A large-strain piezoelectric ceramic material and a method for preparing the same

Abstract

This invention discloses a method for preparing a large-strain piezoelectric ceramic material, comprising: synthesizing a (1-x)Pb(Zr) composition by melt-water quenching method. a Ti 1‑a O3-x(Bi) 0.5 Na 0.5 A glass powder of TiO3-ywt%BaZrO3-βwt%B2O3, where x and a are molar ratios and y and β are mass ratios, was synthesized using a solid-state synthesis method with the composition (1-x)Pb(ZrO3-ywt%BaZrO3-βwt%B2O3). a Ti 1‑a O3-x(Bi) 0.5 Na 0.5 (1-x)Pb(ZrO3) ceramic powder of TiO3-ywt%BaZrO3; using the glass powder and the ceramic powder, (1-x)Pb(ZrO3) was prepared by solid-state sintering. a Ti 1‑a O3-x(Bi) 0.5 Na 0.5 TiO3-yBaZrO3-zGL piezoelectric ceramic material, wherein GL has the composition of (1-x)Pb(Zr) a Ti 1‑a O3-x(Bi) 0.5 Na 0.5 TiO3-ywt%BaZrO3-βwt%B2O3. This invention modifies PZT-based piezoelectric ceramics by adding a special glass component, which significantly improves the strain of the material while optimizing the microstructure of the ceramic material.

Description

Technical Field

[0001] This invention belongs to the field of piezoelectric ceramic materials technology, specifically relating to a large strain piezoelectric ceramic material and its preparation method. Background Technology

[0002] Multilayer piezoelectric ceramic actuators offer advantages such as fast response speed and high resolution. Furthermore, due to the excellent temperature characteristics and electromagnetic interference resistance of piezoelectric ceramics, they are widely used in the driving and positioning systems of precision machining equipment, such as electron beam lithography and focused ion beam cutting. Currently, the mainstream materials for piezoelectric ceramic actuators, such as PZT-5H and PZT-4, have relatively low electrostrain (<0.2%), requiring a high number of stacked layers to achieve a large displacement stroke. This increases production costs and process difficulty, and also hinders the miniaturization and integration of devices.

[0003] The strain of PZT (lead zirconate titanate) piezoelectric ceramics mainly originates from intrinsic contributions related to lattice distortion and extrinsic contributions from ferroelectric domain flipping. The theoretical limit of strain can reach 1%, and its generation process is influenced by various factors such as defect pinning, grain boundary clamping, and continuous 90° domain flipping. Defects pinned near domain walls inhibit domain wall movement and hinder domain flipping; domains are also rigidly hindered by grain boundaries during flipping, while continuous 90° domain flipping is equivalent to 180° domain flipping and contributes nothing to strain. In recent years, researchers have improved the strain value of PZT piezoelectric ceramics through doping with ions and adding a third component, but the strain value still struggles to break through 0.4%.

[0004] Patent application No. 202210753645.7, entitled "A strain-insensitive piezoelectric ceramic material and its preparation method and application," discloses a strain-insensitive piezoelectric ceramic material. Although this material has good chemical stability, its strain is not significantly improved compared to commercial PZT materials. Patent application No. 201110165378.3, entitled "A high Curie temperature, high electrostriction piezoelectric ceramic material and its preparation method," discloses a high Curie temperature, high electrostriction piezoelectric ceramic material. This ceramic material has good temperature stability, but its strain is lower than that of currently commercially available piezoelectric ceramics. Summary of the Invention

[0005] This invention provides a high-strain piezoelectric ceramic material and its preparation method, addressing the problem that the low strain of currently available commercial piezoelectric ceramic materials limits their application in devices. The technical problem to be solved by this invention is achieved through the following technical solution:

[0006] One aspect of the present invention provides a method for preparing a large-strain piezoelectric ceramic material, comprising:

[0007] S1: The composition (1-x)Pb(Zr) was synthesized using the melt-water quenching method. a Ti 1-a O3-x(Bi) 0.5 Na 0.5 Glass powder of TiO3-ywt%BaZrO3-βwt%B2O3, where x and a are molar ratios and y and β are mass ratios;

[0008] S2: The component (1-x)Pb(Zr) was synthesized using a solid-state synthesis method. a Ti 1-a O3-x(Bi) 0.5 Na 0.5 TiO3-ywt%BaZrO3 ceramic powder;

[0009] S3: Using the glass powder and the ceramic powder, (1-x)Pb(Zr) is prepared by solid-state sintering. a Ti 1-a O3-x(Bi) 0.5 Na 0.5 TiO3-yBaZrO3-zGL piezoelectric ceramic material, wherein GL has the composition of (1-x)Pb(Zr) a Ti 1-a O3-x(Bi) 0.5 Na 0.5 )TiO3-ywt%BaZrO3-βwt%B2O3.

[0010] In one embodiment of the present invention, S1 includes:

[0011] S1.1: Using PbO, ZrO2, TiO2, Bi2O3, Na2CO3, BaCO3, and H3BO3 as raw materials, each raw material is processed according to the chemical formula (1-x)Pb(ZrO2) a Ti 1-a O3-x(Bi) 0.5 Na 0.5 The first powder to be ball-milled was prepared by weighing and mixing the TiO3-ywt%BaZrO3-βwt%B2O3 according to the set values, and ball-milling the first powder to be ball-milled was performed using anhydrous ethanol as a solvent.

[0012] S1.2: The material after ball milling and mixing in step S1.1 is placed in a drying oven for drying and then sieved to obtain a first intermediate powder with uniform particle size distribution;

[0013] S1.3: The first intermediate powder is melted, and the resulting melt is poured into deionized water for water quenching to obtain glass fragments. The glass fragments are then ground and sieved to obtain the glass powder.

[0014] In one embodiment of the present invention, in step S1.1, the amount of anhydrous ethanol used is 1.0-3.0 ml of anhydrous ethanol per gram of powder to be ball-milled.

[0015] In one embodiment of the present invention, the heating rate of the melting treatment is 2-10℃ / min, the melting temperature is 1400-1500℃, and the melting time is 1-3h.

[0016] In one embodiment of the present invention, S2 includes:

[0017] S2.1: Using PbO, ZrO2, TiO2, Bi2O3, Na2CO3, and BaCO3 as raw materials, each raw material is processed according to the chemical formula (1-x)Pb(ZrO2) a Ti 1-a O3-x(Bi) 0.5 Na 0.5 The set values ​​of TiO3-ywt%BaZrO3 are weighed and mixed to form the second powder to be ball-milled. Anhydrous ethanol is used as a solvent to ball-mill and mix the second powder to be ball-milled.

[0018] S2.2: The material after ball milling and mixing in step S2.1 is placed in a drying oven for drying and then sieved to obtain a second intermediate powder with uniform particle size distribution;

[0019] S2.3: The second intermediate powder is calcined to obtain a calcined solid. The calcined solid is then ball-milled and sieved to obtain the ceramic powder with a perovskite phase structure.

[0020] In one embodiment of the present invention, S3 includes:

[0021] S3.1: The glass powder and the ceramic powder are mixed according to (1-x)Pb(Zr) a Ti 1-a O3-x(Bi) 0.5 Na 0.5 TiO3-ywt%BaZrO3-zwt%GL set value weighing ratio to form the third powder to be ball-milled, and the third powder to be ball-milled is ball-milled and mixed with anhydrous ethanol as solvent;

[0022] S3.2: The material after ball milling and mixing in step S3.1 is placed in a drying oven for drying and then sieved to obtain a third intermediate powder with uniform particle size distribution;

[0023] S3.3: After granulation and sieving, the third intermediate powder is dry-pressed using a mold to obtain a ceramic green body;

[0024] S3.4: The ceramic green body is subjected to debinding and solid-state sintering to obtain a piezoelectric ceramic block;

[0025] S3.5: After grinding and polishing the piezoelectric ceramic block, silver electrodes are coated and calcined on both sides to obtain (1-x)Pb(Zr) a Ti 1-a O3-x(Bi) 0.5 Na 0.5 TiO3-yBaZrO3-zGL piezoelectric ceramic finished product.

[0026] In one embodiment of the present invention, in S3.3, the granulation process uses a polyvinyl alcohol aqueous solution with a mass fraction of 5-12% as a binder.

[0027] In one embodiment of the present invention, the solid-state sintering includes a crystallization stage and a sintering stage, wherein the heating rate of the crystallization stage is 2-10℃ / min, the crystallization temperature is 700-900℃, and the crystallization time is 1-3h; the heating rate of the sintering stage is 2-10℃ / min, the sintering temperature is 1100-1300℃, and the sintering holding time is 1-3h; the entire solid-state sintering process is completed in a lead oxide atmosphere.

[0028] Another aspect of the present invention provides a large-strain piezoelectric ceramic material, prepared using the preparation method described in any one of the above embodiments, wherein the chemical formula of the large-strain piezoelectric ceramic material is (1-x)Pb(Zr) a Ti 1-a O3-x(Bi) 0.5 Na 0.5 TiO3-ywt%BaZrO3-zwt%GL, where GL has the composition (1-x)Pb(Zr) a Ti 1-a O3-x(Bi) 0.5 Na 0.5 TiO3-ywt%BaZrO3-βwt%B2O3, where x and a are molar ratios, and y, z, and β are mass ratios.

[0029] In one embodiment of the present invention, 0.88≤x≤0.98, 0.40≤a≤0.60, 1.0≤y≤4.0, 0.5≤z≤3.5, and 10≤β≤30.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] 1. The high-strain piezoelectric ceramic material of this invention, through modification by adding a special glass component to PZT-based piezoelectric ceramics, significantly increases the strain of the material by more than four times that of commercial piezoelectric ceramics while optimizing the microstructure of the ceramic material. The prepared high-strain piezoelectric ceramic material can overcome the practical application limitations caused by the low strain of commercial piezoelectric ceramics. Furthermore, due to the simple availability and low cost of raw materials, it is easily commercialized and can be applied to the field of large-stroke piezoelectric ceramic actuators.

[0032] 2. This invention uses ceramic powder as the basic material and B2O3 as the network forging body. After melting at high temperature and water quenching, glass powder is formed. Mixing the glass powder with ceramic powder can prepare high-strain piezoelectric ceramic materials. This optimizes the microstructure of the ceramic material and significantly improves its strain. By adjusting the amount of glass powder added, piezoelectric ceramic materials with different displacement strokes can be prepared, with the applied electric field between 30-100 kV / cm. This piezoelectric ceramic material contains a specially formulated glass component, which suppresses defect pinning and reduces the rigidity of grain boundaries, thereby increasing the material's strain. Furthermore, because the glass component promotes sintering, it improves the density of the piezoelectric ceramic.

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0034] Figure 1 This is a flowchart of a method for preparing a large-strain piezoelectric ceramic material according to an embodiment of the present invention;

[0035] Figure 2 This is a scanning electron microscope (SEM) image of the PZT-BNT-BZ piezoelectric ceramic material prepared in Comparative Example 1;

[0036] Figure 3 The image shows the uniaxial strain curve of the PZT-BNT-BZ piezoelectric ceramic material prepared in Comparative Example 1.

[0037] Figure 4 This is a scanning electron microscope (SEM) image of the PZT-BNT-BZ-0.5wt%GL piezoelectric ceramic material prepared in Example 2 of this invention;

[0038] Figure 5 The image shows the uniaxial strain curve of the PZT-BNT-BZ-1.5wt%GL piezoelectric ceramic material prepared in Example 3 of this invention.

[0039] Figure 6 This is the uniaxial strain curve of the PZT-BNT-BZ-2.0wt%GL piezoelectric ceramic material prepared in Example 4 of this invention. Detailed Implementation

[0040] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following detailed description of the large strain piezoelectric ceramic material and its preparation method according to the present invention is provided in conjunction with the accompanying drawings and specific embodiments.

[0041] The foregoing and other technical contents, features, and effects of the present invention will be clearly presented in the following detailed description of specific embodiments in conjunction with the accompanying drawings. Through the description of the specific embodiments, a more in-depth and concrete understanding can be gained of the technical means and effects adopted by the present invention to achieve its intended purpose. However, the accompanying drawings are for reference and illustration only and are not intended to limit the technical solutions of the present invention.

[0042] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or apparatus that includes said element.

[0043] Example 1

[0044] Please see Figure 1 , Figure 1 This is a flowchart illustrating a method for preparing a large-strain piezoelectric ceramic material according to an embodiment of the present invention. The preparation method includes:

[0045] S1: The composition (1-x)Pb(Zr) was synthesized using the melt-water quenching method. a Ti 1-a O3-x(Bi) 0.5 Na 0.5 (a) Glass powder of TiO3-ywt%BaZrO3-βwt%B2O3, where x and a are molar ratios and y and β are mass ratios.

[0046] Step S1 in this embodiment specifically includes:

[0047] S1.1: Using PbO, ZrO2, TiO2, Bi2O3, Na2CO3, BaCO3, and H3BO3 powders as raw materials, each raw material is processed according to the chemical formula (1-x)Pb(ZrO2) a Ti 1-a O3-x(Bi) 0.5 Na0.5 The first powder to be ball-milled was prepared by weighing and mixing TiO3-ywt%BaZrO3-βwt%B2O3 according to the set values. Anhydrous ethanol was used as the solvent and zirconium balls were used as the ball milling media. The first powder to be ball-milled was placed in a planetary ball mill for ball milling and mixing. The ball milling speed was 250-350 rpm and the time was 8-12 hours. The amount of anhydrous ethanol used was 1.0-3.0 ml of anhydrous ethanol per gram of the first powder to be ball-milled. The ball-to-powder mass ratio (mass ratio of ball milling media to powder to be ball-milled) was (1-2):1.

[0048] S1.2: The material after ball milling is placed in a drying oven for drying and then sieved to obtain a first intermediate powder with uniform particle size distribution. The drying temperature is 60-100℃ and the drying time is 1-3h. The mesh size of the sieve used for sieving is 100-200 mesh.

[0049] S1.3: The first intermediate powder obtained in S1.2 is placed in a corundum crucible and then melted at high temperature in a muffle furnace. The resulting melt is poured into deionized water for water quenching to obtain glass fragments. The glass fragments are then ground and sieved to obtain fine glass powder. Preferably, the heating rate of the high-temperature melting is 2-10℃ / min, the high-temperature melting temperature is 1400-1500℃, and the melting time is 1-3 hours; the sieve used in this step has a mesh size of 100-200 mesh.

[0050] S2: The component (1-x)Pb(Zr) was synthesized using a solid-state synthesis method. a Ti 1-a O3-x(Bi) 0.5 Na 0.5 TiO3-ywt%BaZrO3 ceramic powder.

[0051] Step S2 in this embodiment specifically includes:

[0052] S2.1: Using PbO, ZrO2, TiO2, Bi2O3, Na2CO3, and BaCO3 powders as raw materials, each raw material is processed according to the chemical formula (1-x)Pb(ZrO2)O3. a Ti 1-a O3-x(Bi) 0.5 Na 0.5 The set values ​​of TiO3-ywt%BaZrO3 are weighed and mixed to form a second powder to be ball-milled. Anhydrous ethanol is used as the solvent and zirconium balls are used as the ball milling medium. The second powder to be ball-milled is placed into a planetary ball mill for ball milling and mixing.

[0053] Preferably, the ball milling speed is 260-370 rpm and the time is 8-12 h; the amount of anhydrous ethanol used is: 1.0-3.0 ml of anhydrous ethanol is added for every gram of the second ball milling powder to be formed, and the ball-to-powder mass ratio is (1-2):1.

[0054] S2.2: The material mixed by ball milling in step S2.1 is placed in a drying oven for drying and then sieved to obtain a second intermediate powder with uniform particle size distribution. Preferably, the drying temperature is 80-120℃ and the drying time is 2-5 hours.

[0055] S2.3: The second intermediate powder obtained in step S2.2 is placed in a corundum crucible and then calcined at high temperature in a muffle furnace to obtain a calcined solid. The calcined solid is then ball-milled and sieved to obtain ceramic powder with a perovskite phase structure. Preferably, the calcination heating rate is 2-10℃ / min, the calcination temperature is 700-850℃, and the calcination time is 1-4h; the ball-milling conditions are the same as in S2.1; and the sieve mesh size used is 100-200 mesh.

[0056] S3: (1-x)Pb(Zr) was prepared by solid-state sintering using glass powder and ceramic powder. a Ti 1-a O3-x(Bi) 0.5 Na 0.5 TiO3-yBaZrO3-zGL piezoelectric ceramic material, wherein GL has the composition of (1-x)Pb(Zr) a Ti 1-a O3-x(Bi) 0.5 Na 0.5 )TiO3-ywt%BaZrO3-βwt%B2O3.

[0057] Step S3 in this embodiment specifically includes:

[0058] S3.1: Combine the glass powder obtained in step S1 with the ceramic powder obtained in step S2 according to (1-x)Pb(Zr) a Ti 1-a O3-x(Bi) 0.5 Na 0.5 The third powder to be ball-milled is prepared by weighing and mixing TiO3-ywt%BaZrO3-zwt%GL according to the set values. Anhydrous ethanol is used as the solvent and zirconium balls are used as the ball milling medium. The third powder to be ball-milled is placed in a planetary ball mill for ball milling and mixing. Preferably, the ball milling speed is 250-350 rpm and the time is 8-12 h. The amount of anhydrous ethanol used is 1.0-3.0 ml of anhydrous ethanol per gram of the third powder to be ball-milled, and the ball-to-powder mass ratio is (1-2):1.

[0059] S3.2: The material after ball milling in S3.1 is placed in a drying oven for drying and then sieved to obtain a third intermediate powder with uniform particle size distribution; the drying temperature is 80-150℃ and the drying time is 2-4h; the mesh size of the sieve used is 100-200 mesh.

[0060] S3.3: After granulation and sieving of the third intermediate powder obtained in step S3.2, dry pressing is performed using a cylindrical mold to obtain a ceramic green body.

[0061] Specifically, in this embodiment, the granulation process uses a 5-12% (w / w) polyvinyl alcohol (PVA) aqueous solution as a binder; the sieve mesh size used for sieving is 40-200 mesh; the diameter of the cylindrical mold is 10-13 mm; the dry pressing pressure used for dry pressing is 6-10 MPa, and the dry pressing time is 1-3 min.

[0062] S3.4: The ceramic green body generated in step S3.3 is subjected to debinding and high-temperature solid-state sintering to obtain a piezoelectric ceramic bulk body.

[0063] Preferably, in this embodiment, the heating rate of the glue removal process is 2-10°C / min, the glue removal temperature is 500-600°C, and the glue removal time is 1-4 hours.

[0064] The solid-state sintering process in this embodiment is divided into a crystallization stage and a sintering stage. In the crystallization stage, the ceramic body is not completely dense, and the low-melting-point glass components can fully fill the grain boundaries, thereby effectively reducing the rigid resistance of the grain boundaries to domain wall migration. The heating rate in the crystallization stage is 2-10℃ / min, and the crystallization temperature is 700-900℃. This crystallization temperature is slightly higher than the glass transition temperature, which can keep the glass in a viscoelastic state without causing a large amount of crystallization, thus allowing it to fully fill the ceramic grain boundaries. The crystallization time is 1-3 hours. The heating rate in the sintering stage is 2-10℃ / min, and the sintering temperature is 1100-1300℃. The sintering holding time is 1-3 hours. The entire solid-state sintering process is completed in a lead oxide atmosphere.

[0065] S3.5: After grinding and polishing the piezoelectric ceramic block, electrodes are coated on both sides and then calcined to obtain (1-x)Pb(Zr) a Ti 1-a O3-x(Bi) 0.5 Na 0.5 TiO3-yBaZrO3-zGL piezoelectric ceramic finished product.

[0066] Specifically, the grinding disc used for grinding is 200-1200 mesh; the polishing disc is 1-15μm; the electrode is a silver electrode, and its firing heating rate is 2-10℃ / min, the firing temperature is 550-700℃, and the firing time is 10-30min.

[0067] Furthermore, another embodiment of the present invention provides a large-strain piezoelectric ceramic material with the chemical formula (1-x)Pb(Zr) a Ti 1-a O3-x(Bi) 0.5 Na 0.5 TiO3-ywt%BaZrO3-zwt%GL, where GL has the composition (1-x)Pb(Zr) a Ti 1-a O3-x(Bi) 0.5 Na 0.5 TiO3-ywt%BaZrO3-βwt%B2O3, where x and a are molar ratios, 0.88≤x≤0.98, 0.40≤a≤0.60, and y, z, and β are mass ratios, 1.0≤y≤4.0, 0.5≤z≤3.5, 10≤β≤30;

[0068] This invention provides a method for preparing a high-strain piezoelectric ceramic material. B2O3 is added to the powder raw materials used in ceramic preparation as a glass network forging body. After melting and water quenching at high temperature, B2O3 forms glass powder. The glass powder is then mixed with ceramic powder to prepare a novel piezoelectric ceramic material. The amorphous structure of the glass effectively reduces the bonding effect between Pb-O bonds, hindering the formation of long-range banded ferroelectric domains, thereby reducing the pinning effect of defects on long-range ferroelectric ordered domains. Furthermore, the high elastic modulus of the glassy state distributed at grain boundaries can also reduce the rigidity of grain boundaries hindering domain flipping, thus significantly increasing the strain of the material. By adjusting the amount of glass component added, (1-x)Pb(Zr) is obtained. a Ti 1-a O3-x(Bi) 0.5 Na 0.5 TiO3-ywt%BaZrO3(PZT-BNT-BZ)-zwt%GL piezoelectric ceramic material, where GL represents the composition (1-x)Pb(ZrO3) a Ti 1-a O3-x(Bi) 0.5 Na 0.5 The glass is composed of TiO3-ywt%BaZrO3-βwt%B2O3. The piezoelectric ceramic material prepared by this invention exhibits strain far exceeding that of commercial PZT and existing modified PZT materials, and has a low preparation cost.

[0069] Comparative Example 1

[0070] The present invention also provides a comparative example, wherein the piezoelectric ceramic material of the comparative example is a PZT-BNT-BZ material without added glass components, and its chemical formula is 0.95Pb(Zr) 0.56 Ti0.44 )O3-0.05(Bi 0.5 Na 0.5 TiO3-3wt% BaZrO3. Comparative Example 1 was used to compare the advantages of the PZT-BNT-BZ-GL piezoelectric ceramic materials in Examples 2 to 4 in terms of strain magnitude and microstructure. The PZT-BNT-BZ piezoelectric ceramic material of Comparative Example 1 was prepared by solid-state synthesis and solid-state sintering. The preparation process specifically included the following steps:

[0071] (1) PZT-BNT-BZ powder was prepared by solid-state synthesis: PbO, ZrO2, TiO2, Bi2O3, Na2CO3, and BaCO3 powders were mixed in a ratio of 0.95Pb(ZrO2) / 0.95. 0.56 Ti 0.44 )O3-0.05(Bi 0.5 Na 0.5 The chemical formula of TiO3-3wt%BaZrO3 was weighed and prepared. 2 ml of anhydrous ethanol and 1 g of zirconium balls were added to each gram of powder as solvent and milling medium, respectively. The mixture was ball-milled at 300 rpm for 12 hours. The ball-milled material was dried at 80℃ for 2 hours and passed through a 100-mesh sieve to obtain a uniform powder. This uniform powder was placed in a corundum crucible and then placed in a muffle furnace. The temperature was increased to 800℃ at a rate of 5℃ / min and held for 2 hours. After cooling in the furnace, the synthesized powder was ball-milled a second time and dried, then passed through a 200-mesh sieve to obtain perovskite-structured powder.

[0072] (2) Preparation of PZT-BNT-BZ bulk ceramics by solid-state sintering: 7% (w / w) polyvinyl alcohol (PVA) aqueous solution was used as a binder for granulation. The granulated perovskite structure powder was passed through a 50-mesh sieve and placed in a cylindrical mold, which was pressed into shape under a pressure of 8 MPa to obtain a green body. The green body was placed in a muffle furnace and heated to 600℃ at a heating rate of 2℃ / min, and held for 2 hours to remove the binder. The sample after binder removal was embedded in PbO powder, and then heated to 1200℃ at a heating rate of 5℃ / min, held for 2 hours, and cooled in the furnace to obtain bulk ceramics.

[0073] (3) Ferroelectric performance test: The above-mentioned bulk ceramic was thinned to 0.2 mm on both sides using a 400-mesh grinding wheel, and then polished for 15 min using a 9 μm polishing wheel. Silver electrodes with a diameter of 8 mm were coated on both sides of the polished ceramic block, and the block was placed in a muffle furnace and heated to 650 °C at a heating rate of 5 °C / min. After holding at this temperature for 15 min, the block was cooled with the furnace to obtain the sample to be tested.

[0074] The microstructure of the PZT-BNT-BZ piezoelectric ceramic without added glass components in Comparative Example 1 was observed using a scanning electron microscope, such as... Figure 2As shown, the PZT-BNT-BZ piezoelectric ceramic in Comparative Example 1 exhibits a relatively dense microstructure.

[0075] The PZT-BNT-BZ piezoelectric ceramic prepared in Comparative Example 1 was subjected to uniaxial strain curve testing at room temperature within a test electric field range of 20-50 kV / cm. The results are as follows. Figure 3 As shown, it achieved a strain of 0.41% under an electric field of 50 kV / cm.

[0076] Example 2

[0077] Based on Example 1, this example provides a PZT-BNT-BZ-0.5wt%GL piezoelectric ceramic material, whose chemical formula is 0.95Pb(Zr) 0.56 Ti 0.44 )O3-0.05(Bi 0.5 Na 0.5 TiO3-3wt% BaZrO3-0.5wt% GL, wherein the chemical formula of GL is expressed as 0.95Pb(Zr) 0.56 Ti 0.44 )O3-0.05(Bi 0.5 Na 0.5 TiO3-3wt% BaZrO3-20wt% B2O3. This embodiment uses a melt-water quenching, solid-state synthesis, and solid-state sintering method to prepare PZT-BNT-BZ-0.5wt% GL piezoelectric ceramic material. The specific preparation process includes the following steps:

[0078] (1) Preparation of GL component by melt-water quenching method: PbO, ZrO2, TiO2, Bi2O3, Na2CO3, BaCO3, and H3BO3 powders were mixed in a ratio of 0.95Pb(ZrO2) / 0.95. 0.56 Ti 0.44 )O3-0.05(Bi 0.5 Na 0.5 The chemical formulas TiO3 (3wt%), BaZrO3 (20wt%), and B2O3 were weighed and mixed. 2 ml of anhydrous ethanol and 1 g of zirconium balls were added to each gram of powder as solvent and milling medium, respectively. The mixture was ball-milled at 300 rpm for 12 hours. The ball-milled material was dried at 80℃ for 2 hours and passed through a 100-mesh sieve to obtain a uniform powder. This uniform powder was placed in a corundum crucible and then placed in a muffle furnace. The temperature was increased to 1450℃ at a rate of 5℃ per minute and held for 2 hours for high-temperature melting. The melt obtained from the high-temperature melting was poured into deionized water for quenching to obtain glass fragments. The glass fragments were thoroughly ground and passed through a 200-mesh sieve to obtain fine glass powder.

[0079] (2) PZT-BNT-BZ powder was prepared by solid-state synthesis: PbO, ZrO2, TiO2, Bi2O3, Na2CO3, and BaCO3 powders were mixed in an amount of 0.95Pb(ZrO2) / 0.95. 0.56 Ti 0.44 )O3-0.05(Bi 0.5 Na 0.5 The chemical formula of TiO3-3wt%BaZrO3 was used. 2 ml of anhydrous ethanol and 1 g of zirconium balls were added to each gram of powder as solvent and milling medium, respectively. The mixture was ball-milled at 300 rpm for 12 hours. The ball-milled material was dried at 80℃ for 2 hours and passed through a 100-mesh sieve to obtain a uniform powder. This uniform powder was placed in a corundum crucible and then placed in a muffle furnace. The temperature was increased to 800℃ at a heating rate of 5℃ / min, held for 2 hours, and then cooled with the furnace. The synthesized powder was ball-milled and dried a second time, and then passed through a 200-mesh sieve to obtain a perovskite structure powder.

[0080] (3) Preparation of PZT-BNT-BZ-0.5wt%GL piezoelectric ceramics by solid-state sintering: The glass powder obtained in step (1) and the perovskite structure powder obtained in step (2) were weighed and mixed according to the set value of PZT-BNT-BZ-0.5wt%GL. 2 ml of anhydrous ethanol and 1 g of zirconium balls were added to each gram of powder as solvent and ball milling medium, respectively, and the mixture was ball milled at 300 rpm for 12 h. The ball-milled material was dried at 80℃ for 2 h and passed through a 100-mesh sieve to obtain uniform powder. The uniform powder was granulated using a 7% (w / w) polyvinyl alcohol (PVA) aqueous solution as a binder to obtain granulated powder. The granulated powder was passed through a 50-mesh sieve and placed in a cylindrical mold, and pressed into shape under a pressure of 8 MPa to obtain a green preform. The green preform was placed in a muffle furnace and heated to 600℃ at a heating rate of 2℃ 1 min, and held for 2 h for debinding. The sample after debinding was embedded in PbO powder, and then heated to 850°C at a heating rate of 5°C / min, and held for 2 hours to crystallize the glass components. After that, the temperature was increased to 1150°C at a heating rate of 5°C / min, and then cooled in the furnace to obtain a ceramic block.

[0081] (4) Microstructure test: The ceramic block generated in this embodiment was thinned to 0.2 mm on both sides using a 400-mesh grinding wheel, and then polished for 15 min using a 9 μm polishing wheel. The polished ceramic block was placed in a muffle furnace and heated to 950 °C at a heating rate of 5 °C 1 min. After holding at that temperature for 30 min, it was subjected to hot corrosion and then cooled with the furnace to obtain the sample to be tested.

[0082] The microstructure of the PZT-BNT-BZ-0.5wt%GL piezoelectric ceramic prepared in this embodiment was observed using a scanning electron microscope, such as... Figure 4As shown, the sample exhibits a dense microstructure. Compared to the PZT-BNT-BZ piezoelectric ceramic without added glass components in Comparative Example 1, the PZT-BNT-BZ-0.5wt%GL piezoelectric ceramic prepared in this embodiment has a more uniform grain distribution and lower internal porosity.

[0083] Example 3

[0084] Based on Example 1, this example provides a PZT-BNT-BZ-1.5wt%GL piezoelectric ceramic material, whose chemical formula is 0.95Pb(Zr) 0.56 Ti 0.44 )O3-0.05(Bi 0.5 Na 0.5 TiO3-3wt% BaZrO3-1.5wt% GL, wherein the chemical formula of GL is expressed as 0.95Pb(Zr) 0.56 Ti 0.44 )O3-0.05(Bi 0.5 Na 0.5 The materials used in this embodiment are TiO3-3wt% BaZrO3-20wt% B2O3. PZT-BNT-BZ-1.5wt%GL piezoelectric ceramic material was prepared using a melt-water quenching, solid-state synthesis, and solid-state sintering method. The preparation method is the same as in Example 2, and the ferroelectric performance testing method is the same as in Comparative Example 1.

[0085] The PZT-BNT-BZ-1.5wt%GL piezoelectric ceramic material in this embodiment was subjected to uniaxial strain curve testing at room temperature within a test electric field range of 60-100kV 1cm. The results are as follows: Figure 5 As shown, a strain of 0.50% was obtained under an electric field of 60 kV / cm, and a strain of 0.68% was obtained under an electric field of 90 kV / cm. Compared with the PZT-BNT-BZ piezoelectric ceramic without glass component in Comparative Example 1, the uniaxial strain of the PZT-BNT-BZ-1.5wt%GL piezoelectric ceramic material prepared in this embodiment is improved to a certain extent.

[0086] Example 4

[0087] Based on Example 1, this example provides a PZT-BNT-BZ-2.0wt%GL piezoelectric ceramic material, whose chemical formula is 0.95Pb(Zr) 0.56 Ti 0.44 )O3-0.05(Bi 0.5 Na 0.5 TiO3-3wt% BaZrO3-2.0wt% GL, wherein the chemical formula of GL is expressed as 0.95Pb(Zr) 0.56 Ti 0.44 )O3-0.05(Bi0.5 Na 0.5 The materials used in this embodiment are TiO3-3wt% BaZrO3-20wt% B2O3. PZT-BNT-BZ-2.0wt%GL piezoelectric ceramic material was prepared using a melt-water quenching, solid-state synthesis, and solid-state sintering method. The piezoelectric ceramic preparation method was the same as in Example 2, and the ferroelectric performance testing method was the same as in Comparative Example 1.

[0088] The PZT-BNT-BZ-2.0wt%GL material in this embodiment was subjected to uniaxial strain curve testing at room temperature within a test electric field range of 30-100kV / cm. The results are as follows. Figure 6 As shown, a strain of 0.60% was obtained under an electric field of 50 kV / cm, and a strain of 0.92% was obtained under an electric field of 100 kV / cm. Compared with the PZT-BNT-BZ piezoelectric ceramic without glass component in Comparative Example 1, the uniaxial strain of the PZT-BNT-BZ-2.0wt%GL piezoelectric ceramic material prepared in this embodiment is significantly improved.

[0089] The above results demonstrate that the PZT-BNT-BZ piezoelectric ceramic material exhibits a denser microstructure and higher strain after the addition of the GL component.

[0090] In summary, the high-strain piezoelectric ceramic material prepared by this invention, through modification by adding a special glass component to PZT-based piezoelectric ceramics, significantly increases the strain of the material by more than four times that of commercial piezoelectric ceramics while optimizing the microstructure of the ceramic material. The prepared high-strain piezoelectric ceramic material can overcome the practical application limitations caused by the low strain of commercial piezoelectric ceramics. Furthermore, due to the simple availability and low cost of raw materials, it is easily commercialized and can be applied to the field of large-stroke piezoelectric ceramic actuators.

[0091] This invention uses ceramic powder as the basic material and B2O3 as the network forging body. After melting at high temperature and water quenching, glass powder is formed. Mixing the glass powder with ceramic powder can prepare high-strain piezoelectric ceramic materials. This optimizes the microstructure of the ceramic material and significantly increases its strain. By adjusting the amount of glass powder added, piezoelectric ceramic materials with different displacement strokes can be prepared, with the applied electric field ranging from 30-100 kV / cm. This piezoelectric ceramic material contains a specially formulated glass component, which suppresses defect pinning and reduces the rigidity of grain boundaries, thereby increasing the material's strain. Furthermore, because the glass component promotes sintering, it improves the density of the piezoelectric ceramic.

[0092] In the several embodiments provided by this invention, it should be understood that the apparatus and methods disclosed in this invention can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For example, the division of modules is merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed.

[0093] Furthermore, the functional modules in the various embodiments of the present invention can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated module can be implemented in hardware or in the form of hardware plus software functional modules.

[0094] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A method of producing a large-strain piezoelectric ceramic material, characterized by, include: S1: Synthesis of glass powder GL with composition of (1- x ) Pb(Zr a Ti 1-a )O3- x (Bi 0.5 Na 0.5 )TiO3- y wt% BaZrO3- β wt% B2O3 by using melt-water quenching method, wherein, x , a is a molar ratio, y , β is a mass ratio; S2: The component (1- was synthesized using solid-phase synthesis.) x Pb(Zr) a Ti 1-a O3- x (Bi 0.5 Na 0.5 TiO3- y Ceramic powder containing wt% BaZrO3; S3: Using the glass powder and the ceramic powder, (1-) are prepared by solid-state sintering. x Pb(Zr) a Ti 1-a O3- x (Bi 0.5 Na 0.5 TiO3- y wt%BaZrO3 -z wt% GL piezoelectric ceramic material, wherein GL is composed of (1- x Pb(Zr) a Ti 1-a O3- x (Bi 0.5 Na 0.5 TiO3- y wt%BaZrO3- β wt%B2O3, x =0.05, a =0.56, y =3, 0.5≤ z ≤3.5, β =20.

2. The method for preparing the large strain piezoelectric ceramic material according to claim 1, characterized in that, S1 includes: S1.1: Using PbO, ZrO2, TiO2, Bi2O3, Na2CO3, BaCO3, and H3BO3 as raw materials, each raw material is processed according to the chemical formula (1- x Pb(Zr) a Ti 1-a O3- x (Bi 0.5 Na 0.5 TiO3- y wt%BaZrO3- β Weigh and mix the first powder to be ball-milled using the set value of wt% B2O3, and ball-mill the first powder to be ball-milled using anhydrous ethanol as a solvent. S1.2: The material after ball milling and mixing in step S1.1 is placed in a drying oven for drying and then sieved to obtain a first intermediate powder with uniform particle size distribution; S1.3: The first intermediate powder is melted, and the resulting melt is poured into deionized water for water quenching to obtain glass fragments. The glass fragments are then ground and sieved to obtain the glass powder.

3. The method for preparing large-strain piezoelectric ceramic materials according to claim 2, characterized in that, In S1.1, the amount of anhydrous ethanol used is: 1.0-3.0 ml of anhydrous ethanol is added to each gram of the first powder to be ball-milled.

4. The method for preparing large-strain piezoelectric ceramic materials according to claim 2, characterized in that, The heating rate of the melting process is 2-10℃ / min, the melting temperature is 1400-1500℃, and the melting time is 1-3 h.

5. The method for preparing large-strain piezoelectric ceramic materials according to claim 2, characterized in that, S2 includes: S2.1: Using PbO, ZrO2, TiO2, Bi2O3, Na2CO3, and BaCO3 as raw materials, each raw material is processed according to the chemical formula (1- x Pb(Zr) a Ti 1-a O3- x (Bi 0.5 Na 0.5 TiO3- y Weigh and mix the ingredients according to the set value of wt% BaZrO3 to form the second powder to be ball-milled, and use anhydrous ethanol as a solvent to ball-mill and mix the second powder to be ball-milled. S2.2: The material after ball milling and mixing in step S2.1 is placed in a drying oven for drying and then sieved to obtain a second intermediate powder with uniform particle size distribution; S2.3: The second intermediate powder is calcined to obtain a calcined solid. The calcined solid is then ball-milled and sieved to obtain the ceramic powder with a perovskite phase structure.

6. The method for preparing the large strain piezoelectric ceramic material according to claim 1, characterized in that, S3 includes: S3.1: The glass powder and the ceramic powder are mixed according to (1- x Pb(Zr) a Ti 1-a O3- x (Bi 0.5 Na 0.5 TiO3- y wt%BaZrO3 -z The third powder to be ball-milled is prepared by weighing and mixing according to the set value of wt%GL, and the third powder to be ball-milled is mixed by ball milling with anhydrous ethanol as solvent. S3.2: The material after ball milling and mixing in step S3.1 is placed in a drying oven for drying and then sieved to obtain a third intermediate powder with uniform particle size distribution; S3.3: After granulation and sieving, the third intermediate powder is dry-pressed using a mold to obtain a ceramic green body; S3.4: The ceramic green body is subjected to debinding and solid-state sintering to obtain a piezoelectric ceramic block; S3.5: After grinding and polishing the piezoelectric ceramic block, silver electrodes are coated and calcined on both sides to obtain (1- x Pb(Zr) a Ti 1-a O3- x (Bi 0.5 Na 0.5 TiO3- y wt%BaZrO3 -z wt%GL piezoelectric ceramic finished products.

7. The method for preparing the large strain piezoelectric ceramic material according to claim 6, characterized in that, In S3.3, the granulation process uses a polyvinyl alcohol aqueous solution with a mass fraction of 5-12% as a binder.

8. The method for preparing the large strain piezoelectric ceramic material according to claim 6, characterized in that, The solid-state sintering includes a crystallization stage and a sintering stage. The crystallization stage has a heating rate of 2-10 °C / min, a crystallization temperature of 700-900 °C, and a crystallization time of 1-3 h. The sintering stage has a heating rate of 2-10 °C / min, a sintering temperature of 1100-1300 °C, and a sintering holding time of 1-3 h. The entire solid-state sintering process is completed in a lead oxide atmosphere.

9. A large-strain piezoelectric ceramic material, characterized in that, Prepared using the preparation method according to any one of claims 1 to 8.

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