A piezoelectric ceramic material and its preparation method and piezoelectric device

Abstract

The present application discloses a piezoelectric ceramic material, a preparation method thereof and a piezoelectric device. The chemical formula of the piezoelectric ceramic material is: 0.7Pb(Zr 0.46 Ti 0.54 )O3‑(0.2‑a)Pb(Zn 1 / 3 Nb 2 / 3 )O3‑0.1Pb(Ni 1 / 3 Nb 2 / 3 )O3‑aBi(Zn 1 / 2 Ti 1 / 2 )O3+bwt%Li2CO3; wherein 0.005≤a≤0.05, 0≤b<1. The piezoelectric ceramic material provided by the present application can have good piezoelectric properties at a relatively low sintering temperature, and due to the relatively low sintering temperature, the volatilization of lead vapor is reduced, thereby reducing environmental pollution.

Description

Technical Field

[0001] The present application relates to the technical field of piezoelectric materials, and more specifically, to a piezoelectric ceramic material and a preparation method thereof and a piezoelectric device. Background Art

[0002] Piezoelectric ceramics are functional ceramic materials that can convert mechanical energy into electrical energy. Among them, PZT (lead zirconate titanate)-based piezoelectric ceramics still dominate in actual production applications due to their advantages of easy manufacturing, low cost, excellent electrical properties, and stable performance. However, the sintering temperature of traditional PZT-based piezoelectric ceramics is relatively high, generally between 1100°C and 1300°C, and lead vapor will volatilize at high temperatures above 960°C. In conventional solid-phase reactions, it will not only reduce the electrical properties of the sample, but lead is also one of the heavy metals that is extremely harmful to human health and is prone to environmental pollution. Summary of the invention

[0003] One object of the present application is to provide a new technical solution for a piezoelectric ceramic material and a method for preparing the same, and a piezoelectric device.

[0004] According to the first aspect of the present application, a piezoelectric ceramic material is provided, the chemical formula of which is:

[0005] 0.7Pb(Zr 0.46 Ti 0.54 )O3-(0.2-a)Pb(Zn 1 / 3 Nb 2 / 3 )O3-0.1Pb(Ni 1 / 3 Nb 2 / 3 )O3-aBi(Zn 1 / 2Ti 1 / 2 )O3+bwt%Li2CO3; wherein, 0.005≤a≤0.05, 0≤b<1.

[0006] Optionally, the piezoelectric ceramic material further includes an additive, and the additive is one or more of CeO2, Fe2O3, MgO, and CuO.

[0007] Optionally, the additive is added in an amount of 0-0.5 wt %.

[0008] Optionally, in the piezoelectric ceramic material, the Pb source is PbO or Pb3O4, the Zr source is ZrO2, the Ti source is TiO2, the Zn source is ZnO, the Nb source is Nb2O5, the Ni source is NiO, and the Li source is Li2CO3.

[0009] Optionally, the sintering temperature of the piezoelectric ceramic material is 850°C-950°C.

[0010] Optionally, the piezoelectric ceramic material has a Curie temperature Tc>230°C and a piezoelectric coefficient d33>600pC / N.

[0011] According to a second aspect of the present application, there is provided a method for preparing the piezoelectric ceramic material according to the first aspect, comprising:

[0012] Weigh the raw materials according to the ratio of the chemical formula, add deionized water to the raw materials, and perform dispersion and grinding to obtain a uniformly mixed material I;

[0013] After drying and sieving material I, pre-calcining at a certain pre-calcining temperature to obtain synthetic material II;

[0014] The synthesized material II is ground and dispersed to obtain the piezoelectric ceramic material.

[0015] Optionally, the pre-firing temperature is 750-850°C.

[0016] Optionally, zirconium balls are used as grinding media for dispersion grinding.

[0017] According to a third aspect of the present application, a piezoelectric device is provided, which is prepared using the piezoelectric ceramic material described in the first aspect.

[0018] According to one embodiment of the present application, the piezoelectric ceramic material provided by the present application has good piezoelectric properties at a lower sintering temperature, which not only reduces environmental pollution, but also can match the silver electrode or reduce the palladium content in the silver-palladium electrode when preparing a multilayer piezoelectric ceramic product. Other features and advantages of the present application will become clear through the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the application and, together with the description, serve to explain the principles of the application.

[0020] Figure 1 This is a surface SEM photograph of a piezoelectric ceramic device prepared using the piezoelectric ceramic material provided in this application.

[0021] Figure 2 yes Figure 1 Cross-sectional SEM photograph of the piezoelectric ceramic device in. DETAILED DESCRIPTION

[0022] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application.

[0023] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses.

[0024] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0025] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0026] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0027] According to the first aspect of the present application, a piezoelectric ceramic material is provided, the chemical formula of which is:

[0028] 0.7Pb(Zr 0.46 Ti 0.54 )O3-(0.2-a)Pb(Zn 1 / 3 Nb 2 / 3 )O3-0.1Pb(Ni 1 / 3 Nb 2 / 3 )O3-aBi(Zn 1 / 2Ti 1 / 2 )O3+bwt%Li2CO3; wherein, 0.005≤a≤0.05, 0≤b<1.

[0029] Specifically, in this embodiment, the piezoelectric ceramic material includes 0.7Pb(Zr 0.46 Ti 0.54 )O3-(0.2-a)Pb(Zn 1 / 3Nb 2 / )O3-0.1Pb(Ni 1 / 3 Nb 2 / 3 )O3-aBi(Zn 1 / 2 Ti 1 / 2 )O3 and Li2CO3, among which, the PZT-PZN-PNN system is formed by element doping, and the Pb vacancies formed have charge compensation effect and buffer effect, domain wall movement is easy to proceed, the coercive field is reduced, and the material is soft; by Bi(Zn 1 / 2 Ti 1 / 2)The addition of O3 can, on the one hand, reduce the sintering temperature of the piezoelectric ceramic material, and on the other hand, ensure that the piezoelectric performance of the material does not decrease significantly. The addition of the low-melting-point oxide Li2CO3 promotes liquid phase sintering, further reducing the sintering temperature of the piezoelectric ceramic material. The lower sintering temperature and good piezoelectric properties greatly reduce the preparation cost when using piezoelectric ceramic materials to prepare piezoelectric ceramic devices, and the volatilization of lead vapor is also greatly reduced, reducing environmental pollution. In addition, the melting point of silver is 962°C, and the piezoelectric ceramic material provided in this application has a sintering temperature of 850-950°C, which can match the silver electrode or reduce the palladium content in the silver-palladium electrode, and has a wide range of applications in piezoelectric acoustic devices, tactile feedback, piezoelectric motors and other devices.

[0030] In the process of preparing the above piezoelectric ceramic material, Pb(Zr 0.46 Ti 0.54 )O3、Pb(Zn 1 / 3 Nb 2 / 3 )O3、Pb(Ni 1 / 3Nb 2 / 3 )O3, and Bi(Zn 1 / 2 Ti 1 / 2 )O3 The molar mass ratio between the materials is 0.7: (0.2-a): 0.1: a, where if the value of a is too large or too small, it will affect the piezoelectric properties of the final piezoelectric ceramic material. The value range of a is selected between 0.005 and 0.05, such as 0.006, 0.008, 0.01, 0.02, 0.03, 0.04, etc., so that the piezoelectricity of the prepared piezoelectric ceramic material can be further maintained within a suitable range. In addition, excessive addition of Li2CO3 will sharply deteriorate the piezoelectric performance. It is set to be equal to 0.7Pb(Zr 0.46 Ti 0.54 )O3-(0.2-a)Pb(Zn 1 / 3 Nb 2 / 3 )O3-0.1Pb(Ni 1 / 3 Nb 2 / 3 )O3-aBi(Zn 1 / 2 Ti 1 / 2 )The weight percentage of O3 is less than 1wt%, for example 0.3wt%, 0.5wt%, 0.8wt%, etc., so that the prepared piezoelectric ceramic material has a lower sintering temperature without affecting its piezoelectric properties.

[0031] Optionally, the piezoelectric ceramic material further includes an additive, and the additive is one or more of CeO2, Fe2O3, MgO, and CuO.

[0032] Specifically, in this embodiment, during the preparation of the piezoelectric ceramic material, an additive may be added to further reduce the sintering temperature of the piezoelectric ceramic material. The additive may be one or more of CeO2, Fe2O3, MgO, and CuO, and the additives are all conventional materials and are suitable for mass production.

[0033] Optionally, the additive is added in an amount of 0-0.5 wt %.

[0034] Specifically, in practical applications, excessive addition of additives will lead to a sharp deterioration in piezoelectric performance. Setting the proportion of the additive within 0.5wt%, such as 0.1wt%, 0.3wt%, 0.4wt%, etc., can ensure that the material has a lower sintering temperature and better piezoelectric performance. Optionally, in the piezoelectric ceramic material, the Pb source uses PbO or Pb3O4, the Zr source uses ZrO2, the Ti source uses TiO2, the Zn source uses ZnO, the Nb source uses Nb2O5, the Ni source uses NiO, and the Li source uses Li2CO3.

[0035] Specifically, in the actual preparation process, the raw materials for preparing piezoelectric ceramic materials can be selected from any Pb, Zr, Ti, Zn, Nb, Ni, and Li sources. In actual production, in order to ensure the stability of mass production, the Pb source is usually PbO or Pb3O4, the Zr source is ZrO2, the Ti source is TiO2, the Zn source is ZnO, the Nb source is Nb2O5, the Ni source is NiO, and the Li source is Li2CO3.

[0036] Optionally, the sintering temperature of the piezoelectric ceramic material is 850°C-950°C.

[0037] Specifically, in this embodiment, the sintering temperature of the piezoelectric ceramic material is 850°C-950°C, which is significantly lower than the sintering temperature of the piezoelectric ceramic material in the prior art, which is usually above 1100°C. The reduction in sintering temperature can make it possible to use silver inner electrodes or reduce the content of palladium in the silver-palladium electrode in the process of preparing multilayer piezoelectric ceramics using the piezoelectric ceramic material in this application, thereby significantly reducing costs.

[0038] For example, in one embodiment, when using piezoelectric ceramic materials to prepare multilayer piezoelectric ceramic devices, it is usually desirable to use silver internal electrodes in order to reduce costs. However, since the melting point of silver is 962°C, the piezoelectric ceramic materials in the prior art cannot meet this requirement. The sintering temperature of the piezoelectric ceramic material provided in this application is only 850°C-950°C, and the silver electrodes can be matched when the multilayer piezoelectric ceramic device is sintered, so that it has a wide range of applications in piezoelectric acoustic devices, tactile feedback, piezoelectric motors and other devices, reducing material costs.

[0039] Optionally, the piezoelectric ceramic material has a Curie temperature Tc>230°C and a piezoelectric coefficient d33>600pC / N.

[0040] Specifically, in the prior art, Pb(Zn 1 / 3 Nb 2 / 3 )O3-Pb(Ni 1 / 3 Nb 2 / 3 )The addition of O3 components can reduce the sintering temperature, but the reduction in sintering temperature is limited and cannot meet the temperature requirement of silver electrodes below 950°C. When the amount added is too much, the piezoelectric properties of the material will deteriorate sharply, and the Curie temperature of the piezoelectric ceramic will be seriously reduced. If the Curie temperature is too low, the electrode will easily depolarize at high temperatures, resulting in poor performance stability of the piezoelectric ceramic device. The Curie temperature Tc of the piezoelectric ceramic material provided in the present application can reach above 230°C, and the piezoelectric coefficient d33 can reach above 600pC / N, which strikes a good balance between low sintering temperature and high Curie temperature, while ensuring the piezoelectric properties of the material.

[0041] According to a second aspect of the present application, there is provided a method for preparing the piezoelectric ceramic material according to the first aspect, comprising:

[0042] S01: weigh the raw materials according to the ratio of the chemical formula, add deionized water to the raw materials, and disperse and grind them to obtain a uniformly mixed material I.

[0043] In this step, after weighing the raw materials according to the set ratio, deionized water can be added to the raw materials, and after the raw materials are synthesized by the solid phase method, zirconium balls are used as grinding media to disperse and grind them so that the raw materials are evenly mixed.

[0044] S02: After drying and sieving material I, pre-calcining it at a certain pre-calcining temperature to obtain synthetic material II.

[0045] In this step, material I is further processed, that is, it is dried and sieved, and is placed in a crucible for pre-calcination at 750-850° C. and heat preservation for 2-4 hours.

[0046] S03: Grind and disperse the synthesized material II to obtain the piezoelectric ceramic material. The obtained piezoelectric ceramic material can be further sintered to form a piezoelectric ceramic product.

[0047] According to the third aspect of the present application, reference Figure 1 to Figure 2 , providing a piezoelectric device, which is prepared using the piezoelectric ceramic material described in the first aspect.

[0048] Specifically, in this embodiment, the piezoelectric device is made of the piezoelectric ceramic material provided in the first aspect of the present application, and the surface photograph of the manufactured piezoelectric device is referenced to Figure 1, cross-section photo reference Figure 2 . Since the piezoelectric ceramic material provided by the present application has a lower sintering temperature and a higher Curie temperature, the performance stability of the piezoelectric ceramic device is guaranteed, so that it can be applied to the preparation of a variety of piezoelectric devices. For example, piezoelectric acoustic devices, piezoelectric motors or tactile feedback devices and other fields. In the actual production process, the low sintering temperature reduces the volatilization of lead vapor, reducing environmental pollution and manufacturing costs.

[0049] In order to make the technical effects of the present application more clear, a number of embodiments and comparative examples are provided below.

[0050] Embodiment 1:

[0051] In this embodiment, a=0.005, b=0, and the additive content c=0, that is, the weight of each raw material is as follows: 0.7Pb(Zr 0.46 Ti 0.54 )O3-0.195Pb(Zn 1 / 3 Nb 2 / 3 )O3-0.1Pb(Ni 1 / 3 Nb 2 / 3 )O3-0.005Bi(Zn 1 / 2 Ti 1 / 2 )O3 is used for mixing. That is, 100g of the above materials are taken, among which 68.34g of Pb3O4, 11.92g of ZrO2, 9.13g of TiO2, 1.65g of ZnO, 7.86g of Nb2O5, 0.75g of NiO, and 0.35g of Bi2O3 are weighed, and the piezoelectric ceramic material is prepared by the preparation method provided in the second aspect of the present application, and the sintering temperature thereof is measured to be 950°C.

[0052] The obtained piezoelectric ceramic material was granulated to prepare discs, which were sintered at 950°C. The electrodes on the formed discs were polarized at 120°C and 3KV / mm. The performance of the discs was tested, and its piezoelectric performance d33 was measured to be 658pC / N.

[0053] Embodiment 2:

[0054] In this embodiment, a=0.001, b=0, and the additive content c=0, that is, the above materials with a total weight of 100 g are taken, among which 68.03 g of Pb3O4, 11.93 g of ZrO2, 9.20 g of TiO2, 1.67 g of ZnO, 7.73 g of Nb2O5, 0.75 g of NiO, and 0.70 g of Bi2O3 are weighed, and the piezoelectric ceramic material is prepared according to the preparation method in Example 1. The sintering temperature is 940°C, and the piezoelectric performance of the sintered disc is d33=650pC / N.

[0055] Embodiment 3:

[0056] In this embodiment, a=0.003, b=0, and the additive content c=0, that is, the above materials with a total weight of 100g are taken, among which 66.77g of Pb3O4, 11.95g of ZrO2, 9.46g of TiO2, 1.76g of ZnO, 7.21g of Nb2O5, 0.75g of NiO, and 2.11g of Bi2O3 are weighed, and the piezoelectric ceramic material is prepared according to the preparation method in Example 1. The sintering temperature is 925°C, and the piezoelectric performance of the sintered disc is d33=633pC / N.

[0057] Embodiment 4:

[0058] In this embodiment, a=0.05, b=0, and the additive content c=0, that is, the above materials with a total weight of 100g are taken, among which 65.52g of Pb3O4, 11.97g of ZrO2, 9.71g of TiO2, 1.84g of ZnO, 6.68g of Nb2O5, 0.75g of NiO, and 3.52g of Bi2O3 are weighed, and the piezoelectric ceramic material is prepared according to the preparation method in Example 1. The sintering temperature is 920°C, and the piezoelectric performance of the sintered disc is d33=620pC / N.

[0059] Embodiment 5:

[0060] In this embodiment, a=0.005, b=0.1, and the additive content c=0, that is, the above materials with a total weight of 100g are taken, among which 68.27g of Pb3O4, 11.91g of ZrO2, 9.12g of TiO2, 1.65g of ZnO, 7.85g of Nb2O5, 0.75g of NiO, 0.35g of Bi2O3, and 0.10g of Li2CO3 are weighed, and the piezoelectric ceramic material is prepared according to the preparation method in Example 1. The sintering temperature is 940°C, and the piezoelectric performance of the sintered disc is d33=670pC / N.

[0061] Embodiment 6:

[0062] In this embodiment, a=0.005, b=0.3, and the additive content c=0, that is, take the above materials with a total weight of 100g, among which 68.13g of Pb3O4, 11.89g of ZrO2, 9.11g of TiO2, 1.65g of ZnO, 7.83g of Nb2O5, 0.75g of NiO, 0.35g of Bi2O3, and 0.30g of Li2CO3 are weighed, and the piezoelectric ceramic material is prepared according to the preparation method in Example 1. The sintering temperature is 920°C, and the piezoelectric performance of the sintered disc is d33=653pC / N.

[0063] Example 7:

[0064] In this embodiment, a=0.005, b=0.5, and the additive content c=0, that is, the above materials with a total weight of 100g are taken, among which 68.00g of Pb3O4, 11.86g of ZrO2, 9.09g of TiO2, 1.64g of ZnO, 7.82g of Nb2O5, 0.74g of NiO, 0.35g of Bi2O3, and 0.50g of Li2CO3 are weighed, and the piezoelectric ceramic material is prepared according to the preparation method in Example 1. The sintering temperature is 900°C, and the piezoelectric performance of the sintered disc is d33=640pC / N.

[0065] Example 8:

[0066] In this embodiment, a=0.005, b=0.3, and Fe2O3 is selected as the additive with a content of 0.05wt%, that is, 100g of the above materials are taken, among which 68.10g of Pb3O4, 11.88g of ZrO2, 9.10g of TiO2, 1.65g of ZnO, 7.83g of Nb2O5, 0.75g of NiO, 0.35g of Bi2O3, 0.30g of Li2CO3, and 0.05g of Fe2O3 are weighed. After the piezoelectric ceramic material is prepared according to the preparation method in Example 1, the sintering temperature is 920°C, and the piezoelectric performance of the sintered disc is d33=663pC / N.

[0067] Example 9:

[0068] In this embodiment, a=0.005, b=0.3, CeO2 is selected as the additive, and the content is 0.05wt%, that is, 100g of the above materials are taken, among which 68.10g of Pb3O4, 11.88g of ZrO2, 9.10g of TiO2, 1.65g of ZnO, 7.83g of Nb2O5, 0.75g of NiO, 0.35g of Bi2O3, 0.30g of Li2CO3, and 0.05g of CeO2 are weighed, and the piezoelectric ceramic material is prepared according to the preparation method in Example 1, and the sintering temperature is 920°C, and the piezoelectric performance of the sintered disc is d33=660pC / N.

[0069] Comparative Example:

[0070] In this comparative example, a=0, b=0, and additive c=0, that is, the above materials with a total weight of 100 g are taken, among which 68.65 g of Pb3O4, 11.92 g of ZrO2, 9.07 g of TiO2, 1.63 g of ZnO, 7.98 g of Nb2O5, and 0.75 g of NiO are weighed, and the piezoelectric ceramic material is prepared according to the preparation method in Example 1. The sintering temperature is 1180°C, and the piezoelectric performance of the sintered disc is d33=641pC / N.

[0071] It can be seen from the above embodiments and comparative examples that the piezoelectric ceramic material provided in the present application has a lower sintering temperature and can ensure that the piezoelectric performance is maintained within a relatively high range, thereby improving the performance stability of devices made of piezoelectric ceramic materials.

[0072] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0073] Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are only for illustration, not for limiting the scope of the present application. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. A piezoelectric ceramic material, characterized in that: The chemical formula is: 0.7Pb(Zr 0.46 The 0.54 )O3-(0.2-a)Pb(Zn 1 / 3 Nb 2 / 3 )O3-0.1Pb(Ni 1 / 3 Nb 2 / 3 )O3-aBi(Zn 1 / 2 The 1 / 2 )O3+ bwt%Li2CO3,0.005≤a≤0.05,04b<1 The piezoelectric ceramic material further includes an additive, wherein the additive is one or more of CeO2, Fe2O3, MgO, and CuO, and the additive ratio is 0-0.5wt%; The sintering temperature of the piezoelectric ceramic material is 850° C.-950° C., the Curie temperature Tc of the piezoelectric ceramic material is greater than 230° C., and the piezoelectric coefficient d33 is greater than 600 pC / N.

2. The piezoelectric ceramic material according to claim 1, characterized in that: in, The Pb source uses PbO or Pb3O4, the Zr source uses ZrO2, the Ti source uses TiO2, the Zn source uses ZnO, the Nb source uses Nb2O5, the Ni source uses NiO, and the Li source uses Li2CO3.

3. A method for preparing a piezoelectric ceramic material as claimed in claim 1 or 2, characterized in that: include: Weigh the raw materials according to the ratio of the chemical formula, add deionized water to the raw materials, and perform dispersion and grinding to obtain a uniformly mixed material I; After drying and sieving material I, pre-calcining at a certain pre-calcining temperature to obtain synthetic material II, the pre-calcining temperature is 750-850°C; The synthesized material II is ground and dispersed to obtain the piezoelectric ceramic material.

4. The method for preparing a piezoelectric ceramic material according to claim 3, characterized in that: Zirconium balls are used as grinding media for dispersion grinding.

5. A piezoelectric device, characterized in that: The piezoelectric ceramic material is prepared using the piezoelectric ceramic material according to claim 1 or 2.

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