Manganese-zinc Ferrite with High Magnetic Permeability at Negative Temperature and Low Loss at High Temperature and Method for Preparing Same

Abstract

A manganese-zinc ferrite with a high magnetic permeability at negative temperature and low loss at high temperature consists of Fe.sub.2O.sub.3, MnO and ZnO, and additives consisting of CaCO.sub.3, ZrO.sub.2, Co.sub.2O.sub.3 and SnO.sub.2 are also added. A method for preparing the manganese-zinc ferrite is further provided. According to the method, by reasonably adjusting a ratio of Mn to Zn to Fe and appropriately increasing the content of Co in the additives, a manganese-zinc ferrite material with both a high magnetic permeability and low loss at about −20° C. and low loss at 120-140° C. is obtained. The manganese-zinc ferrite material has two loss valleys at about −20° C. and about 100° C. in a temperature range of −30° C. to 140° C., which expands the application range of the manganese-zinc ferrite material.

Claims

1. A manganese-zinc ferrite with a high magnetic permeability at negative temperature and low loss at high temperature, comprising main materials consisting of the following raw materials by mole percent: 52.35-52.45 mol % of Fe.sub.2O.sub.3, 37.6-37.97 mol % of MnO and 9.65-10.05 mol % of ZnO.

2. The manganese-zinc ferrite according to claim 1, further comprising additives consisting of the following raw materials by weight percent: in the additives, based on a total weight of the main materials, 0.06-0.10 wt % of CaCO.sub.3, 0.015-0.04 w t% of ZrO.sub.2, 0.3-0.45 wt % of Co.sub.2O.sub.3 and 0.1-0.2 wt % of SnO.sub.2.

3. The manganese-zinc ferrite according to claim 2, wherein, the additives are added after the main materials are mixed and sintered to obtain a pre-sintered material.

4. A method for preparing the manganese-zinc ferrite according to claim 1, comprising the following steps: (a) mixing various components in the main materials, and conducting primary ball milling and drying to obtain a ball milled powder; (b) adding a first binder aqueous solution into the ball milled powder for uniform mixing, and conducting spray granulation and pre-sintering to obtain a pre-sintered material; (c) adding additives into the pre-sintered material, and conducting secondary ball milling and drying to obtain a secondary ball milled powder; and (d) adding a second binder aqueous solution into the secondary ball milled powder for uniform mixing, conducting spray granulation and compression molding to obtain a blank, and sintering the blank to obtain the manganese-zinc ferrite.

5. The method according to claim 4, wherein, each of the first binder aqueous solution and the second binder aqueous solution is a polyvinyl alcohol solution with a concentration of 7-8 wt %, and the first binder aqueous solution is added at 8-12 wt % of a weight of the ball milled powder and the second binder aqueous solution is added at 8-12 wt % of the weight of the secondary ball milled powder.

6. The method according to claim 4, wherein, in step (a), water is used as a ball milling medium in the primary ball milling, a weight ratio of the main materials to a ball to the water is 1:(5-7):(0.5-0.6), and the primary ball milling is conducted for 50-70 min.

7. The method according to claim 4, wherein, in step (c), water is used as a ball milling medium in the secondary ball milling, a weight ratio of the main materials to a ball to the water is 1:(5-7):(0.4-0.5), and the secondary ball milling is conducted for 50-120 min.

8. The method according to claim 4, wherein, in step (b), the pre-sintering is conducted at a temperature of 900-920° C.

9. The method according to claim 4, wherein, in step (d), the compression molding is conducted under a pressure of 6-10 MPa.

10. The method according to claim 4, wherein, in step (d), the sintering is conducted at a temperature of 1,280-1,320° C.

11. The method according to claim 4, wherein the additives consists of the following raw materials by weight percent: in the additives, based on a total weight of the main materials, 0.06-0.10 wt % of CaCO.sub.3, 0.015-0.04 wt % of ZrO.sub.2, 0.3-0.45 wt % of Co.sub.2O.sub.3 and 0.1-0.2 wt % of SnO.sub.2.

12. The method according to claim 4, wherein, the additives are added after the main materials are mixed and sintered to obtain a pre-sintered material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 shows a loss Pcv curve of the manganese-zinc ferrite material obtained in Example 1 of the present invention in a temperature range of −30° C. to 140° C.

DETAILED DESCRIPTION

[0022] The technical solutions of the present invention are further described below in conjunction with specific embodiments.

[0023] Apparently, the described examples are merely a part, rather than all of examples of the present invention. Based on the examples of the present invention, all other examples obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0024] In the present invention, unless otherwise specified, all equipment and raw materials may be purchased from the market or are commonly used in the industry. Unless otherwise specified, methods in the following examples are conventional methods in the field.

Example 1

[0025] A manganese-zinc ferrite with a high magnetic permeability at negative temperature and low loss at high temperature included main materials consisting of the following raw materials by mole percent:

[0026] 52.35 mol % of Fe.sub.2O.sub.3, 37.6 mol % of MnO and 10.05 mol % of ZnO.

[0027] The manganese-zinc ferrite further included additives consisting of the following raw materials by weight percent: in the additives, based on a total weight of a pre-sintered material, 0.08 wt % of CaCO.sub.3, 0.02 wt % of ZrO.sub.2, 0.4 wt % of Co.sub.2O.sub.3 and 0.1 wt % of SnO.sub.2.

[0028] A method for preparing the manganese-zinc ferrite with a high magnetic permeability at negative temperature and low loss at high temperature included the following steps:

(a) various components in the main materials were mixed, and primary sanding was conducted for 60 min by using deionized water as a sanding medium to obtain a sanded slurry, where, a weight ratio of the materials to a ball to the deionized water was 1:6:0.55;
(b) a binder aqueous solution was added into the sanded slurry for uniform mixing, spray granulation was conducted, and then pre-sintering was conducted at 900° C. to obtain a pre-sintered material, where, the binder aqueous solution was a polyvinyl alcohol solution with a concentration of 7.5 wt %, and was added at 10 wt % of the weight of the main materials;
(c) the additives were added into the pre-sintered material, and secondary sanding was conducted for 120 min by using deionized water as a sanding medium to obtain a secondary sanded slurry, where, a weight ratio of the materials to a ball to the deionized water was 1:6:0.45; and
(d) a binder aqueous solution was added into the secondary sanded slurry for uniform mixing, spray granulation was conducted, compression molding was conducted under a pressure of 8 MPa to obtain a standard ring, and the standard ring was sintered at a temperature of 1,300° C. to obtain the manganese-zinc ferrite, where, the binder aqueous solution was a polyvinyl alcohol solution with a concentration of 7.5 wt %, and was added at 10 wt % of the weight of the pre-sintered material.

Example 2

[0029] A manganese-zinc ferrite with a high magnetic permeability at negative temperature and low loss at high temperature included main materials consisting of the following raw materials by mole percent:

[0030] 52.45 mol % of Fe.sub.2O.sub.3, 37.9 mol % of MnO and 9.65 mol % of ZnO.

[0031] The manganese-zinc ferrite further included additives consisting of the following raw materials by weight percent: in the additives, based on a total weight of a pre-sintered material, 0.08 wt % of CaCO.sub.3, 0.02 wt % of ZrO.sub.2, 0.44 wt % of Co.sub.2O.sub.3 and 0.1 wt % of SnO.sub.2.

[0032] A method for preparing the manganese-zinc ferrite with a high magnetic permeability at negative temperature and low loss at high temperature included the following steps:

(a) various components in the main materials were mixed, and primary sanding was conducted for 60 min by using deionized water as a sanding medium to obtain a sanded slurry, where, a weight ratio of the materials to a ball to the deionized water was 1:6:0.55;
(b) a binder aqueous solution was added into the sanded slurry for uniform mixing, spray granulation was conducted, and then pre-sintering was conducted at 920° C. to obtain a pre-sintered material, where, the binder aqueous solution was a polyvinyl alcohol solution with a concentration of 7.5 wt %, and was added at 10 wt % of the weight of the main materials;
(c) the additives were added into the pre-sintered material, and secondary sanding was conducted for 140 min by using deionized water as a sanding medium to obtain a secondary sanded slurry, where, a weight ratio of the materials to a ball to the deionized water was 1:6:0.45; and
(d) a binder aqueous solution was added into the secondary sanded slurry for uniform mixing, spray granulation was conducted, compression molding was conducted under a pressure of 8 MPa to obtain a standard ring, and the standard ring was sintered at a temperature of 1,300° C. to obtain the manganese-zinc ferrite, where, the binder aqueous solution was a polyvinyl alcohol solution with a concentration of 7.5 wt %, and was added at 10 wt % of the weight of the pre-sintered material.

Example 3

[0033] A manganese-zinc ferrite with a high magnetic permeability at negative temperature and low loss at high temperature included main materials consisting of the following raw materials by mole percent:

[0034] 52.45 mol % of Fe.sub.2O.sub.3, 37.8 mol % of MnO and 9.75 mol % of ZnO.

[0035] The manganese-zinc ferrite further included additives consisting of the following raw materials by weight percent: in the additives, based on a total weight of a pre-sintered material, 0.06 wt % of CaCO.sub.3, 0.015 wt % of ZrO.sub.2, 0.3 wt % of Co.sub.2O.sub.3 and 0.15 wt % of SnO.sub.2.

[0036] A method for preparing the manganese-zinc ferrite with a high magnetic permeability at negative temperature and low loss at high temperature included the following steps:

(a) various components in the main materials were mixed, and primary sanding was conducted for 70 min by using deionized water as a sanding medium to obtain a sanded slurry, where, a weight ratio of the materials to a ball to the deionized water was 1:5:0.5;
(b) a binder aqueous solution was added into the sanded slurry for uniform mixing, spray granulation was conducted, and then pre-sintering was conducted at 910° C. to obtain a pre-sintered material, where, the binder aqueous solution was a polyvinyl alcohol solution with a concentration of 7 wt %, and was added at 12 wt % of the weight of the main materials;
(c) the additives were added into the pre-sintered material, and secondary sanding was conducted for 160 min by using deionized water as a sanding medium to obtain a secondary sanded slurry, where, a weight ratio of the materials to a ball to the deionized water was 1:5:0.4; and
(d) a binder aqueous solution was added into the secondary sanded slurry for uniform mixing, spray granulation was conducted, compression molding was conducted under a pressure of 7 MPa to obtain a standard ring, and the standard ring was sintered at a temperature of 1,280° C. to obtain the manganese-zinc ferrite, where, the binder aqueous solution was a polyvinyl alcohol solution with a concentration of 7 wt %, and was added at 12 wt % of the weight of the pre-sintered material.

Example 4

[0037] A manganese-zinc ferrite with a high magnetic permeability at negative temperature and low loss at high temperature included main materials consisting of the following raw materials by mole percent:

[0038] 52.43 mol % of Fe.sub.2O.sub.3, 37.65 mol % of MnO and 9.92 mol % of ZnO.

[0039] The manganese-zinc ferrite further included additives consisting of the following raw materials by weight percent: in the additives, based on a total weight of a pre-sintered material, 0.07 wt % of CaCO.sub.3, 0.025 wt % of ZrO.sub.2, 0.45 wt % of Co.sub.2O.sub.3 and 0.2 wt % of SnO.sub.2.

[0040] A method for preparing the manganese-zinc ferrite with a high magnetic permeability at negative temperature and low loss at high temperature included the following steps:

(a) various components in the main materials were mixed, and primary sanding was conducted for 50 min by using deionized water as a sanding medium to obtain a sanded slurry, where, a weight ratio of the materials to a ball to the deionized water was 1:7:0.6;
(b) a binder aqueous solution was added into the sanded slurry for uniform mixing, spray granulation was conducted, and then pre-sintering was conducted at 920° C. to obtain a pre-sintered material, where, the binder aqueous solution was a polyvinyl alcohol solution with a concentration of 8 wt %, and was added at 8 wt % of the weight of the main materials;
(c) the additives were added into the pre-sintered material, and secondary sanding was conducted for 120 min by using deionized water as a sanding medium to obtain a secondary sanded slurry, where, a weight ratio of the materials to a ball to the deionized water was 1:7:0.5; and
(d) a binder aqueous solution was added into the secondary sanded slurry for uniform mixing, spray granulation was conducted, compression molding was conducted under a pressure of 9 MPa to obtain a standard ring, and the standard ring was sintered at a temperature of 1,310° C. to obtain the manganese-zinc ferrite, where, the binder aqueous solution was a polyvinyl alcohol solution with a concentration of 8 wt %, and was added at 8 wt % of the weight of the pre-sintered material.

Example 5

[0041] A manganese-zinc ferrite with a high magnetic permeability at negative temperature and low loss at high temperature included main materials consisting of the following raw materials by mole percent:

[0042] 52.40 mol % of Fe.sub.2O.sub.3, 37.90 mol % of MnO and 9.70 mol % of ZnO.

[0043] The manganese-zinc ferrite further included additives consisting of the following raw materials by weight percent: in the additives, based on a total weight of a pre-sintered material, 0.10 wt % of CaCO.sub.3, 0.04 wt % of ZrO.sub.2, 0.35 wt % of Co.sub.2O.sub.3 and 0.13 wt % of SnO.sub.2.

[0044] A method for preparing the manganese-zinc ferrite with a high magnetic permeability at negative temperature and low loss at high temperature included the following steps:

(a) various components in the main materials were mixed, and primary sanding was conducted for 60 min by using deionized water as a sanding medium to obtain a sanded slurry, where, a weight ratio of the materials to a ball to the deionized water was 1:6:0.55;
(b) a binder aqueous solution was added into the sanded slurry for uniform mixing, spray granulation was conducted, and then pre-sintering was conducted at 910° C. to obtain a pre-sintered material, where, the binder aqueous solution was a polyvinyl alcohol solution with a concentration of 7.5 wt %, and was added at 10 wt % of the weight of the main materials;
(c) the additives were added into the pre-sintered material, and secondary sanding was conducted for 140 min by using deionized water as a sanding medium to obtain a secondary sanded slurry, where, a weight ratio of the materials to a ball to the deionized water was 1:6:0.45; and
(d) a binder aqueous solution was added into the secondary sanded slurry for uniform mixing, spray granulation was conducted, compression molding was conducted under a pressure of 8 MPa to obtain a standard ring, and the standard ring was sintered at a temperature of 1,300° C. to obtain the manganese-zinc ferrite, where, the binder aqueous solution was a polyvinyl alcohol solution with a concentration of 7.5 wt %, and was added at 10 wt % of the weight of the pre-sintered material.

Example 6

[0045] A manganese-zinc ferrite with a high magnetic permeability at negative temperature and low loss at high temperature included main materials consisting of the following raw materials by mole percent:

[0046] 52.38 mol % of Fe.sub.2O.sub.3, 37.85 mol % of MnO and 9.77 mol % of ZnO.

[0047] The manganese-zinc ferrite further included additives consisting of the following raw materials by weight percent: in the additives, based on a total weight of a pre-sintered material, 0.09 wt % of CaCO.sub.3, 0.03 wt % of ZrO.sub.2, 0.39 wt % of Co.sub.2O.sub.3 and 0.18 wt % of SnO.sub.2.

[0048] A method for preparing the manganese-zinc ferrite with a high magnetic permeability at negative temperature and low loss at high temperature included the following steps:

(a) various components in the main materials were mixed, and primary sanding was conducted for 60 min by using deionized water as a sanding medium to obtain a sanded slurry, where, a weight ratio of the materials to a ball to the deionized water was 1:6:0.55;
(b) a binder aqueous solution was added into the sanded slurry for uniform mixing, spray granulation was conducted, and then pre-sintering was conducted at 900° C. to obtain a pre-sintered material, where, the binder aqueous solution was a polyvinyl alcohol solution with a concentration of 7.5 wt %, and was added at 10 wt % of the weight of the main materials;
(c) the additives were added into the pre-sintered material, and secondary sanding was conducted for 150 min by using deionized water as a sanding medium to obtain a secondary sanded slurry, where, a weight ratio of the materials to a ball to the deionized water was 1:6:0.45; and
(d) a binder aqueous solution was added into the secondary sanded slurry for uniform mixing, spray granulation was conducted, compression molding was conducted under a pressure of 8 MPa to obtain a standard ring, and the standard ring was sintered at a temperature of 1,300° C. to obtain the manganese-zinc ferrite, where, the binder aqueous solution was a polyvinyl alcohol solution with a concentration of 7.5 wt %, and was added at 10 wt % of the weight of the pre-sintered material.

Comparative Example 1

[0049] A manganese-zinc ferrite included main materials consisting of the following raw materials by mole percent:

[0050] 52.75 mol % of Fe.sub.2O.sub.3, 37.2 mol % of MnO and 10.05 mol % of ZnO.

[0051] In this comparative example, additives of the manganese-zinc ferrite and a method for preparing the manganese-zinc ferrite were the same with those in Example 1.

Comparative Example 2

[0052] A manganese-zinc ferrite included main materials consisting of the following raw materials by mole percent:

[0053] 52.25 mol % of Fe2O.sub.3, 38.00 mol % of MnO and 9.75 mol % of ZnO.

[0054] In this comparative example, additives of the manganese-zinc ferrite and a method for preparing the manganese-zinc ferrite were the same with those in Example 1.

Comparative Example 3

[0055] A manganese-zinc ferrite included main materials consisting of the following raw materials by mole percent:

[0056] 52.44 mol % of Fe.sub.2O.sub.3, 37.96 mol % of MnO and 9.60 mol % of ZnO.

[0057] In this comparative example, additives of the manganese-zinc ferrite and a method for preparing the manganese-zinc ferrite were the same with those in Example 1.

Comparative Example 4

[0058] A manganese-zinc ferrite included main materials consisting of the following raw materials by mole percent:

[0059] 52.35 mol % of Fe.sub.2O.sub.3, 37.55 mol % of MnO and 10.10 mol % of ZnO.

[0060] In this comparative example, additives of the manganese-zinc ferrite and a method for preparing the manganese-zinc ferrite were the same with those in Example 1.

Comparative Example 5

[0061] A manganese-zinc ferrite included main materials consisting of the following raw materials by mole percent:

[0062] 52.25 mol % of Fe.sub.2O.sub.3, 37.75 mol % of MnO and 10.00 mol % of ZnO.

[0063] In this comparative example, additives of the manganese-zinc ferrite and a method for preparing the manganese-zinc ferrite were the same with those in Example 1.

Comparative Example 6

[0064] A manganese-zinc ferrite included main materials consisting of the following raw materials by mole percent:

[0065] 52.55 mol % of Fe.sub.2O.sub.3, 37.70 mol % of MnO and 9.75 mol % of ZnO.

[0066] In this comparative example, additives of the manganese-zinc ferrite and a method for preparing the manganese-zinc ferrite were the same with those in Example 1.

Comparative Example 7

[0067] Main materials of a manganese-zinc ferrite and a method for preparing the manganese-zinc ferrite were the same with those in Example 1.

[0068] The manganese-zinc ferrite included following additives by weight percent: based on a total weight of a pre-sintered material, 0.08 wt % of CaCO.sub.3, 0.02 wt % of ZrO.sub.2, 0.20 wt % of Co.sub.2O.sub.3 and 0.1 wt % of SnO.sub.2.

Comparative Example 8

[0069] Main materials of a manganese-zinc ferrite and a method for preparing the manganese-zinc ferrite were the same with those in Example 1.

[0070] The manganese-zinc ferrite included following additives by weight percent: based on a total weight of a pre-sintered material, 0.08 wt % of CaCO.sub.3, 0.02 wt % of ZrO.sub.2, 0.50 wt % of Co.sub.2O.sub.3 and 0.1 wt % of SnO.sub.2.

Performance Testing

[0071] Performance of the manganese-zinc ferrite materials obtained in each of the examples and comparative examples above was tested, including the magnetic permeability μi at −20° C. and the loss Pcv at 120° C. and 140° C. (100 kHz 200 mT), as shown in the Table 1 below.

[0072] A loss Pcv curve of the manganese-zinc ferrite material obtained in Example 1 in a temperature range of −30° C. to 140° C. was drawn according to actual conditions, as shown in FIG. 1.

TABLE-US-00001 TABLE 1 Magnetic Loss Pcv (kW/m.sup.3) permeability μi 100 kHz 200 mT −20° C. 120° C. 140° C. Example 1 2,800 300 336 Example 2 2,680 313 345 Example 3 2,720 315 345 Example 4 2,760 310 340 Example 5 2,710 305 335 Example 6 2,695 310 343 Comparative 1,500 450 520 Example 1 Comparative 1,700 430 530 Example 2 Comparative 1,450 445 530 Example 3 Comparative 1,200 450 540 Example 4 Comparative 1,520 480 560 Example 5 Comparative 1,487 450 510 Example 6 Comparative 1,700 420 480 Example 7 Comparative 1,100 410 470 Example 8
From Table 1, following information could be known.
1. In Comparative Example 1, since the content of the Fe.sub.2O.sub.3 was too high and the content of the MnO was low, the loss at high temperature was high, and the magnetic permeability at −20° C. was much lower than that of the samples in the examples.
2. In Comparative Example 2, since the content of the Fe.sub.2O.sub.3 was low and the content of the MnO was too high, the loss at high temperature was high, and the magnetic permeability at −20° C. was much lower than that of the samples in the examples but slightly higher than that of the sample in Comparative Example 1.
3. In Comparative Example 3, since the content of the MnO was too high and the content of the ZnO was low, the loss at high temperature was high, and the magnetic permeability at −20° C. was much lower than that of the samples in the examples.
4. In Comparative Example 4, since the content of the MnO was low and the content of the ZnO was too high, the loss at high temperature was high, and the magnetic permeability at −20° C. was much lower than that of the samples in the examples and lower than that of the sample in Comparative Example 3.
5. In Comparative Example 5, since the content of the Fe.sub.2O.sub.3 was low, the loss at high temperature was much higher than that of the samples in the examples, and the magnetic permeability at −20° C. was low.
6. In Comparative Example 6, since the content of the Fe.sub.2O.sub.3 was too high, the loss at high temperature was much higher than that of the samples in the examples, and the magnetic permeability at −20° C. was low and even lower than that of the sample in Comparative Example 5.
7. In Comparative Example 7, since the content of the Co.sub.2O.sub.3 was low, the loss at high temperature was high, and the magnetic permeability at −20° C. was low.
8. In Comparative Example 8, since the content of the Co.sub.2O.sub.3 was too high, the loss at high temperature was high, and the magnetic permeability at −20° C. was greatly reduced and even lower than that of the sample in Comparative Example 7.

[0073] It should be understood that improvements and modifications may be made by those of ordinary skill in the art based on the descriptions above, and all these improvements and modifications shall fall within the protection scope of the appended claims of the present invention.