A high-power piezoelectric ceramic, a preparation method and application thereof

Abstract

This application discloses a high-power piezoelectric ceramic, its preparation method, and its applications, relating to the field of piezoelectric ceramic technology. The high-power piezoelectric ceramic provided in this application achieves advantages such as synergistic control of soft and hard properties, dense and uniform microstructure, and low loss and high stability under strong fields. Simultaneously, it avoids the problems of traditional technologies, such as the mutual constraint between piezoelectric activity and mechanical quality factor, insufficient powder activity leading to poor sintering densification, and thermal instability and rapid performance degradation under strong fields. It can adapt to the application requirements of various fields for high electromechanical conversion efficiency, low energy dissipation, high service reliability, and long-term stable operation under extreme conditions.

Description

Technical Field

[0001] This application relates to the field of piezoelectric ceramics technology, and in particular to a high-power piezoelectric ceramic, its preparation method, and its application. Background Technology

[0002] Piezoelectric ceramics, as core functional materials for electromechanical energy conversion, play an irreplaceable role in advanced manufacturing, electronic information, deep-sea exploration, and national defense equipment. They are widely used in key components such as transducers, actuators, and sensors, and their performance directly determines the energy conversion efficiency and operational reliability of the system. Key parameters for evaluating the performance of piezoelectric ceramics include piezoelectric constant, dielectric loss, and mechanical quality factor. A high piezoelectric constant corresponds to stronger piezoelectric performance and electromechanical coupling capability, contributing to improved electromechanical conversion efficiency; a high mechanical quality factor and low dielectric loss help reduce energy dissipation and improve stability. Based on these performance characteristics, piezoelectric ceramics are generally divided into two categories: soft and hard. The former has high piezoelectric activity and a high piezoelectric constant, while the latter exhibits a high mechanical quality factor and low dielectric loss. Meanwhile, density, as a fundamental structural parameter of the material, plays a crucial supporting role in performance. High density can effectively reduce internal porosity and microstructural defects, enhance intergranular bonding, and thus ensure the full realization of piezoelectric performance and the mechanical stability of the material.

[0003] In high-power applications, piezoelectric materials require significant mechanical vibrations driven by a strong electric field to achieve efficient electromechanical energy conversion. However, continuous large-amplitude vibrations lead to substantial internal friction and dielectric loss within the material, accompanied by significant heat accumulation, which in turn causes thermal instability, stress damage, and fatigue failure. Furthermore, traditional fabrication processes suffer from uneven powder particle size distribution, insufficient sintering densification, and numerous oxygen vacancy defects, further limiting the material's performance stability and reliability under high-power conditions. Therefore, developing a piezoelectric material that combines a high piezoelectric constant (ensuring efficient output) with a high mechanical quality factor (reducing spontaneous heat generation), high density, and excellent thermal stability has become an urgent need for high-power devices.

[0004] Although existing technologies have improved the performance of piezoelectric ceramics to some extent through composition design and process optimization, several key issues remain in high-power applications: First, due to the influence of ferroelectric domain structure and its motion mechanism, performance parameters such as piezoelectric constant, mechanical quality factor, and Curie temperature exhibit significant mutual constraints. High softness is often accompanied by a low mechanical quality factor and Curie temperature, while improving hardness inhibits piezoelectric response, making it difficult to achieve synergistic optimization of multiple properties. Second, existing preparation processes mostly rely on conventional ball milling and air atmosphere sintering, resulting in a wide particle size distribution and insufficient activity, which is not conducive to obtaining a uniform and dense microstructure. Third, traditional sintering processes easily leave pores and form uneven microstructures, leading to insufficient material density, thereby reducing the mechanical quality factor and increasing dielectric loss, severely restricting its stability under high-power conditions. In addition, under strong electric fields, material properties are prone to degradation, making it difficult to meet the requirements for long-term stable operation under complex conditions.

[0005] To address the technical shortcomings, there is an urgent need to improve existing technologies. Summary of the Invention

[0006] In view of this, this application provides a high-power piezoelectric ceramic, its preparation method, and its application. This piezoelectric ceramic has the advantages of synergistic control of soft and hard properties, dense and uniform microstructure, and low loss and high stability under strong field. At the same time, it avoids the problems of mutual restriction between piezoelectric activity and mechanical quality factor, poor sintering densification due to insufficient powder activity, thermal instability and rapid performance degradation under strong field driving in traditional technologies. It can meet the application requirements of high electromechanical conversion efficiency, low energy dissipation, high service reliability, and long-term stable operation under extreme conditions of high-power piezoelectric ceramics in different fields.

[0007] In the first aspect, this application provides a high-power piezoelectric ceramic, the composition of which is expressed as (0.1-x)Pb(Yb) in atomic percentage as follows: 1 / 2 Nb 1 / 2 )O3-0.9Pb(Zr 0.47 Ti 0.53 O3-xPb(Mn) 1 / 3 Sb 2 / 3 O3, where x is the molar coefficient, with a value ranging from 0.04 to 0.08.

[0008] Secondly, this application provides a method for preparing the high-power piezoelectric ceramic described in the foregoing scheme, comprising the following steps: S1. Weigh YbNbO4 precursor powder, Pb3O4, ZrO2, TiO2, MnO2 and Sb2O3 according to the stoichiometric ratio, mix them, and then perform sand milling, drying and sieving in sequence to obtain mixed powder. S2. After the mixed powder is compacted, it is pre-calcined and then ground to obtain pre-calcined powder; S3. The pre-calcined powder is milled, dried and sieved to obtain high-power piezoelectric ceramic powder; S4. The high-power piezoelectric ceramic powder is pressed and shaped, and then subjected to cold isostatic pressing to obtain a ceramic blank. S5. The ceramic blank is embedded in homogeneous powder, placed in a sealed saggar, and sintered in a pressureless sealed environment with flowing oxygen atmosphere to obtain a ceramic green body. S6. The ceramic blank is polished, silver-plated and polarized in sequence to obtain a high-power piezoelectric ceramic.

[0009] Optionally, in step S1, the sand milling uses zirconium balls as grinding balls, anhydrous ethanol as the sand milling medium, and the sand milling time is 18~24h.

[0010] Optionally, in step S1, the drying temperature is 80~100℃ and the drying time is 12~24h.

[0011] Optionally, in step S1, the sieve mesh size is 80 to 200 mesh.

[0012] Optionally, in step S2, the heating rate of the pre-firing treatment is 2~10℃ / min, the pre-firing temperature is 750~850℃, and the holding time is 2~5h.

[0013] Optionally, in step S3, the sand milling is carried out at a speed of 150~300 r / min for 12~24 hours, and after drying, it is passed through an 80~200 mesh sieve.

[0014] Optionally, in step S4, the pressure of the cold isostatic pressing treatment is 200~300MPa, and the holding time is 15~20min.

[0015] Optionally, in step S5, the heating rate of the pressureless sealed sintering is 2~5℃ / min, the sintering temperature is 1100~1300℃, and the holding time is 3~5h.

[0016] Optionally, in step S6, the polishing process involves grinding and polishing the ceramic blank to a thickness of 0.8~1.2mm, ultrasonically cleaning it with deionized water and ethanol, and then drying it.

[0017] Optionally, in step S6, the silver plating process involves applying silver paste and then holding it at 500℃~850℃ for 5~60 minutes.

[0018] Optionally, in step S6, the polarization treatment involves polarizing along the thickness direction in silicone oil, with a polarization temperature of 90~150℃, a polarization voltage of 10~50kV / cm, and a polarization holding time of 10~60min. Optionally, the preparation method of the YbNbO4 precursor powder includes the following steps: Yb₂O₃ and Nb₂O₅ were weighed according to the stoichiometric ratio, mixed, and then ball-milled, dried, and calcined in sequence to obtain the YbNbO₄ precursor powder.

[0019] Optionally, the ball milling process is performed at a rotation speed of 150~300 r / min and for a milling time of 18~24 h.

[0020] Optionally, the drying temperature is 80~100℃, the drying time is 12~24h, and the sieve mesh size is 80 mesh.

[0021] Optionally, the calcination temperature is 1000~1100℃, and the calcination holding time is 5~10h.

[0022] Thirdly, this application provides the application of the high-power piezoelectric ceramics described in the foregoing scheme in transducers, drivers or sensors.

[0023] The high-density, high-power piezoelectric ceramic provided in this application achieves synergistic control of soft and hard properties, construction of a high-density microstructure, and low-loss, high-stability performance adaptation under strong fields. It effectively addresses extreme conditions encountered in high-power device applications, such as strong-field-driven thermal instability and long-term performance degradation. It solves the core technical pain points of traditional high-power piezoelectric ceramics, namely the mutual constraint between piezoelectric activity and mechanical quality factor, insufficient densification, and poor stability under strong fields. Compared to existing technologies, this piezoelectric ceramic has the outstanding characteristic of strong adaptability to high-power conditions, and its preparation process is simple and controllable, with strong adaptability to large-scale production. It can meet the long-term application needs of different fields and has potential for industrial application. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a SEM image of the high-power piezoelectric ceramic in Example 2; Figure 2 This is a density comparison diagram of the high-power piezoelectric ceramics prepared in Example 2 and Comparative Example 1; Figure 3 These are hysteresis loop diagrams of the high-power piezoelectric ceramics prepared in Example 2 and Comparative Example 1; Figure 4 These are graphs showing the variation of dielectric constant with temperature for the high-power piezoelectric ceramics prepared in Examples 1-3. Figure 5 The impedance diagram and phase angle of the high-power piezoelectric ceramic prepared in Example 2 are shown. Figure 6 This is a vibration velocity diagram of the high-power piezoelectric ceramic prepared in Example 2. Detailed Implementation

[0026] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In addition, it should be understood that the specific implementation methods described herein are only for illustration and explanation of this application and are not intended to limit this application.

[0027] In the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc. are used merely as illustrative purposes and do not impose numerical requirements or establish an order.

[0028] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0029] In this application, "at least one" means one or more, and "more than one" means two or more. "One or more", "at least one of the following", or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0030] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0031] The present application will be specifically described below through specific embodiments. The following embodiments are only some embodiments of the present application and are not intended to limit the present application.

[0032] In the first aspect, this application provides a high-power piezoelectric ceramic, the composition of which is expressed as (0.1-x)Pb(Yb) in atomic percentage as follows: 1 / 2 Nb 1 / 2 )O3-0.9Pb(Zr 0.47 Ti 0.53 O3-xPb(Mn) 1 / 3 Sb 2 / 3 O3, where x is the molar coefficient, and the value of x ranges from 0.04 to 0.08.

[0033] It should be noted that the piezoelectric ceramic of this application constructs a synergistic modification system of PYN-PZT matrix and PMS solid solution doping, realizing the synergistic unity of soft and hard properties of high voltage response activity and high mechanical quality factor. The entire material system does not require the harsh design of complex multi-element doping, and the components have strong compatibility, making it easy to prepare in industrial batches and control the performance stability of batches, which can fully meet the core application requirements of high power devices.

[0034] In this application, (0.1-x)Pb(Yb 1 / 2 Nb 1 / 2 )O3-0.9Pb(Zr 0.47 Ti 0.53 O3-xPb(Mn) 1 / 3 Sb 2 / 3 The O3 (PYN-PZT) perovskite matrix serves as the main functional phase of the piezoelectric ceramic, providing the system with excellent intrinsic piezoelectric response activity, high electromechanical coupling efficiency, and stable high-temperature service performance; Pb (Yb 1 / 2 Nb 1 / 2The PMS (polystyrene-oxygenated mineral) solid solution of O3 serves as a synergistic unit for regulating both soft and hard properties. Its Mn donor doping sites achieve domain wall pinning to improve the mechanical quality factor and reduce dielectric loss, while Sb donor doping sites optimize perovskite lattice distortion to retain piezoelectric activity. Through uniform solid solution doping, a synergistic modification system that complements piezoelectric activity enhancement and loss suppression is formed within the intrinsic structure of the material. The highly active powder system constructed from the pre-synthesis of YbNbO4 precursors combined with a refined sand milling process serves as a unit for regulating the uniformity of the microstructure. Pre-synthesis of the precursors ensures atomic-level uniformity of Yb and Nb elements. The fine sand milling process achieves a narrow particle size distribution and high sintering activity in the powder, providing a stable precursor for the uniform and dense growth of ceramic grains. The densification system constructed by the oxygen atmosphere pressureless closed sintering process serves as a defect suppression and structural strengthening unit. The oxygen partial pressure of the system is controlled by the flow of oxygen atmosphere to reduce oxygen vacancy defects. The homogeneous powder burial combined with closed saggar sintering suppresses the high-temperature volatilization of lead, promotes the uniform growth of ceramic grains, and eliminates internal pore defects. This fundamentally avoids the problems of insufficient density, uneven microstructure, increased dielectric loss, and decreased mechanical quality factor caused by traditional air atmosphere sintering.

[0035] Secondly, this application provides a method for preparing the high-power piezoelectric ceramic described in the foregoing scheme, comprising the following steps: S01. Weigh YbNbO4 precursor powder, Pb3O4, ZrO2, TiO2, MnO2 and Sb2O3 according to the stoichiometric ratio, mix them, and then perform sand milling, drying and sieving in sequence to obtain mixed powder. S02. After the mixed powder is compacted, it is pre-calcined and then ground to obtain pre-calcined powder; S03. The pre-calcined powder is milled, dried and sieved to obtain high-power piezoelectric ceramic powder; S04. The high-power piezoelectric ceramic powder is pressed and shaped, and then subjected to cold isostatic pressing to obtain a ceramic blank. S05. The ceramic blank is embedded in homogeneous powder, placed in a sealed saggar, and sintered in a pressureless sealed environment with flowing oxygen atmosphere to obtain a ceramic green body. S06. The ceramic blank is polished, silver-plated and polarized in sequence to obtain a high-power piezoelectric ceramic.

[0036] In some embodiments, in step S01, the sand milling uses zirconium balls as grinding balls, anhydrous ethanol as the sand milling medium, and the sand milling time is 18~24h.

[0037] In some embodiments, in step S01, the drying temperature is 80~100℃ and the drying time is 12~24h.

[0038] In step S01: S01. Weigh YbNbO4 precursor powder, Pb3O4, ZrO2, TiO2, MnO2 and Sb2O3 according to the stoichiometric ratio, mix them, and then perform sand milling, drying and sieving in sequence to obtain mixed powder.

[0039] This step uses pre-synthesized YbNbO4 precursor powder as raw material, instead of directly adding Yb2O3 and Nb2O5 oxides. This allows for the pre-combination reaction of Yb and Nb elements, avoiding the problems of uneven element distribution, insufficient high-temperature solidification, and residual impurities caused by direct mixing of multiple oxides. This ensures the uniform formation of the perovskite main crystal phase from the raw material end. At the same time, sand milling is used instead of traditional ball milling, which can achieve ultrafine powder and narrow particle size distribution, greatly improving the sintering activity and mixing uniformity of the powder. This avoids the inherent defects of traditional ball milling, such as wide particle size distribution, severe agglomeration, and insufficient activity.

[0040] In some embodiments, in step S01, the sieve mesh size is 80 to 200 mesh.

[0041] In step S02: S02. After the mixed powder is compacted, it is pre-calcined and then ground to obtain pre-calcined powder.

[0042] This step involves first compacting the mixed powder and then pre-firing it. This increases the contact area between powder particles, reduces the activation energy of the solid-phase reaction, ensures the full synthesis of the perovskite main crystalline phase during pre-firing, and avoids the residue of unreacted free oxides. The pre-firing process at 750~850℃ allows for the synthesis of the main crystalline phase under mild conditions, avoiding the problems of excessive grain growth and sharp decline in sintering activity caused by high-temperature pre-firing. The grinding process following pre-firing breaks up the soft agglomerates of powder formed during pre-firing, further optimizes the powder dispersibility, and provides a uniform material basis for subsequent secondary sand milling for fine processing.

[0043] In some embodiments, in step S02, the heating rate of the pre-firing treatment is 2~10℃ / min, the pre-firing temperature is 750~850℃, and the holding time is 2~5h.

[0044] In step S03: S03. The pre-fired powder is milled, dried and sieved to obtain high-power piezoelectric ceramic powder.

[0045] This step involves secondary sand milling to refine the pre-fired powder, which further breaks down the powder agglomerates formed during pre-fired processing. This allows for precise control of powder particle size and morphology, resulting in ceramic powder with uniform particle size distribution, large specific surface area, and high sintering activity. Compared to the traditional single-stage ball milling process, secondary sand milling continuously optimizes the dispersibility and reactivity of the powder, effectively solving the industry pain points of high sintering temperature and high densification difficulty caused by insufficient powder activity in traditional processes. It enables grain densification growth at lower temperatures in subsequent sintering, reducing element volatilization and lattice defects caused by high-temperature processing.

[0046] In some embodiments, in step S03, the sand milling is performed at a speed of 150~300 r / min for 12~24 h, and after drying, it is passed through an 80~200 mesh sieve.

[0047] In step S04: S04. The high-power piezoelectric ceramic powder is pressed and shaped, and then subjected to cold isostatic pressing to obtain a ceramic blank.

[0048] This step employs a composite molding process combining pressing and isostatic pressing. First, an initial green body is obtained through dry pressing pre-forming, followed by cold isostatic pressing at 200~300MPa. This process ensures uniform pressure in all directions on the green body, significantly improving its density and structural uniformity. It completely eliminates molding defects such as internal density gradients, porosity, and delamination caused by dry pressing. The high-density, defect-free, and uniform green body ensures synchronous and uniform grain growth during subsequent sintering, avoiding problems such as abnormal grain growth, residual pores, and microcracks caused by uneven green body density. This provides a core molding foundation for achieving a high-density, uniform microstructure in the final ceramic.

[0049] In some embodiments, in step S04, the pressure of the cold isostatic pressing treatment is 200~300MPa, and the holding time is 15~20min.

[0050] In step S05: S05. The ceramic blank is embedded in homogeneous powder, placed in a sealed sagger, and sintered in a pressureless sealed environment with flowing oxygen atmosphere to obtain a ceramic green body.

[0051] In this step, the homogeneous powder embedding and closed saggar sintering create a local atmosphere with high lead partial pressure during sintering, effectively suppressing the high-temperature volatilization of lead in the ceramic body. This avoids problems such as deviations in stoichiometry, increased oxygen vacancy defects, and impurity phase formation caused by lead volatilization, ensuring the uniformity of material composition and the stability of intrinsic properties. Flowing oxygen atmosphere sintering allows for precise control of the oxygen partial pressure in the sintering system, significantly reducing oxygen vacancy defects inside the ceramic, lowering dielectric loss, and improving the mechanical quality factor. This process fundamentally solves the core pain points of traditional air atmosphere sintering, such as numerous oxygen vacancy defects, high losses, and poor strong field stability. The pressureless sintering process is simple to operate, requiring no expensive equipment such as hot pressing or hot isostatic pressing, and is highly compatible with existing piezoelectric ceramic industrial production lines. Simultaneously, it can achieve a ceramic density ≥7.97 g / cm³. 3 This yields a dense microstructure with uniform grains and minimal pores, fully ensuring the synergistic improvement of the material's mechanical and piezoelectric properties.

[0052] In some embodiments, in step S05, the heating rate of the pressureless sealed sintering is 2~5℃ / min, the sintering temperature is 1100~1300℃, and the holding time is 3~5h.

[0053] In step S06: S06. The ceramic blank is polished, silver-plated and polarized in sequence to obtain a high-power piezoelectric ceramic.

[0054] This step utilizes standardized post-processing across the entire process of polishing, silver plating, and polarization to maximize and stabilize the piezoelectric properties of the material. Precise double-sided polishing yields ceramic sheets with high parallelism and smooth surfaces, ensuring a tight bond between the subsequent electrodes and the ceramic substrate. This avoids problems such as uneven electric field distribution, insufficient polarization, and localized breakdown caused by surface unevenness. The high-temperature silver infiltration electrode process forms an electrode layer with strong adhesion to the ceramic substrate and excellent conductivity, ensuring uniform electric field loading during polarization and efficient charge transfer during subsequent device operation. The high-temperature silicone oil bath polarization process lowers the domain wall flipping barrier at 90~150℃, combined with a 10~50kV / cm high-voltage electric field, achieving full directional alignment of ferroelectric domains, maximizing the piezoelectric properties of the material, and ensuring the performance stability and consistency of batch products.

[0055] In some embodiments, in step S06, the polishing process involves grinding and polishing the ceramic blank to a thickness of 0.8~1.2mm, ultrasonically cleaning it with deionized water and ethanol, and then drying it.

[0056] In some embodiments, in step S06, the silver plating process involves applying silver paste and then holding it at 500°C to 850°C for 5 to 60 minutes.

[0057] In some embodiments, in step S06, the polarization treatment involves polarizing along the thickness direction in silicone oil, with a polarization temperature of 90~150℃, a polarization voltage of 10~50kV / cm, and a polarization holding time of 10~60min. In some embodiments, the method for preparing the YbNbO4 precursor powder includes the following steps: Yb₂O₃ and Nb₂O₅ were weighed according to the stoichiometric ratio, mixed, and then ball-milled, dried, and calcined in sequence to obtain the YbNbO₄ precursor powder.

[0058] In some embodiments, the ball milling rotation speed is 150~300 r / min, and the ball milling time is 18~24 h.

[0059] In some embodiments, the drying temperature is 80~100℃, the drying time is 12~24h, and the sieve mesh size is 80 mesh.

[0060] In some embodiments, the calcination temperature is 1000~1100℃, and the calcination holding time is 5~10h.

[0061] Thirdly, this application provides the application of the high-power piezoelectric ceramics described in the foregoing scheme in transducers, drivers or sensors.

[0062] The present application will be specifically described below through specific embodiments. The following embodiments are only some embodiments of the present application and are not intended to limit the present application.

[0063] Example 1

[0064] This embodiment provides a high-power piezoelectric ceramic, the composition of which, expressed as atomic percentage, is: 0.06Pb(Yb 1 / 2Nb 1 / 2 )O3-0.9Pb(Zr 0.47 Ti 0.53 O3-0.04Pb(Mn) 1 / 3 Sb 2 / 3 )O3.

[0065] The preparation method of this high-power piezoelectric ceramic includes the following steps: S01. Weigh out 68.1809g of Pb3O4 (99.9% purity), 2.9535g of YbNbO4, 15.4418g of ZrO2 (99.9% purity), 11.4382g of TiO2 (99.9% purity), 0.3458g of MnO2 (99% purity), and 1.7361g of Sb2O3 (99% purity) as raw materials. Place the raw material mixture into a sand mill jar, use zirconium balls as grinding balls and anhydrous ethanol as the sand milling medium, with a mass ratio of anhydrous ethanol to the raw material mixture of 1:1.2, and sand mill at 250 rpm for 48 hours. Separate the zirconium balls, place the raw material mixture in a drying oven and dry at 80℃ for 14 hours, grind it in a mortar and pestle for 30 minutes, and pass it through an 80-mesh sieve to obtain a mixed powder. S02. Place the mixed powder in an alumina crucible, compact it with an agate rod to make its compaction density 1.5 g / cm3, cover it, place it in a resistance furnace, heat it to 850℃ at a heating rate of 3℃ / min for 5 hours, cool it naturally to room temperature, remove it from the furnace, grind it with a mortar and pestle for 30 minutes to obtain pre-calcined powder. S03. The pre-fired powder is loaded into a nylon can. Zirconium balls are used as grinding balls and anhydrous ethanol is used as the grinding medium. The mass ratio of anhydrous ethanol to pre-fired powder is 1:1.2. The powder is ground in a sand mill at 250 rpm for 72 hours. The zirconium balls are separated. The pre-fired powder is placed in a drying oven and dried at 80°C for 15 hours. It is then ground in a mortar for 10 minutes and passed through a 200-mesh sieve to obtain high-power piezoelectric ceramic powder. S04. Press the high-power piezoelectric ceramic powder into a cylindrical blank using a powder press, and then perform cold isostatic pressing at 300MPa for 20 minutes to obtain a ceramic blank. S05. The ceramic blank is embedded in homogeneous powder, placed on a zirconia plate, and the zirconia plate is placed in an alumina sealed sagger. The temperature is raised to 1300°C at a heating rate of 2°C / min, and sintered in a flowing oxygen atmosphere for 5 hours. The blank is then naturally cooled to room temperature in the furnace to obtain a ceramic green body. S06. The upper and lower surfaces of the ceramic blank are polished with 2000-grit sandpaper, and then polished with metallographic sandpaper to a thickness of 1 mm. After that, they are ultrasonically cleaned with deionized water and ethanol respectively, and dried. Then, silver paste is evenly coated on the two polished surfaces of the ceramic, and placed in a resistance furnace. The furnace is kept at 650°C for 60 min and then naturally cooled to room temperature. The silver-plated piezoelectric ceramic is then placed in silicone oil and polarized along the thickness direction using a DC or AC electric field. The polarization temperature is 140°C, the polarization voltage is 40 kV / cm, and the polarization voltage holding time is 60 min to obtain a high-power piezoelectric ceramic.

[0066] The preparation method of YbNbO4 includes the following steps: 59.7804 g of Yb₂O₃ with a purity of 99.9% and 40.3197 g of Nb₂O₅ with a purity of 99.9% were weighed as raw materials. All the weighed raw materials were mixed evenly and placed in a nylon can. Zirconia balls were used as grinding balls and anhydrous ethanol was used as the ball milling medium. The mass ratio of anhydrous ethanol to the raw material mixture was 1:1.2. The mixture was ball milled at 250 rpm for 48 h. The zirconia balls were separated, and the raw material mixture was placed in a drying oven and dried at 80 ºC for 24 h. The mixture was then ground in a mortar for 30 min and passed through a 200-mesh sieve. The sieved powder was placed in an alumina crucible, covered, and calcined at 1000 ºC for 4 h to synthesize YbNbO₄ precursor powder.

[0067] Example 2

[0068] This embodiment provides a high-power piezoelectric ceramic, the composition of which, expressed as atomic percentage, is: 0.04Pb(Yb 1 / 2Nb 1 / 2 )O3-0.9Pb(Zr 0.47 Ti 0.53 O3-0.06Pb(Mn) 1 / 3 Sb 2 / 3 )O3.

[0069] The preparation method of this high-power piezoelectric ceramic includes the following steps: S01. Weigh out 68.7382g of Pb3O4 (99.9% purity), 1.9851g of YbNbO4, 15.5680g of ZrO2 (99.9% purity), 11.5317g of TiO2 (99.9% purity), 0.5230g of MnO2 (99% purity), and 1.7503g of Sb2O3 (99% purity) as raw materials. Place the raw material mixture into a sand mill jar, use zirconium balls as grinding balls and anhydrous ethanol as the sand milling medium, with a mass ratio of anhydrous ethanol to the raw material mixture of 1:1.2, and sand mill at 250 rpm for 48 hours. Separate the zirconium balls, place the raw material mixture in a drying oven and dry at 80℃ for 14 hours, grind it in a mortar and pestle for 30 minutes, and pass it through an 80-mesh sieve to obtain a mixed powder. S02. Place the mixed powder in an alumina crucible, compact it with an agate rod to make its compaction density 1.5 g / cm3, cover it, place it in a resistance furnace, heat it to 850℃ at a heating rate of 3℃ / min for 5 hours, cool it naturally to room temperature, remove it from the furnace, grind it with a mortar and pestle for 30 minutes to obtain pre-calcined powder. S03. The pre-fired powder is loaded into a nylon can. Zirconium balls are used as grinding balls and anhydrous ethanol is used as the grinding medium. The mass ratio of anhydrous ethanol to pre-fired powder is 1:1.2. The powder is ground in a sand mill at 250 rpm for 72 hours. The zirconium balls are separated. The pre-fired powder is placed in a drying oven and dried at 80°C for 15 hours. It is then ground in a mortar for 10 minutes and passed through a 200-mesh sieve to obtain high-power piezoelectric ceramic powder. S04. Press the high-power piezoelectric ceramic powder into a cylindrical blank using a powder press, and then perform cold isostatic pressing at 300MPa for 20 minutes to obtain a ceramic blank. S05. The ceramic blank is embedded in homogeneous powder, placed on a zirconia plate, and the zirconia plate is placed in an alumina sealed sagger. The temperature is raised to 1300°C at a heating rate of 2°C / min, and sintered in a flowing oxygen atmosphere for 5 hours. The blank is then naturally cooled to room temperature in the furnace to obtain a ceramic green body. S06. The upper and lower surfaces of the ceramic blank are polished with 2000-grit sandpaper, and then polished with metallographic sandpaper to a thickness of 1 mm. After that, they are ultrasonically cleaned with deionized water and ethanol respectively, and dried. Then, silver paste is evenly coated on the two polished surfaces of the ceramic, and placed in a resistance furnace. The furnace is kept at 650°C for 60 min and then naturally cooled to room temperature. The silver-plated piezoelectric ceramic is then placed in silicone oil and polarized along the thickness direction using a DC or AC electric field. The polarization temperature is 140°C, the polarization voltage is 40 kV / cm, and the polarization voltage holding time is 60 min to obtain a high-power piezoelectric ceramic.

[0070] The preparation method of YbNbO4 includes the following steps: 59.7804 g of Yb₂O₃ with a purity of 99.9% and 40.3197 g of Nb₂O₅ with a purity of 99.9% were weighed as raw materials. All the weighed raw materials were mixed evenly and placed in a nylon can. Zirconia balls were used as grinding balls and anhydrous ethanol was used as the ball milling medium. The mass ratio of anhydrous ethanol to the raw material mixture was 1:1.2. The mixture was ball milled at 250 rpm for 48 h. The zirconia balls were separated, and the raw material mixture was placed in a drying oven and dried at 80 ºC for 24 h. The mixture was then ground in a mortar for 30 min and passed through a 200-mesh sieve. The sieved powder was placed in an alumina crucible, covered, and calcined at 1000 ºC for 4 h to synthesize YbNbO₄ precursor powder.

[0071] Depend on Figure 1 It can be seen that the high-power piezoelectric ceramic provided in Example 2 has uniform grain size and dense structure.

[0072] Example 3

[0073] This embodiment provides a high-power piezoelectric ceramic, the composition of which, expressed as atomic percentage, is: 0.02Pb(Yb 1 / 2Nb 1 / 2 )O3-0.9Pb(Zr 0.47 Ti 0.53 O3-0.08Pb(Mn) 1 / 3 Sb 2 / 3 )O3.

[0074] The preparation method of this high-power piezoelectric ceramic includes the following steps: S01. Weigh 69.3047g of Pb3O4 (99.9% purity), 1.0007g of YbNbO4, 15.6963g of ZrO2 (99.9% purity), 11.6268g of TiO2 (99.9% purity), 0.7031g of MnO2 (99% purity), and 1.7665g of Sb2O3 (99% purity) as raw materials. Place the raw material mixture into a sand mill jar, use zirconium balls as grinding balls and anhydrous ethanol as the sand milling medium, with a mass ratio of anhydrous ethanol to the raw material mixture of 1:1.2, and sand mill at 250 rpm for 48 hours. Separate the zirconium balls, place the raw material mixture in a drying oven and dry at 80℃ for 14 hours, grind it in a mortar and pestle for 30 minutes, and pass it through an 80-mesh sieve to obtain a mixed powder. S02. Place the mixed powder in an alumina crucible, compact it with an agate rod to make its compaction density 1.5 g / cm3, cover it, place it in a resistance furnace, heat it to 850℃ at a heating rate of 3℃ / min for 5 hours, cool it naturally to room temperature, remove it from the furnace, grind it with a mortar and pestle for 30 minutes to obtain pre-calcined powder. S03. The pre-fired powder is loaded into a nylon can. Zirconium balls are used as grinding balls and anhydrous ethanol is used as the grinding medium. The mass ratio of anhydrous ethanol to pre-fired powder is 1:1.2. The powder is ground in a sand mill at 250 rpm for 72 hours. The zirconium balls are separated. The pre-fired powder is placed in a drying oven and dried at 80°C for 15 hours. It is then ground in a mortar for 10 minutes and passed through a 200-mesh sieve to obtain high-power piezoelectric ceramic powder. S04. Press the high-power piezoelectric ceramic powder into a cylindrical blank using a powder press, and then perform cold isostatic pressing at 300MPa for 20 minutes to obtain a ceramic blank. S05. The ceramic blank is embedded in homogeneous powder, placed on a zirconia plate, and the zirconia plate is placed in an alumina sealed sagger. The temperature is raised to 1300°C at a heating rate of 2°C / min, and sintered in a flowing oxygen atmosphere for 5 hours. The blank is then naturally cooled to room temperature in the furnace to obtain a ceramic green body. S06. The upper and lower surfaces of the ceramic blank are polished with 2000-grit sandpaper, and then polished with metallographic sandpaper to a thickness of 1 mm. After that, they are ultrasonically cleaned with deionized water and ethanol respectively, and dried. Then, silver paste is evenly coated on the two polished surfaces of the ceramic, and placed in a resistance furnace. The furnace is kept at 650°C for 60 min and then naturally cooled to room temperature. The silver-plated piezoelectric ceramic is then placed in silicone oil and polarized along the thickness direction using a DC or AC electric field. The polarization temperature is 140°C, the polarization voltage is 40 kV / cm, and the polarization voltage holding time is 60 min to obtain a high-power piezoelectric ceramic.

[0075] The preparation method of YbNbO4 includes the following steps: 59.7804 g of Yb₂O₃ with a purity of 99.9% and 40.3197 g of Nb₂O₅ with a purity of 99.9% were weighed as raw materials. All the weighed raw materials were mixed evenly and placed in a nylon can. Zirconia balls were used as grinding balls and anhydrous ethanol was used as the ball milling medium. The mass ratio of anhydrous ethanol to the raw material mixture was 1:1.2. The mixture was ball milled at 250 rpm for 48 h. The zirconia balls were separated, and the raw material mixture was placed in a drying oven and dried at 80 ºC for 24 h. The mixture was then ground in a mortar for 30 min and passed through a 200-mesh sieve. The sieved powder was placed in an alumina crucible, covered, and calcined at 1000 ºC for 4 h to synthesize YbNbO₄ precursor powder.

[0076] Comparative Example 1

[0077] This comparative example provides a high-power piezoelectric ceramic, the composition of which, expressed as atomic percentage, is: 0.04Pb(Yb) 1 / 2Nb 1 / 2 )O3-0.9Pb(Zr 0.47 Ti 0.53 O3-0.06Pb(Mn) 1 / 3 Sb 2 / 3 )O3.

[0078] The preparation method of this high-power piezoelectric ceramic includes the following steps: S01. Weigh out 68.7382g of Pb3O4 (99.9% purity), 1.9851g of YbNbO4, 15.5680g of ZrO2 (99.9% purity), 11.5317g of TiO2 (99.9% purity), 0.5230g of MnO2 (99% purity), and 1.7503g of Sb2O3 (99% purity) as raw materials. Place the raw material mixture into a sand mill jar, use zirconium balls as grinding balls and anhydrous ethanol as the sand milling medium, with a mass ratio of anhydrous ethanol to the raw material mixture of 1:1.2, and sand mill at 250 rpm for 48 hours. Separate the zirconium balls, place the raw material mixture in a drying oven and dry at 80℃ for 14 hours, grind it in a mortar and pestle for 30 minutes, and pass it through an 80-mesh sieve to obtain a mixed powder. S02. Place the mixed powder in an alumina crucible, compact it with an agate rod to make its compaction density 1.5 g / cm3, cover it, place it in a resistance furnace, heat it to 850℃ at a heating rate of 3℃ / min for 5 hours, cool it naturally to room temperature, remove it from the furnace, grind it with a mortar and pestle for 30 minutes to obtain pre-calcined powder. S03. The pre-fired powder is loaded into a nylon can. Zirconium balls are used as grinding balls and anhydrous ethanol is used as the grinding medium. The mass ratio of anhydrous ethanol to pre-fired powder is 1:1.2. The powder is ground in a sand mill at 250 rpm for 72 hours. The zirconium balls are separated. The pre-fired powder is placed in a drying oven and dried at 80°C for 15 hours. It is then ground in a mortar for 10 minutes and passed through a 200-mesh sieve to obtain high-power piezoelectric ceramic powder. S04. Press the high-power piezoelectric ceramic powder into a cylindrical blank using a powder press, and then perform cold isostatic pressing at 300MPa for 20 minutes to obtain a ceramic blank. S05. The ceramic blank is embedded in homogeneous powder, placed on a zirconia plate, and the zirconia plate is placed in an alumina sealed sagger. The temperature is raised to 1300°C at a heating rate of 2°C / min, and sintered in a flowing air atmosphere for 5 hours. The blank is then naturally cooled to room temperature in the furnace to obtain a ceramic green body. S06. The upper and lower surfaces of the ceramic blank are polished with 2000-grit sandpaper, and then polished with metallographic sandpaper to a thickness of 1 mm. After that, they are ultrasonically cleaned with deionized water and ethanol respectively, and dried. Then, silver paste is evenly coated on the two polished surfaces of the ceramic, and placed in a resistance furnace. The furnace is kept at 650°C for 60 min and then naturally cooled to room temperature. The silver-plated piezoelectric ceramic is then placed in silicone oil and polarized along the thickness direction using a DC or AC electric field. The polarization temperature is 140°C, the polarization voltage is 40 kV / cm, and the polarization voltage holding time is 60 min to obtain a high-power piezoelectric ceramic.

[0079] The preparation method of YbNbO4 includes the following steps: 59.7804 g of Yb₂O₃ with a purity of 99.9% and 40.3197 g of Nb₂O₅ with a purity of 99.9% were weighed as raw materials. All the weighed raw materials were mixed evenly and placed in a nylon can. Zirconia balls were used as grinding balls and anhydrous ethanol was used as the ball milling medium. The mass ratio of anhydrous ethanol to the raw material mixture was 1:1.2. The mixture was ball milled at 250 rpm for 48 h. The zirconia balls were separated, and the raw material mixture was placed in a drying oven and dried at 80 ºC for 24 h. The mixture was then ground in a mortar for 30 min and passed through a 200-mesh sieve. The sieved powder was placed in an alumina crucible, covered, and calcined at 1000 ºC for 4 h to synthesize YbNbO₄ precursor powder.

[0080] The high-density, high-power piezoelectric ceramics prepared in Examples 1-3 and Comparative Example 1 were subjected to product performance tests, and the test results are shown in Table 1.

[0081] Product performance testing items and methods Bulk density: The Archimedes displacement method was used to test the bulk density by accurately weighing the dry mass and the suspended mass in water, and then calculating the bulk density using the formula. Curie temperature: The sample is heated at a rate of 3℃ / min at a frequency of 1kHz, and the dielectric constant is recorded as a function of temperature. The temperature corresponding to the peak dielectric constant is taken as the Curie temperature. Piezoelectric constant: The piezoelectric constant value of the sample was directly measured and read using a quasi-static piezoelectric constant measuring instrument at room temperature. Mechanical quality factor: The mechanical quality factor is calculated by measuring the impedance-phase angle curve of the sample using an impedance analyzer and then using the resonant frequency and anti-resonant frequency. Coercive field: An electric field of 40 kV / cm is applied to the sample at room temperature, and the hysteresis loop is measured using a ferroelectric analyzer to directly read the coercive field value; Internal bias field: The internal bias field value of the sample is calculated based on the hysteresis loop offset measured by the ferroelectric analyzer. Vibration velocity: The peak vibration velocity of the sample under the resonant state was measured using a laser vibrometer driven by an AC electric field of 175Vpp / mm. Strong field loss change rate: The dielectric loss before and after driving with a strong alternating electric field is measured using an impedance analyzer, and the loss change amplitude is calculated to obtain the strong field loss change rate.

[0082] Table 1 Product Performance Test Results

[0083] In addition, by Figure 2 It can be seen that the density of the high-power piezoelectric ceramic provided by Comparative Example 1 is lower than that of Example 2, which is due to the fact that Comparative Example 1 was sintered in an air atmosphere.

[0084] Depend on Figure 3 It can be seen that, under an electric field of 40 kV / cm, the coercive field of the high-power piezoelectric ceramic provided in Example 2 is 28 kV / cm; the coercive field of the high-power piezoelectric ceramic provided in Comparative Example 1 is 24 kV / cm. Since a larger coercive field can improve the withstand voltage threshold of the piezoelectric ceramic, the high-power piezoelectric ceramic provided in Example 2 of this application is more suitable for high-power device applications.

[0085] Depend on Figure 4 It can be seen that the Curie temperature of the high-power piezoelectric ceramics provided in Embodiments 1-3 of this application is higher than 330°C. Therefore, the high-power piezoelectric ceramics provided in Embodiments 1-3 of this application can be applied in high-temperature environments.

[0086] Depend on Figure 5 It can be seen that the mechanical quality factor Qm of the high-power piezoelectric ceramic provided in Embodiment 2 of this application is 2087, thus exhibiting excellent power performance. Figure 6 It can be seen that the high-power piezoelectric ceramic provided in Embodiment 2 of this application can maintain stable vibration under an AC electric field of 175Vpp / mm, and the vibration speed can reach 2.5m / s.

[0087] The technical solutions provided by the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A high-power piezoelectric ceramic, characterized in that, Its composition, expressed as an atomic percentage, is: (0.1-x)Pb(Yb) 1 / 2Nb 1 / 2 )O3-0.9Pb(Zr 0.47 Ti 0.53 O3-xPb(Mn) 1 / 3 Sb 2 / 3 O3, where x is the molar coefficient, with a value ranging from 0.04 to 0.

08.

2. A method for preparing the high-power piezoelectric ceramic according to claim 1, characterized in that, Includes the following steps: S1. Weigh YbNbO4 precursor powder, Pb3O4, ZrO2, TiO2, MnO2 and Sb2O3 according to the stoichiometric ratio, mix them, and then perform sand milling, drying and sieving in sequence to obtain mixed powder. S2. After the mixed powder is compacted, it is pre-calcined and then ground to obtain pre-calcined powder; S3. The pre-calcined powder is milled, dried and sieved to obtain high-power piezoelectric ceramic powder; S4. The high-power piezoelectric ceramic powder is pressed and shaped, and then subjected to cold isostatic pressing to obtain a ceramic blank. S5. The ceramic blank is embedded in homogeneous powder, placed in a sealed saggar, and sintered in a pressureless sealed environment with flowing oxygen atmosphere to obtain a ceramic green body. S6. The ceramic blank is polished, silver-plated and polarized in sequence to obtain a high-power piezoelectric ceramic.

3. The method for preparing high-power piezoelectric ceramics according to claim 2, characterized in that, In step S1, the sand milling uses zirconium balls as grinding balls and anhydrous ethanol as the sand milling medium, and the sand milling time is 18~24h; and / or In step S1, the drying temperature is 80~100℃, and the drying time is 12~24h; and / or In step S1, the sieve mesh size is 80~200 mesh.

4. The method for preparing high-power piezoelectric ceramics according to claim 2, characterized in that, In step S2, the heating rate of the pre-firing treatment is 2~10℃ / min, the pre-firing temperature is 750~850℃, and the holding time is 2~5h; and / or In step S3, the sand milling is carried out at a speed of 150~300r / min for 12~24h, and after drying, it is passed through an 80~200 mesh sieve.

5. The method for preparing high-power piezoelectric ceramics according to claim 2, characterized in that, In step S4, the pressure of the cold isostatic pressing treatment is 200~300MPa, and the holding time is 15~20min.

6. The method for preparing high-power piezoelectric ceramics according to claim 2, characterized in that, In step S5, the heating rate of the pressureless sealed sintering is 2~5℃ / min, the sintering temperature is 1100~1300℃, and the holding time is 3~5h.

7. The method for preparing high-power piezoelectric ceramics according to claim 2, characterized in that, In step S6, the polishing process involves grinding and polishing the ceramic blank to a thickness of 0.8~1.2mm, ultrasonically cleaning it with deionized water and ethanol, and then drying it; and / or In step S6, the silver plating process involves applying silver paste and then holding it at 500℃~850℃ for 5~60 minutes; and / or In step S6, the polarization treatment is to polarize in silicone oil along the thickness direction, with a polarization temperature of 90~150℃, a polarization voltage of 10~50kV / cm, and a polarization holding time of 10~60min.

8. The method for preparing high-power piezoelectric ceramics according to any one of claims 2 to 7, characterized in that, The preparation method of the YbNbO4 precursor powder includes the following steps: Yb₂O₃ and Nb₂O₅ were weighed according to the stoichiometric ratio, mixed, and then ball-milled, dried, and calcined in sequence to obtain the YbNbO₄ precursor powder.

9. The method for preparing high-power piezoelectric ceramics according to claim 8, characterized in that, The ball milling process is carried out at a rotation speed of 150~300 r / min and a milling time of 18~24 h; and / or The drying temperature is 80~100℃, the drying time is 12~24h, and the sieve mesh size is 80 mesh; and / or The calcination temperature is 1000~1100℃, and the calcination holding time is 5~10h.

10. The application of the high-power piezoelectric ceramic of claim 1 in transducers, actuators or sensors.

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