High-performance microwave dielectric ceramic material and preparation method thereof

Abstract

The invention discloses a microwave dielectric ceramic material with high performance. The microwave dielectric ceramic material is prepared from the following raw materials in parts by weight: 1233 to 1236 parts of TiO2, 484 to 487 parts of MgCO3, 114 to 116 parts of CaCO3, 157 to 158 parts of La2O3, 35 to 40 parts of ZrO2 and 10 to 60 parts of Co2O3. The technical problems that an existing microwave dielectric ceramic material is large in loss and low in comprehensive performance are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of ceramic materials, and in particular relates to a high-performance microwave dielectric ceramic material and a preparation method thereof. Background Art

[0002] With the rapid development of microwave application technologies such as terrestrial mobile communications, vehicle-mounted radar, satellite live television, and global satellite positioning systems, high-end frequency, integration, miniaturization, and low cost have become the inevitable trend of the development of microwave technology.

[0003] Microwave dielectric ceramics refer to a new type of ceramic functional material used in microwave frequency band circuits (mainly 300MHz to 300GHz frequency band). It can be made into microwave components such as dielectric resonators, duplexers, dielectric filters, dielectric waveguide circuits, etc., and is used in mobile communications, satellite communications, military radars, and satellite positioning and navigation systems.

[0004] At present, with the continuous development of electronic devices and communication technology, the demand for microwave dielectric ceramic materials is getting higher and higher, and at the same time, higher requirements are also placed on the performance of microwave dielectric ceramic materials. Summary of the invention

[0005] The invention provides a high-performance microwave dielectric ceramic material and a preparation method thereof, which are used to solve the technical problems of large loss and low comprehensive performance of existing microwave dielectric ceramic materials.

[0006] In view of this, the present invention provides a high-performance microwave dielectric ceramic material, comprising the following raw materials in parts by weight: 1233-1236 parts of TiO2, 484-487 parts of MgCO3, 114-116 parts of CaCO3, 157-158 parts of La2O3, 35-40 parts of ZrO2, and 10-60 parts of Co2O3.

[0007] A method for preparing a high-performance microwave dielectric ceramic material comprises the following steps:

[0008] S1: adding zirconium balls and deionized water to the raw materials for primary ball milling, followed by drying, crushing, and sieving to obtain a mixed material;

[0009] S2: pre-calcining the mixed material to obtain an intermediate material;

[0010] S3: adding zirconium balls and deionized water to the intermediate material for secondary ball milling, followed by drying, crushing, sieving, and manual granulation to obtain granulated material;

[0011] S4: pressurizing the granulated material to take out the green pellet;

[0012] S5: Sintering the green body to obtain a ceramic material.

[0013] Furthermore, a method for preparing a high-performance microwave dielectric ceramic material comprises the following steps:

[0014] S1: Add zirconium balls and deionized water to the raw materials, perform primary ball milling in a multi-axis ball mill lined with a polyurethane tank, and then dry at a temperature of 100-120° C., crush, and pass through an 80-mesh sieve to obtain a mixed material;

[0015] S2: pre-calcining the mixed material to obtain an intermediate material;

[0016] S3: Add zirconium balls and deionized water to the intermediate material, perform secondary ball milling in a multi-axis ball mill lined with a polyurethane tank, and then dry at a temperature of 100-120° C., crush, pass through an 80-mesh sieve, and granulate manually to obtain a granulated material;

[0017] S4: pressurizing the granulated material to take out the green pellet;

[0018] S5: sintering the green body to obtain a ceramic material;

[0019] The drying temperature for both times is preferably 110°C.

[0020] Optionally, the diameter of the zirconium balls used in the initial ball milling in step S1 is 6 mm, the ball milling speed is 70-80 rpm, and the ball milling time is 11-13 h.

[0021] Furthermore, in step S1, the diameter of the zirconium balls used in the initial ball milling is 6 mm, the ball milling speed is 75 rpm, and the ball milling time is 12 h.

[0022] Optionally, in step S1, the weight ratio of the raw material, zirconium balls and deionized water is 1:3:1.2.

[0023] Optionally, the specific steps of pre-burning in step S2 are:

[0024] S2.1: Heating from room temperature to 1050°C for 8 hours;

[0025] S2.2: Keep at 1050°C for 6h;

[0026] S2.3: Cool down to room temperature at a rate of 1.5°C / min.

[0027] Optionally, the diameter of the zirconium balls used in the secondary ball milling in step S3 is 6 mm, the ball milling speed is 70-80 rpm, and the ball milling time is 11-13 h.

[0028] Furthermore, in step S3, the diameter of the zirconium balls used in the secondary ball milling is 6 mm, the ball milling speed is 75 rpm, and the ball milling time is 12 h.

[0029] Optionally, in step S3, the weight ratio of the intermediate material, zirconium balls and deionized water is 1:3:1.2.

[0030] Optionally, 4 wt % PVA of the sieved material is added during granulation in step S3.

[0031] Optionally, in step S4, the granulated material is placed into a mold with a diameter of 21 mm, and the mold groove depth is adjusted to 16-18 mm, and the pressurization pressure is 8-12 MPa.

[0032] Furthermore, in step S4, the granulated material is placed into a mold with a diameter of 21 mm, and the mold groove depth is adjusted to 17 mm and the pressurization pressure is 10 MPa.

[0033] Optionally, the specific steps of sintering in step S5 are:

[0034] S5.1: Heat from room temperature to 1350°C for 8 hours;

[0035] S5.2: Keep at 1350°C for 5h;

[0036] S5.3: Cool down to room temperature at a rate of 1°C / min.

[0037] It can be seen from the above technical solutions that the embodiments of the present invention have the following advantages:

[0038] The microwave dielectric ceramic material of the present application has the characteristics of low loss, optimizes the performance of the microwave dielectric ceramic material, makes the ceramic material have better comprehensive performance, and the performance is more stable, meeting the comprehensive performance requirements of the electronic component market for materials. Its preparation process cost is low, mainly by changing the components and the content of the components, the sintering temperature, the holding time and the temperature rise and fall curve, and the process has good stability.

[0039] The appropriate amount of lanthanum oxide doping can reduce dielectric loss and increase structural stability. At the same time, the appropriate amount of zirconium oxide doping can reduce dielectric loss and enhance the mechanical properties of ceramic materials. Finally, cobalt oxide doping can improve the dielectric properties of dielectric ceramics; the appropriate amount of doping can reduce dielectric loss, increase insulation resistance and improve temperature drift. DETAILED DESCRIPTION

[0040] In order to make the technical scheme of the present invention better understood by the personnel of the technical field, the technical scheme in the embodiment of the present invention is clearly and completely described below. Obviously, the described embodiment is only a part of the embodiment of the present invention, rather than all the embodiments. Based on the embodiment in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention. Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or can be prepared by existing methods.

[0041] Example

[0042] Example 1

[0043] A high-performance microwave dielectric ceramic material, the raw material ratio of which is shown in Table 1.

[0044] A method for preparing a high-performance microwave dielectric ceramic material comprises the following steps:

[0045] S1: Add zirconium balls with a diameter of 6 mm and deionized water to the raw materials, perform primary ball milling in a multi-axis ball mill lined with a polyurethane tank, the ball milling speed is 75 rpm, the ball milling time is 12 h, and then dry at a temperature of 110° C., crush, and pass through an 80-mesh sieve to obtain a mixed material;

[0046] S2: pre-calcining the mixed material, first heating it from room temperature to 1050°C for 8 hours, and keeping it at 1050°C for 6 hours, and finally cooling it to room temperature at a rate of 1.5°C / min to obtain an intermediate material;

[0047] S3: Add zirconium balls with a diameter of 6 mm and deionized water to the intermediate material, perform secondary ball milling in a multi-axis ball mill lined with a polyurethane tank, the ball milling speed is 75 rpm, the ball milling time is 12 h, and then dry at a temperature of 110° C., crush, pass through an 80-mesh sieve, and then add 4 wt% of PVA to the sieved material for manual granulation to obtain a granulated material;

[0048] S4: putting the granulated material into a mold with a diameter of 21 mm, adjusting the depth of the mold groove to 17 mm, applying pressure of 10 MPa to take out the green billet;

[0049] S5: sintering the green body, first heating from room temperature to 1350° C. for 8 hours, and keeping at 1350° C. for 5 hours, and finally cooling to room temperature at a rate of 1° C. / min to obtain a ceramic material;

[0050] Among them, the weight ratio of raw materials, zirconium balls and deionized water in step S1 is 1:3:1.2. In this embodiment, the amount of raw materials added is 2091.4d, the amount of zirconium balls added is 6274.2g, and the amount of water added is 2509.68g. The weight ratio of intermediate materials, zirconium balls and deionized water in step S3 is 1:3:1.2. In this embodiment, the amount of intermediate materials added is 2091.4g, the amount of zirconium balls added is 6274.2g, and the amount of water added is 2509.68g.

[0051] Embodiment 2-5

[0052] A high-performance microwave dielectric ceramic material is different from Example 1 in that the raw material ratio of the ceramic material is different. The raw material ratio is shown in Table 1.

[0053] Table 1 Weight of each raw material (g)

[0054] raw material Example 1 Example 2 Example 3 Example 4 Example 5 <![CDATA[TiO2]]> 1233 1234.6 1236 1234.6 1234.6 <![CDATA[MgCO3]]> 484 485.6 487 485.6 485.6 <![CDATA[CaCO3]]> 114 115.6 116 115.6 115.6 <![CDATA[La2O3]]> 157 157.6 158 157.6 157.6 <![CDATA[ZrO2]]> 35 38 40 38 38 <![CDATA[Co2O3]]> 60 60 60 30 10

[0055] Comparative Example

[0056] Comparative Example 1

[0057] A high-performance microwave dielectric ceramic material, which differs from Example 1 in that the amount of Co2O3 added to the raw material of the ceramic material is 0g.

[0058] Comparative Example 2

[0059] A high-performance side microwave dielectric ceramic material, which is different from Example 1 in that the amount of Co2O3 added to the ceramic material is 5g.

[0060] Comparative Example 3

[0061] A high-performance side microwave dielectric ceramic material, which is different from Example 1 in that the amount of Co2O3 added to the ceramic material is 80g.

[0062] Performance testing

[0063] The following performance tests were performed on the microwave dielectric ceramic materials in Examples 1-5 and Comparative Examples 1-3:

[0064] Relative dielectric constant: The relative dielectric constant of ceramic materials was measured according to GB / T 23260-2009. The test results are shown in Table 2.

[0065] Dielectric loss: The dielectric loss of ceramic materials was measured according to GB / T 23260-2009. The test results are shown in Table 2.

[0066] Temperature drift: The temperature drift of ceramic materials was measured according to GB / T 23260-2009. The test results are shown in Table 2.

[0067] Insulation resistance: The insulation resistance of ceramic materials was measured according to GB / T 23260-2009. The test results are shown in Table 2.

[0068] Table 2 Test results

[0069] project Relative dielectric constant <![CDATA[Dielectric loss (×10 -4 )]]> Temperature drift (ppm / ℃) <![CDATA[Insulation Resistance (×10 7 MΩ)]]> Example 1 29.8 0.7 -3 2.1 Example 2 30.2 0.7 -2.6 2.3 Example 3 30 1 -2 2 Example 4 30 0.8 -1.5 2.3 Example 5 31 0.8 -1.8 2.1 Comparative Example 1 32 10 10 0.8 Comparative Example 2 32 3 -8 1 Comparative Example 3 31 12 16 0.6

[0070] As can be seen from Table 1, the present application utilizes the synergistic effect between the various raw materials, and also optimizes the performance of the microwave dielectric ceramic material by changing the sintering temperature, holding time and heating and cooling curve, so that it has better comprehensive performance and lower dielectric loss, which makes it easier to meet the comprehensive performance requirements of ceramic materials for electrical components.

[0071] Combining Example 1 and Comparative Examples 1-3, it can be seen that the addition amount of each raw material in Example 1 is more appropriate, and the appropriate amount of lanthanum oxide doping can reduce dielectric loss and increase structural stability. At the same time, the appropriate amount of zirconium oxide doping can reduce dielectric loss and enhance the mechanical properties of ceramic materials. Finally, cobalt oxide doping can improve the dielectric properties of dielectric ceramics; appropriate doping can reduce dielectric loss, increase insulation resistance and improve temperature drift.

[0072] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-performance microwave dielectric ceramic material, characterized in that: The invention comprises the following raw materials in parts by weight: 1233-1236 parts of TiO2, 484-487 parts of MgCO3, 114-116 parts of CaCO3, 157-158 parts of La2O3, 35-40 parts of ZrO2, and 10-60 parts of Co2O3.

2. A method for preparing a high-performance microwave dielectric ceramic material as claimed in claim 1, characterized in that: The steps include: S1: adding zirconium balls and deionized water to the raw materials for primary ball milling, followed by drying, crushing, and sieving to obtain a mixed material; S2: pre-calcining the mixed material to obtain an intermediate material; S3: adding zirconium balls and deionized water to the intermediate material for secondary ball milling, followed by drying, crushing, sieving, and manual granulation to obtain granulated material; S4: pressurizing the granulated material to take out the green pellet; S5: Sintering the green body to obtain a ceramic material.

3. The method for preparing a high-performance microwave dielectric ceramic material according to claim 2, characterized in that: The diameter of the zirconium balls used in the initial ball milling in step S1 is 6 mm, the ball milling speed is 70-80 rpm, and the ball milling time is 11-13 h.

4. The method for preparing a high-performance microwave dielectric ceramic material according to claim 2, characterized in that: In step S1, the weight ratio of the raw material, zirconium balls and deionized water is 1:3:1.

2.

5. The method for preparing a high-performance microwave dielectric ceramic material according to claim 2, characterized in that: The specific steps of pre-burning in step S2 are: S2.1: Heating from room temperature to 1050°C for 8 hours; S2.2: Keep at 1050°C for 6h; S2.3: Cool down to room temperature at a rate of 1.5°C / min.

6. The method for preparing a high-performance microwave dielectric ceramic material according to claim 2, characterized in that: The diameter of the zirconium balls used in the secondary ball milling in step S3 is 6 mm, the ball milling speed is 70-80 rpm, and the ball milling time is 11-13 h.

7. The method for preparing a high-performance microwave dielectric ceramic material according to claim 2, characterized in that: In step S3, the weight ratio of the intermediate material, zirconium balls and deionized water is 1:3:1.

2.

8. The method for preparing a high-performance microwave dielectric ceramic material according to claim 2, characterized in that: During granulation in step S3, 4 wt% PVA of the sieved material is added.

9. The method for preparing a high-performance microwave dielectric ceramic material according to claim 2, characterized in that: In step S4, the granulated material is placed into a mold with a diameter of 21 mm, and the mold groove depth is adjusted to 16-18 mm and the pressurization pressure is 8-12 MPa.

10. The method for preparing a high-performance microwave dielectric ceramic material according to claim 2, characterized in that: The specific steps of sintering in step S5 are: S5.1: Heat from room temperature to 1350°C for 8 hours; S5.2: Keep at 1350°C for 5h; S5.3: Cool down to room temperature at a rate of 1°C / min.