperature increase rate of 2 ℃/min;
s8d, increasing the temperature from 750 ℃ to 900 ℃ at the temperature increase rate of 1.5 ℃/min;
s8e, heating from 900 ℃ to 1080-1100 ℃ at the heating rate of 1.0 ℃/min;
s8f, preserving heat for 3-5h at the temperature of 1080-1100 ℃;
s8g, cooling from 1080-1100 ℃ to 1000 ℃ at a cooling rate of 1.0 ℃/min;
s8h, reducing the temperature from 1000 ℃ to 300 ℃ at the cooling rate of 2.0 ℃/min;
and S8i, naturally cooling to the room temperature from the temperature of 300 ℃.
10. The method for preparing a high-frequency ferrite material according to claim 9, wherein in step S8f, the temperature is kept for 5h at 1080 ℃ and kept for 3-5h at 1100 ℃.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006151741A (en) * | 2004-11-29 | 2006-06-15 | Tdk Corp | Ferrite material and electronic component using the same |
| CN102165543A (en) * | 2008-09-30 | 2011-08-24 | 双信电机株式会社 | Composite electronic component |
| WO2013121972A1 (en) * | 2012-02-13 | 2013-08-22 | 戸田工業株式会社 | Ni-Zn-Cu-BASED FERRITE POWDER, GREEN SHEET COMPRISING SAID Ni-Zn-Cu-BASED FERRITE POWDER, AND SINTERED Ni-Zn-Cu-BASED FERRITE |
| CN103332928A (en) * | 2012-11-02 | 2013-10-02 | 横店集团东磁股份有限公司 | Soft-magnetic nickel-copper-zinc ferrite material and preparation method thereof |
| CN108558383A (en) * | 2018-04-04 | 2018-09-21 | 电子科技大学 | NiZn Ferrite Materials and preparation method |
| CN110655397A (en) * | 2019-11-04 | 2020-01-07 | 宝鸡文理学院 | Wide-temperature-range high-permeability low-loss NiCuZn soft magnetic ferrite material and preparation method thereof |
-
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- 2023-02-14 CN CN202310110545.7A patent/CN115947594B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006151741A (en) * | 2004-11-29 | 2006-06-15 | Tdk Corp | Ferrite material and electronic component using the same |
| CN102165543A (en) * | 2008-09-30 | 2011-08-24 | 双信电机株式会社 | Composite electronic component |
| WO2013121972A1 (en) * | 2012-02-13 | 2013-08-22 | 戸田工業株式会社 | Ni-Zn-Cu-BASED FERRITE POWDER, GREEN SHEET COMPRISING SAID Ni-Zn-Cu-BASED FERRITE POWDER, AND SINTERED Ni-Zn-Cu-BASED FERRITE |
| CN103332928A (en) * | 2012-11-02 | 2013-10-02 | 横店集团东磁股份有限公司 | Soft-magnetic nickel-copper-zinc ferrite material and preparation method thereof |
| CN108558383A (en) * | 2018-04-04 | 2018-09-21 | 电子科技大学 | NiZn Ferrite Materials and preparation method |
| CN110655397A (en) * | 2019-11-04 | 2020-01-07 | 宝鸡文理学院 | Wide-temperature-range high-permeability low-loss NiCuZn soft magnetic ferrite material and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| ZHAO, QIANG等: "Low-temperature sintering synthesis and electromagnetic properties of NiCuZn/BaTiO3 composite materials", JOURNAL OF ALLOYS AND COMPOUNDS, vol. 788, pages 44 - 49, XP085645982, DOI: 10.1016/j.jallcom.2019.01.309 * |
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