Lead-based piezoelectric ceramic material and preparation method thereof

Abstract

The invention relates to the technical field of piezoelectric ceramics, and provides a lead-based piezoelectric ceramic material which is prepared by taking lead zirconate titanate PbZrTiO3 as a basis, externally doping lanthanum oxide La2O3, niobium pentoxide Nb2O5 and aluminum oxide Al2O3, replacing lead ions at A sites in the lead zirconate titanate PbZrTiO3 with part of lanthanum ions, and partially replacing titanium ions at B sites in the lead zirconate titanate PbZrTiO3 with niobium ions. The chemical general formula of the lead-based piezoelectric ceramic material is Pb (Zr < 0.53 > Ti < 0.47-x-y >) O < 3-x > PbNbO < 3-y > LaTiO < 3 > + awt% Al2O3 + bwt% Nb2O5 + cwt% La2O3, and x is equal to 0 to 0.01, y is equal to 0.001 to 0.01, a is equal to 0.001 to 0.5, b is equal to 0 to 0.5, and c is equal to 0 to 0.5. On the basis, the cost can be reduced while the high performance of the piezoelectric ceramic is maintained. In addition, the invention also provides a preparation method of the lead-based piezoelectric ceramic material.

Description

Technical Field

[0001] The invention relates to the technical field of piezoelectric ceramics, and in particular to a lead-based piezoelectric ceramic material and a preparation method thereof. Background Art

[0002] At present, the most widely used piezoelectric ceramic materials in the market mainly include lead zirconate titanate (PZT) piezoelectric ceramics and bismuth layered piezoelectric ceramics. PZT piezoelectric ceramics are known for their high piezoelectric constant (d 33 ≥300pC / N) has been widely used in high-performance devices, but its low Curie temperature (≤300℃) limits its use in high-temperature environments. Bismuth layered piezoelectric ceramics perform well in high-temperature environments with their extremely high Curie temperature (≥600℃), but their low piezoelectric constant (no more than 20pC / N) limits their use in high-sensitivity devices.

[0003] Although BiScO3-PbTiO3 piezoelectric ceramics are an ideal candidate material, they have the advantages of high piezoelectric constant and high Curie temperature, and theoretically can solve the shortcomings of the above two types of materials. However, due to the high price of its raw material Sc2O3, the production cost is high, so it is not suitable for large-scale industrial production at present.

[0004] Therefore, the present application studies a lead-based piezoelectric ceramic material that reduces the cost while maintaining high piezoelectric performance and high Curie temperature, thereby promoting the widespread application of piezoelectric ceramics. Summary of the invention

[0005] In order to reduce the cost of piezoelectric ceramics while maintaining high piezoelectric performance and high Curie temperature.

[0006] On the one hand, the present application provides a lead-based piezoelectric ceramic material, which adopts the following technical solution:

[0007] A lead-based piezoelectric ceramic material is based on lead zirconate titanate PbZrTiO3, externally doped with lanthanum oxide La2O3, niobium pentoxide Nb2O5 and aluminum oxide Al2O3, and partially lanthanum ions are used to replace the lead ions at the A position in the lead zirconate titanate PbZrTiO3, and niobium ions are partially used to replace the titanium ions at the B position in the lead zirconate titanate PbZrTiO3; the chemical formula of the lead-based piezoelectric ceramic material is: Pb(Zr 0.53 Ti 0.47-x-y )O3-xPbNbO3-yLaTiO3+awt%Al2O3+bwt%Nb2O5+cwt%La2O3, wherein x=0~0.01, y=0.001~0.01, a=0.001~0.5, b=0~0.5, c=0~0.5.

[0008] By adopting the above technical solution, the piezoelectric constant d of the lead-based piezoelectric ceramic material is 33 ≥500pC / N, Curie temperature greater than 390℃, so it has excellent piezoelectric constant while also having high Curie temperature and depolarization temperature, and the raw materials are widely available and cheap, so it can meet the application needs in high temperature and high sensitivity environments and reduce production costs.

[0009] On the other hand, the present application provides a method for preparing a lead-based piezoelectric ceramic material, which adopts the following technical solution:

[0010] A method for preparing the lead-based piezoelectric ceramic material comprises the following steps:

[0011] S1: ball milling, weigh analytically pure raw materials Pb3O4, ZrO2, TiO2, Al2O3, La2O3, Nb2O5 according to chemical measurement, put them into a ball milling jar, mix and ball mill to obtain ball mill material;

[0012] S2: secondary ball milling, pre-burning the ball mill material, and then performing secondary ball milling on the pre-burned powder to obtain secondary ball mill material;

[0013] S3: Molding: drying the secondary ball milled material, adding a binder, grinding it evenly, granulating it, screening it, and pressing it into a thin round blank, and then performing a plastic removal process to obtain a ceramic round blank;

[0014] S4: sintering: sintering the ceramic round blank to obtain a sintered ceramic sheet;

[0015] S5: Polarization: Polish both sides of the sintered ceramic sheet and print electrodes, place it in silicone oil and apply voltage for polarization to obtain a lead-based piezoelectric ceramic material.

[0016] Optionally, in step S1, the ball milling time is 8-12 h, and the ball milling speed is 200-250 r / min.

[0017] Optionally, in step S2, the pre-firing temperature is 820-880° C., and the pre-firing time is 2-4 hours.

[0018] Optionally, in step S2, the secondary ball milling time is 16-24 hours.

[0019] Optionally, in step S3, the binder is a PVA solution, and the granulated powder is formed into a thin round billet of 11 mm, and a demolding treatment is performed at a temperature of 650-750°C.

[0020] Optionally, in step S4, the ceramic round blank is sintered at a temperature of 1170-1210° C. for 2 hours.

[0021] Optionally, in step S5, the Ag electrode is further silver-sintered to serve as an electrode, and the silver-sintering temperature is 650-700° C. and the time is 20-40 min.

[0022] Optionally, in step S5, the polarization temperature is 140°C, the electric field strength is 3 kV / mm, and the holding time is 15 min.

[0023] In summary, this application includes the following beneficial technical effects:

[0024] 1. High piezoelectric constant d of lead-based piezoelectric ceramic materials 33 ≥500pC / N, Curie temperature greater than 390℃, so it has excellent piezoelectric constant and high Curie temperature and depolarization temperature, and the raw materials are widely available and cheap, so it can meet the application needs in high temperature and high sensitivity environment and reduce costs;

[0025] 2. The lead-based piezoelectric material provided by the present invention can meet the service requirements of ultrasonic motors, transducers, sensors and other sensitive components in a high temperature environment of 288°C, and has practical application value in high temperature electronic devices;

[0026] 3. The lead-based piezoelectric ceramic material with high piezoelectric performance, high Curie temperature and high depolarization temperature provided by the present invention has a simple and stable preparation process, is easy to operate, is suitable for promotion of large-scale industrial production, and has practical application value and broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0028] In the figure:

[0029] Figure 1 is the XRD diffraction pattern of the lead-based piezoelectric ceramic material prepared in Example 1 of the present application;

[0030] Figure 2 It is the dielectric temperature spectrum of the lead-based piezoelectric ceramic material prepared in Examples 1-4 of the present application. DETAILED DESCRIPTION

[0031] The following is combined with Figure 1-2 This application is described in further detail.

[0032] Reference Figure 1 and Figure 2, the embodiment of the present application discloses a method for preparing a lead-based piezoelectric ceramic material.

[0033] Embodiment 1:

[0034] A method for preparing a lead-based piezoelectric ceramic material.

[0035] This embodiment provides a method for preparing a piezoelectric ceramic material having a chemical composition of Pb(Zr 0.53 Ti 0.47-x-y )O3-xPbNbO3-yLaTiO3+awt%Al2O3+bwt%Nb2O5+cwt%La2O3, wherein x=0.005, y=0.005, a=0.05, b=0.04, c=0.05, is a lead-based piezoelectric ceramic material.

[0036] The preparation method described in this embodiment comprises the following steps:

[0037] S1: ball milling, according to the above chemical measurement, weigh analytically pure raw materials Pb3O4, ZrO2, TiO2, Al2O3, La2O3, Nb2O5, put them into a ball milling jar, mix and ball mill for 12 hours to obtain ball milled materials, and use a planetary ball mill to ball mill at a speed of 250r / min;

[0038] S2: secondary ball milling, the ball mill material is pre-sintered at 850°C for 2 hours, and the pre-sintered powder is subjected to secondary ball milling for 24 hours to obtain secondary ball mill material;

[0039] S3: Molding: Dry the secondary ball milled material, add the binder PVA solution, grind it evenly, granulate it, screen it, and press it into a thin round blank with a diameter of 11 mm. Then, perform a plastic removal treatment at a temperature of 650°C to obtain a ceramic round blank.

[0040] S4: sintering: sintering the ceramic round blank at 1210°C for 2h to obtain a sintered ceramic sheet;

[0041] S5: Polarization: Polish both sides of the sintered ceramic sheet and print the Ag electrode and then burn the silver electrode. The silver burning temperature is 650℃ for 20min. Place it in 140℃ silicone oil and apply a DC electric field of 3kV / mm for 15 minutes for polarization to obtain a lead-based piezoelectric ceramic material.

[0042] Embodiment 2:

[0043] A method for preparing a lead-based piezoelectric ceramic material.

[0044] This embodiment provides a method for preparing a piezoelectric ceramic material having a chemical composition of Pb(Zr 0.53 Ti 0.47-x-y)O3-xPbNbO3-yLaTiO3+awt%Al2O3+bwt%Nb2O5+cwt%La2O3, wherein x=0.005, y=0.005, a=0.08, b=0.04, c=0.05 is a lead-based piezoelectric ceramic material.

[0045] The preparation method described in this embodiment comprises the following steps:

[0046] S1: ball milling, according to the above chemical measurement, weigh analytically pure raw materials Pb3O4, ZrO2, TiO2, Al2O3, La2O3, Nb2O5, put them into a ball milling jar, mix and ball mill for 12 hours to obtain ball milled materials, and use a planetary ball mill to ball mill at a speed of 250r / min;

[0047] S2: secondary ball milling, the ball mill material is pre-sintered at 850°C for 2 hours, and the pre-sintered powder is subjected to secondary ball milling for 24 hours to obtain secondary ball mill material;

[0048] S3: Molding: Dry the secondary ball milled material, add the binder PVA solution, grind it evenly, granulate it, screen it, and press it into a thin round blank with a diameter of 11 mm. Then, perform a plastic removal treatment at a temperature of 650°C to obtain a ceramic round blank.

[0049] S4: sintering: sintering the ceramic round blank at 1190°C for 2h to obtain a sintered ceramic sheet;

[0050] S5: Polarization: Polish both sides of the sintered ceramic sheet and print the Ag electrode and then burn the silver electrode. The silver burning temperature is 650℃ for 20min. Place it in 140℃ silicone oil and apply a DC electric field of 3kV / mm for 15 minutes for polarization to obtain a lead-based piezoelectric ceramic material.

[0051] Embodiment 3:

[0052] A method for preparing a lead-based piezoelectric ceramic material.

[0053] This embodiment provides a method for preparing a piezoelectric ceramic material having a chemical composition of Pb(Zr 0.53 Ti 0.47-x-y )O3-xPbNbO3-yLaTiO3+awt%Al2O3+bwt%Nb2O5+cwt%La2O3, wherein x=0.005, y=0.005, a=0.10, b=0.04, c=0.05 is a lead-based piezoelectric ceramic material.

[0054] The preparation method described in this embodiment comprises the following steps:

[0055] S1: ball milling, according to the above chemical measurement, weigh analytically pure raw materials Pb3O4, ZrO2, TiO2, Al2O3, La2O3, Nb2O5, put them into a ball milling jar, mix and ball mill for 12 hours to obtain ball milled materials, and use a planetary ball mill to ball mill at a speed of 250r / min;

[0056] S2: secondary ball milling, the ball mill material is pre-sintered at 850°C for 2 hours, and the pre-sintered powder is subjected to secondary ball milling for 24 hours to obtain secondary ball mill material;

[0057] S3: Molding: Dry the secondary ball milled material, add the binder PVA solution, grind it evenly, granulate it, screen it, and press it into a thin round blank with a diameter of 11 mm. Then, perform a plastic removal treatment at a temperature of 650°C to obtain a ceramic round blank.

[0058] S4: sintering: sintering the ceramic round blank at 1170°C for 2h to obtain a sintered ceramic sheet;

[0059] S5: Polarization: Polish both sides of the sintered ceramic sheet and print the Ag electrode and then burn the silver electrode. The silver burning temperature is 650℃ for 20min. Place it in 140℃ silicone oil and apply a DC electric field of 3kV / mm for 15 minutes for polarization to obtain a lead-based piezoelectric ceramic material.

[0060] Embodiment 4:

[0061] A method for preparing a lead-based piezoelectric ceramic material.

[0062] This embodiment provides a method for preparing a piezoelectric ceramic material having a chemical composition of Pb(Zr 0.53 Ti 0.47-x-y )O3-xPbNbO3-yLaTiO3+awt%Al2O3+bwt%Nb2O5+cwt%La2O3, wherein x=0.005, y=0.002, a=0.08, b=0.04, c=0.05 is a lead-based piezoelectric ceramic material.

[0063] The preparation method described in this embodiment comprises the following steps:

[0064] S1: ball milling, according to the above chemical measurement, weigh analytically pure raw materials Pb3O4, ZrO2, TiO2, Al2O3, La2O3, Nb2O5, put them into a ball milling jar, mix and ball mill for 12 hours to obtain ball milled materials, and use a planetary ball mill to ball mill at a speed of 250r / min;

[0065] S2: secondary ball milling, the ball mill material is pre-sintered at 850°C for 2 hours, and the pre-sintered powder is subjected to secondary ball milling for 24 hours to obtain secondary ball mill material;

[0066] S3: Molding: Dry the secondary ball milled material, add the binder PVA solution, grind it evenly, granulate it, screen it, and press it into a thin round blank with a diameter of 11 mm. Then, perform a plastic removal treatment at a temperature of 650°C to obtain a ceramic round blank.

[0067] S4: sintering: sintering the ceramic round blank at 1190°C for 2h to obtain a sintered ceramic sheet;

[0068] S5: Polarization: Polish both sides of the sintered ceramic sheet and print the Ag electrode and then burn the silver electrode. The silver burning temperature is 650℃ for 20min. Place it in 140℃ silicone oil and apply a DC electric field of 3kV / mm for 15 minutes for polarization to obtain a lead-based piezoelectric ceramic material.

[0069] Performance Testing

[0070] The detection method is as follows: piezoelectric constant d 33 Use quasi-static 33 Tester test; Curie temperature T c The dielectric loss tanδ is measured using an impedance analyzer; the depolarization temperature T d Tested using thermal depolarization method; relative dielectric constant ε r The calculation formula is based on the ceramic capacitance C, the ceramic electrode area S and thickness d, and the vacuum dielectric constant ε0:

[0071] The piezoelectric properties of the lead-based piezoelectric ceramic materials prepared in Examples 1-4 were tested using the above-mentioned testing method. The test results are shown in Table 1.

[0072] Table 1

[0073]

[0074]

[0075] According to Table 1, Examples 1-4 of the present application have relatively high piezoelectric properties, all higher than 520pC / N, and the Curie temperatures are all higher than 398°C. Among them, the piezoelectric constant in Example 2 is the best, which can reach 615pC / N and the Curie temperature is 412°C; the Curie temperature in Example 1 is the best, which can reach 428°C, and the piezoelectric constant also reaches 590pC / N, while maintaining relatively low dielectric loss. Therefore, the lead-based piezoelectric ceramic material of the present application has the advantages of high piezoelectric performance, high Curie temperature and high depolarization temperature, which can meet the service requirements of sensitive components such as ultrasonic motors, transducers, and sensors in a high temperature environment of 288°C, and has practical application value in high-temperature electronic devices, and has low cost and simple process, which is conducive to wide application.

[0076] according to Figure 1It can be seen that Example 1 successfully prepared a PZT piezoelectric ceramic material whose main crystal phase is a perovskite structure.

[0077] according to Figure 2 It can be seen that the Curie temperatures of the piezoelectric ceramic materials in the four embodiments are between 398° C. and 428° C., which indicates that the piezoelectric ceramic materials of the present invention can be used in high temperature environments.

[0078] The above are exemplary embodiments disclosed in the present invention, but it should be noted that various changes and modifications may be made without departing from the scope disclosed in the embodiments of the present invention as defined in the claims. The functions, steps and / or actions of the method claims according to the disclosed embodiments described herein do not need to be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or required in individual form, they may also be understood as multiple unless explicitly limited to the singular.

[0079] It should be understood that, as used herein, the singular form "a" or "an" is intended to include the plural form as well, unless the context clearly supports an exception. It should also be understood that, as used herein, "and / or" refers to any and all possible combinations of one or more of the items listed in association. The serial numbers of the embodiments disclosed in the above embodiments of the present invention are for description only and do not represent the advantages and disadvantages of the embodiments.

[0080] A person skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the embodiments of the present invention as above, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the protection scope of the embodiments of the present invention.

Claims

1. A lead-based piezoelectric ceramic material, characterized in that: Based on lead zirconate titanate PbZrTiO3, lanthanum oxide La2O3, niobium pentoxide Nb2O5 and aluminum oxide Al2O3 are externally doped, and the lead ions at the A position in the lead zirconate titanate PbZrTiO3 are partially replaced by lanthanum ions, and the titanium ions at the B position in the lead zirconate titanate PbZrTiO3 are partially replaced by niobium ions; The general chemical formula of lead-based piezoelectric ceramic materials is: Pb(Zr 0.53 Ti 0.47-x-y )O3-xPbNbO3-yLaTiO3+awt%Al2O3+bwt%Nb2O5+cwt%La2O3, wherein x=0~0.01, y=0.001~0.01, a=0.001~0.5, b=0~0.5, c=0~0.

5.

2. A method for preparing the lead-based piezoelectric ceramic material according to claim 1, characterized in that: The following steps are involved: S1: ball milling, weigh analytically pure raw materials Pb3O4, ZrO2, TiO2, Al2O3, La2O3, Nb2O5 according to chemical measurement, put them into a ball milling jar, mix and ball mill to obtain ball mill material; S2: secondary ball milling, pre-burning the ball mill material, and then performing secondary ball milling on the pre-burned powder to obtain secondary ball mill material; S3: Molding: drying the secondary ball milled material, adding a binder, grinding it evenly, granulating it, screening it, and pressing it into a thin round blank, and then performing a plastic removal process to obtain a ceramic round blank; S4: sintering: sintering the ceramic round blank to obtain a sintered ceramic sheet; S5: Polarization: Polish both sides of the sintered ceramic sheet and print electrodes, place it in silicone oil and apply voltage for polarization to obtain a lead-based piezoelectric ceramic material.

3. The method for preparing a lead-based piezoelectric ceramic material according to claim 2, characterized in that: In step S1, the ball milling time is 8-12 h, and the ball milling speed is 200-250 r / min.

4. The method for preparing a lead-based piezoelectric ceramic material according to claim 2, characterized in that: In step S2, the pre-firing temperature is 820-880°C and the pre-firing time is 2-4h.

5. The method for preparing a lead-based piezoelectric ceramic material according to claim 2, characterized in that: In step S2, the secondary ball milling time is 16-24 h.

6. The method for preparing a lead-based piezoelectric ceramic material according to claim 2, characterized in that: In step S3, the binder is a PVA solution, and the granulated powder is formed into a thin round billet of 11 mm, and a demolding treatment is performed at a temperature of 650-750°C.

7. The method for preparing a lead-based piezoelectric ceramic material according to claim 2, characterized in that: In step S4, the ceramic round blank is sintered at a temperature of 1170-1210°C for 2 hours.

8. The method for preparing a lead-based piezoelectric ceramic material according to claim 2, characterized in that: In step S5, the Ag electrode is further silver-sintered to form an electrode at a temperature of 650-700° C. for 20-40 minutes.

9. The method for preparing a lead-based piezoelectric ceramic material according to claim 2, characterized in that: In step S5, the polarization temperature is 140°C, the electric field strength is 3 kV / mm, and the holding time is 15 min.

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