阅读说明：本技术 掺杂堇青石的复相微波介质陶瓷材料、制备方法及其应用 (Cordierite-doped complex-phase microwave dielectric ceramic material, preparation method and application thereof ) 是由 王秀红 黄庆焕 叶荣 顾国治 王斌华 于 2021-03-15 设计创作，主要内容包括：本发明提供了一种掺杂堇青石的复相微波介质陶瓷材料、制备方法及其应用,涉及5G微波介质陶瓷材料的技术领域。本发明提供的掺杂堇青石的复相微波介质陶瓷材料,包括主材和改性掺杂剂,其中主材为CaTiO-3-SmAlO-3；改性掺杂剂为堇青石,堇青石的组成为2MgO·2Al-2O-3·5SiO-2,其在复相微波介质陶瓷材料的添加量为0.5％-2％。本发明提供的复相微波介质陶瓷材料具有良好的综合性能,其介电常数εr可达45,品质因数Qf≥45000,抗弯强度≥278MPa,热震温度为150℃,可靠性更强,可满足微波元器高频化、微型化、多功能化的要求,还能适应恶劣的工作环境,具有良好的应用前景。(The invention provides a cordierite-doped complex-phase microwave dielectric ceramic material, a preparation method and application thereof, and relates to the technical field of 5G microwave dielectric ceramic materials. The cordierite-doped complex-phase microwave dielectric ceramic material provided by the invention comprises a main material and a modified dopant, wherein the main material is CaTiO 3 ‑SmAlO 3 (ii) a The modified dopant is cordierite with the composition of 2 MgO.2Al 2 O 3 ·5SiO 2 The addition amount of the ceramic material in the complex phase microwave dielectric ceramic material is 0.5 to 2 percent. The invention provides a complex phase microwave dielectric ceramicThe material has good comprehensive performance, the dielectric constant epsilon r of the material can reach 45, the quality factor Qf is more than or equal to 45000, the bending strength is more than or equal to 278MPa, the thermal shock temperature is 150 ℃, the reliability is stronger, the requirements of high frequency, miniaturization and multifunction of a microwave element device can be met, the material can also adapt to severe working environment, and the material has good application prospect.)

1. The composite microwave dielectric ceramic material doped with cordierite is characterized by comprising a main material and a modified dopant;

wherein the main material is CaTiO₃-SmAlO₃；

The modified dopant is cordierite, and the composition of the cordierite is 2 MgO.2Al₂O₃·5SiO₂。

2. The cordierite-doped composite microwave dielectric ceramic material of claim 1 wherein the cordierite is present in an amount of from 0.5% to 2%.

3. The cordierite-doped composite microwave dielectric ceramic material of claim 1 prepared by mixing MgO and Al₂O₃And SiO₂Mixing and sintering to obtain;

preferably, the sintering temperature is 1400-1500 ℃, and the sintering time is 3-6 h.

4. The cordierite doped composite microwave dielectric ceramic material of claim 1 further comprising a sintering aid;

preferably, the sintering aid comprises Y₂O₃；

Preferably, said Y is₂O₃The addition amount of (B) is 0.01-1%.

5. The cordierite doped complex phase microwave dielectric ceramic material of any of claims 1-4 wherein the CaTiO₃-SmAlO₃From TiO₂、Sm₂O₃CaO and Al₂O₃Composition of, wherein TiO₂30 to 40 percent of Sm accounting for the mass fraction of the main material₂O₃25-36 percent of CaO, 20-29 percent of Al and the balance of the balance₂O₃5-15% of the main material;

preferably, the CaTiO₃-SmAlO₃From TiO₂、Sm₂O₃CaO and Al₂O₃Mixing and pre-sintering to obtain;

preferably, the pre-sintering temperature is 1200-1400 ℃, and the pre-sintering time is 2-4 h.

6. The method of producing a cordierite-doped composite microwave dielectric ceramic material as in any of claims 1-5, wherein the cordierite-doped composite microwave dielectric ceramic material is obtained by mixing and sintering the primary material, the cordierite and an optional sintering aid.

7. The method of claim 6 wherein the sintering temperature is 1400-1500 ℃ and the sintering time is 1-6 h.

8. The method of claim 6 wherein the mixing comprises ball milling;

preferably, the rotation speed of the ball mill is 300r/min-400 r/min;

preferably, the time of ball milling is 4h to 6 h.

9. The method of claim 6 wherein the cordierite-doped composite microwave dielectric ceramic material is sintered after being pelletized and dry pressed to form a green body;

preferably, the pressure of the dry pressing is 70MPa-100 MPa.

10. Use of the cordierite-doped complex phase microwave dielectric ceramic material according to any one of claims 1 to 5 or the cordierite-doped complex phase microwave dielectric ceramic material prepared by the preparation method according to any one of claims 6 to 9 in resonators, filters, microwave dielectric antennas, frequency oscillators and dielectric waveguide transmission lines.

Technical Field

The invention relates to the technical field of 5G microwave dielectric ceramic materials, in particular to a cordierite-doped complex-phase microwave dielectric ceramic material, a preparation method and application thereof.

Background

The microwave dielectric ceramic material is widely applied to components such as resonators, filters, microwave dielectric antennas, frequency oscillators, dielectric waveguide transmission lines and the like. The existing microwave dielectric ceramic material is easy to generate microcracks in the process of rapid heating or rapid cooling at high temperature due to the inherent brittleness, and the catastrophic damage such as failure, stripping and the like of a microwave dielectric ceramic device can be caused along with the rapid increase and expansion of the microcracks.

In view of the above, the present invention is particularly proposed.

Disclosure of Invention

One of the purposes of the invention is to provide a cordierite-doped complex-phase microwave dielectric ceramic material so as to relieve the technical problems of poor thermal shock resistance and low comprehensive performance of the existing microwave dielectric ceramic material.

The second purpose of the invention is to provide the preparation method of the cordierite-doped complex-phase microwave dielectric ceramic material, which has simple steps, easy operation and controllable process and is suitable for large-scale industrial production.

The third purpose of the invention is to provide the application of the cordierite-doped complex-phase microwave dielectric ceramic material in resonators, filters, microwave dielectric antennas, frequency oscillators or dielectric waveguide transmission lines, the application meets the requirements of 5G microwave dielectric ceramic materials, and the application prospect is wide.

In order to solve the technical problems, the invention adopts the following technical scheme:

the invention provides a cordierite-doped complex-phase microwave dielectric ceramic material, which comprises a main material and a modified dopant;

wherein the main material is CaTiO₃-SmAlO₃；

The modified dopant is cordieriteThe composition of the bluestone is 2 MgO.2Al₂O₃·5SiO₂。

Further, the addition amount of the cordierite is 0.5% -2%.

Furthermore, the preparation method of the cordierite is to mix MgO and Al₂O₃And SiO₂Mixing and sintering to obtain;

preferably, the sintering temperature is 1400-1500 ℃, and the sintering time is 3-6 h.

Further, the material also comprises a sintering aid;

preferably, the sintering aid comprises Y₂O₃；

Preferably, said Y is₂O₃The addition amount of (B) is 0.01-1%.

Further, the CaTiO₃-SmAlO₃From TiO₂、Sm₂O₃CaO and Al₂O₃Composition of, wherein TiO₂30 to 40 percent of Sm accounting for the mass fraction of the main material₂O₃25-36 percent of CaO, 20-29 percent of Al and the balance of the balance₂O₃5-15% of the main material;

preferably, the CaTiO₃-SmAlO₃From TiO₂、Sm₂O₃CaO and Al₂O₃Mixing and pre-sintering to obtain;

preferably, the pre-sintering temperature is 1200-1400 ℃, and the pre-sintering time is 2-4 h.

The invention provides a preparation method of the cordierite-doped complex phase microwave dielectric ceramic material, which comprises the step of mixing and sintering the main material, the cordierite and an optional sintering auxiliary agent to obtain the cordierite-doped complex phase microwave dielectric ceramic material.

Furthermore, the sintering temperature is 1400-1500 ℃, and the sintering time is 1-6 h.

Further, the mixing means includes ball milling;

preferably, the rotation speed of the ball mill is 300r/min-400 r/min.

Preferably, the time of ball milling is 4h to 6 h.

Further, after the mixing, granulating, dry-pressing and forming to prepare a green body, and then sintering;

preferably, the pressure of the dry pressing is 70MPa-100 MPa.

The third aspect of the invention provides the application of the cordierite-doped complex-phase microwave dielectric ceramic material in a resonator, a filter, a microwave dielectric antenna, a frequency oscillator or a dielectric waveguide transmission line.

The cordierite-doped complex phase microwave dielectric ceramic material provided by the invention has good comprehensive performance, the dielectric constant Epsilon can reach 45, the quality factor Qf is more than or equal to 45000, and the resonant frequency temperature coefficient tau at minus 40-85 DEG C_f6.5 ppm/DEG C, bending strength of more than or equal to 278MPa, thermal shock temperature of 150 ℃, and higher reliability, can meet the requirement that microwave elements such as dielectric resonators and filters are continuously developed towards the direction of high frequency, miniaturization, integration, modularization and multi-functionalization, can also adapt to severe working environments such as large day and night temperature difference, and has good application prospect.

The preparation method of the cordierite-doped complex-phase microwave dielectric ceramic material provided by the invention is easy to operate, controllable in process, high in production efficiency and suitable for large-scale industrial production.

The cordierite-doped complex-phase microwave dielectric ceramic material provided by the invention is applied to resonators, filters, microwave dielectric antennas, frequency oscillators or dielectric waveguide transmission lines, and the application is that 5G microwave dielectric ceramic material meets the requirements of microwave elements on high frequency, miniaturization, integration, modularization and multifunction, can also adapt to severe working environments with large day-night temperature difference and the like, and has good application prospect.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. The components of embodiments of the present invention may be arranged and designed in a wide variety of different configurations.

In recent years, with the rapid development of mobile communication and satellite communication technologies, as electronic components are continuously developed in the directions of high frequency, miniaturization, integration, modularization and multi-functionalization, people have increasingly high requirements on the performance of the components. In the 5G era, high-performance microwave dielectric ceramic materials cannot be separated. Compared with other materials, the microwave dielectric ceramic has excellent dielectric properties of high dielectric constant (epsilon r), lower dielectric loss (tan) and near-zero temperature coefficient (tau f) of resonant frequency, good mechanical properties and chemical stability, and the dielectric ceramic material is widely applied to components such as resonators, filters, microwave dielectric antennas, frequency oscillators, dielectric waveguide transmission lines and the like. Microwave dielectric ceramics have become one of the most active research areas of functional ceramics in recent years. However, because of the inherent brittleness of the ceramic, microcracks are easily generated during rapid heating or rapid cooling at high temperature, and as the microcracks rapidly increase and expand, catastrophic failures such as failure, peeling and the like of the microwave dielectric ceramic device can be caused. Therefore, it is an important subject to develop a microwave dielectric ceramic material with high comprehensive performance.

The invention provides a cordierite-doped complex-phase microwave dielectric ceramic material on one hand, which comprises a main material and a modified dopant; wherein the main material is CaTiO₃-SmAlO₃(ii) a The modified dopant is cordierite, and the composition of the cordierite is 2 MgO.2Al₂O₃·5SiO₂。

The cordierite-doped complex phase microwave dielectric ceramic material provided by the invention is prepared by adding CaTiO serving as a main material₃-SmAlO₃Adding cordierite into CaTiO main material₃-SmAlO₃Forming long columnar crystal grains inside the ceramic, which are criss-cross and distributed irregularly, connecting any one of the long columnar crystal grains with a plurality of surrounding strip-shaped tissues in different directions, mutually restricting and reinforcing the long columnar crystal grains, better resisting crack propagation caused by thermal shock, improving energy required by crack propagation, and greatly improving the main material CaTiO₃-SmAlO₃Bending strength and thermal shock resistance. The cordierite-doped complex phase microwave dielectric ceramic material provided by the invention has good comprehensive performance, the dielectric constant Epsilon can reach 45, the quality factor Qf is more than or equal to 45000, and the resonant frequency temperature coefficient tau at minus 40-85 DEG C_f6.5 ppm/DEG C, bending strength of more than or equal to 278MPa, thermal shock temperature of 150 ℃, and higher reliability, can meet the requirement that microwave elements such as dielectric resonators and filters are continuously developed towards the direction of high frequency, miniaturization, integration, modularization and multi-functionalization, can also adapt to severe working environments such as large day and night temperature difference, and has good application prospect.

Cordierite is a silicate mineral, and has good fire resistance and low thermal expansion rate. The chemical composition of cordierite is 2 MgO.2Al₂O₃·5SiO₂. Cordierite is expressed as long columnar grains in a cordierite-doped complex-phase microwave dielectric ceramic material main body, the axial length of the long columnar grains is about 10-15 mu m, the radial length of the long columnar grains is about 5-10 mu m, the long columnar grains are criss-cross and are arranged in the ceramic in a disordered way, any one long columnar grain is connected with surrounding strip-shaped tissues in different directions and mutually restricted and strengthened, and the high-length-diameter ratio particles can greatly enhance the thermal shock resistance of the material. In addition, CaTiO₃-SmAlO₃The main crystal phase is filled with cordierite with low melting point, thus effectively improving the thermal conductivity of the material, reducing local thermal stress and greatly improving the bending strength and thermal shock resistance of the composite ceramic main body.

Further, the addition amount of the cordierite is 0.5% -2%.

In some embodiments of the invention, cordierite is typically, but not by way of limitation, added in an amount of 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, or 2%.

Furthermore, the preparation method of the cordierite is to mix MgO and Al₂O₃And SiO₂Mixing and sintering to obtain;

preferably, the sintering temperature is 1400-1500 ℃, and the sintering time is 3-6 h.

In some embodiments of the invention, the sintering temperature is typically, but not limited to, 1400 ℃, 1450 ℃, or 1500 ℃, and the time of the sintering process is typically, but not limited to, 3 hours, 4 hours, 5 hours, or 6 hours.

Further, the material also comprises a sintering aid.

The sintering aid is also called as sintering aid, and is an oxide or non-oxide which is added in the sintering process of the microwave dielectric ceramic material and is used for promoting sintering densification.

Preferably, the sintering aid comprises Y₂O₃。

Y₂O₃It is white yellowish crystalline powder, insoluble in water and alkali, soluble in acid and alcohol. When exposed to air, it is liable to absorb carbon dioxide and water to deteriorate. When preparing the cordierite-doped complex-phase microwave dielectric ceramic material, Y₂O₃Can promote the generated complex phase microwave dielectric ceramic material to be compact.

Preferably, said Y is₂O₃The addition amount of (B) is 0.01-1%.

In some embodiments of the invention, Y₂O₃Are typically, but not limited to, 0.01%, 0.1%, 0.3%, 0.5%, 0.7%, 0.9%, and 1%.

Further, the CaTiO₃-SmAlO₃From TiO₂、Sm₂O₃CaO and Al₂O₃Composition of, wherein TiO₂30 to 40 percent of Sm accounting for the mass fraction of the main material₂O₃25-36 percent of CaO, 20-29 percent of Al and the balance of the balance₂O₃5 to 15 percent of the main material.

Complex phase microwave medium ceramic material, main material CaTiO₃-SmAlO₃The mass ratio of each component greatly influences the dielectric property and the comprehensive property of the obtained complex-phase microwave dielectric ceramic material. The invention is realized by using 30-40 wt% of titanium dioxide (TiO)₂) 25 to 36 weight percent of samarium oxide (Sm)₂O₃) 20 to 29 weight percent of calcium oxide (CaO) and 5 to 15 weight percent of aluminum oxide (Al)₂O₃) Composition of main material CaTiO₃-SmAlO₃While generating aluminum titanate (Al)₂O₃·TiO₂) The crystal structure of the aluminum titanate is that three octahedrons form a unit together with a vertex to form an infinitely long O-Ti chain along a C axis, and the chain is connected with the chain by Al ions. As the temperature increases, the chain twists. This structure determines the anisotropy of its thermal expansion. It is also determined to have a low coefficient of thermal expansion. Meanwhile, the aluminum titanate serving as the reinforcing particles is embedded on the matrix, so that the expansion of cracks can be prevented, the thermal stress is effectively relieved, and the thermal shock resistance of the material is improved.

In some embodiments of the invention, the TiO is₂A mass fraction of the main material typically but not exclusively 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39% or 40%; sm₂O₃A mass fraction of the primary material typically, but not limited to, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, or 36%; CaO typically, but not limited to, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, or 29% by mass of the primary material; al (Al)₂O₃Typically, but not limited to, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or 15% by mass of the primary material.

Preferably, the CaTiO₃-SmAlO₃From TiO₂、Sm₂O₃CaO and Al₂O₃Mixing and pre-sintering to obtain;

preferably, the pre-sintering temperature is 1200-1400 ℃, and the pre-sintering time is 2-4 h.

In some embodiments of the invention, the temperature of the pre-sintering is typically, but not limited to, 1200 ℃, 1300 ℃, or 1400 ℃, and the time of the pre-sintering is typically, but not limited to, 2 hours, 3 hours, or 4 hours.

The invention provides a preparation method of the cordierite-doped complex phase microwave dielectric ceramic material, which comprises the step of mixing and sintering the main material, the cordierite and an optional sintering auxiliary agent to obtain the cordierite-doped complex phase microwave dielectric ceramic material.

The preparation method of the cordierite-doped complex-phase microwave dielectric ceramic material provided by the invention is easy to operate, controllable in process, high in production efficiency and suitable for large-scale industrial production.

Furthermore, the sintering temperature is 1400-1500 ℃, and the sintering time is 1-6 h.

The sintering treatment can lead the green body to generate a series of physical and chemical reactions at high temperature, and further to be converted into the complex phase microwave dielectric ceramic material. The proper sintering temperature and time are beneficial to the migration of substances and the growth of crystal grains, so that the prepared complex phase microwave dielectric ceramic material is more compact and has better performance. The problem of overburning is easy to occur due to overhigh sintering temperature or overlong time, and pores in the material cannot be removed in time, so that the dielectric loss is increased; the sintering temperature is too low or the sintering time is too short, the obtained complex phase microwave dielectric ceramic material has poor compactness and influenced dielectric property.

In some embodiments of the invention, the sintering temperature is typically, but not limited to, 1400 ℃, 1450 ℃, or 1500 ℃, and the time of the sintering process is typically, but not limited to, 1h, 2h, 3h, 4h, 5h, or 6 h.

Further, the mixing means includes ball milling.

Ball milling is the process of crushing and mixing materials by the impact of falling milling bodies (such as steel balls, cobblestones, etc.) and the milling action of the milling bodies and the inner wall of the ball mill. When the ball mill rotates, the grinding bodies and the inner wall of the ball mill are in friction action. The grinding body is brought up along the rotating direction and then falls down. The material is thus continuously comminuted.

Preferably, the rotation speed of the ball mill is 300r/min-400 r/min.

In some embodiments of the invention, the rotational speed of the ball mill is typically, but not limited to, 300r/min, 320r/min, 340r/min, 360r/min, or 400 r/min.

Preferably, the time of ball milling is 4h to 6 h.

In some embodiments of the invention, the time of ball milling is typically, but not limited to, 4 hours, 5 hours, or 6 hours.

Further, after the mixing, granulating, dry-pressing and forming to prepare a green body, and then sintering;

preferably, the pressure of the dry pressing is 70MPa-100 MPa.

In some preferred embodiments of the present invention, in order to facilitate granulation and subsequent processing, a proper amount of additives such as a binder, a defoaming agent, and a plasticizer may be added to the mixture to form a powder with better fluidity; the green body can be obtained by compressing powder through a powder tablet machine.

Dry pressing is a kind of blank forming method, powder is added with a small amount of adhesive to granulate, then put into a mould, and pressed on a press machine to make the powder and powder approach each other in the mould and firmly combined by internal friction force to form a blank with a certain shape. The pressure of the dry-pressing is typically, but not limited to, 70MPa, 80MPa, 90MPa or 100 MPa.

The third aspect of the invention provides the application of the cordierite-doped complex-phase microwave dielectric ceramic material in a resonator, a filter, a microwave dielectric antenna, a frequency oscillator or a dielectric waveguide transmission line.

The cordierite-doped complex-phase microwave dielectric ceramic material provided by the invention is applied to resonators, filters, microwave dielectric antennas, frequency oscillators or dielectric waveguide transmission lines, meets the requirements of microwave elements on high frequency, miniaturization, integration, modularization and multifunction for 5G microwave dielectric ceramic materials, can adapt to severe working environments such as large day and night temperature difference and has good application prospect.

It should be noted that the dielectric constant refers to the ratio of the original external electric field (in vacuum) to the electric field in the final material, i.e., the dielectric constant, also called the dielectric rate, and is related to the frequency. The relative dielectric constant of an ideal conductor is infinite.

The quality factor is a dimensionless parameter in physics and engineering, is a physical quantity representing the damping property of the oscillator, and can also represent the size of the resonance frequency of the oscillator relative to the bandwidth, the high quality factor represents that the rate of the energy loss of the oscillator is slow, the oscillation can be continued for a long time, and the general damping of the oscillator with the high quality factor is also small.

The temperature coefficient of the resonant frequency is a parameter for describing the thermal stability of the resonator, and refers to the shift degree of the resonant frequency of the microwave dielectric ceramic material when the temperature changes. Microwave dielectric materials with large absolute values of temperature coefficients of resonant frequencies are not suitable for microwave resonators, because such materials cannot guarantee a stable resonant frequency, which causes carrier signals to drift along with temperature fluctuation, thereby affecting the use performance of equipment, and therefore, in microwave resonators, the temperature coefficient of resonant frequencies of ceramic materials is required to be as 0 as possible.

Flexural strength refers to the ability of a material to resist bending without breaking, and is proportional to the maximum pressure to which it is subjected.

The thermal shock temperature refers to the maximum temperature difference that the material can bear when bearing rapid temperature change, and the thermal shock temperature is an important index for evaluating the breakage resistance of the material.

Some embodiments of the present invention will be described in detail below with reference to examples. The embodiments described below and the features of the embodiments can be combined with each other without conflict.

Example 1

This example provides a cordierite-doped composite microwave dielectric ceramic material, which is prepared from 99.45 wt% of main material CaTiO₃-SmAlO₃0.5 wt% of cordierite and 0.05 wt% of sintering aid Y₂O₃And (4) preparing.

(1) Main material CaTiO₃-SmAlO₃The preparation steps are as follows: weighing 34 wt% of TiO₂31 wt% of Sm₂O₃25 wt% CaO and 10 wt% Al₂O₃And (3) burdening to obtain a mixture, wherein the mixture, yttrium-stabilized zirconium balls and deionized water are mixed according to a mass ratio of 1: 5: 3 ball milling in a ball milling tank for 5 hr. And drying the slurry obtained by ball milling at 100 ℃ for 20 hours, and then sieving the dried slurry with a 100-mesh sieve to obtain main material powder. Presintering the main material powder in a high-temperature box type furnace for 3h at the presintering temperature of 1200 ℃ to obtain a main material CaTiO₃-SmAlO₃。

(2) The cordierite preparation steps are as follows: weighing 14 wt% ofMgO, 35 wt% Al₂O₃And 51 wt% SiO₂And (3) burdening to obtain a mixture, wherein the mixture, yttrium-stabilized zirconium balls and deionized water are mixed according to a mass ratio of 1: 5: 3 ball milling in a ball milling tank for 5 hr. And drying the slurry obtained by ball milling at 100 ℃ for 20 hours, and then sieving the slurry by a 100-mesh sieve to obtain cordierite raw material powder. Placing cordierite raw material powder in a high-temperature box type furnace, and keeping the temperature for 5 hours at 1400 ℃ to obtain cordierite.

(3) The preparation method of the cordierite-doped complex-phase microwave dielectric ceramic material comprises the following steps: the main material CaTiO₃-SmAlO₃Cordierite and sintering aid Y₂O₃Mixing, ball milling for 6 hours by a wet milling method, drying, sieving, adding a binder, a defoaming agent and a plasticizer, granulating, and pressing into a green body (the diameter is 12.9mm, and the height is 6.3mm) by a powder tablet press. Sintering the prepared green body at 1500 ℃, and preserving heat for 4 hours to prepare the cordierite-doped complex-phase microwave dielectric ceramic material.

Example 2

The embodiment provides a cordierite-doped complex phase microwave dielectric ceramic material, which is different from the embodiment 1 in that a main material CaTiO₃-SmAlO₃99.15 wt%, cordierite 0.8 wt% and sintering aid Y₂O₃The content was 0.05 wt%, and the remaining raw materials and steps were the same as in example 1 and will not be described again.

Example 3

The embodiment provides a cordierite-doped complex phase microwave dielectric ceramic material, which is different from the embodiment 1 in that a main material CaTiO₃-SmAlO₃98.95 wt% of cordierite, 1 wt% of sintering aid Y₂O₃The content was 0.05 wt%, and the remaining raw materials and steps were the same as in example 1 and will not be described again.

Example 4

The embodiment provides a cordierite-doped complex phase microwave dielectric ceramic material, which is different from the embodiment 1 in that a main material CaTiO₃-SmAlO₃98.55 wt%, 1.4 wt% of cordierite and Y as sintering aid₂O₃The content was 0.05 wt%, and the remaining raw materials and steps were the same as in example 1 and will not be described again.

Example 5

The embodiment provides a cordierite-doped complex phase microwave dielectric ceramic material, which is different from the embodiment 1 in that a main material CaTiO₃-SmAlO₃98.25 wt%, cordierite 1.7 wt% and sintering aid Y₂O₃The content was 0.05 wt%, and the remaining raw materials and steps were the same as in example 1 and will not be described again.

Example 6

The embodiment provides a cordierite-doped complex phase microwave dielectric ceramic material, which is different from the embodiment 1 in that a main material CaTiO₃-SmAlO₃97.95 wt%, 2 wt% cordierite and Y as sintering aid₂O₃The content was 0.05 wt%, and the remaining raw materials and steps were the same as in example 1 and will not be described again.

Example 7

The embodiment provides a cordierite-doped complex phase microwave dielectric ceramic material, which is different from the embodiment 1 in that a main material CaTiO₃-SmAlO₃99.85 wt%, cordierite 0.1 wt% and sintering aid Y₂O₃The content was 0.05 wt%, and the remaining raw materials and steps were the same as in example 1 and will not be described again.

Example 8

The embodiment provides a cordierite-doped complex phase microwave dielectric ceramic material, which is different from the embodiment 1 in that a main material CaTiO₃-SmAlO₃96.95 wt% of cordierite, 3 wt% of sintering aid Y₂O₃The content was 0.05 wt%, and the remaining raw materials and steps were the same as in example 1 and will not be described again.

Comparative example 1

This comparative example provides a host material, CaTiO₃-SmAlO₃Unlike example 1, cordierite and the bonding assistant Y were not contained in the raw materials₂O₃And CaTiO₃-SmAlO₃Medium TiO 2₂30 wt% of Sm₂O₃Is 36wt%, CaO 29 wt%, Al₂O₃5 wt%, the remaining raw materials and steps were the same as in example 1 and are not described again.

Comparative example 2

This comparative example provides a host material, CaTiO₃-SmAlO₃Unlike comparative example 1, TiO₂32 wt% of Sm₂O₃34 wt% of CaO, 27 wt% of Al₂O₃The content was 7 wt%, and the remaining raw materials and steps were the same as in comparative example 1 and will not be described again.

Comparative example 3

This comparative example provides a host material, CaTiO₃-SmAlO₃Unlike comparative example 1, TiO₂34 wt% of Sm₂O₃31 wt%, CaO 25 wt%, Al₂O₃10 wt%, the remaining raw materials and steps were the same as in comparative example 1 and will not be described again.

Comparative example 4

This comparative example provides a host material, CaTiO₃-SmAlO₃Unlike comparative example 1, TiO₂36 wt% of Sm₂O₃29 wt%, CaO 23 wt%, Al₂O₃The content was 12 wt%, and the remaining raw materials and steps were the same as in comparative example 1 and will not be described again.

Comparative example 5

This comparative example provides a host material, CaTiO₃-SmAlO₃Unlike comparative example 1, TiO₂38 wt% of Sm₂O₃27 wt%, CaO 21 wt%, Al₂O₃The content was 14 wt%, and the remaining raw materials and steps were the same as in comparative example 1 and will not be described again.

Comparative example 6

This comparative example provides a host material, CaTiO₃-SmAlO₃Unlike comparative example 1, TiO₂40 wt% of Sm₂O₃25 wt%, CaO 20 wt%, Al₂O₃15 wt%, the remaining raw materials and steps were the same as in comparative example 1 and will not be described again.

Comparative example 7

This comparative example provides a host material, CaTiO₃-SmAlO₃Unlike comparative example 1, TiO₂20 wt% of Sm₂O₃36 wt%, CaO 29 wt%, Al₂O₃15 wt%, the remaining raw materials and steps were the same as in comparative example 1 and will not be described again.

Comparative example 8

This comparative example provides a host material, CaTiO₃-SmAlO₃Unlike comparative example 1, TiO₂50 wt% of Sm₂O₃25 wt%, CaO 20 wt%, Al₂O₃5 wt%, the remaining raw materials and steps were the same as in comparative example 1 and will not be described again.

Comparative example 9

This comparative example provides a CaTiO₃-SmAlO₃Based on the multiphase microwave dielectric ceramic material, the material is different from the embodiment 1 in that the material does not contain cordierite, and the main material CaTiO₃-SmAlO₃99.99 wt% of a sintering aid Y₂O₃The content was 0.01 wt%, and the remaining raw materials and steps were the same as in example 1 and will not be described again.

Comparative example 10

This comparative example provides a CaTiO₃-SmAlO₃Based on the multiphase microwave dielectric ceramic material, the difference with the comparative example 9 is that the main material CaTiO₃-SmAlO₃99.97 wt% of a sintering aid Y₂O₃The content was 0.03 wt%, and the remaining raw materials and steps were the same as in comparative example 9, and will not be described again.

Comparative example 11

This comparative example provides a CaTiO₃-SmAlO₃Based on the multiphase microwave dielectric ceramic material, the difference with the comparative example 9 is that the main material CaTiO₃-SmAlO₃99.95 wt% of sintering aid Y₂O₃0.05 wt%, and the remaining raw materials and steps were the same as in comparative example 9 and will not be described again.

Comparative example 12

This comparative example provides a CaTiO₃-SmAlO₃Based on a complex phase microwave dielectric ceramic material,unlike comparative example 9, the host material CaTiO₃-SmAlO₃99.93 wt% of sintering aid Y₂O₃0.07 wt%, and the remaining raw materials and steps are the same as in comparative example 9, and are not described in detail.

Comparative example 13

This comparative example provides a CaTiO₃-SmAlO₃Based on the multiphase microwave dielectric ceramic material, the difference with the comparative example 9 is that the main material CaTiO₃-SmAlO₃99.9 wt% of a sintering aid Y₂O₃0.1 wt%, and the remaining raw materials and steps are the same as in comparative example 9 and will not be described again.

Comparative example 14

This comparative example provides a CaTiO₃-SmAlO₃Based on the multiphase microwave dielectric ceramic material, the difference with the comparative example 9 is that the main material CaTiO₃-SmAlO₃99 wt% of a sintering aid Y₂O₃The amount of 1 wt% was determined, and the remaining raw materials and steps were the same as in comparative example 9 and thus will not be described in detail.

Comparative example 15

This comparative example provides a CaTiO₃-SmAlO₃Based on the multiphase microwave dielectric ceramic material, the difference with the comparative example 9 is that the main material CaTiO₃-SmAlO₃98 wt% of a sintering aid Y₂O₃The content was 2 wt%, and the remaining raw materials and steps were the same as in comparative example 9 and will not be described again.

Test example 1

The dielectric property, thermal shock temperature and bending strength of the materials prepared in examples 1-8 and comparative examples 1-15 were tested by the following specific test methods:

dielectric property test

The dielectric constant and the Qf value are tested by adopting an open cavity method and using a dielectric constant testing tool of GB/T7265.2-1987 and a vector network analyzer (E5071C 300 KHZ-14 GHZ), and the resonant frequency temperature coefficient is tested by adopting a high-low temperature box and the vector network analyzer (E5071C 300 KHZ-14 GHZ).

Temperature of thermal shock

The microwave dielectric ceramic material is sintered into a sample of 3mm multiplied by 4mm multiplied by 36mm through dry pressing, the sample is placed in an incubator at a specific temperature (80, 85, 90, 95, 100, 105, 110 and the like, experiments are carried out at intervals of 5 ℃), the sample is kept for 15min, then the sample is quenched in water at room temperature for 15min, and then dyeing is carried out for 30min, and the sample is observed under a microscope until the material has cracks. The microwave dielectric ceramic material is characterized by the maximum temperature difference (highest tolerance temperature-water temperature) without damage.

Bending strength

The microwave dielectric ceramic material is made into a long rod shape with a rectangular cross section, the dimension is 3mm multiplied by 4mm multiplied by 36mm, four edge chamfers in the length direction are 0.1-0.3mm multiplied by 45 degrees, 5 samples are measured for each sample, and an average value is taken. The flexural strength of the material was measured by a three-point bending method on an Instron-1186 electronic universal tester.

TABLE 1 microwave dielectric ceramic material Property data sheet

As can be seen from the data in Table 1, the microwave dielectric ceramic materials provided in comparative examples 1 to 8 have TiO-associated structure₂And Al₂O₃The content is increased, the dielectric constant of the obtained complex phase microwave dielectric ceramic material is gradually reduced, and the thermal shock resistance and the bending strength have the tendency of increasing first and then decreasing when the TiO is added₂(wt％)＝34％，Sm₂O₃(wt％)＝31％，CaO(wt％)＝25％，Al₂O₃When the weight percent is 10 percent, the bending strength and the thermal shock resistance of the microwave dielectric ceramic material reach better states, because the TiO is accompanied with the ceramic material₂And Al₂O₃The aluminum titanate is generated in the composite ceramic due to the increase of the content, the aluminum titanate is embedded on the matrix as reinforcing particles in the form of white particles, the crack can be prevented from expanding, and on the other hand, the aluminum titanate has a smaller thermal expansion coefficient, and the thermal shock resistance of the ceramic is favorably improved. But as it is generatedThe increase in the aluminum titanate content tends to lower the relative density of the ceramic, which reduces the overall performance of the composite ceramic.

As can be seen from Table 1, the present invention adds Y₂O₃The ceramic material is used as a sintering aid to reduce the sintering temperature, has no great influence on the thermal shock and bending strength of the microwave dielectric ceramic material, and is not suitable to be added too high, otherwise, the electrical property is deteriorated. The incorporation of cordierite greatly improves the thermal shock resistance and bending strength of the ceramic material, but slightly reduces the Qf value of the material, and example 2 provides CaTiO doped with 0.8 wt% cordierite₃-SmAlO₃The composite microwave dielectric ceramic material has the best comprehensive performance, the thermal shock temperature can reach 150 ℃, the bending strength can reach 278MPa, and the composite microwave dielectric ceramic material has excellent comprehensive performance, can meet the requirement of the miniaturization development of microwave components such as dielectric resonators, filters and the like, and enables the reliability of the obtained components to be stronger.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.