Piezoelectric ceramic material with high piezoelectric property and high temperature stability and preparation method thereof

Abstract

The invention belongs to the field of ceramic composition and preparation, and mainly provides a piezoelectric ceramic material with high piezoelectric property and high temperature stability, the chemical structural general formula of the piezoelectric ceramic material is Pb [(Sb1 / 2Nb1 / 2) x (ZryTi0.98-y) (1-x) O3] + z mol% BiAlO3 + 0.3 wt% Pb3O4, 0 < x < = 0.03, 0.50 < y < 0.53, and 0 < z < = 3. The invention also provides a method for preparing the piezoelectric ceramic. According to the piezoelectric ceramic material prepared by the method, the piezoelectric property and the temperature stability of the piezoelectric ceramic material are improved, and the problems that the safe use temperature of conventional PZT piezoelectric ceramic does not exceed 1 / 2Tc (that is, the temperature is less than or equal to 180 DEG C) and the piezoelectric property and the temperature stability are difficult to consider at the same time are solved. The preparation method has the advantages of simple and stable process, convenience in large-scale production and the like, and can be used for various transceiving high-temperature (about 200 DEG C) piezoelectric devices.

Description

Technical Field

[0001] The present invention relates to a piezoelectric ceramic, and in particular to a piezoelectric ceramic material with high high voltage electrical performance and high temperature stability and a preparation method thereof. The piezoelectric ceramic material is mainly used in various transceiver-transmitter-type high temperature (~200°C) transducers, sensors and other related piezoelectric devices, and belongs to the field of ceramic composition and preparation. Background Art

[0002] In recent years, as the application scope of piezoelectric ceramics has been further expanded, new challenges have been raised to the service performance of piezoelectric ceramics in some extreme environments. For example, in the field of oil exploration, during the drilling process, the probe transducer needs to collect data such as the temperature, pressure, and flow rate of the surrounding environment. The ambient temperature near the probe will vary in a wide range, which requires the relevant piezoelectric transducer to be able to withstand higher temperatures. As the drilling depth of oil fields becomes deeper and deeper (depth exceeding 7000m), the downhole temperature has reached 200°C, which poses new challenges to oil logging transducers and piezoelectric materials: that is, the performance of piezoelectric materials must be stable under high temperature conditions (200°C), so as to ensure that the transducer maintains high transmission power, sensitivity, frequency consistency, etc. in this environment, and meet good measurement accuracy and measurement efficiency requirements. Conventional PZT piezoelectric ceramics, its Curie temperature T c Generally, it is between 200 and 360°C, and its safe use temperature does not exceed 1 / 2T c (ie ≤180℃), if the service temperature of piezoelectric ceramics exceeds 1 / 2T c , which will cause serious depolarization of piezoelectric ceramics and even lose their piezoelectric properties. 1 / 2 Na 1 / 2 Although the Curie temperature of lead-free piezoelectric ceramics based on NbO3 (abbreviated as KNN) is 420℃, the potassium and sodium volatilize seriously during high-temperature sintering, making it difficult to sinter and densify pure KNN ceramics. At the same time, KNN-based ceramics have an orthorhombic→tetragonal ferroelectric→ferroelectric phase transition point (T O-T ), which limits its application at high temperatures. Therefore, the research and preparation of piezoelectric ceramics with high piezoelectric properties and high temperature stability is of great significance for the preparation of high-temperature piezoelectric transducers.

[0003] Generally speaking, the higher the Curie temperature of a piezoelectric material, the better its temperature stability, but the worse its piezoelectric performance. For example, the Chinese patent with the authorization announcement number CN 106518071 B discloses a piezoelectric ceramic material with a high Curie temperature and high stability and its preparation method. Its Curie temperature is as high as 925-941°C, but its piezoelectric constant is only 16.8pC / N at most. Eitel, based on the MPB theory, combined the perovskite structure tolerance factor t with the Curie temperature T cBased on the relationship analysis between the two, a new bismuth scandate-lead titanate (BiScO3-PbTiO3, BSPT) system with a stable perovskite structure was designed and successfully prepared. The system has excellent electrical properties: the piezoelectric constant d 33 =450pC / N, electromechanical coupling coefficient k p =0.56, Curie temperature T c Up to 450℃, but there is also a mechanical quality factor Q m Problems such as too low dielectric loss tgδ and high dielectric loss tgδ have seriously restricted its practical application. At present, the research on high-temperature piezoelectric ceramics is more focused on seeking to obtain a high Curie temperature formulation system in the hope of increasing its operating temperature; however, as mentioned above, the higher the Curie temperature, the worse the piezoelectric performance. Therefore, the preparation of piezoelectric ceramics with high piezoelectric performance, high temperature stability and excellent comprehensive electrical properties and related process research and development has always been a difficult problem that needs to be solved in this field. Summary of the invention

[0004] In view of the problem that existing piezoelectric ceramic materials are difficult to simultaneously obtain high voltage electrical performance, high temperature stability and excellent comprehensive electrical properties, the purpose of the present invention is to provide a piezoelectric ceramic material with high voltage electrical performance and high temperature stability and a preparation method thereof.

[0005] The object of the present invention is achieved by the following technical solution. A piezoelectric ceramic material with high high voltage performance and high temperature stability, the chemical structure of the piezoelectric ceramic material is Pb[(Sb 1 / 2 Nb 1 / 2 ) x (Zr y Ti 0.98-y ) (1-x) O3]+zmol%BiAlO3+0.3wt%Pb3O4, where 0<x≤0.03, 0.50<y<0.53, 0<z≤3.

[0006] As a preferred embodiment, the piezoelectric ceramic material with high high voltage electrical performance and high temperature stability provided by the present invention has the following general chemical structure formula: Pb[(Sb 1 / 2 Nb 1 / 2 ) x (Zr y Ti 0.98-y ) (1-x) O3] + z mol% BiAlO3 + 0.3wt% Pb3O4, where 0.005≤x≤0.03, 0.51≤y≤0.52, 0.1≤z≤3;

[0007] As a preferred solution, the piezoelectric ceramic material with high piezoelectric performance and high temperature stability provided by the present invention has a chemical structure in which 0.002≤x / z≤0.3.

[0008] As a preferred solution, the piezoelectric ceramic material with high piezoelectric performance and high temperature stability provided by the present invention has a single perovskite structure.

[0009] As a preferred solution, the piezoelectric ceramic material with high piezoelectric performance and high temperature stability provided by the present invention has a piezoelectric constant d 33 ≥320pC / N.

[0010] As a preferred solution, the piezoelectric ceramic material with high high voltage electrical performance and high temperature stability provided by the present invention has an electromechanical coupling coefficient k p There is no depolarization at 200°C.

[0011] In addition, the present invention also provides a method for preparing the piezoelectric ceramic material with high piezoelectric performance and high temperature stability, comprising the following steps:

[0012] (1) Mixing: Pb3O4, Zr02, Ti02, Nb2O5, Sb2O3, Bi2O3 and Al2O3 are weighed in molar ratio, added into a drum mill and wet mixed for 18 to 20 hours, and the mixture is fully mixed and then slurried;

[0013] (2) Pre-sintering: The mixed slurry is dried, pressed into blocks and placed in an alumina crucible, and then pre-sintered at 850°C for 2 hours;

[0014] (3) Fine grinding: The pre-burned material blocks are crushed and then placed in a sand mill for fine grinding;

[0015] (4) Granulation: Add polyvinyl alcohol binder to the finely ground slurry and then granulate it in a spray tower;

[0016] (5) Forming: The green body is formed by dry pressing;

[0017] (6) Plastic removal: The green body is kept at 700-750℃ for 2 hours for plastic removal;

[0018] (7) Sintering: After plastic removal, the green body is sealed in an Al2O3 crucible and sintered at 1180°C for 2-3 hours;

[0019] (8) Silvering: After sintering, the porcelain body is ground, cleaned and then silvered at 780℃;

[0020] (9) Polarization: In silicone oil at 135°C, a 2.0-2.5 kV / mm DC electric field is applied for polarization to produce piezoelectric ceramics with high high voltage electrical performance and high temperature stability.

[0021] As a preferred embodiment, the fine grinding time in step (3) is at least 10 minutes.

[0022] The beneficial effects of the present invention are: providing a piezoelectric ceramic material with high high voltage electrical performance, high temperature stability and good comprehensive electrical performance, by 1 / 2 Nb 1 / 2 ) x (Zr y Ti 0.98-y ) (1-x) The introduction of an appropriate amount of BiAlO3 components into the piezoelectric ceramic improves the piezoelectric performance and temperature stability of the piezoelectric ceramic, and solves the problem that the safe use temperature of conventional PZT piezoelectric ceramics does not exceed 1 / 2T c (ie ≤180℃). The piezoelectric ceramic has a high piezoelectric constant d 33 (≥320pC / N) and temperature stability, its electromechanical coupling coefficient k p There is no depolarization at 200°C and it can be used in various high-temperature (~200°C) transducers, sensors and other related piezoelectric devices for dual-purpose transmission and reception. This material shows good application prospects in the field of oil exploration. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art or ordinary technicians, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 is the XRD spectrum of the piezoelectric ceramic material of Example 1 of the present invention;

[0025] Figure 2 is the XRD spectrum of the piezoelectric ceramic material of Example 2 of the present invention;

[0026] Figure 3 is an impedance-temperature spectrum of the piezoelectric ceramic material of Example 1 of the present invention;

[0027] Figure 4 is an impedance-temperature spectrum of a piezoelectric ceramic material according to Example 2 of the present invention;

[0028] Figure 5 is an electromechanical coupling coefficient-temperature spectrum of the piezoelectric ceramic material of Example 1 of the present invention;

[0029] Figure 6 This is a graph of the electromechanical coupling coefficient-temperature spectrum of the piezoelectric ceramic material of Example 2 of the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0031] Embodiment 1:

[0032] 1) Mixing: Based on the chemical structure of a piezoelectric ceramic material with high high voltage performance and high temperature stability, Pb[(Sb 1 / 2 Nb 1 / 2 ) 0.019 (Zr 0.517 Ti 0.463 ) 0.981 O3] + 1.0 mol% BiAlO3 + 0.3 wt% Pb3O4, Pb3O4, ZrO2, TiO2, Nb2O5, Sb2O3, Bi2O3 and Al2O3 are weighed in molar ratio, added into a drum mill for wet mixing for 18 to 20 hours, and the mixture is fully mixed and then slurried;

[0033] 2) Pre-sintering: The mixed slurry is dried, pressed into blocks and placed in an alumina crucible, and then pre-sintered at 850°C for 2 hours;

[0034] 3) Fine grinding: The pre-burned material block is crushed and then placed in a sand mill for fine grinding for 15 minutes;

[0035] 4) Granulation: Add polyvinyl alcohol binder to the finely ground slurry and then granulate it in a spray tower;

[0036] 5) Molding: Made by dry pressing green body;

[0037] 6) Plastic removal: The green body is kept at 730℃ for 2 hours for plastic removal;

[0038] 7) Sintering: After plastic removal, the green body is sealed in an Al2O3 crucible and sintered at 1180°C for 2 hours; Figure 1 The XRD pattern of the sintered ceramics shows a pure perovskite structure without pyrochlore impurities;

[0039] 8) Silver: After sintering, the porcelain body is ground and processed into The porcelain pieces are washed and then silvered, and the silver is fired at 780°C;

[0040] 9) Polarization: In 135℃ silicone oil, 2.2kv / mm DC electric field is applied to polarize to obtain high voltage electrical performance and high temperature stability.

[0041] Piezoelectric ceramics;

[0042] 10) Measurement: The polarized piezoelectric ceramics were placed at room temperature for 24 hours before testing their piezoelectric properties; the impedance-temperature spectrum of the piezoelectric ceramic material was tested using a box furnace in conjunction with an impedance analyzer, such as Figure 3 As shown, the electromechanical coupling coefficient-temperature spectrum of the piezoelectric ceramic material is obtained, such as Figure 5 shown.

[0043] Embodiment 2:

[0044] 1) Mixing: Based on the chemical structure of a piezoelectric ceramic material with high high voltage performance and high temperature stability, Pb[(Sb 1 / 2 Nb 1 / 2 ) 0.022 (Zr 0.515 Ti 0.465 ) 0.978 O3] + 2.0 mol% BiAlO3 + 0.3 wt% Pb3O4, Pb3O4, ZrO2, TiO2, Nb2O5, Sb2O3, Bi2O3 and Al2O3 are weighed in molar ratio, added into a drum mill for wet mixing for 18 to 20 hours, and the mixture is fully mixed and then slurried;

[0045] 2) Pre-sintering: The mixed slurry is dried, pressed into blocks and placed in an alumina crucible, and then pre-sintered at 850°C for 2 hours;

[0046] 3) Fine grinding: The pre-burned material block is crushed and then placed in a sand mill for fine grinding for 20 minutes;

[0047] 4) Granulation: Add polyvinyl alcohol binder to the finely ground slurry and then granulate it in a spray tower;

[0048] 5) Molding: Made by dry pressing green body;

[0049] 6) Plastic removal: The green body is kept at 730℃ for 2 hours for plastic removal;

[0050] 7) Sintering: After plastic removal, the green body is sealed in an Al2O3 crucible and sintered at 1180°C for 3 hours; Figure 2 The XRD pattern of the sintered ceramics shows a pure perovskite structure without pyrochlore impurities;

[0051] 8) Silver: After sintering, the porcelain body is ground and processed into The porcelain pieces are washed and then silvered, and the silver is fired at 780°C;

[0052] 9) Polarization: In 135℃ silicone oil, 2.2kv / mm DC electric field is applied to polarize to obtain high voltage electrical performance and high temperature stability.

[0053] Piezoelectric ceramics;

[0054] 10) Measurement: The polarized piezoelectric ceramics were placed at room temperature for 24 hours before testing their piezoelectric properties; the impedance-temperature spectrum of the piezoelectric ceramic material was tested using a box furnace in conjunction with an impedance analyzer, such as Figure 4 As shown, the electromechanical coupling coefficient-temperature spectrum of the piezoelectric ceramic material is obtained, such as Figure 6 shown.

[0055] Embodiment 3:

[0056] 1) Mixing: Based on the chemical structure of a piezoelectric ceramic material with high high voltage performance and high temperature stability, Pb[(Sb 1 / 2 Nb 1 / 2 ) 0.025 (Zr 0.52 Ti 0.46 ) 0.975 Pb3O4, ZrO2, TiO2, Nb2O5, Sb2O3, Bi2O3 and Al2O3 are weighed in molar ratio and added into a drum mill for wet mixing for 18 to 20 hours.

[0057] After mixing evenly, slurry is produced;

[0058] Steps 2)-10) are the same as in Example 1.

[0059] The properties of the piezoelectric ceramic materials prepared in the above embodiments are listed in Table 1.

[0060] Table 1 Performance of piezoelectric ceramic materials in various embodiments of the present invention

[0061] NO <![CDATA[ε T 33 ]]> tgδ(%) <![CDATA[k p ]]> <![CDATA[d 33 (pC / N)]]> <![CDATA[Q m ]]> <![CDATA[T c (℃)]]> Example 1 847 1.9 0.658 340 70 347 Example 2 872 1.9 0.653 337 71 340 Example 3 869 2.0 0.655 336 69 337

[0062] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A piezoelectric ceramic material with high piezoelectric performance and high temperature stability, characterized in that: The chemical structure of the piezoelectric ceramic material is Pb[(Sb 1 / 2 Nb 1 / 2 ) x (Zr y Ti 0.98-y ) (1-x) O3]+z mol%BiAlO3+0.3wt%Pb3O4, wherein 0<x≤0.03, 0.50<y<0.53, 0<z≤3.

2. The piezoelectric ceramic material with high high voltage electrical performance and high temperature stability according to claim 1, characterized in that: The chemical structure of the piezoelectric ceramic material is Pb[(Sb 1 / 2 Nb 1 / 2 ) x (Zr y Ti 0.98-y ) (1-x) O3]+z mol%BiAlO3+0.3wt%Pb3O4, where 0.005≤x≤0.03, 0.51≤y≤0.52, 0.1≤z≤3.

3. The piezoelectric ceramic material with high high voltage electrical performance and high temperature stability according to claim 1 or 2, characterized in that: In the general chemical structure formula of the piezoelectric ceramic material, 0.002≤x / z≤0.

3.

4. The piezoelectric ceramic material with high high voltage electrical performance and high temperature stability according to claim 1 or 2, characterized in that: The piezoelectric ceramic material has a single perovskite structure.

5. The piezoelectric ceramic material with high high voltage electrical performance and high temperature stability according to claim 1 or 2, characterized in that: The piezoelectric constant d of the piezoelectric ceramic material 33 ≥320pC / N.

6. The piezoelectric ceramic material with high high voltage electrical performance and high temperature stability according to claim 1 or 2, characterized in that: The electromechanical coupling coefficient k of the piezoelectric ceramic material p There is no depolarization at 200°C.

7. A method for preparing a piezoelectric ceramic material with high high voltage electrical performance and high temperature stability as claimed in claim 1 or 2, characterized in that: The steps include: (1) Mixing: Pb3O4, Zr02, Ti02, Nb2O5, Sb2O3, Bi2O3 and Al2O3 are weighed in molar ratio, added into a drum mill and wet mixed for 18 to 20 hours, and the mixture is fully mixed and then slurried; (2) Pre-sintering: The mixed slurry is dried, pressed into blocks and placed in an alumina crucible, and then pre-sintered at 850°C for 2 hours; (3) Fine grinding: The pre-burned material blocks are crushed and then placed in a sand mill for fine grinding; (4) Granulation: Add polyvinyl alcohol binder to the finely ground slurry and then granulate it in a spray tower; (5) Forming: The green body is formed by dry pressing; (6) Plastic removal: The green body is kept at 700-750℃ for 2 hours for plastic removal; (7) Sintering: After plastic removal, the green body is sealed in an Al2O3 crucible and sintered at 1180°C for 2-3 hours; (8) Silvering: After sintering, the porcelain body is ground, cleaned and then silvered at 780℃; (9) Polarization: In silicone oil at 135°C, a 2.0-2.5 kV / mm DC electric field is applied to produce piezoelectric ceramics with high voltage electrical performance and high temperature stability.

8. The method for preparing a piezoelectric ceramic with high high voltage electrical performance and high temperature stability according to claim 7, characterized in that: The fine grinding time in step (3) is at least 10 minutes.

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