NICKEL-ZINC FERRITE MATERIAL, AND PREPARATION METHOD THEREFOR AND USE THEREOF

Abstract

Provided in the present application are a nickel-zinc ferrite material, and a preparation method therefor and the use thereof. The nickel-zinc ferrite material comprises a main material, a functional additive and a correcting agent, wherein the main material comprises Fe.sub.2O.sub.3, Ni.sub.2O.sub.3, ZnO and CuO; the functional additive comprises a combination of any three or at least four of Mn.sub.3O.sub.4, TiO.sub.2, Ta.sub.2O.sub.5, Co.sub.2O.sub.3 or Sm.sub.2O.sub.3; and the correcting agent comprises Fe.sub.2O.sub.3 and Ni.sub.2O.sub.3. In the present invention, an appropriate main formula correction process is used, and a suitable and inexpensive correcting agent and a functional additive are added to a ferrite material, such that the power loss of the prepared nickel-zinc ferrite material at 13.56 MHz can be significantly reduced.

Claims

1. A NiZn ferrite material, which comprises a main material, a functional additive and a corrector, and the main material comprises Fe.sub.2O.sub.3, Ni.sub.2O.sub.3, ZnO and CuO, the functional additive comprises any three or a combination of at least four of Mn.sub.3O.sub.4, TiO.sub.2, Ta.sub.2O.sub.5, Co.sub.2O.sub.3 or Sm.sub.2O.sub.3, and the corrector comprises Fe.sub.2O.sub.3 and Ni.sub.2O.sub.3.

2. The NiZn ferrite material according to claim 1, wherein based on the molar amount of the main material being 100%, a molar fraction of Fe.sub.2O.sub.3 is 47.5-49.9%.

3. The NiZn ferrite material according to claim 1, wherein based on the molar amount of the main material being 100%, a molar fraction of Ni.sub.2O.sub.3 is 18.5-22.5%.

4. The NiZn ferrite material according to claim 1, wherein based on the molar amount of the main material being 100%, a molar fraction of ZnO is 21.5-25.5%.

5. The NiZn ferrite material according to claim 1, wherein based on the molar amount of the main material being 100%, a molar fraction of CuO is 3.5-7.5%.

6. The NiZn ferrite material according to claim 1, wherein based on the total mass of the main material after pre-sintering, an additive amount of Mn.sub.3O.sub.4 is 1000-1100 ppm.

7. The NiZn ferrite material according to claim 1, wherein based on the total mass of the main material after pre-sintering, an additive amount of Fe.sub.2O.sub.3 is 1300-2100 ppm.

8. A preparation method for the NiZn ferrite material according to claim 1, which comprises the following steps: (1) wet-mixing the main material to obtain a slurry, drying and then pre-sintering the slurry to obtain a powder material; (2) mixing the functional additive, the corrector and the powder material, wet-grinding and then drying the same, adding a polyvinyl alcohol solution and subjecting to granulation treatment; and (3) pressing a material obtained from the granulation treatment in step (2), and then subjecting the material to sintering treatment to obtain the nickel-zinc ferrite material.

9. The preparation method according to claim 8, wherein the wet-mixing in step (1) comprises wet ball milling.

10. The preparation method according to claim 9, wherein zirconium balls used in the wet ball milling comprise a 1:1:1 combination of zirconium balls of 6 mm, 14 mm, 22 mm; optionally, the wet ball milling comprises planetary ball milling; optionally, a ball-to-material ratio of the wet ball milling is 1:(2-4).

11. The preparation method according to claim 8, wherein the pre-sintering in step (1) is performed at a temperature of 850-980 C.; optionally, the pre-sintering is performed for a period of 2.5-3.5 h; optionally, cooling to room temperature with furnace is performed after the pre-sintering.

12. The preparation method according to claim 8, wherein the wet-grinding in step (2) is performed for a period of 90-150 min; optionally, a mass concentration of the polyvinyl alcohol solution is 8-12 wt %.

13. The preparation method according to claim 8, wherein a sieving treatment is performed before the pressing in step (3); optionally, a screen mesh number of the sieving treatment is 40-100 mesh; optionally, a density of the material after the pressing is more than or equal to 3.0 g/cm.sup.3.

14. The preparation method according to claim 8, wherein the sintering treatment is performed at a temperature of 1050-1150 C.; optionally, the sintering treatment is performed for a period of 3-5 h.

15. (canceled)

16. The NiZn ferrite material according to claim 6, wherein an additive amount of TiO2 is 0-150 ppm.

17. The NiZn ferrite material according to claim 6, wherein an additive amount of Ta.sub.2O.sub.5 is 300-500 ppm.

18. The NiZn ferrite material according to claim 6, wherein an additive amount of Co.sub.2O.sub.3 is 1500-3500 ppm.

19. The NiZn ferrite material according to claim 6, wherein an additive amount of Sm.sub.2O.sub.3 is 500-1200 ppm.

20. The NiZn ferrite material according to claim 7, wherein an additive amount of Ni.sub.2O.sub.3 is 1700-2300 ppm

21. A preparation method for magnetic cores, comprising using the NiZn ferrite material according to claim 1.

Description

DETAILED DESCRIPTION

[0050] The technical solutions of the present application are further described below in terms of specific embodiments. It should be clear to those skilled in the art that the embodiments are merely used for a better understanding of the present application and should not be regarded as a specific limitation to the present application.

Example 1

[0051] This example provides a nickel-zinc ferrite material, and the main material of the nickel-zinc ferrite material is composed of 23.5 mol % ZnO, 49.5 mol % Fe.sub.2O.sub.3, 20.5 mol % Ni.sub.2O.sub.3, and 6.5 mol % CuO. The preparation method of the nickel-zinc ferrite material is as follows: [0052] (1) the four raw materials of Fe.sub.2O.sub.3, Ni.sub.2O.sub.3, ZnO, and CuO were weighed and mixed by the above ratio, and then subjected to wet ball milling, wherein zirconium balls of 6 mm, 14 mm and 22 mm were combined by 1:1:1 and a material-to-ball ratio was 1:3, to obtain a slurry; the slurry was dried, pre-sintered at 950 C. with heat preserved for 3 h in air atmosphere, and cooled to room temperature with the furnace to obtain a powder material; [0053] (2) auxiliary functional additives Mn.sub.3O.sub.4, TiO.sub.2, Ta.sub.2O.sub.5, Co.sub.2O.sub.3 and main formula correctors Fe.sub.2O.sub.3 and Ni.sub.2O.sub.3 of analytical pure were weighed as per the mass ratio relative to the powder material obtained after the pre-sintering in step (3), and added to the powder material to obtain a doped powder, wherein the doped ratio was based on the mass of the weighed powder material obtained in step (3): 1050 ppm Mn.sub.3O.sub.4, 100 ppm TiO.sub.2, 400 ppm Ta.sub.2O.sub.5, 2500 ppm Co.sub.2O.sub.3, 1700 ppm Fe.sub.2O.sub.3, and 2000 ppm Ni.sub.2O.sub.3, and the obtained material was placed in a planetary ball mill and subjected to wet ball milling for 120 min, wherein zirconium balls of 4 mm and 5 mm were combined by 1:1 and a material-to-ball ratio was 1:7, to obtain a slurry; the slurry was dried and added with a 10 wt % polyvinyl alcohol (PVA) solution, mixed in a mortar and pre-pressed into a round pancake shape with a press, so that the polyvinyl alcohol (PVA) solution was fully mixed with the dried powder; and [0054] (3) the obtained powder was sieved through a 80-mesh screen and then pressed into a solid annular green part with a density of more than or equal to 3.0 g/cm.sup.3; the obtained green part was sintered in a bell-type air sintering furnace at a sintering temperature of 1040 C. with heat preserved for 4 h to obtain the nickel-zinc ferrite material.

Example 2

[0055] This example is only different from Example 1 where 49 mol % Fe.sub.2O.sub.3, 22.5 mol % Ni.sub.2O.sub.3 and 5 mol % CuO were used. Because the change of Fe.sub.2O.sub.3 and ZnO content in the main formula can directly affect the temperature characteristics of the material, the best performance temperature range of the material will shift, and in order to make the best performance temperature range always fall within the range of 25-100 C., the doping amount of Co.sub.2O.sub.3 additive with the same modification effect needs to be adjusted according to the example. Therefore, the additive amount of cobalt was changed to 2500 ppm, and other conditions and parameters were exactly the same as those in Example 1.

Example 3

[0056] This example is only different from Example 1 where 47.5 mol % Fe.sub.2O.sub.3, 22.0 mol % Ni.sub.2O.sub.3 and 7 mol % CuO were used. Because the change of Fe.sub.2O.sub.3 and ZnO content in the main formula can directly affect the temperature characteristics of the material, the best performance temperature range of the material will shift, and in order to make the best performance temperature range always fall within the range of 25-100 C., the doping amount of Co.sub.2O.sub.3 additive with the same modification effect needs to be adjusted according to the example. Therefore, the additive amount of cobalt was changed to 1500 ppm, and other conditions and parameters were exactly the same as those in Example 1.

Example 4

[0057] This example is only different from Example 1 where 49.5 mol % Fe.sub.2O.sub.3, 18.6 mol % Ni.sub.2O.sub.3, 25.5 mol % ZnO and 6.4 mol % CuO were used. Because the change of Fe.sub.2O.sub.3 and ZnO content in the main formula can directly affect the temperature characteristics of the material, the best performance temperature range of the material will shift, and in order to make the best performance temperature range always fall within the range of 25-100 C., the doping amount of Co.sub.2O.sub.3 additive with the same modification effect needs to be adjusted according to the example. Therefore, the additive amount of cobalt was changed to 3000 ppm, and other conditions and parameters were exactly the same as those in Example 1.

Example 5

[0058] This example is only different from Example 1 where 49.9 mol % Fe.sub.2O.sub.3, 22.5 mol % Ni.sub.2O.sub.3, 21.5 mol % ZnO and 6.1 mol % CuO were used. Because the change of Fe.sub.2O.sub.3 and ZnO content in the main formula can directly affect the temperature characteristics of the material, the best performance temperature range of the material will shift, and in order to make the best performance temperature range always fall within the range of 25-100 C., the doping amount of Co.sub.2O.sub.3 additive with the same modification effect needs to be adjusted according to the example. Therefore, the additive amount of cobalt was changed to 2000 ppm, and other conditions and parameters were exactly the same as those in Example 1.

Example 6

[0059] This example is different from Example 2 only in that the wet ball milling in step (2) was performed for a period of 90 min, the abrasion and iron loss of zirconium balls were less than those of Example 2, and the doped contents of main formula correctors Fe.sub.2O.sub.3 and Ni.sub.2O.sub.3 were 1300 ppm and 1700 ppm, respectively, and other conditions and parameters were exactly the same as those in Example 1.

Example 7

[0060] This example is different from Example 2 only in that the wet ball milling in step (2) was performed for a period of 150 min, the abrasion and iron loss of zirconium balls were less than those of Example 2, and the doped contents of main formula correctors Fe.sub.2O.sub.3 and Ni.sub.2O.sub.3 were 2100 ppm and 2300 ppm, respectively, and other conditions and parameters were exactly the same as those in Example 1.

Example 8

[0061] This example is different from Example 2 only in that the wet ball milling in step (2) was replaced by conventional sand milling, and other conditions and parameters were exactly the same as those in Example 1.

Comparative Example 1

[0062] This comparative example is different from Example 2 only in that no corrector was added, and other conditions and parameters were exactly the same as those in Example 1.

Comparative Example 2

[0063] This comparative example is different from Example 2 only in that corrector Fe.sub.2O.sub.3 was added alone, and other conditions and parameters were exactly the same as those in Example 1.

Comparative Example 3

[0064] This comparative example is different from Example 2 only in that corrector Ni.sub.2O.sub.3 was added alone, and other conditions and parameters were exactly the same as those in Example 1.

Comparative Example 4

[0065] This comparative example is different from Example 2 only in that no functional additive was added, and other conditions and parameters were exactly the same as those in Example 1.

Comparative Example 5

[0066] This comparative example is different from Example 2 only in that merely two functional additives Mn.sub.3O.sub.4 and Co.sub.2O.sub.3 were added and other conditions and parameters were exactly the same as those in Example 1.

Performance Test

[0067] The samples obtained in Examples 1-7 and Comparative Examples 1-2 were subjected to test for initial magnetic permeability at 1 KHz/0.25 V, and magnetic flux density at 25 C. and 100 C., and Japanese Iwatsu SY8218 B-H analyzer was used to test the unit volume loss Pcv, and then samples obtained in Example 8 and Comparative Examples 1-5 were selectively subjected to tests for initial magnetic permeability, and magnetic core loss at 30 mT. The test results are shown in Table 1.

TABLE-US-00001 TABLE 1 Initial Magnetic flux Magnetic core loss at 13.56 MHz (kW/m.sup.3) magnetic density (mT) 30 mT/ 20 mT/ 30 mT/ 20 mT/ permeability 25 C. 100 C. 25 C. 25 C. 100 C. 100 C. Example 1 101 430 375 310 265 415 374 Example 2 85 445 383 336 275 428 383 Example 3 90 440 380 320 271 421 380 Example 4 110 420 365 302 260 410 366 Example 5 79 449 390 346 279 436 388 Example 6 100 440 380 316 265 419 373 Example 7 88 435 373 335 272 426 384 Example 8 72 420 352 1235 1162 1426 1307 Comparative 96 376 344 581 690 602 746 Example 1 Comparative 148 388 329 604 633 667 705 Example 2 Comparative 88 399 351 652 620 618 731 Example 3 Comparative 56 390 358 670 644 625 729 Example 4 Comparative 63 395 361 678 699 705 811 Example 5

[0068] As can be seen from Table 1, the following can be obtained from Examples 1-7: the nickel-zinc ferrite in the present application has an initial magnetic permeability of the range of 10025%, a saturation magnetic flux density at 25 C. of more than or equal to 420 mT, and a saturation magnetic flux density at 100 C. of more than or equal to 360 mT; under the condition of 13.56 MHz, a magnetic core loss at 30 mT/25 C. can reach 346 kW/m.sup.3 or less, a magnetic core loss at 20 mT/25 C. can reach 279 kW/m.sup.3 or less, a magnetic core loss at 30 mT/100 C. can reach 436 kW/m.sup.3 or less, and a magnetic core loss at 20 mT/100 C. can reach 388 kW/m.sup.3 or less.

[0069] As can be seen from the comparison of Example 1 and Comparative Examples 6-7, in the present application, the additive amount of the corrector can be adjusted by the period of ball milling, and the method is flexible and controllable with an obvious effect.

[0070] As can be seen from the comparison of Example 2 and Example 8, in the present application, the grinding method has an obvious influence on the obtained nickel-zinc ferrite during the preparation process of the nickel-zinc ferrite. If the ball milling method adopts conventional sand grinding instead of planetary ball milling, there are obvious deficiencies in both loss and magnetic permeability performance. The planetary ball milling with high material-to-ball ratio adopted in the present application can effectively grind the powder particles and the particle size distribution can be narrower and more uniform in a short time.

[0071] As can be seen from the comparison of Example 2 and Comparative Examples 1-3, in absence of corrector Fe.sub.2O.sub.3 and/or Ni.sub.2O.sub.3, the loss and temperature performance of the prepared nickel-zinc ferrite material changed, and the loss at 25 C. and 100 C. increases. The present application adopts a suitable main formula correction process, which can significantly reduce the power loss at 13.56 MHz.

[0072] As can be seen from the comparison of Example 2 and Comparative Examples 4-5, in the present application, a variety of functional additives are appropriately added to the nickel-zinc ferrite material, in which the addition of an appropriate amount of Mn.sub.3O.sub.4 can greatly increase the resistivity and improve the power consumption characteristics; the addition of an appropriate amount of TiO.sub.2 can inhibit the participation of Fe.sup.2+ in the conductive mechanism, reduce the material loss, and reduce the sintering temperature without promoting the growth of grains, thereby improving the comprehensive magnetic properties; the addition of a small amount of Co.sub.2O.sub.3 can improve the frequency and loss characteristics of the material, in which Co.sup.2+ can form uniaxial anisotropy, resulting in a deep energy valley and freezing the domain wall, thereby increasing the resonance frequency of the domain wall; the addition of an appropriate amount of Sm.sub.2O.sub.3 can effectively control the magnetostriction coefficient of the material; and the addition of an appropriate amount of Ta.sub.2O.sub.5 can make the temperature curve more flat.

[0073] The applicant declares that the above is only specific examples of the present application, but the present application is not limited to the above examples. Those skilled in the art should understand that any change or replacement that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application shall fall within the protection scope and disclosure scope of the present application.