High-performance PZT piezoelectric ceramic material based on grain structure optimization and preparation method therefor

Abstract

The present invention belongs to the technical field of PZT piezoelectric ceramic materials. Disclosed are a high-performance PZT piezoelectric ceramic material based on grain structure optimization and a preparation method therefor. The basic composition of the high-performance PZT piezoelectric ceramic material is PZT and Sb2O3 or MnO2. When the content of Sb2O3 is 0.6-0.8 wt%, a ceramic crystal surface is the most complete and most compact; the solid solubility of Sb2O3 in a PZT perovskite lattice is about 0.6 wt%; and PZT doped with 0.5 wt% of manganese can be sintered into compact ceramic at 1200°C, and the volume density of the compact ceramic reaches 7.8 g·cm-3. An appropriate amount of Sb2O3 promotes trigonal-tetragonal phase transition in a system and significantly improves the piezoelectric property of ceramic. The present invention reveals the microscopic mechanism of manganese-doping-based modification and obtains a low-temperature-sintered high-performance piezoelectric material satisfying the need of multilayer piezoelectric ceramic transformers.

Description

High-performance PZT piezoelectric ceramic material and preparation method based on grain structure optimization Technical Field

[0001] The present invention belongs to the technical field of piezoelectric ceramic materials, and in particular relates to a high-performance PZT piezoelectric ceramic material based on grain structure optimization and a preparation method thereof. Background Art

[0002] Lead zirconate titanate ceramics, due to their excellent piezoelectric and dielectric properties, are widely used in piezoelectric devices such as filters, transducers, transformers, ignition and detonation devices, and ultrasonic delay lines. With the development of the electronics industry, electronic components are moving towards miniaturization, high performance, and high reliability. This has led to increasingly stringent requirements for piezoelectric materials and devices, and binary PZT is no longer sufficient. In search of high-quality and highly stable piezoelectric ceramics, ternary and quaternary piezoelectric ceramics have been extensively studied, with doping and modification continuously employed to enhance their performance and meet application requirements.

[0003] Sb is a commonly used doping element, and the effects of Sb doping on the structure and properties of PZT-based ceramics have been widely studied. Katiyar et al. studied the effect of Sb doping on the dielectric and piezoelectric properties of PZT ceramics at the quasi-modular phase boundary (MPB) and found that the dielectric and piezoelectric properties of the ceramics showed maximum values ​​when the Sb2O3 doping amount was 0.32 mol%. Cheon and Park's research showed that Sb2O3 doping is beneficial to improving the temperature stability of the resonant frequency of PZT ceramics and increasing the frequency constant. Lee's research showed that Sb2O3 doping can change the temperature coefficient of PZT ceramics from positive to negative, reduce the change in resonant frequency caused by thermal aging, and thus significantly improve the thermal vibration resistance of PZT ceramics. Whatmore et al. studied 0.025Pb(Mg 1 / 3 Nb 2 / 3 )O3-0.975Pb(Zr 0.825 Ti 0.175 )O3 ceramics. The results show that when the Sb2O3 doping amount is around 0.3mol%, the dielectric loss and pyroelectric coefficient of the system reach the minimum. Jung et al. studied the effect of Sb2O3 on 0.4Pb(Mg 1 / 3 Nb 2 / 3 )O3-0.3Pb(Mg 1 / 3 Ta 2 / 3 )O3-0.3PbTiO3 multicomponent system, and found that a small amount of Sb doping can promote grain growth and significantly improve its electrical properties.

[0004] Manganese is a commonly used "hard" additive element. Studies have shown that an appropriate amount of manganese doping can significantly improve the mechanical quality factor (Qm) of PZT materials without reducing the electromechanical coupling coefficient (Kp). However, research on the effects of manganese doping on the microstructure, sintering characteristics, and piezoelectric properties of PZT materials has not been reported. Technical issues

[0005] Through the above analysis, the problems and defects of the existing technology are: the research on the microstructure, sintering characteristics and piezoelectric properties of low-temperature sintered high-performance Sb and manganese-doped PZT piezoelectric ceramic materials based on grain structure optimization has not been reported. Technical Solutions

[0006] In view of the problems existing in the prior art, the present invention provides a high-performance PZT piezoelectric ceramic material based on grain structure optimization and a preparation method thereof.

[0007] The present invention is achieved by providing a high-performance PZT piezoelectric ceramic material based on grain structure optimization, wherein the basic components of the high-performance PZT piezoelectric ceramic material based on grain structure optimization are PZT and Sb2O3 or MnO2.

[0008] Furthermore, when the Sb2O3 content is between 0.6 and 0.8 wt%, the ceramic crystal surface is the most complete and dense.

[0009] Furthermore, the best piezoelectric performance is obtained at the solid solubility limit of Sb2O3: ε r =1354, tanδ=0.01625, d 33 =350pC / N,k p =0.66, Q m =4705.

[0010] Furthermore, the solid solubility of Sb2O3 in the PZT perovskite lattice is about 0.6wt%.

[0011] Furthermore, PZT doped with 0.5 wt% manganese can be sintered at 1150 °C to form dense ceramics with a bulk density of 7.8 g·cm -3 .

[0012] Furthermore, manganese doping has the best dielectric and piezoelectric properties: ε 33 T / ε=1241,tanδ=0.02,K p =0.62, Q m =1364,d 33 =250PC·N -1 .

[0013] A method for preparing a high-performance PZT piezoelectric ceramic material based on grain structure optimization comprises the following steps:

[0014] Step 1: Place the oxide in a ball mill and wet-mill for 24 h at a ratio of material: alcohol: zirconium balls of 1:1.2:5;

[0015] Step 2: The ball-milled slurry was heated in a drying oven for 3 h and then sieved;

[0016] Step 3: pre-sintering in an Al2O3 crucible for 2 h at a temperature of 800°C;

[0017] Step 4: Add 5% polyvinyl alcohol (PVA) to granulate, mold under a pressure of 25 MPa, press into 10 mm × 1 mm ceramic sheets, and debind at 550 °C for 1 h;

[0018] Step 5: The prepared samples were sintered at 1200 °C for 140 min and kept at this temperature for 2 h;

[0019] Step 6: The fired sample is polished, then ultrasonically cleaned and dried, coated with silver electrodes, silver is fired, and the sample is subjected to high-voltage polarization in silicone oil. Beneficial effects

[0020] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0021] First, the present invention selected PZT piezoelectric ceramics, known for their excellent sintering characteristics and piezoelectric properties, as the research substrate and systematically investigated the effects of Sb2O3 and MnO2 doping on the ceramic's microstructure and electrical properties. The results showed that an appropriate amount of Sb2O3 promoted the rhombohedral-tetragonal phase transition and significantly improved the ceramic's piezoelectric properties. Furthermore, manganese-doped PZT materials met the requirements for multilayer piezoelectric ceramic transformers.

[0022] This invention utilizes a modified solid-solid synthesis method, utilizing lower synthesis temperatures and shorter ball milling times to synthesize PZT powder. By doping and modifying the PZT ceramic with antimony trioxide and manganese dioxide, the grain structure is optimized, resulting in a low-temperature sinterable ceramic material with excellent piezoelectric properties that fully meets the requirements of MPT. This method offers simple preparation, low-cost raw materials, and excellent piezoelectric properties, making it suitable for large-scale industrial production.

[0023] Second, the expected benefits and commercial value of the technical solution of the present invention after transformation are:

[0024] Piezoelectric materials, intelligent materials capable of converting mechanical energy into electrical energy, have become a massive industry with an annual market value of nearly US$10 billion. Their applications range from consumer electronics like mobile phones to aerospace, naval sonar, and high-speed trains. PZT piezoelectric ceramics, based on optimized grain structure, offer advantages such as simple preparation, low raw material costs, and excellent piezoelectric properties. This technological solution will facilitate the optimization of existing PZT material preparation, effectively reducing costs and generating significant commercial profits.

[0025] Third, the significant technological progress of high-performance PZT piezoelectric ceramic materials based on grain structure optimization can be explained from the following aspects:

[0026] 1) Lattice Structure Optimization: By doping Sb2O3 and MnO2, the PZT perovskite lattice was optimized. In particular, the solid solubility of Sb2O3 in the PZT lattice is approximately 0.6wt%. At this ratio, the material's crystal plane is more complete and dense, thereby improving the material's mechanical strength and stability.

[0027] 2) Significantly Improved Piezoelectric Properties: At the solid solubility limit of Sb2O3, piezoelectric ceramics exhibit excellent piezoelectric properties, such as a high piezoelectric coefficient (d33 = 350pC / N), a high electromechanical coupling coefficient (kp = 0.66), and a very high mechanical quality factor (Qm = 4705). These improvements in performance indicators broaden the application prospects of the material in precision sensing and actuation applications.

[0028] 3) Optimization of dielectric properties: After doping with Sb2O3 and MnO2, PZT ceramics exhibit improved dielectric properties. For example, PZT doped with 0.5wt% manganese exhibits excellent dielectric constant (ε33T / ε=1241) and low dielectric loss (tanδ=0.02), which are crucial for frequency stability and energy conversion efficiency.

[0029] 4) High density and sintering performance: PZT doped with 0.5wt% manganese can form a volume density of up to 7.8g / cm³ when sintered at 1150℃, indicating that the material can achieve high density sintering at a relatively low temperature, which not only saves production costs but also improves the overall performance of the material.

[0030] 5) Optimization of the manufacturing process: By precisely controlling the content of Sb2O3 and MnO2, PZT piezoelectric ceramics with excellent performance can be produced. This optimized manufacturing process makes the material's performance more stable and predictable, facilitating its widespread application in various industrial and scientific fields.

[0031] The high-performance PZT piezoelectric ceramic material based on grain structure optimization provided by the present invention has become an important progress in the field of piezoelectric technology due to its excellent physical properties and controllable manufacturing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0033] FIG1 is an SEM image of a high-performance PZT piezoelectric ceramic material based on grain structure optimization provided by an embodiment of the present invention; (a), Sb2O3 content 0.6wt%; (b), MnO2 content 0.5wt%;

[0034] 2 is a flow chart of a method for preparing a high-performance PZT piezoelectric ceramic material based on grain structure optimization according to an embodiment of the present invention;

[0035] 3 is a graph showing the change in dielectric constant of PZT ceramics at different Sb2O3 doping levels provided by an embodiment of the present invention;

[0036] FIG4 is a graph showing the change in dielectric loss of PZT ceramics at different Sb2O3 doping levels provided by an embodiment of the present invention;

[0037] 5 is a graph showing changes in the electromechanical coupling coefficient of PZT ceramics under different Sb2O3 doping amounts provided in an embodiment of the present invention;

[0038] 6 is a graph showing the change in the piezoelectric constant of PZT ceramics at different Sb2O3 doping levels provided by an embodiment of the present invention;

[0039] 7 is a graph showing the change in mechanical quality factor of PZT ceramics at different Sb2O3 doping levels provided by an embodiment of the present invention;

[0040] 8 is a graph showing the change in dielectric constant of PZT ceramics at different MnO2 doping levels according to an embodiment of the present invention;

[0041] 9 is a graph showing changes in the electromechanical coupling coefficient of PZT ceramics under different MnO2 doping amounts according to an embodiment of the present invention;

[0042] 10 is a graph showing the change in the piezoelectric constant of PZT ceramics at different MnO2 doping amounts according to an embodiment of the present invention;

[0043] FIG11 is a graph showing changes in mechanical quality factor of PZT ceramics at different MnO2 doping amounts provided by an embodiment of the present invention. Modes for Carrying Out the Invention

[0044] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0045] In view of the problems existing in the prior art, the present invention provides a high-performance PZT piezoelectric ceramic material based on grain structure optimization and a preparation method thereof.

[0046] Based on high-performance PZT piezoelectric ceramic materials with optimized grain structure, the following are two specific embodiments and their implementation solutions:

[0047] Application Example 1: High-Precision Piezoelectric Sensor

[0048] 1) Material preparation: PZT was doped with 0.6 wt% Sb2O3 and 0.5 wt% MnO2 as described to obtain the best grain structure and piezoelectric properties.

[0049] 2) Molding and sintering: The doped PZT powder is dry pressed or isostatically pressed to form a piezoelectric element of the desired shape, and then sintered at 1150°C to obtain a dense ceramic.

[0050] 3) Electrode fabrication and polarization: Silver paste is applied to the sintered ceramic surface to form electrodes, and polarization treatment is performed to activate their piezoelectric properties.

[0051] 4) Sensor assembly: Assemble the polarized ceramic sheet into the sensor housing and connect the necessary electronic circuits and output interfaces.

[0052] 5) Performance test: Perform piezoelectric performance test on the sensor in a laboratory environment to verify whether its sensitivity and stability meet the design requirements.

[0053] Application Example 2: Piezoelectric Energy Harvester

[0054] 1) Material preparation: PZT piezoelectric ceramic material doped with 0.6 wt% Sb2O3 and 0.5 wt% MnO2 was prepared by the above method.

[0055] 2) Molding and sintering: The powder is dry pressed or injection molded into the desired size and shape, and then sintered at 1150°C to obtain high-density piezoelectric ceramics.

[0056] 3) Electrode preparation and polarization: Conductive silver paste is coated on the sintered ceramic to make electrodes, and appropriate polarization treatment is performed to enhance the piezoelectric effect.

[0057] 4) Energy harvester assembly: The polarized piezoelectric ceramics are combined with the necessary circuits and energy storage elements to form an energy harvester.

[0058] 5) Performance evaluation: Test the efficiency and reliability of the energy harvester in actual application scenarios (e.g., on a vibration platform or in vehicle motion), and make necessary adjustments and optimizations based on the test results.

[0059] These two embodiments fully utilize the excellent properties of high-performance PZT piezoelectric ceramic materials optimized by grain structure, and demonstrate their application potential in the fields of precision sensing and energy harvesting, respectively.

[0060] As shown in FIG1 , an embodiment of the present invention provides a high-performance PZT piezoelectric ceramic material based on grain structure optimization, wherein basic components of the high-performance PZT piezoelectric ceramic material based on grain structure optimization are PZT and Sb 2 O 3 or MnO 2 .

[0061] Furthermore, when the Sb2O3 content is between 0.6 and 0.8 wt%, the ceramic crystal surface is the most complete and dense.

[0062] Furthermore, the best piezoelectric performance is obtained at the solid solubility limit of Sb2O3: ε r =1354, tanδ=0.01625, d 33 =350pC / N,k p =0.66, Q m =4705.

[0063] Furthermore, the solid solubility of Sb2O3 in the PZT perovskite lattice is about 0.6wt%.

[0064] Furthermore, PZT doped with 0.5 wt% manganese can be sintered at 1150 °C to form dense ceramics with a bulk density of 7.8 g·cm -3 .

[0065] Furthermore, manganese doping has the best dielectric and piezoelectric properties: ε 33 T / ε=1241,tanδ=0.02,K p =0.62, Q m =1364,d 33 =250PC·N -1 .

[0066] As shown in FIG2 , the method for preparing a high-performance PZT piezoelectric ceramic material based on grain structure optimization provided by an embodiment of the present invention includes the following steps:

[0067] Step 1: Place the oxide in a ball mill and wet-mill for 24 h at a ratio of material: alcohol: zirconium balls of 1:1.2:5;

[0068] Step 2: The ball-milled slurry was heated in a drying oven for 3 h and then sieved;

[0069] Step 3: pre-sintering in an Al2O3 crucible for 2 h at a temperature of 800°C;

[0070] Step 4: Add 5% polyvinyl alcohol (PVA) to granulate, mold under a pressure of 25 MPa, press into 10 mm × 1 mm ceramic sheets, and debind at 550 °C for 1 h;

[0071] Step 5: The prepared sample was sealed and sintered at 1150 °C for 140 min and kept at this temperature for 2 h;

[0072] Step 6: The fired sample is polished, then ultrasonically cleaned and dried, coated with silver electrodes, silver is fired, and the sample is subjected to high-voltage polarization in silicone oil.

[0073] (1) Example 1

[0074] Step 1: According to the general formula PbZr 0.53 Ti 0.47 Weigh the raw materials (expressed as O3(PZT)+xSb2O3, where x = 0.2 wt%). Place the PZT and oxide in a ball mill and wet-mill the raw materials, alcohol, and zirconium balls in the appropriate proportions for 24 h.

[0075] Step 2: The wet material after ball milling is placed in a drying oven for heating;

[0076] Step 3: Grind the dry powder into powder, place it in a corundum crucible with a lid, and pre-calcine it at 850°C for 2 hours;

[0077] Step 4: The pre-calcined powder was ball-milled again for 12 hours, dried, granulated with PVA, dry-pressed to form a disc sample, and the binder was removed at 500°C;

[0078] Step 5: The prepared sample was sealed and sintered at 1250 °C for 2 h.

[0079] Furthermore, the step monoxide is antimony trioxide.

[0080] Furthermore, in step 1, the ratio of raw materials: alcohol: zirconium balls is 1:1.2:5.

[0081] Furthermore, in step 2, the heating temperature is about 100° C. and the heating time is 5 h.

[0082] Furthermore, in step 4, 5% polyvinyl alcohol (PVA) is added for granulation.

[0083] Furthermore, in step 4, the ceramic sheet is pressed into a size of 10 mm×1 mm.

[0084] Furthermore, in step five, the disc sample is directly placed in a single-layer crucible for sintering.

[0085] Furthermore, the fired sample was ground and polished, and then coated with silver paste on the upper and lower surfaces. The silver electrode was fired at 560° C. for 20 minutes, and the sample was subjected to high-voltage polarization in silicone oil.

[0086] Furthermore, the polarization of the sample was carried out in methyl silicone oil at a temperature of 120°C, a polarization voltage of 3 KV / mm, and a polarization time of 30 min.

[0087] (2) Example 2

[0088] Step 1: According to the general formula PbZr 0.53 Ti 0.47 Weigh the raw materials (expressed as O3(PZT)+xSb2O3, where x = 0.4 wt%). Place the PZT and oxide in a ball mill and wet-mill the raw materials, alcohol, and zirconium balls in the appropriate proportions for 24 h.

[0089] Step 2: The wet material after ball milling is placed in a drying oven for heating;

[0090] Step 3: Grind the dry powder into powder, place it in a corundum crucible with a lid, and pre-calcine it at 850°C for 2 hours;

[0091] Step 4: The pre-calcined powder was ball-milled again for 12 hours, dried, granulated with PVA, dry-pressed to form a disc sample, and the binder was removed at 500°C;

[0092] Step 5: The prepared sample was sealed and sintered at 1200°C for 2 h.

[0093] Furthermore, the step monoxide is antimony trioxide.

[0094] Furthermore, in step 1, the ratio of raw materials: alcohol: zirconium balls is 1:1.2:5.

[0095] Furthermore, in step 2, the heating temperature is about 100° C. and the heating time is 5 h.

[0096] Furthermore, in step 4, 5% polyvinyl alcohol (PVA) is added for granulation.

[0097] Furthermore, in step 4, the ceramic sheet is pressed into a size of 10 mm×1 mm.

[0098] Furthermore, in step five, the disc sample is directly placed in a single-layer crucible for sintering.

[0099] Furthermore, the fired sample was ground and polished, and then coated with silver paste on the upper and lower surfaces. The silver electrode was fired at 560° C. for 20 minutes, and the sample was subjected to high-voltage polarization in silicone oil.

[0100] Furthermore, the polarization of the sample was carried out in methyl silicone oil at a temperature of 120°C, a polarization voltage of 3 KV / mm, and a polarization time of 30 min.

[0101] (3) Example 3

[0102] Step 1: According to the general formula PbZr 0.53 Ti 0.47 Weigh the raw materials (expressed as O3(PZT)+xSb2O3, where x = 0.6 wt%). Place the PZT and oxide in a ball mill and wet-mill the raw materials, alcohol, and zirconium balls in the appropriate proportions for 24 h.

[0103] Step 2: The wet material after ball milling is placed in a drying oven for heating;

[0104] Step 3: Grind the dry powder into powder, place it in a corundum crucible with a lid, and pre-calcine it at 850°C for 2 hours;

[0105] Step 4: The pre-calcined powder was ball-milled again for 12 hours, dried, granulated with PVA, dry-pressed to form a disc sample, and the binder was removed at 500°C;

[0106] Step 5: The prepared sample was sealed and sintered at 1150 °C for 2 h.

[0107] Furthermore, the step monoxide is antimony trioxide.

[0108] Furthermore, in step 1, the ratio of raw materials: alcohol: zirconium balls is 1:1.2:5.

[0109] Furthermore, in step 2, the heating temperature is about 100° C. and the heating time is 5 h.

[0110] Furthermore, in step 4, 5% polyvinyl alcohol (PVA) is added for granulation.

[0111] Furthermore, in step 4, the ceramic sheet is pressed into a size of 10 mm×1 mm.

[0112] Furthermore, in step five, the disc sample is directly placed in a single-layer crucible for sintering.

[0113] Furthermore, the fired sample was ground and polished, and then coated with silver paste on the upper and lower surfaces. The silver electrode was fired at 560° C. for 20 minutes, and the sample was subjected to high-voltage polarization in silicone oil.

[0114] Furthermore, the polarization of the sample was carried out in methyl silicone oil at a temperature of 120°C, a polarization voltage of 3 KV / mm, and a polarization time of 30 min.

[0115] (4) Example 4

[0116] Step 1: According to the general formula PbZr0.53 Ti 0.47 Weigh the raw materials (expressed as O3(PZT)+xSb2O3, where x = 0.8 wt%). Place the PZT and oxide in a ball mill and wet-mill the raw materials, alcohol, and zirconium balls in the appropriate proportions for 24 h.

[0117] Step 2: The wet material after ball milling is placed in a drying oven for heating;

[0118] Step 3: Grind the dry powder into powder, place it in a corundum crucible with a lid, and pre-calcine it at 850°C for 2 hours;

[0119] Step 4: The pre-calcined powder was ball-milled again for 12 hours, dried, granulated with PVA, dry-pressed to form a disc sample, and the binder was removed at 500°C;

[0120] Step 5: The prepared sample was sealed and sintered at 1100°C for 2 h.

[0121] Furthermore, the step monoxide is antimony trioxide.

[0122] Furthermore, in step 1, the ratio of raw materials: alcohol: zirconium balls is 1:1.2:5.

[0123] Furthermore, in step 2, the heating temperature is about 100° C. and the heating time is 5 h.

[0124] Furthermore, in step 4, 5% polyvinyl alcohol (PVA) is added for granulation.

[0125] Furthermore, in step 4, the ceramic sheet is pressed into a size of 10 mm×1 mm.

[0126] Furthermore, in step five, the disc sample is directly placed in a single-layer crucible for sintering.

[0127] Furthermore, the fired sample was ground and polished, and then coated with silver paste on the upper and lower surfaces. The silver electrode was fired at 560° C. for 20 minutes, and the sample was subjected to high-voltage polarization in silicone oil.

[0128] Furthermore, the polarization of the sample was carried out in methyl silicone oil at a temperature of 120°C, a polarization voltage of 3 KV / mm, and a polarization time of 30 min.

[0129] (5) Example 5

[0130] Step 1: According to the general formula PbZr 0.53 Ti 0.47 Weigh the raw materials (expressed as O3(PZT)+xSb2O3, where x = 1.0 wt%). Place the PZT and oxide in a ball mill and wet-mill the raw materials, alcohol, and zirconium balls in the appropriate proportions for 24 h.

[0131] Step 2: The wet material after ball milling is placed in a drying oven for heating;

[0132] Step 3: Grind the dry powder into powder, place it in a corundum crucible with a lid, and pre-calcine it at 850°C for 2 hours;

[0133] Step 4: The pre-calcined powder was ball-milled again for 12 hours, dried, granulated with PVA, dry-pressed to form a disc sample, and the binder was removed at 500°C;

[0134] Step 5: The prepared sample was sealed and sintered at 1050 °C for 2 h.

[0135] Furthermore, the step monoxide is antimony trioxide.

[0136] Furthermore, in step 1, the ratio of raw materials: alcohol: zirconium balls is 1:1.2:5.

[0137] Furthermore, in step 2, the heating temperature is about 100° C. and the heating time is 5 h.

[0138] Furthermore, in step 4, 5% polyvinyl alcohol (PVA) is added for granulation.

[0139] Furthermore, in step 4, the ceramic sheet is pressed into a size of 10 mm×1 mm.

[0140] Furthermore, in step five, the disc sample is directly placed in a single-layer crucible for sintering.

[0141] Furthermore, the fired sample was ground and polished, and then coated with silver paste on the upper and lower surfaces. The silver electrode was fired at 560° C. for 20 minutes, and the sample was subjected to high-voltage polarization in silicone oil.

[0142] Furthermore, the polarization of the sample was carried out in methyl silicone oil at a temperature of 120°C, a polarization voltage of 3 KV / mm, and a polarization time of 30 min.

[0143] (6) Example 6

[0144] Step 1: According to the general formula PbZr 0.53 Ti 0.47 Weigh the raw materials as represented by O3(PZT)+xMnO2 (x=0.1wt%). Place the PZT and oxide in a ball mill and wet-mill the raw materials, alcohol, and zirconium balls in the appropriate proportions for 24 hours.

[0145] Step 2: The wet material after ball milling is placed in a drying oven for heating;

[0146] Step 3: Grind the dry powder into powder, place it in a corundum crucible with a lid, and pre-calcine it at 850°C for 2 hours;

[0147] Step 4: The pre-calcined powder was ball-milled again for 12 hours, dried, granulated with PVA, dry-pressed to form a disc sample, and the binder was removed at 500°C;

[0148] Step 5: The prepared sample was sealed and sintered at 1250 °C for 2 h.

[0149] Furthermore, the step monoxide is manganese dioxide.

[0150] Furthermore, in step 1, the ratio of raw materials: alcohol: zirconium balls is 1:1.2:5.

[0151] Furthermore, in step 2, the heating temperature is about 100° C. and the heating time is 5 h.

[0152] Furthermore, in step 4, 5% polyvinyl alcohol (PVA) is added for granulation.

[0153] Furthermore, in step 4, the ceramic sheet is pressed into a size of 10 mm×1 mm.

[0154] Furthermore, in step five, the disc sample is directly placed in a single-layer crucible for sintering.

[0155] Furthermore, the fired sample was ground and polished, and then coated with silver paste on the upper and lower surfaces. The silver electrode was fired at 560° C. for 20 minutes, and the sample was subjected to high-voltage polarization in silicone oil.

[0156] Furthermore, the polarization of the sample was carried out in methyl silicone oil at a temperature of 120°C, a polarization voltage of 3 KV / mm, and a polarization time of 30 min.

[0157] (7) Example 7

[0158] Step 1: According to the general formula PbZr 0.53 Ti 0.47 Weigh the raw materials as represented by O3(PZT)+xMnO2 (x=0.3wt%). Place the PZT and oxide in a ball mill and wet-mill the raw materials, alcohol, and zirconium balls in the appropriate proportions for 24 hours.

[0159] Step 2: The wet material after ball milling is placed in a drying oven for heating;

[0160] Step 3: Grind the dry powder into powder, place it in a corundum crucible with a lid, and pre-calcine it at 850°C for 2 hours;

[0161] Step 4: The pre-calcined powder was ball-milled again for 12 hours, dried, granulated with PVA, dry-pressed to form a disc sample, and the binder was removed at 500°C;

[0162] Step 5: The prepared sample was sealed and sintered at 1200°C for 2 h.

[0163] Furthermore, the step monoxide is manganese dioxide.

[0164] Furthermore, in step 1, the ratio of raw materials: alcohol: zirconium balls is 1:1.2:5.

[0165] Furthermore, in step 2, the heating temperature is about 100° C. and the heating time is 5 h.

[0166] Furthermore, in step 4, 5% polyvinyl alcohol (PVA) is added for granulation.

[0167] Furthermore, in step 4, the ceramic sheet is pressed into a size of 10 mm×1 mm.

[0168] Furthermore, in step five, the disc sample is directly placed in a single-layer crucible for sintering.

[0169] Furthermore, the fired sample was ground and polished, and then coated with silver paste on the upper and lower surfaces. The silver electrode was fired at 560° C. for 20 minutes, and the sample was subjected to high-voltage polarization in silicone oil.

[0170] Furthermore, the polarization of the sample was carried out in methyl silicone oil at a temperature of 120°C, a polarization voltage of 3 KV / mm, and a polarization time of 30 min.

[0171] (8) Example 8

[0172] Step 1: According to the general formula PbZr 0.53 Ti 0.47 Weigh the raw materials (expressed as O3(PZT)+xMnO2, where x = 0.5 wt%). Place the PZT and oxide in a ball mill and wet-mill the raw materials, alcohol, and zirconium balls in the appropriate proportions for 24 h.

[0173] Step 2: The wet material after ball milling is placed in a drying oven for heating;

[0174] Step 3: Grind the dry powder into powder, place it in a corundum crucible with a lid, and pre-calcine it at 850°C for 2 hours;

[0175] Step 4: The pre-calcined powder was ball-milled again for 12 hours, dried, granulated with PVA, dry-pressed to form a disc sample, and the binder was removed at 500°C;

[0176] Step 5: The prepared sample was sealed and sintered at 1150 °C for 2 h.

[0177] Furthermore, the step monoxide is manganese dioxide.

[0178] Furthermore, in step 1, the ratio of raw materials: alcohol: zirconium balls is 1:1.2:5.

[0179] Furthermore, in step 2, the heating temperature is about 100° C. and the heating time is 5 h.

[0180] Furthermore, in step 4, 5% polyvinyl alcohol (PVA) is added for granulation.

[0181] Furthermore, in step 4, the ceramic sheet is pressed into a size of 10 mm×1 mm.

[0182] Furthermore, in step five, the disc sample is directly placed in a single-layer crucible for sintering.

[0183] Furthermore, the fired sample was ground and polished, and then coated with silver paste on the upper and lower surfaces. The silver electrode was fired at 560° C. for 20 minutes, and the sample was subjected to high-voltage polarization in silicone oil.

[0184] Furthermore, the polarization of the sample was carried out in methyl silicone oil at a temperature of 120°C, a polarization voltage of 3 KV / mm, and a polarization time of 30 min.

[0185] (9) Example 9

[0186] Step 1: According to the general formula PbZr 0.53 Ti 0.47 Weigh the raw materials (expressed as O3(PZT)+xMnO2, where x = 0.7 wt%). Place the PZT and oxide in a ball mill and wet-mill the raw materials, alcohol, and zirconium balls in the appropriate proportions for 24 h.

[0187] Step 2: The wet material after ball milling is placed in a drying oven for heating;

[0188] Step 3: Grind the dry powder into powder, place it in a corundum crucible with a lid, and pre-calcine it at 850°C for 2 hours;

[0189] Step 4: The pre-calcined powder was ball-milled again for 12 hours, dried, granulated with PVA, dry-pressed to form a disc sample, and the binder was removed at 500°C;

[0190] Step 5: The prepared sample was sealed and sintered at 1100°C for 2 h.

[0191] Furthermore, the step monoxide is manganese dioxide.

[0192] Furthermore, in step 1, the ratio of raw materials: alcohol: zirconium balls is 1:1.2:5.

[0193] Furthermore, in step 2, the heating temperature is about 100° C. and the heating time is 5 h.

[0194] Furthermore, in step 4, 5% polyvinyl alcohol (PVA) is added for granulation.

[0195] Furthermore, in step 4, the ceramic sheet is pressed into a size of 10 mm×1 mm.

[0196] Furthermore, in step five, the disc sample is directly placed in a single-layer crucible for sintering.

[0197] Furthermore, the fired sample was ground and polished, and then coated with silver paste on the upper and lower surfaces. The silver electrode was fired at 560° C. for 20 minutes, and the sample was subjected to high-voltage polarization in silicone oil.

[0198] Furthermore, the polarization of the sample was carried out in methyl silicone oil at a temperature of 120°C, a polarization voltage of 3 KV / mm, and a polarization time of 30 min.

[0199] (10) Example 10

[0200] Step 1: According to the general formula PbZr 0.53 Ti 0.47 Weigh the raw materials as represented by O3(PZT)+xMnO2 (x=0.9wt%). Place the PZT and oxide in a ball mill and wet-mill the raw materials, alcohol, and zirconium balls in the appropriate proportions for 24 hours.

[0201] Step 2: The wet material after ball milling is placed in a drying oven for heating;

[0202] Step 3: Grind the dry powder into powder, place it in a corundum crucible with a lid, and pre-calcine it at 850°C for 2 hours;

[0203] Step 4: The pre-calcined powder was ball-milled again for 12 hours, dried, granulated with PVA, dry-pressed to form a disc sample, and the binder was removed at 500°C;

[0204] Step 5: The prepared sample was sealed and sintered at 1050 °C for 2 h.

[0205] Furthermore, the step monoxide is manganese dioxide.

[0206] Furthermore, in step 1, the ratio of raw materials: alcohol: zirconium balls is 1:1.2:5.

[0207] Furthermore, in step 2, the heating temperature is about 100° C. and the heating time is 5 h.

[0208] Furthermore, in step 4, 5% polyvinyl alcohol (PVA) is added for granulation.

[0209] Furthermore, in step 4, the ceramic sheet is pressed into a size of 10 mm×1 mm.

[0210] Furthermore, in step five, the disc sample is directly placed in a single-layer crucible for sintering.

[0211] Furthermore, the fired sample was ground and polished, and then coated with silver paste on the upper and lower surfaces. The silver electrode was fired at 560° C. for 20 minutes, and the sample was subjected to high-voltage polarization in silicone oil.

[0212] Furthermore, the polarization of the sample was carried out in methyl silicone oil at a temperature of 120°C, a polarization voltage of 3 KV / mm, and a polarization time of 30 min.

[0213] The embodiments of the present invention have achieved some positive results during the development or use process, and indeed have great advantages over the existing technology. The following content describes them in conjunction with data, charts, etc. from the experimental process.

[0214] 1. Sb doping

[0215] 1.1 Dielectric properties

[0216] Figure 3 shows the change of dielectric constant εr of the sample at room temperature with doping level. Dielectric constant is an important parameter to measure the polarization behavior of the dielectric, or the ability of the dielectric to store charge. It is usually called dielectric coefficient or permittivity, reflecting the dielectric properties or polarization properties of the material, usually expressed as ε. In practice, relative dielectric constant ε is often used. r , and the relationship between it and the dielectric constant is:

[0217] ε r =ε / ε0

[0218] Where: ε0=8.55 10 -12 (F·m -1 ), ε r Dimensionless.

[0219] The dielectric constant measured under different mechanical conditions of the sample is also different. The dielectric constant measured under mechanically free conditions is called the free dielectric constant, expressed as ε T The dielectric constant measured under mechanical clamping conditions is called the clamping dielectric constant, expressed as ε S express.

[0220] The dielectric constant exhibits a distinct "factory"-like change with increasing doping levels. Initially, it increases gradually and rapidly, then slows down when the Sb2O3 content reaches 0.4wt%, peaking at 0.6wt%, before fluctuating gently with small fluctuations.

[0221] Figure 4 plots the change in dielectric loss of PZT ceramics at different Sb2O3 doping levels. Dielectric loss, tanδ, refers to the energy loss caused by heat generation in a dielectric under an alternating electric field. Ceramic dielectric materials can store charge under an electric field, but they also convert some electrical energy into heat, consuming energy as the ceramic body heats up. The energy consumed per unit time by heat generation in a dielectric under an electric field is called dielectric loss. As shown in Figure 4, the change in dielectric loss follows a similar pattern to the dielectric constant, showing an overall trend of first increasing and then decreasing. The peak value, approximately 1.65wt%, occurs when the Sb2O3 content reaches 0.8wt%.

[0222] 1.2 Piezoelectric properties

[0223] Figure 5 shows the electromechanical coupling coefficient K of PZT ceramics at different Sb2O3 doping levels. p The electromechanical coupling coefficient, K, is a parameter that comprehensively reflects the performance of piezoelectric materials. It represents the coupling relationship between mechanical and electrical energy in a piezoelectric material. The electromechanical coupling coefficient reflects the material's ability to convert electromechanical energy into electrical energy and is distinct from electromechanical efficiency. It is related to parameters such as the material's piezoelectric constant, dielectric constant, and elastic constant, making it a relatively comprehensive parameter. During vibration, a piezoelectric vibrator converts mechanical energy into electrical energy, and vice versa. The degree of this energy conversion is expressed by the electromechanical coupling coefficient. The overall trend in the figure also shows an increase followed by a decrease with the Sb2O3 doping level, reaching a maximum of approximately 0.65 when the doping level approaches 0.4wt%.

[0224] Figure 6 shows the piezoelectric constant d of the ceramic sample 33 The piezoelectric constant is a key characteristic parameter of piezoelectric ceramics. It represents the proportionality constant of the piezoelectric dielectric's conversion of mechanical (or electrical) energy into electrical (or mechanical) energy. It reflects the relationship between stress or strain and the electric field or displacement, and directly reflects the strength of the piezoelectric effect. As shown in the figure, the piezoelectric constant increases with increasing Sb2O3 doping, and begins to fluctuate steadily after exceeding a certain content. Initially, the increase is gradual and rapid, but the rate of increase slows down when the Sb2O3 content reaches 0.4wt%, reaching a peak of approximately 350 at 0.6wt%, followed by a gentle, small fluctuation.

[0225] Figure 7 lists the mechanical quality factor Q m Changes with Sb2O3 doping. Mechanical quality factor Q m It is a physical quantity that measures the amount of energy consumed by a piezoelectric body to overcome internal friction when it resonates. For practical piezoelectric transformer materials, high Q mA high resonant current and low tanδ are essential because they help reduce the performance degradation caused by heat generation during the resonant operation of the piezoelectric transformer. Various piezoelectric components, such as piezoelectric filters, resonant transducers, piezoelectric tuning forks, and ultrasonic cleaners, primarily utilize the resonant effect of piezoelectric elements. If the frequency of the applied electric field matches the resonant frequency of the piezoelectric element, significant mechanical resonance occurs due to the inverse piezoelectric effect, converting electrical energy into mechanical energy or outputting an electrical signal of a specific frequency at the other end of the piezoelectric element through the piezoelectric effect. When the piezoelectric element is subjected to an electric field and mechanically resonates, some energy is consumed by overcoming the internal friction generated by lattice deformation, resulting in mechanical losses. The mechanical quality factor, Qm, reflects the extent of these losses.

[0226] The larger the mechanical quality factor, the smaller the energy loss. m The size of is also related to the corresponding resonance mode, but unless otherwise stated, it usually refers to the mechanical quality factor of radial vibration.

[0227] Q in Figure 7 m It first increases and then decreases with the increase of doping amount, which shows that Sb doping can harden the material properties. This can be explained by the internal bias field theory. 3+ In the replacement (Ti, Zr) 4+ The oxygen vacancies generated when the perovskite is in the same position cause the oxygen octahedron family to produce obvious distortion. The distorted oxygen octahedron causes the electric domain to turn and produce a "pinning effect", which hinders the polarization reversal and thus makes the Q m improve.

[0228] 2. Manganese doping

[0229] 2.1 Dielectric properties

[0230] Figure 8 shows the change of dielectric constant εr of the sample at room temperature with doping amount. Test conditions:

[0231] Frequency 1KHz, temperature 25℃.

[0232] The dielectric constant is an important parameter that measures the polarization behavior of a medium or the ability of the medium to store charge. It is also called the dielectric constant or permittivity, reflecting the dielectric properties or polarization properties of the material. It is usually expressed as ε. In practice, the relative dielectric constant ε is often used. r , and the relationship between it and the dielectric constant is:

[0233] ε r =ε / ε0

[0234] Where: ε0=8.55 10 -12 (F·m -1 ), ε r Dimensionless.

[0235] The dielectric constant measured under different mechanical conditions of the sample is also different. The dielectric constant measured under mechanically free conditions is called the free dielectric constant, expressed as ε T The dielectric constant measured under mechanical clamping conditions is called the clamping dielectric constant, expressed as ε S express.

[0236] As can be seen, the dielectric constant exhibits a distinct "G-shaped" change with increasing doping levels. Initially, it increases gradually and rapidly, then slows down when the MnO2 content reaches 0.3wt%, peaks at 0.5wt%, and then begins to decline rapidly, reaching a bottom of approximately 1750 at 0.7wt%. It then continues to increase slightly.

[0237] Figure 9 shows the electromechanical coupling coefficient K of PZT ceramics at different MnO2 doping levels. p During vibration, a piezoelectric vibrator converts mechanical energy into electrical energy, or vice versa. The degree of this energy conversion is expressed by the electromechanical coupling coefficient. The electromechanical coupling coefficient, K, is a parameter that comprehensively reflects the performance of piezoelectric materials. It describes the coupling relationship between mechanical and electrical energy. It reflects the material's ability to convert electromechanical energy into electrical energy and is distinct from electromechanical efficiency. It is related to parameters such as the material's piezoelectric constant, dielectric constant, and elastic constant. Therefore, the electromechanical coupling coefficient is a relatively comprehensive parameter. The overall trend is that it first increases and then decreases with the MnO2 doping level, reaching a maximum of approximately 0.38 at a doping level close to 0.5wt%. It reaches a low point of approximately 0.31 at a doping level of 0.7wt%, and then continues to increase gradually.

[0238] Figure 10 shows the piezoelectric constant d of the ceramic sample. 33 and sintering temperature relationship curve. Piezoelectric constant d 33 Characterizes the relationship between the mechanical stress T and the polarization intensity P when the polarization direction is consistent with the mechanical vibration direction, and the electromechanical coupling coefficient K p The figure comprehensively reflects the coupling relationship between the mechanical and electrical energy of piezoelectric ceramics. The piezoelectric constant is a key characteristic parameter of piezoelectric ceramics. It is the proportional constant of the piezoelectric medium converting mechanical energy (or electrical energy) into electrical energy (or mechanical energy). It reflects the connection between stress or strain and the electric field or displacement, and directly reflects the strength of the piezoelectric effect. As can be seen from the figure, the piezoelectric constant exhibits a "J"-shaped change with increasing MnO2 doping, first increasing, then stabilizing, then decreasing, and then continuing to steadily increase. Initially, the increase is gradual and rapid, reaching its peak of approximately 250 when the MnO2 content reaches 0.3wt%.

[0239] From Figure 10,9 we can see that d33 and K p The two have similar changing patterns with the increase of manganese content, which are first rising, then falling and then rising again, which is consistent with the research results of Seok JY et al. on MnO2 doped PZT-PYW system. 33 With k p Affected by the grain size, it increases with the increase of grain size, but at the same time, the oxygen vacancies caused by manganese doping hinder the movement of ferroelectric domain walls and reduce the d 33 With K p Therefore, the above two complex interactions determine d 33 With K p The change pattern with increasing manganese content.

[0240] Figure 11 lists the mechanical quality factor Q m Changes with MnO2 doping. Mechanical quality factor Q m It is a physical quantity that measures the amount of energy consumed by a piezoelectric body to overcome internal friction when it resonates. For practical piezoelectric transformer materials, high Q m A low tanδ is extremely necessary because it helps to reduce the performance degradation caused by heat in the resonant working state of the piezoelectric transformer. m It first increases and then decreases with the increase of doping amount, which shows that Sb doping can harden the material properties. This can be explained by the internal bias field theory. 2+ In the replacement (Ti, Zr) 4+ The oxygen vacancies generated when the perovskite is in the same position cause the oxygen octahedron family to produce obvious distortion. The distorted oxygen octahedron causes the electric domain to turn and produce a "pinning effect", which hinders the polarization reversal and thus makes the Q m improve.

[0241] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with this technical field within the technical scope disclosed by the present invention and within the spirit and principles of the present invention should be covered by the scope of protection of the present invention.

Claims

1. A high-performance PZT piezoelectric ceramic material based on grain structure optimization, characterized in that, The components of the high-performance PZT piezoelectric ceramic material based on grain structure optimization include PZT and Sb 2 O 3 or MnO 2 .

2. The high-performance PZT piezoelectric ceramic material based on grain structure optimization according to claim 1, characterized in that, Sb 2 O 3 When the content of 2 O 3 is in the range of 0.6 - 0.8 wt%, the ceramic crystal plane is the most complete and dense.

3. The high-performance PZT piezoelectric ceramic material based on grain structure optimization according to claim 1, characterized in that, The best piezoelectric properties are obtained at the solid solubility limit of Sb 2 O 3 : ε r = 1354, tanδ = 0.01625, d 33 = 350 pC / N, k p = 0.66, Q m = 4705.

4. The high-performance PZT piezoelectric ceramic material based on grain structure optimization according to claim 1, characterized in that, Sb 2 O 3 The solid solubility in the PZT perovskite lattice is approximately 0.6 wt%.

5. The high-performance PZT piezoelectric ceramic material based on grain structure optimization according to claim 1, characterized in that, PZT doped with 0.5 wt% manganese can be sintered into dense ceramics at 1200 °C, with a bulk density of 7.8 g·cm -3 .

6. The high-performance PZT piezoelectric ceramic material based on grain structure optimization according to claim 1, characterized in that, Optimal Dielectric and Piezoelectric Properties with Manganese Doping: ε 33 T / ε = 1241, tanδ = 0.02, K p = 0.62, Q m = 1364, d 33 = 250 PC·N -1 .

7. A preparation method of the high-performance PZT piezoelectric ceramic material based on grain structure optimization according to any one of claims 1 to 6, characterized in that, comprising the following steps: Step 1, placing the oxide in a ball milling tank, wet ball milling for 24 h according to the ratio of material: alcohol: zirconia balls of 1:1.2:5; Step 2, heating the ball-milled slurry in a drying oven for 3 h, and then sieving; Step 3, pre-burn in an Al 2 O 3 crucible for 2 h at a pre-burning temperature of 800 °C; Step 4, adding 5% polyvinyl alcohol for granulation, molding under a pressure of 25 MPa, pressing into a ceramic sheet of 10 mm×1 mm, and debinding at 550 °C for 1 h; Step 5, sealing and sintering the prepared sample at a temperature of 1200 °C for 140 min and holding for 2 h; Step 6, grinding the fired sample, then ultrasonic cleaning and drying, coating with silver electrodes, firing silver, and performing high-voltage polarization on the sample in silicone oil.

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