Grain-oriented piezoelectric ceramic and method for manufacturing the same

Abstract

This invention belongs to the field of intelligent piezoelectric materials technology, and discloses a grain-oriented piezoelectric ceramic material and its preparation method. The grain-oriented piezoelectric ceramic material is... <001> Oriented and ferromagnetic barium titanate / strontium-based template seed crystals, with the general formula: X Pb 1‑1.5x R x (B1,B2)O3- Y Pb 1‑y A y (B1,B2)O3-(1- X - Y-Z PbB3O3- Z The ceramic matrix of PbTiO3, wherein A is one or more of barium, strontium, calcium, and bismuth; B1 is one or more of magnesium, nickel, indium, and scandium; B2 is one or more of niobium, tantalum, and antimony; B3 is zirconium or tin; and R is one or more of Sm, La, Nd, Eu, Ce, Pr, Dy, and Er. x is between 0.001 and 0.2, y does not exceed 0.1; X is between 0.1 and 0.3, Y is between 0 and 0.2, and X+Y+Z=1. The raw materials are calcined according to the general formula to obtain perovskite powder. Subsequently, through casting, lamination, cutting, debinding, and calcination, the grain-oriented piezoelectric ceramic is finally obtained. This process can achieve high piezoelectric performance while maintaining a high Curie temperature, solving the problem of the incompatibility between high piezoelectric performance and high phase transition temperature in materials.

Description

Technical Field

[0001] This invention relates to the field of intelligent piezoelectric materials technology, specifically to a grain-oriented piezoelectric ceramic and its preparation method. Background Technology

[0002] The current research and development of high-performance piezoelectric materials relies on a variety of mature basic technologies, mainly including the following three approaches: Quasi-isomorphic phase boundary control: Early perovskite materials, represented by lead zirconate titanate, utilized quasi-isomorphic phase boundary structure control to optimize domain structure and piezoelectric response, becoming a classic design approach for improving piezoelectric performance; Microscopic control: With advancements in microscopic characterization techniques, microstructural optimization methods such as polar nanoscale micro-region control and domain wall engineering have been applied. By precisely controlling the domain wall motion state, the high piezoelectric coefficient, low loss, and operational stability of the material can be effectively balanced; Texture engineering: Researchers arrange ceramic grains along specific directions to form grain-oriented textured piezoelectric ceramics. This material can achieve the maximum piezoelectric performance of piezoelectric materials, which is 2-3 times that of traditional ceramic piezoelectric performance. These approaches lay a solid technical foundation for the component design, structural modification, and performance optimization of novel high-performance piezoelectric materials.

[0003] 1) Design Background of Perovskite Structure and Quasi-Isomorphic Phase Boundary (MPB) The classic PZT (lead zirconate titanate) system was discovered in 1950. Based on the ABO3 perovskite structure, it exhibits a trigonal-tetragonal quasi-isomorphic phase boundary (MPB) near Zr / Ti≈52 / 48. At the MPB, PZT piezoelectric materials exhibit minimal polarization anisotropy and easy domain wall inversion. 33 k p Significant improvement; becoming the core guiding principle for subsequent high-performance piezoelectric design. MPB design and element doping, although they improve the piezoelectricity of materials (d... 33 (~500~700pC / N), however, it will also reduce its piezoelectric properties, for example, d 33 The Curie temperature of ~700pC / N piezoelectric ceramics is only 180℃, which is insufficient to meet the requirements of devices that have both high voltage performance and high Curie temperature.

[0004] 2) Nanodomain and domain wall engineering (polar nanodomains, domain wall pinning / depinning) Since 2010, transmission electron microscopy and synchrotron radiation have revealed the correlation between polar nanoregions (PNR) in relaxor ferroelectrics and the high performance of piezoelectric materials; domain wall density and mobility directly determine d 33 Regarding dielectric loss, researchers have disrupted the long-range order of ferroelectric domains by introducing polar nanodomains at the mesoscale, thereby controlling defects and interface engineering to achieve high-density movable domain walls with moderate pinning, significantly improving the piezoelectric properties of the material. However, this disruption of the long-range order of ferroelectric domains significantly reduces the material's phase transition temperature and Curie temperature (<120℃), limiting its application in devices.

[0005] 3) Texturing Engineering Researchers have developed textured ceramics by inducing the directional growth of ceramic powder using templates to achieve preferred orientations. These materials leverage the anisotropy of crystalline piezoelectric properties, maximizing piezoelectric performance in the preferred direction and thus enhancing both the piezoelectric and electromechanical coupling properties of the ceramic. Currently, the piezoelectric coefficient d... 33 It can reach 1000pC / N, the highest d of Eu-PMN-PT textured ceramics. 33 It can reach 1900 pC / N, but its Curie temperature is only 80°C, which severely limits its use in devices.

[0006] In summary, although the above design schemes can improve the piezoelectric properties of the material, they all come at the cost of sacrificing the Curie temperature of the material. They cannot overcome the contradictory relationship between piezoelectric properties and Curie temperature, that is, the higher the piezoelectric properties, the lower the Curie temperature. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a grain-oriented piezoelectric ceramic with both high piezoelectric properties and a high phase transition temperature, as well as its preparation method. This material can achieve high piezoelectric properties (d 33 While maintaining a high Curie temperature (>1500pC / N), it also has a high Curie temperature (T). c >200℃), which solves the technical problem that existing materials cannot simultaneously achieve high voltage electrical properties and high phase transition temperature.

[0008] To achieve the above objectives, the present invention provides a grain-oriented piezoelectric ceramic material, wherein the grain-oriented piezoelectric ceramic material is... <001> Oriented, ferromagnetic barium titanate or strontium titanate-based sheet templates, with the general formula: X Pb 1-1.5x R x (B1,B2)O3- Y Pb 1-y A y (B1,B2)O3-(1- X - YZ PbB3O3- Z The ceramic matrix of PbTiO3 is wherein A is one or more of barium, strontium, calcium, and bismuth; B1 is one or more of magnesium, nickel, indium, and scandium; B2 is one or more of niobium, tantalum, and antimony; B3 is one of zirconium and tin; R is one or more of Sm, La, Nd, Eu, Ce, Pr, Dy, and Er; x is between 0.001 and 0.2, y does not exceed 0.1; X is between 0.1 and 0.3, Y is between 0 and 0.2, and X+Y+Z=1.

[0009] Furthermore, the physical properties satisfy at least one of the following characteristics: (1) Piezoelectric coefficient d 33 The value is 1500~1900 pC / N. (2) Dielectric loss is 0.3%~0.9%, (3) Curie temperature is above 200℃, (4) Electromechanical coupling coefficient k 33 >0.85%.

[0010] Furthermore, a ferromagnetic template sheet is used for orientation under a strong magnetic field. The general formula for ferromagnetic templates is BaTi. 1-x (Fe 1 / 2 B4) x O3, x=0.05-0.15, B4 is niobium, tantalum or vanadium.

[0011] A method for preparing the above-mentioned grain-oriented piezoelectric ceramic material is also provided, comprising the following steps: Raw materials are prepared according to the general formula for grain-oriented piezoelectric ceramic materials. The raw materials are mixed evenly by wet ball milling and then dried to obtain a dry mixed powder. The dried mixed powder is sieved and calcined at 750℃-880℃ for 2-4 hours to obtain ceramic powder. The ceramic powder is mixed evenly with solvent, dispersant, binder, plasticizer, sintering aid and sheet template with ferromagnetic properties to obtain casting slurry; The casting paste is cast into a thin film under the action of an external magnetic field; The film is cut, hot-pressed and laminated, and then heated to remove organic matter to obtain a green body; The obtained green body was sintered to obtain a grain-oriented piezoelectric ceramic material.

[0012] Furthermore, the raw materials are all oxides of the corresponding metal elements.

[0013] Furthermore, a 40-mesh sieve is used when sieving the dried mixed powder.

[0014] Furthermore, the sintering temperature of the obtained green body is 1200℃-1280℃, and the sintering time is 2-15h.

[0015] Furthermore, the applied magnetic field strength is 0.06T-0.1T.

[0016] Furthermore, the ferromagnetic sheet template has a length of 3–25 micrometers, a thickness of 0.2 ± 2 micrometers, an aspect ratio greater than 8, and x = 0.05–0.15. The general formula for the ferromagnetic sheet template is BaTi. 1-x (Fe 1 / 2 B4) xO3 and B4 are niobium, tantalum, or vanadium.

[0017] Furthermore, the solvent is 1 to 5 times the mass of the powder, and the solvent can be one or more of ethanol, xylene, ethyl acetate, and methyl ethyl ketone; the dispersant is 0.5 wt.% to 5 wt.% of the powder mass, and the dispersant can be KD-1 or triolein; the binder is 4 wt.% to 8 wt.% of the powder mass, and the binder is PVB; the plasticizer is 1 wt.% to 12 wt.% of the powder mass, and the plasticizer is one or more of polyethylene glycol, butyl benzyl phthalate, and polyethylene glycol; the sintering aid is 0.1 wt.% to 2 wt.% of the powder mass, and the sintering aid is copper oxide, manganese oxide, or lithium carbonate; and the sheet-like template with ferromagnetic properties is 0.5 wt.% to 7 wt.% of the powder mass.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects: The material of this invention utilizes template seed crystals with ferromagnetic properties and magnetic field-assisted casting to further enhance the orientation degree of artificially oriented ceramic grains, thereby obtaining higher piezoelectric properties and electromechanical coupling properties. This invention utilizes rare earth elements to regulate the microstructure of ceramics, further improving the piezoelectric properties and electromechanical coupling properties of grain-oriented ceramics. This invention utilizes the reactivity of rare earth elements to modify the ceramic matrix and template, reducing the risk of template seed crystals being corroded or reacted away, curbing the decrease in ceramic Curie temperature and phase transformation temperature, and ensuring the high Curie temperature of artificially oriented piezoelectric ceramics. Attached Figure Description

[0019] Figure 1 To implement BaTi in Case Six 1-x (Fe 1 / 2 Ta 1 / 2 ) x SEM image of O3 (x=0.15) sheet-like template seed crystal; Figure 2 To implement the 0.1Pb in Case 7 0.7 Nd 0.2 (Ni 1 / 2 Nb 2 / 3 O3-0.2Pb 0.9 Ba 0.1 (Ni 1 / 2 Nb 2 / 3 XRD patterns of artificially oriented and unoriented piezoelectric ceramics with O3-0.30PbZrO3-0.40PbTiO3 grains; Figure 3To implement Case 8, SEM images and average grain size data of Sm and Ba co-doped PIN-PSN-PT grain artificially oriented piezoelectric ceramics were obtained. Figure 4 To implement the 0.1Pb in Case 7 0.7 Nd 0.2 (Ni 1 / 2 Nb 2 / 3 O3-0.2Pb 0.9 Ba 0.1 (Ni 1 / 2 Nb 2 / 3 Electrostrain curves of artificially oriented piezoelectric ceramics with grains of O3-0.30PbZrO3-0.40PbTiO3; Figure 5 Implementation Case 6: 0.1 Pb 0.7 Er 0.2 (Mg 1 / 2 Nb 2 / 3 O3-0.2Pb 0.9 Sr 0.1 (Mg 1 / 2 Nb 2 / 3 Dielectric temperature spectrum of artificially oriented piezoelectric ceramics with grains of O3-0.30PbZrO3-0.40PbTiO3. Detailed Implementation

[0020] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Unless otherwise specified, all embodiments and preferred methods mentioned in this invention can be combined to form new technical solutions.

[0022] Unless otherwise specified, all technical features and preferred features mentioned in this invention can be combined to form new technical solutions.

[0023] Example 1: The 0.25Pb alloy described in this invention possesses both high voltage electrical properties and a high phase transition temperature. 0.9985 Sm 0.001 (Mg 1 / 2Nb 2 / 3 O3-0.15Pb 0.9 Ba 0.1 (Mg 1 / 2 Ta 2 / 3The preparation process of artificially oriented piezoelectric ceramics with O3-0.2PbSnO3-0.4PbTiO3 grains includes the following steps: Step 1: Preparation of ceramic powder (11) Using high-purity lead oxide, samarium oxide, magnesium oxide, niobium oxide, barium carbonate, tantalum oxide, tin oxide, and titanium oxide as raw materials, according to 0.25Pb 0.9985 Sm 0.001 (Mg 1 / 2 Nb 2 / 3 O3-0.15Pb 0.95 Ba 0.1 (Mg 1 / 2 Ta 2 / 3 Weigh the materials according to the stoichiometric ratio of O3-0.2PbSnO3-0.4PbTiO3; (12) The above raw materials are mixed by wet ball milling and then dried; (13) Pass the dried powder from step (12) through a 40-mesh sieve to obtain a uniform and well-dispersed powder, and calcine it at 850°C for 2 hours to obtain ceramic powder; Step 2: Preparation of grain-oriented piezoelectric ceramics (21) Ceramic powder (100g) is mixed with solvent (500g of xylene and alcohol in a 1:1 ratio), dispersant (KD-10.5g), binder (PVB10g), plasticizer (12g of polyethylene glycol and butyl benzyl phthalate), sintering aid (copper oxide0.1g), and BaTi with ferromagnetic properties. 1-x (Fe 1 / 2 Nb 1 / 2 ) x O3 (x=0.05) flake template seed crystals (7g) were mixed evenly to obtain casting slurry; (22) The slurry in (21) is cast into a film in a magnetic field with a magnetic field strength of 0.1T using a casting machine; (23) Cut the film strip in step (22) into a specific size, stack it in a hot press to obtain a blank, and remove the organic matter at 600°C to obtain a green blank; (24) The blank in step (23) is sintered at 1200℃ for 15h to allow the ceramic matrix to grow directionally around the template to obtain piezoelectric ceramic with artificially oriented grains.

[0024] Measurements showed that the piezoelectric coefficient d of this grain-oriented piezoelectric ceramic material was... 33 ~1550pC / N, Curie temperature 269℃, dielectric loss ~0.35%, electromechanical coupling coefficient k 33 ~0.90.

[0025] Figure 1BaTi used in Example 1 1-x (Fe 1 / 2 Ta 1 / 2 ) x SEM image of O3 (x=0.05) sheet-like template seed crystal. The image shows that the powder has a sheet-like structure. The side length of the sheet-like template is between 5-15 μm and the thickness is between 0.2-1 μm.

[0026] Example 2: The 0.15Pb alloy described in this invention possesses both high voltage electrical properties and a high phase transition temperature. 0.91 Sm 0.06 (Mg 1 / 2Nb 2 / 3 O3-0.10Pb 0.95 Sr 0.05 (Mg 1 / 2 Nb 2 / 3 The preparation method of artificially oriented piezoelectric ceramics with O3-0.31PbZrO3-0.44PbTiO3 grains includes the following steps: Step 1: Preparation of ceramic powder (11) Using high-purity lead oxide, samarium oxide, magnesium oxide, niobium oxide, strontium carbonate, zirconium oxide, and titanium oxide as raw materials, according to 0.15Pb 0.91 Sm 0.06 (Mg 1 / 2 Nb 2 / 3 O3-0.10Pb 0.95 Sr 0.05 (Mg 1 / 2 Nb 2 / 3 Weigh the materials according to the stoichiometric ratio of O3-0.31PbZrO3-0.44PbTiO3; (12) The above raw materials are mixed by wet ball milling and then dried; (13) Pass the dried powder from step (12) through a 40-mesh sieve to obtain a uniform and well-dispersed powder, and calcine it at 750°C for 4 hours to obtain ceramic powder; Step 2: Preparation of grain-oriented piezoelectric ceramics (21) Ceramic powder (200g) is mixed with solvent (xylene 800g), dispersant (trioleyl glycerol 2g), binder (PVB 10g), plasticizer (butyl benzyl phthalate 8g), sintering aid (manganese oxide 4g), and BaTi, which has ferromagnetic properties. 1-x (Fe 1 / 2 Nb 1 / 2 ) x O3 (x=0.1) flake template seed crystals (10g) were mixed evenly to obtain casting slurry; (22) The slurry from step (21) is cast into a film using a casting machine in a magnetic field with a magnetic field strength of 0.08T; (23) Cut the film strip in step (22) into a specific size, stack it in a hot press to obtain a blank, and remove the organic matter at 600°C to obtain a green blank; (24) The blank in step (23) is sintered at 1250°C for 10 hours to allow the ceramic matrix to grow directionally around the template to obtain piezoelectric ceramic with artificially oriented grains.

[0027] Measurements showed that the piezoelectric coefficient d of this grain-oriented piezoelectric ceramic material was... 33 ~1650pC / N, Curie temperature 243℃, dielectric loss ~0.43%, electromechanical coupling coefficient k 33 ~0.92.

[0028] Example 3: The 0.10Pb alloy described in this invention possesses both high voltage electrical properties and a high phase transition temperature. 0.7 La 0.2 (Ni 1 / 2 Nb 2 / 3 O3-0.15Pb 0.95 Ca 0.05 (Mg 1 / 2 Nb 2 / 3 The preparation method of artificially oriented piezoelectric ceramics with O3-0.33PbZrO3-0.42PbTiO3 grains includes the following steps: Step 1: Preparation of ceramic powder (11) Using high-purity lead oxide, lanthanum oxide, nickel oxide, niobium oxide, calcium carbonate, zirconium oxide, and titanium oxide as raw materials, according to 0.10Pb 0.7 La 0.2 (Ni 1 / 2 Nb 2 / 3 O3-0.15Pb 0.95 Ca 0.05 (Mg 1 / 2 Nb 2 / 3 Weigh the materials according to the stoichiometric ratio of O3-0.33PbZrO3-0.42PbTiO3; (12) The above raw materials are mixed by wet ball milling and then dried; (13) Pass the dried powder from step (12) through a 40-mesh sieve to obtain a uniform and well-dispersed powder, and calcine it at 800°C for 3 hours to obtain ceramic powder; Step 2: Preparation of grain-oriented piezoelectric ceramics (21) Combine ceramic powder (200g) with solvent (xylene 200g), dispersant (KD-110g), binder (PVB 6g), plasticizer (butyl benzyl phthalate and polyethylene glycol total 2g, mass ratio 1:1), sintering aid (copper oxide 4g), and BaTi with ferromagnetic properties. 1-x (Fe1 / 2 Ta 1 / 2 ) x O3 (x=0.15) flake template seed crystals (1g) were mixed evenly to obtain a casting slurry; (22) The slurry in (21) is cast into a film using a casting machine in a magnetic field with a magnetic field strength of 0.06T; (3) Cut the film strip in step (22) into a specific size, stack it in a hot press to obtain a blank, and remove the organic matter at 600°C to obtain a green blank; (24) The blank in step (23) is sintered at 1220°C for 12 hours to allow the ceramic matrix to grow directionally around the template to obtain piezoelectric ceramic with artificially oriented grains.

[0029] Measurements showed that the piezoelectric coefficient d of this grain-oriented piezoelectric ceramic material was... 33 ~1780pC / N, Curie temperature 255℃, dielectric loss ~0.53%, electromechanical coupling coefficient k 33 ~0.93.

[0030] Example 4: The 0.30Pb alloy described in this invention possesses both high voltage electrical properties and a high phase transition temperature. 0.85 Eu 0.1 (Ni 1 / 2Nb 2 / 3 The preparation method of artificially oriented piezoelectric ceramics with O3-0.30PbZrO3-0.40PbTiO3 grains includes the following steps: Step 1: Preparation of ceramic powder (11) Using high-purity lead oxide, europium oxide, nickel oxide, niobium oxide, zirconium oxide, and titanium oxide as raw materials, according to 0.30Pb 0.85 Eu 0.1 (Ni 1 / 2 Nb 2 / 3 Weigh the materials according to the stoichiometric ratio of O3-0.30PbZrO3-0.40PbTiO3; (12) The above raw materials are mixed by wet ball milling and then dried; (13) Pass the dried powder from step (12) through a 40-mesh sieve to obtain a uniform and well-dispersed powder, and calcine it at 880°C for 2 hours to obtain ceramic powder; Step 2: Preparation of grain-oriented piezoelectric ceramics (21) Mix ceramic powder (150g) with solvent (ethanol and butanone total 400g, mass ratio 1:1), dispersant (KD-15g), binder (PVB 10g), plasticizer (butyl benzyl phthalate and polyethylene glycol total 10g, mass ratio 1:1), sintering aid (copper oxide 2g), and BaTi with ferromagnetic properties. 1-x (Fe1 / 2 Ta 1 / 2 ) x O3 (x=0.1) flake template seed crystals (2g) were mixed evenly to obtain casting slurry; (22) The slurry from step (21) is cast into a film using a casting machine in a magnetic field with a magnetic field strength of 0.09T; (23) Cut the film strip in step (22) into a specific size, stack it in a hot press to obtain a blank, and remove the organic matter at 600°C to obtain a green blank; (24) The blank in step (23) is sintered at 1200℃ for 15h to allow the ceramic matrix to grow directionally around the template to obtain piezoelectric ceramic with artificially oriented grains.

[0031] Measurements showed that the piezoelectric coefficient d of this grain-oriented piezoelectric ceramic material was... 33 ~1700pC / N, Curie temperature 240℃, dielectric loss ~0.32%, electromechanical coupling coefficient k 33 ~0.92.

[0032] Example 5: The 0.15Pb alloy described in this invention possesses both high voltage electrical properties and a high phase transition temperature. 0.85 Dy 0.1 (Mg 1 / 2Nb 2 / 3 O3-0.15Pb 0.95 Sr 0.05 (Mg 1 / 2 Nb 2 / 3 The preparation method of artificially oriented piezoelectric ceramics with O3-0.30PbZrO3-0.40PbTiO3 grains includes the following steps: Step 1: Preparation of ceramic powder (11) Using high-purity lead oxide, dysprosium oxide, magnesium oxide, niobium oxide, strontium carbonate, zirconium oxide, and titanium oxide as raw materials, according to 0.15Pb 0.85 Dy 0.1 (Mg 1 / 2 Nb 2 / 3 O3-0.15Pb 0.95 Sr 0.05 (Mg 1 / 2 Nb 2 / 3 Weigh the materials according to the stoichiometric ratio of O3-0.30PbZrO3-0.40PbTiO3; (12) The above raw materials are mixed by wet ball milling and then dried; (13) Pass the dried powder from step (12) through a 40-mesh sieve to obtain a uniform and well-dispersed powder, and calcine it at 850°C for 2 hours to obtain ceramic powder; Step 2: Preparation of grain-oriented piezoelectric ceramics (21) Combine ceramic powder (200g) with solvent (600g of ethanol and ethyl acetate in a mass ratio of 1:1), dispersant (5g of trioleic acid glyceride), binder (12g of PVB), plasticizer (12g of butyl benzyl phthalate and polyethylene glycol in a mass ratio of 1:1), sintering aid (3g of lithium carbonate), and BaTi with ferromagnetic properties. 1-x (Fe 1 / 2 Ta 1 / 2 ) x O3 (x=0.1) flake template seed crystals (3g) were mixed evenly to obtain casting slurry; (22) The slurry from step (21) is cast into a film using a casting machine in a magnetic field with a magnetic field strength of 0.08T; (23) Cut the film strip in step (22) into a specific size, stack it in a hot press to obtain a blank, and remove the organic matter at 600°C to obtain a green blank; (24) The blank in step (23) is sintered at 1270°C for 5 hours to allow the ceramic matrix to grow directionally around the template to obtain piezoelectric ceramic with artificially oriented grains.

[0033] Measurements showed that the piezoelectric coefficient d of this grain-oriented piezoelectric ceramic material was... 33 ~1650pC / N, Curie temperature 265℃, dielectric loss ~0.68%, electromechanical coupling coefficient k 33 ~0.92.

[0034] Example 6: The 0.1Pb described in this invention possesses both high voltage electrical properties and a high phase transition temperature. 0.7 Er 0.2 (Mg 1 / 2 Nb 2 / 3 O3-0.2Pb 0.9 Sr 0.1 (Mg 1 / 2 Nb 2 / 3 The preparation method of artificially oriented piezoelectric ceramics with O3-0.30PbZrO3-0.40PbTiO3 grains includes the following steps: Step 1: Preparation of ceramic powder (11) Using high-purity lead oxide, erbium oxide, magnesium oxide, niobium oxide, strontium carbonate, zirconium oxide, and titanium oxide as raw materials, according to 0.1Pb 0.7 Er 0.2 (Mg 1 / 2 Nb 2 / 3 O3-0.2Pb 0.9 Sr 0.1 (Mg 1 / 2 Nb 2 / 3Weigh the materials according to the stoichiometric ratio of O3-0.30PbZrO3-0.40PbTiO3; (12) The above raw materials are mixed by wet ball milling and then dried; (13) Pass the dried powder from step (12) through a 40-mesh sieve to obtain a uniform and well-dispersed powder, and calcine it at 850°C for 2 hours to obtain ceramic powder; Step 2: Preparation of grain-oriented piezoelectric ceramics (21) Mix ceramic powder (200g) with solvent (600g of ethanol and xylene in a mass ratio of 1:1), dispersant (8g of trioleic acid glyceride), binder (16g of PVB), plasticizer (12g of butyl benzyl phthalate and polyethylene glycol in a mass ratio of 1:1), sintering aid (2g of lithium carbonate), and BaTi with ferromagnetic properties. 1-x (Fe 1 / 2 Ta 1 / 2 ) x O3 (x=0.15) flake template seed crystals (3g) were mixed evenly to obtain casting slurry; (22) The slurry from step (21) is cast into a film using a casting machine in a magnetic field with a magnetic field strength of 0.07T; (23) Cut the film strip in step (22) into a specific size, stack it in a hot press to obtain a blank, and remove the organic matter at 600°C to obtain a green blank; (24) The blank in step (23) is sintered at 1280°C for 2 hours to allow the ceramic matrix to grow oriented around the template to obtain piezoelectric ceramic with artificially oriented grains.

[0035] Measurements showed that the piezoelectric coefficient d of this grain-oriented piezoelectric ceramic material was... 33 ~1675pC / N, Curie temperature 265℃, dielectric loss ~0.60%, electromechanical coupling coefficient k 33 ~0.91.

[0036] Figure 5 For example, 0.1Pb in Example 6 0.7 Er 0.2 (Mg 1 / 2 Nb 2 / 3 O3-0.2Pb 0.9 Sr 0.1 (Mg 1 / 2 Nb 2 / 3 The dielectric temperature spectrum of artificially oriented piezoelectric ceramics with O3-0.30PbZrO3-0.40PbTiO3 grains is shown in the figure. The Curie temperature of this ceramic reaches 265℃, which shows a high Curie temperature.

[0037] Example 7: The 0.1Pb alloy of the present invention possesses both high voltage electrical properties and a high phase transition temperature. 0.7 Nd 0.2 (Ni 1 / 2 Nb 2 / 3 O3-0.2Pb 0.9 Ba 0.1 (Ni 1 / 2 Nb 2 / 3 The preparation method of artificially oriented piezoelectric ceramics with O3-0.30PbZrO3-0.40PbTiO3 grains includes the following steps: Step 1: Preparation of ceramic powder (11) Using high-purity lead oxide, neodymium oxide, nickel oxide, niobium oxide, barium carbonate, zirconium oxide, and titanium oxide as raw materials, according to 0.1Pb 0.7 Nd 0.2 (Ni 1 / 2 Nb 2 / 3 O3-0.2Pb 0.9 Ba 0.1 (Ni 1 / 2 Nb 2 / 3 Weigh the materials according to the stoichiometric ratio of O3-0.30PbZrO3-0.40PbTiO3; (12) The above raw materials are mixed by wet ball milling and then dried; (13) Pass the dried powder from step (12) through a 40-mesh sieve to obtain a uniform and well-dispersed powder, and calcine it at 800°C for 3 hours to obtain ceramic powder; Step 2: Preparation of grain-oriented piezoelectric ceramics (21) Mix ceramic powder (200g) with solvent (600g of ethanol and xylene in a mass ratio of 1:1), dispersant (5g of trioleic acid glyceride), binder (12g of PVB), plasticizer (12g of butyl benzyl phthalate and polyethylene glycol in a mass ratio of 1:1), sintering aid (3g of lithium carbonate), and BaTi with ferromagnetic properties. 1-x (Fe 1 / 2 Nb 1 / 2 ) x O3 (x=0.15) flake template seed crystals (3g) were mixed evenly to obtain casting slurry; (22) The slurry from step (21) is cast into a film using a casting machine in a magnetic field with a magnetic field strength of 0.06T; (23) Cut the film strip in step (22) into a specific size, stack it in a hot press to obtain a blank, and remove the organic matter at 600°C to obtain a green blank; (24) The blank in step (23) is sintered at 1250°C for 8 hours to allow the ceramic matrix to grow directionally around the template to obtain piezoelectric ceramic with artificially oriented grains.

[0038] Measurements showed that the piezoelectric coefficient d of this grain-oriented piezoelectric ceramic material was... 33 ~1750pC / N, Curie temperature 261℃, dielectric loss ~0.52%, electromechanical coupling coefficient k 33 ~0.92.

[0039] Figure 2 To implement the 0.1Pb in Case 7 0.7 Nd 0.2 (Ni 1 / 2 Nb 2 / 3 O3-0.2Pb 0.9 Ba 0.1 (Ni 1 / 2 Nb 2 / 3 XRD patterns of artificially oriented and unoriented piezoelectric ceramics (O3-0.30PbZrO3-0.40PbTiO3) are shown. The figures reveal that both exhibit a pure perovskite phase structure. The artificially oriented piezoelectric ceramic possesses strong... <001> The orientation fully demonstrates the anisotropy of the grains. Figure 4 0.1Pb in Example 7 0.7 Nd 0.2 (Ni 1 / 2 Nb 2 / 3 O3-0.2Pb 0.9 Ba 0.1 (Ni 1 / 2 Nb 2 / 3 The figure shows the electro-strain curve of the artificially oriented piezoelectric ceramic with grains of O3-0.30PbZrO3-0.40PbTiO3. The strain of this artificially oriented piezoelectric ceramic reaches more than 0.6% under an electric field of 30kV / cm, which is much higher than that of single crystal (0.4%) and commercial ceramics (0.2%), showing high piezoelectric performance.

[0040] Example 8: The 0.10Pb alloy described in this invention possesses both high voltage electrical properties and a high phase transition temperature. 0.7 Sm 0.1 Nd 0.1 (In 1 / 2Nb 1 / 2 O3-0.48Pb 0.9 Ba 0.1 (Sc 1 / 2 Nb 1 / 2 The preparation method of artificially oriented piezoelectric ceramics with O3-0.42PbTiO3 grains includes the following steps: Step 1: Preparation of ceramic powder (11) Using high-purity lead oxide, samarium oxide, magnesium oxide, nickel oxide, niobium oxide, barium carbonate, zirconium oxide, and titanium oxide as raw materials, according to 0.10Pb0.7 Sm 0.1 Nd 0.1 (Mg 1 / 2 Nb 2 / 3 O3-0.15Pb 0.9 Ba 0.1 (Ni 1 / 2 Nb 2 / 3 Weigh the materials according to the stoichiometric ratio of O3-0.33PbZrO3-0.42PbTiO3; (12) The above raw materials are mixed by wet ball milling and then dried; (13) Pass the dried powder from step (12) through a 40-mesh sieve to obtain a uniform and well-dispersed powder, and calcine it at 800°C for 3 hours to obtain ceramic powder; Step 2: Preparation of grain-oriented piezoelectric ceramics (21) Combine ceramic powder (200g) with solvent (660g of ethanol and ethyl acetate in a mass ratio of 1:1), dispersant (KD-16g), binder (PVB12g), plasticizer (13g of butyl benzyl phthalate and polyethylene glycol in a mass ratio of 1:1), sintering aid (3g of copper oxide), and BaTi with ferromagnetic properties. 1-x (Fe 1 / 2 Nb 1 / 2 ) x O3 (x=0.1) flake template seed crystals (2g) were mixed evenly to obtain casting slurry; (22) The slurry from step (21) is cast into a film using a casting machine in a magnetic field with a magnetic field strength of 0.06T; (23) Cut the film strip in step (22) into a specific size, stack it in a hot press to obtain a blank, and remove the organic matter at 600°C to obtain a green blank; (24) The blank in step (23) is sintered at 1250°C for 10 hours to allow the ceramic matrix to grow directionally around the template to obtain piezoelectric ceramic with artificially oriented grains.

[0041] Measurements showed that the piezoelectric coefficient d of this grain-oriented piezoelectric ceramic material was... 33 ~1850pC / N, Curie temperature 252℃, dielectric loss ~0.43%, electromechanical coupling coefficient k 33 ~0.91.

[0042] Figure 3To illustrate the SEM images and average grain size data of the Sm, Nd, and Ba co-doped PIN-PSN-PT grain-oriented piezoelectric ceramics in Case Study 8, the template content was 2 vol.%, and the Sm doping content was 0~2 mol%. The SEM images show that the templates are arranged in parallel, further confirming the high orientation of the ceramics. In terms of grain size, the undoped grain size is greater than 20 μm, while the grain size gradually decreases with the increase of Sm doping content. Generally, the grain size of perfectly oriented piezoelectric ceramics is only related to the content and size of the template. In experiments, the template content and size were consistent, and the theoretical grain size was approximately 10.5 μm. For undoped ceramics, the ceramic reacts with the template. A decrease in template content leads to an increase in the grain size of the artificially oriented piezoelectric ceramic. With the increase of Sm element doping content, rare earth elements modify the reactivity between the template and the powder, reducing the erosion of the template seed crystal by the matrix powder, thus leading to a decrease in the grain size of the artificially oriented piezoelectric ceramic. For lead-based piezoelectric ceramics, the solid solution of the BT-based template leads to a decrease in the phase transition temperature and Curie temperature of the artificially oriented piezoelectric ceramic. Therefore, the modification of the template and matrix powder by rare earth elements avoids the decrease in the phase transition temperature and Curie temperature of the artificially oriented piezoelectric ceramic.

[0043] Example 9: The 0.15Pb alloy of the present invention, which combines high voltage electrical performance and high phase transition temperature. 0.7 Sm 0.2 (Mg 1 / 2 Nb 2 / 3 O3-0.1Pb 0.9 Ba 0.1 (Ni 1 / 2 Ta 2 / 3 The preparation method of artificially oriented piezoelectric ceramics with O3-0.33PbZrO3-0.42PbTiO3 grains includes the following steps: Step 1: Preparation of ceramic powder (11) Using high-purity lead oxide, samarium oxide, magnesium oxide, nickel oxide, niobium oxide, barium carbonate, tantalum oxide, zirconium oxide, and titanium oxide as raw materials, according to 0.15Pb 0.7 Sm 0.2 (Mg 1 / 2 Nb 2 / 3 O3-0.1Pb 0.9 Ba 0.1 (Ni 1 / 2 Ta 2 / 3 Weigh the materials according to the stoichiometric ratio of O3-0.33PbZrO3-0.42PbTiO3; (12) The above raw materials are mixed by wet ball milling and then dried; (13) Pass the dried powder from step (12) through a 40-mesh sieve to obtain a uniform and well-dispersed powder, and calcine it at 800°C for 3 hours to obtain ceramic powder; Step 2: Preparation of grain-oriented piezoelectric ceramics (21) Mix ceramic powder (200g) with solvent (700g of ethanol and ethyl acetate in a mass ratio of 1:1), dispersant (KD-14g), binder (PVB 12g), plasticizer (15g of butyl benzyl phthalate and polyethylene glycol in a mass ratio of 1:1), sintering aid (copper oxide 2g), and BaTi with ferromagnetic properties. 1-x (Fe 1 / 2 Nb 1 / 2 ) x O3 (x=0.1) flake template seed crystals (2g) were mixed evenly to obtain casting slurry; (22) The slurry from step (21) is cast into a film using a casting machine in a magnetic field with a magnetic field strength of 0.06T; (23) Cut the film strip in step (22) into a specific size, stack it in a hot press to obtain a blank, and remove the organic matter at 600°C to obtain a green blank; (24) The blank in step (23) is sintered at 1250°C for 10 hours to allow the ceramic matrix to grow directionally around the template to obtain piezoelectric ceramic with artificially oriented grains.

[0044] Measurements showed that the piezoelectric coefficient d of this grain-oriented piezoelectric ceramic material was... 33 ~1810 pC / N, Curie temperature 256℃, dielectric loss ~0.44%, electromechanical coupling coefficient k 33 ~0.91.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A grain-oriented piezoelectric ceramic material, characterized in that, The grain-oriented piezoelectric ceramic material is <001> Oriented, ferromagnetic barium titanate or strontium titanate-based sheet templates, with the general formula: X Pb 1-1.5x R x (B1,B2)O3- Y Pb 1-y A y (B1,B2)O3-(1- X - YZ PbB3O3- Z The ceramic matrix of PbTiO3 is wherein A is one or more of barium, strontium, calcium, and bismuth; B1 is one or more of magnesium, nickel, indium, and scandium; B2 is one or more of niobium, tantalum, and antimony; B3 is one of zirconium and tin; R is one or more of Sm, La, Nd, Eu, Ce, Pr, Dy, and Er; x is between 0.001 and 0.2, y does not exceed 0.1; X is between 0.1 and 0.3, Y is between 0 and 0.2, and X+Y+Z=1.

2. The grain-oriented piezoelectric ceramic material according to claim 1, characterized in that, Physical properties satisfy at least one of the following characteristics: (1) Piezoelectric coefficient d 33 The value is 1500~1900 pC / N. (2) Dielectric loss is 0.3%~0.9%, (3) Curie temperature is above 200℃, (4) Electromechanical coupling coefficient k 33 >0.85%.

3. The grain-oriented piezoelectric ceramic material according to claim 1, characterized in that, Orientation is achieved using sheet-like templates with ferromagnetic properties under a strong magnetic field. The general formula for ferromagnetic templates is BaTi. 1-x (Fe 1 / 2 B4) x O3, x=0.05-0.15, B4 is niobium, tantalum or vanadium.

4. The method for preparing the grain-oriented piezoelectric ceramic material according to any one of claims 1-3, characterized in that, The steps include the following: Raw materials are prepared according to the general formula for grain-oriented piezoelectric ceramic materials. The raw materials are mixed evenly by wet ball milling and then dried to obtain a dry mixed powder. The dried mixed powder is sieved and calcined at 750℃-880℃ for 2-4 hours to obtain ceramic powder. The ceramic powder is mixed evenly with solvent, dispersant, binder, plasticizer, sintering aid and sheet template with ferromagnetic properties to obtain casting slurry; The casting paste is cast into a thin film under the action of an external magnetic field; The film is cut, hot-pressed and laminated, and then heated to remove organic matter to obtain a green body; The obtained green body was sintered to obtain a grain-oriented piezoelectric ceramic material.

5. The preparation method according to claim 4, characterized in that, The raw materials are all oxides of the corresponding metal elements.

6. The preparation method according to claim 4, characterized in that, When sieving the dried mixed powder, use a 40-mesh sieve.

7. The preparation method according to claim 4, characterized in that, The sintering temperature of the obtained green body is 1200℃-1280℃, and the sintering time is 2-15h.

8. The preparation method according to claim 4, characterized in that, The applied magnetic field strength is 0.06T-0.1T.

9. The preparation method according to claim 4, characterized in that, The ferromagnetic sheet templates have a length of 3–25 micrometers, a thickness of 0.2 ± 2 micrometers, an aspect ratio greater than 8, and x = 0.05–0.

15. The general formula for ferromagnetic sheet templates is BaTi. 1-x (Fe 1 / 2 B4) x O3 and B4 are niobium, tantalum, or vanadium.

10. The preparation method according to claim 4, characterized in that, The solvent is 1 to 5 times the mass of the powder, and the solvent is one or more of ethanol, xylene, ethyl acetate, and methyl ethyl ketone; the dispersant is 0.5 wt.% to 5 wt.% of the powder mass, and the dispersant is KD-1 or trioleyl ester; the binder is 3 wt.% to 10 wt.% of the powder mass, and the binder is PVB; the plasticizer is 1 wt.% to 12 wt.% of the powder mass, and the plasticizer is one or more of polyethylene glycol, butyl benzyl phthalate, and polyalkylene glycol; the sintering aid is 0.1 wt.% to 2 wt.% of the powder mass, and the sintering aid is copper oxide, manganese oxide, or lithium carbonate; the sheet-like template with ferromagnetic properties is 0.5 wt.% to 7 wt.% of the powder mass.

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