Piezoelectric ceramic material, method for producing the same, and piezoelectric device

Abstract

This invention relates to a piezoelectric ceramic material, its preparation method, and a piezoelectric device. The chemical formula of the piezoelectric ceramic material is (1-x)Pb(Mg). 1 / 3 Nb 2 / 3 The formula is (1-x)Pb(Mg)O3:y(La2O3+SrCO3), where 0.30≤x≤0.34, 0.00<y≤0.03, and x and y are molar ratios. This is compared to (1-x)Pb(Mg)O3 without the introduction of La2O3 and SrCO3. 1 / 3 Nb 2 / 3 Compared with O3-xPbTiO3 ceramics, the piezoelectric ceramic material of the present invention has higher piezoelectric performance. Experimental verification shows that the piezoelectric coefficient d of the piezoelectric ceramic material of the present invention... 33 The piezoelectric ceramic material can reach 730 pC / N. Furthermore, this invention also includes a method for preparing the above-mentioned piezoelectric ceramic material and a piezoelectric device comprising the above-mentioned piezoelectric ceramic material.

Description

Technical Field

[0001] This invention relates to the field of piezoelectric ceramics technology, and in particular to a piezoelectric ceramic material, its preparation method, and a piezoelectric device. Background Technology

[0002] Piezoelectric materials are crucial functional materials capable of converting between electrical and mechanical energy. They have found widespread application in high-tech military and civilian fields such as medical ultrasound probes, precision drives, and underwater acoustic transducers, resulting in a huge and continuously growing market. Therefore, the development of high-performance piezoelectric ceramics is of great significance for improving the working accuracy and applicability of devices, promoting industrial upgrading, boosting national economic development, and supporting national defense.

[0003] Lead magnesium niobate-lead titanate (Pb(Mg) 1 / 3 Nb 2 / 3 Lead-based piezoelectric ceramics, represented by Pb(MgO3-PbTiO3), are among the most widely used material systems. However, Pb(MgO3-PbTiO3)... 1 / 3 Nb 2 / 3 There is still room for improvement in the piezoelectric properties of O3-PbTiO3 ceramics. Summary of the Invention

[0004] Therefore, it is necessary to provide a piezoelectric ceramic material, its preparation method, and a piezoelectric device to address the issue of how to significantly improve the piezoelectric properties of ceramic materials.

[0005] A piezoelectric ceramic material, wherein the chemical formula of the piezoelectric ceramic material is (1-x)Pb(Mg) 1 / 3 Nb 2 / 3 )O3-xPbTiO3:y(La2O3+SrCO3), where 0.30≤x≤0.34, 0.00<y≤0.03, and x and y are molar ratios.

[0006] (1-x)Pb(Mg) without the introduction of La2O3 and SrCO3 1 / 3 Nb 2 / 3 Compared with O3-xPbTiO3 ceramics, the piezoelectric ceramic material of the present invention has higher piezoelectric performance. Experimental verification shows that the piezoelectric coefficient d of the piezoelectric ceramic material of the present invention... 33 It can reach 730pC / N.

[0007] In one feasible implementation, the piezoelectric ceramic material has the chemical formula 0.68Pb(Mg) 1 / 3 Nb 2 / 3 )O3-0.32PbTiO3:y(La2O3+SrCO3), where 0.01≤y≤0.03, and y is the molar ratio.

[0008] A method for preparing a piezoelectric ceramic material includes the following steps:

[0009] According to the stoichiometric ratio of MgNb2O6, MgO powder and Nb2O5 powder are mixed evenly, dried and sintered to obtain precursor MgNb2O6 powder.

[0010] According to (1-x)Pb(Mg) 1 / 3 Nb 2 / 3 The stoichiometric ratio of MgNb2O6 powder, Pb3O4 powder, and TiO2 powder is given, where 0.30 ≤ x ≤ 0.34, and x is the molar ratio. The MgNb2O6 powder, Pb3O4 powder, and TiO2 powder are mixed evenly, dried, and then sintered to obtain (1-x)Pb(Mg)O3-xPbTiO3. 1 / 3 Nb 2 / 3 O3-xPbTiO3 powder; and

[0011] According to (1-x)Pb(Mg) 1 / 3 Nb 2 / 3 The stoichiometric ratio of (1-x)PbTiO3:y(La2O3+SrCO3) is given, where 0.30≤x≤0.34, 0.00<y≤0.03, and x and y are molar ratios. 1 / 3 Nb 2 / 3 O3-xPbTiO3 powder, La2O3 powder, and SrCO3 powder are mixed evenly, dried, and then mixed with a binder. After pressing and molding, they are sintered to obtain piezoelectric ceramic materials.

[0012] In one feasible implementation, the sintering process involves uniformly mixing MgO powder and Nb2O5 powder, drying it, and then sintering it. The sintering temperature is 1100°C to 1200°C, the sintering time is 4 hours to 5 hours, and the heating and cooling rates are both 5°C / min to 10°C / min.

[0013] In one feasible implementation, during the process of uniformly mixing the MgNb2O6 powder, Pb3O4 powder, and TiO2 powder, the excess amount of Pb3O4 is 2 mol% to 5 mol%.

[0014] In one feasible implementation, the MgNb2O6 powder, Pb3O4 powder, and TiO2 powder are mixed evenly, dried, and then sintered. The sintering temperature is 850°C to 950°C, the sintering time is 2 hours to 4 hours, and the heating and cooling rates are both 5°C / min to 10°C / min.

[0015] In one feasible implementation, the adhesive is an aqueous solution of polyvinyl alcohol, the concentration of which is 5 wt% to 10 wt%.

[0016] In one feasible implementation, the (1-x)Pb(Mg) 1 / 3 Nb 2 / 3 O3-xPbTiO3 powder, La2O3 powder, and SrCO3 powder are mixed evenly, dried, and then mixed with a binder. After pressing and molding, the mixture is sintered at a temperature of 1150°C to 1250°C for 1 hour to 3 hours, with heating and cooling rates of 5°C / min to 10°C / min.

[0017] In one feasible implementation, the powder is mixed uniformly by ball milling, with a ball-to-powder ratio of 20:1 to 30:1, a ball mill speed of 250 rpm to 350 rpm, and a ball milling time of 20 to 30 hours.

[0018] The uniformly mixed powder is dried at a temperature of 80°C to 100°C for 8 to 10 hours.

[0019] The preparation method of the piezoelectric ceramic material of the present invention is simple and efficient. Compared with the traditional method of replacing the host, the preparation method of the present invention is simple, efficient, low-cost and has relaxed preparation conditions. The preparation method of the present invention can significantly improve the piezoelectric properties of the piezoelectric ceramic material.

[0020] A piezoelectric device comprising the aforementioned piezoelectric ceramic material.

[0021] The piezoelectric device of the present invention includes the above-mentioned piezoelectric ceramic material. By introducing La2O3 and SrCO3, the piezoelectric properties of the piezoelectric ceramic material can be enhanced, thereby enhancing the performance of the piezoelectric device and facilitating its wide application. Attached Figure Description

[0022] Figure 1 This is a flowchart of a method for preparing a piezoelectric ceramic material according to an embodiment of the present invention;

[0023] Figure 2 X-ray diffraction images of the piezoelectric ceramic materials prepared in the examples and comparative examples;

[0024] Figure 3 The dielectric constant of the piezoelectric ceramic materials prepared in the examples and comparative examples varies with temperature.

[0025] Figure 4 The piezoelectric coefficient of the piezoelectric ceramic materials prepared in the examples and comparative examples varies with the composition. Detailed Implementation

[0026] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0028] The chemical formula of the piezoelectric ceramic material in one embodiment is (1-x)Pb(Mg) 1 / 3 Nb 2 / 3 )O3-xPbTiO3:y(La2O3+SrCO3), where 0.30≤x≤0.34, 0.00<y≤0.03, and x and y are molar ratios.

[0029] Based on the aforementioned embodiments, the chemical formula of the piezoelectric ceramic material is 0.68Pb(Mg) 1 / 3 Nb 2 / 3 The reaction is: O3-0.32PbTiO3:y(La2O3+SrCO3), where 0.01≤y≤0.03, and y is the molar ratio. Preferably, y is 0.01, 0.02, or 0.03. Of course, y can also be any value between 0.01 and 0.03.

[0030] (1-x)Pb(Mg) without the introduction of La2O3 and SrCO3 1 / 3 Nb 2 / 3 Compared with O3-xPbTiO3 ceramics, the piezoelectric ceramic material of the present invention has higher piezoelectric performance. Experimental verification shows that the piezoelectric coefficient d of the piezoelectric ceramic material of the present invention... 33 It can reach 730pC / N.

[0031] Please see Figure 1 The method for preparing piezoelectric ceramic materials according to an embodiment of the present invention is characterized by comprising the following steps:

[0032] S10. According to the stoichiometric ratio of MgNb2O6, MgO powder and Nb2O5 powder are mixed evenly, dried and sintered to obtain precursor MgNb2O6 powder.

[0033] In one feasible implementation, the sintering process involves uniformly mixing MgO powder and Nb2O5 powder, drying it, and then sintering it. The sintering temperature is 1100°C to 1200°C, the sintering time is 4 hours to 5 hours, and the heating and cooling rates are both 5°C / min to 10°C / min.

[0034] In one feasible implementation, in step S10, the operation of mixing the powder evenly is to use ball milling, with a ball-to-material ratio of 20:1 to 30:1, a ball mill speed of 250 rpm to 350 rpm, and a ball milling time of 20 hours to 30 hours.

[0035] In one feasible implementation, the uniformly mixed powder is dried at a temperature of 80°C to 100°C for 8 to 10 hours.

[0036] S20, according to (1-x)Pb(Mg) 1 / 3 Nb 2 / 3 The stoichiometric ratio of MgNb2O6 powder, Pb3O4 powder, and TiO2 powder obtained in step S10 is determined, where 0.30 ≤ x ≤ 0.34, and x is the molar ratio. The MgNb2O6 powder, Pb3O4 powder, and TiO2 powder obtained in step S10 are mixed evenly, dried, and then sintered to obtain (1-x)Pb(Mg)O3-xPbTiO3. 1 / 3 Nb 2 / 3 O3-xPbTiO3 powder.

[0037] In one feasible implementation, during the process of uniformly mixing the MgNb2O6 powder, Pb3O4 powder, and TiO2 powder obtained in step S10, the excess amount of Pb3O4 is 2 mol% to 5 mol%. This can avoid the loss of raw materials due to Pb volatilization.

[0038] In one feasible implementation, the MgNb2O6 powder, Pb3O4 powder, and TiO2 powder obtained in step S20 are mixed evenly, dried, and then sintered. The sintering temperature is 850°C to 950°C, the sintering time is 2 hours to 4 hours, and the heating and cooling rates are both 5°C / min to 10°C / min.

[0039] In one feasible implementation, in step S20, the operation of mixing the powder evenly is to use ball milling, with a ball-to-powder ratio of 20:1 to 30:1, a ball mill speed of 250 rpm to 350 rpm, and a ball milling time of 20 hours to 30 hours.

[0040] In one feasible implementation, the uniformly mixed powder is dried at a temperature of 80°C to 100°C for 8 to 10 hours.

[0041] S30, according to (1-x)Pb(Mg)1 / 3 Nb 2 / 3 The stoichiometric ratio of (1-x)PbTiO3:y(La2O3+SrCO3) is given, where 0.30≤x≤0.34, 0.00<y≤0.03, and x and y are molar ratios. The (1-x)Pb(Mg)O3 obtained in step S20 is then used as the stoichiometric ratio. 1 / 3 Nb 2 / 3 O3-xPbTiO3 powder, La2O3 powder, and SrCO3 powder are mixed evenly, dried, and then mixed with a binder. After pressing and molding, they are sintered to obtain piezoelectric ceramic materials.

[0042] In one feasible implementation, the mass ratio of the dried mixed powder to the binder is 100:(5-15).

[0043] In one feasible implementation, the binder is an aqueous solution of polyvinyl alcohol, with a concentration of 5 wt% to 10 wt%.

[0044] In one feasible implementation, the (1-x)Pb(Mg) obtained in step S20 is... 1 / 3 Nb 2 / 3 O3-xPbTiO3 powder, La2O3 powder, and SrCO3 powder are mixed evenly, dried, and then mixed with a binder. After pressing and molding, the mixture is sintered at a temperature of 1150°C to 1250°C for 1 hour to 3 hours, with heating and cooling rates of 5°C / min to 10°C / min.

[0045] In one feasible implementation, in step S30, the operation of mixing the powder evenly is to use ball milling, with a ball-to-powder ratio of 20:1 to 30:1, a ball mill speed of 250 rpm to 350 rpm, and a ball milling time of 20 hours to 30 hours.

[0046] In one feasible implementation, the uniformly mixed powder is dried at a temperature of 80°C to 100°C for 8 to 10 hours.

[0047] In one feasible implementation, the pressing operation is as follows: pressing a cylindrical blank with a diameter of 10 mm and a thickness of 2 mm under a pressure of 5 MPa to 10 MPa.

[0048] The preparation method of the piezoelectric ceramic material of the present invention is simple and efficient. Compared with the traditional method of replacing the host, the preparation method of the present invention is simple, efficient, low-cost and has relaxed preparation conditions. The preparation method of the present invention can significantly improve the piezoelectric properties of the piezoelectric ceramic material.

[0049] A piezoelectric device comprising the aforementioned piezoelectric ceramic material.

[0050] The type of piezoelectric device is not limited and can be any piezoelectric device that can use the above-mentioned piezoelectric ceramic material.

[0051] The piezoelectric device of the present invention includes the above-mentioned piezoelectric ceramic material. By introducing La2O3 and SrCO3, the piezoelectric properties of the piezoelectric ceramic material can be enhanced, thereby enhancing the performance of the piezoelectric device and facilitating its wide application.

[0052] Referring to the above implementation details, in order to make the technical solution of this application more specific, clear, and easy to understand, examples of the technical solution of this application are given below. However, it should be noted that the content to be protected by this application is not limited to the following embodiments.

[0053] Example 1 (x = 0.32, y = 0.01)

[0054] Example 1 provides a piezoelectric lead magnesium niobate-lead zirconate titanate ceramic material and its preparation method. The chemical formula of the piezoelectric ceramic material is 0.68Pb(Mg) 1 / 3 Nb 2 / 3 The preparation method of 0.32PbTiO3:0.01(La2O3+SrCO3) includes the following steps:

[0055] (1) Preparation of precursor MgNb2O6 powder

[0056] Based on the stoichiometric ratio of MgNb2O6, 6.0456 g of MgO powder and 39.9114 g of Nb2O5 powder were weighed, mixed, and ball-milled for 24 hours. After drying, the mixture was placed in a muffle furnace for sintering at a temperature of 1100 degrees Celsius for 4 hours. The heating and cooling rates were both 5 degrees Celsius / minute, thus obtaining the precursor MgNb2O6 powder.

[0057] (2) Preparation of 0.68Pb(Mg) 1 / 3 Nb 2 / 3 O3-0.32PbTiO3 powder

[0058] Based on 0.68Pb(Mg) 1 / 3 Nb 2 / 3 To obtain 0.68Pb(MgO)O3 with a stoichiometric ratio of 0.32PbTiO3, 14.0172 g of MgNb2O6 powder obtained in step (1), 48.0160 g of Pb3O4 powder, and 5.1633 g of TiO2 powder were weighed, with Pb3O4 powder in excess by 5 mol%. The mixture was ball-milled for 24 hours, dried, and then sintered in a muffle furnace at a temperature of 850°C for 3 hours. The heating and cooling rates were both 5°C / min. 1 / 3 Nb 2 / 3O3-0.32PbTiO3 powder.

[0059] (3) Preparation of piezoelectric ceramic materials

[0060] Based on 0.68Pb(Mg) 1 / 3 Nb 2 / 3 The stoichiometric ratio of 0.32PbTiO3:0.01(La2O3+SrCO3) was used to add 50 grams of the 0.68Pb(MgO) obtained in step (2). 1 / 3 Nb 2 / 3 0.32 g of PbTiO3 powder, 0.2561 g of La2O3 powder, and 0.2320 g of SrCO3 powder were weighed, mixed, and ball-milled for 24 hours. After drying, 5 g of 7 wt% polyvinyl alcohol aqueous solution was added, and then the mixture was pressed into a cylindrical blank with a diameter of 10 mm and a thickness of 2 mm under a pressure of 10 MPa. The blank was then sintered in a muffle furnace at a sintering temperature of 1160 degrees Celsius for 2 hours, with a heating and cooling rate of 5 degrees Celsius / minute, to obtain the lead magnesium niobate-lead titanate piezoelectric ceramic material of Example 1.

[0061] Example 2 (x = 0.32, y = 0.02)

[0062] Example 2 provides a piezoelectric lead magnesium niobate-lead zirconate titanate ceramic material and its preparation method. The chemical formula of the piezoelectric ceramic material is 0.68Pb(Mg) 1 / 3 Nb 2 / 3 The preparation method of 0.32PbTiO3:0.02(La2O3+SrCO3) includes the following steps:

[0063] (1) Preparation of precursor MgNb2O6 powder

[0064] Based on the stoichiometric ratio of MgNb2O6, 6.0456 g of MgO powder and 39.9114 g of Nb2O5 powder were weighed, mixed, and ball-milled for 24 hours. After drying, the mixture was placed in a muffle furnace for sintering at a temperature of 1100 degrees Celsius for 4 hours. The heating and cooling rates were both 5 degrees Celsius / minute, thus obtaining the precursor MgNb2O6 powder.

[0065] (2) Preparation of 0.68Pb(Mg) 1 / 3 Nb 2 / 3 O3-0.32PbTiO3 powder

[0066] Based on 0.68Pb(Mg) 1 / 3 Nb 2 / 3To obtain 0.68Pb(MgO)O3 with a stoichiometric ratio of 0.32PbTiO3, 14.0172 g of MgNb2O6 powder obtained in step (1), 48.0160 g of Pb3O4 powder, and 5.1633 g of TiO2 powder were weighed, with Pb3O4 powder in excess by 5 mol%. The mixture was ball-milled for 24 hours, dried, and then sintered in a muffle furnace at a temperature of 850°C for 3 hours. The heating and cooling rates were both 5°C / min. 1 / 3 Nb 2 / 3 O3-0.32PbTiO3 powder.

[0067] (3) Preparation of piezoelectric ceramic materials

[0068] Based on 0.68Pb(Mg) 1 / 3 Nb 2 / 3 The stoichiometric ratio of 0.32PbTiO3:0.02(La2O3+SrCO3) was used to add 50 grams of the 0.68Pb(MgO) obtained in step (2). 1 / 3 Nb 2 / 3 0.32 g of PbTiO3 powder, 0.5121 g of La2O3 powder, and 0.4641 g of SrCO3 powder were weighed, mixed, and ball-milled for 24 hours. After drying, 5 g of 7 wt% polyvinyl alcohol aqueous solution was added, and then the mixture was pressed into a cylindrical blank with a diameter of 10 mm and a thickness of 2 mm under a pressure of 10 MPa. The blank was then sintered in a muffle furnace at a sintering temperature of 1170 degrees Celsius for 2 hours, with a heating and cooling rate of 5 degrees Celsius / minute, to obtain the lead magnesium niobate-lead titanate piezoelectric ceramic material of Example 2.

[0069] Example 3 (x = 0.32, y = 0.03)

[0070] Example 3 provides a piezoelectric lead magnesium niobate-lead zirconate titanate ceramic material and its preparation method. The chemical formula of the piezoelectric ceramic material is 0.68Pb(Mg) 1 / 3 Nb 2 / 3 The preparation method of 0.32PbTiO3:0.03(La2O3+SrCO3) includes the following steps:

[0071] (1) Preparation of precursor MgNb2O6 powder

[0072] Based on the stoichiometric ratio of MgNb2O6, 6.0456 g of MgO powder and 39.9114 g of Nb2O5 powder were weighed, mixed, and ball-milled for 24 hours. After drying, the mixture was placed in a muffle furnace for sintering at a temperature of 1100 degrees Celsius for 4 hours. The heating and cooling rates were both 5 degrees Celsius / minute, thus obtaining the precursor MgNb2O6 powder.

[0073] (2) Preparation of 0.68Pb(Mg) 1 / 3 Nb 2 / 3 O3-0.32PbTiO3 powder

[0074] Based on 0.68Pb(Mg) 1 / 3 Nb 2 / 3 To obtain 0.68Pb(MgO)O3 with a stoichiometric ratio of 0.32PbTiO3, 14.0172 g of MgNb2O6 powder obtained in step (1), 48.0160 g of Pb3O4 powder, and 5.1633 g of TiO2 powder were weighed, with Pb3O4 powder in excess by 5 mol%. The mixture was ball-milled for 24 hours, dried, and then sintered in a muffle furnace at a temperature of 850°C for 3 hours. The heating and cooling rates were both 5°C / min. 1 / 3 Nb 2 / 3 O3-0.32PbTiO3 powder.

[0075] (3) Preparation of piezoelectric ceramic materials

[0076] Based on 0.68Pb(Mg) 1 / 3 Nb 2 / 3 The stoichiometric ratio of 0.32PbTiO3:0.03(La2O3+SrCO3) was used to add 50 grams of the 0.68Pb(MgO) obtained in step (2). 1 / 3 Nb 2 / 3 0.32 g of PbTiO3 powder, 0.7682 g of La2O3 powder, and 0.6961 g of SrCO3 powder were weighed, mixed, and ball-milled for 24 hours. After drying, 5 g of 7 wt% polyvinyl alcohol aqueous solution was added, and then the mixture was pressed into a cylindrical blank with a diameter of 10 mm and a thickness of 2 mm under a pressure of 10 MPa. The blank was then sintered in a muffle furnace at a sintering temperature of 1190 degrees Celsius for 2 hours, with a heating and cooling rate of 5 degrees Celsius / minute, to obtain the lead magnesium niobate-lead titanate piezoelectric ceramic material of Example 3.

[0077] Comparative Example 1 (x = 0.32, y = 0)

[0078] Comparative Example 1 provides a piezoelectric lead magnesium niobate-lead zirconate titanate ceramic and its preparation method. The chemical formula of the piezoelectric ceramic material is 0.68Pb(Mg) 1 / 3 Nb 2 / 3 The preparation method of O3-0.32PbTiO3 includes the following steps:

[0079] (1) Preparation of precursor MgNb2O6 powder

[0080] Based on the stoichiometric ratio of MgNb2O6, 6.0456 g of MgO powder and 39.9114 g of Nb2O5 powder were weighed, mixed, and ball-milled for 24 hours. After drying, the mixture was placed in a muffle furnace for sintering at a temperature of 1100 degrees Celsius for 4 hours. The heating and cooling rates were both 5 degrees Celsius / minute, thus obtaining the precursor MgNb2O6 powder.

[0081] (2) Preparation of 0.68Pb(Mg) 1 / 3 Nb 2 / 3 O3-0.32PbTiO3 powder

[0082] Based on 0.68Pb(Mg) 1 / 3 Nb 2 / 3 To obtain 0.68Pb(MgO)O3 with a stoichiometric ratio of 0.32PbTiO3, 14.0172 g of MgNb2O6 powder obtained in step (1), 48.0160 g of Pb3O4 powder, and 5.1633 g of TiO2 powder were weighed, with Pb3O4 powder in excess by 5 mol%. The mixture was ball-milled for 24 hours, dried, and then sintered in a muffle furnace at a temperature of 850°C for 3 hours. The heating and cooling rates were both 5°C / min. 1 / 3 Nb 2 / 3 O3-0.32PbTiO3 powder.

[0083] (3) Preparation of piezoelectric ceramic materials

[0084] The 0.68Pb(Mg) obtained in step (2) 1 / 3 Nb 2 / 3 The O3-0.32PbTiO3 powder was ball-milled again for 24 hours, dried, and then 5 grams of 7wt% polyvinyl alcohol aqueous solution were added. Subsequently, it was pressed into a cylindrical blank with a diameter of 10 mm and a thickness of 2 mm under a pressure of 10 MPa. The blank was placed in a muffle furnace for sintering at a sintering temperature of 1150 degrees Celsius for 2 hours, with a heating and cooling rate of 5 degrees Celsius / minute, to obtain the lead magnesium niobate-lead titanate piezoelectric ceramic material of Comparative Example 1.

[0085] Performance testing:

[0086] X-ray diffraction was performed on the ceramic samples prepared in Examples 1-3 and Comparative Example 1 to obtain... Figure 2 .Depend on Figure 2 It can be seen that all X-ray diffraction peaks originate from the perovskite structure, with no impurity phases or second phases appearing, indicating that adding small amounts of La2O3 and SrCO3 will not affect the crystal structure of the ceramic.

[0087] The dielectric constants of the ceramic samples prepared in Examples 1-3 and Comparative Example 1 were tested to obtain... Figure 3.Depend on Figure 3 It can be seen that the Curie temperature of piezoelectric ceramics decreases with the increase of the amount of La2O3 and SrCO3 added, but the room temperature dielectric constant increases.

[0088] The piezoelectric coefficients of the ceramic samples prepared in Examples 1-3 and Comparative Example 1 were tested to obtain... Figure 4 .Depend on Figure 4 It can be seen that the piezoelectric coefficient d 33 The piezoelectric coefficient d of the piezoelectric ceramic material first increases and then decreases with increasing La2O3 and SrCO3 addition. When the addition amount is 0.02 mol, the piezoelectric coefficient d of the piezoelectric ceramic material is... 33 The maximum value of 730 pC / N was reached. This indicates that the piezoelectric ceramic materials of Examples 1-3 of this invention can significantly increase piezoelectric performance.

[0089] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0090] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A piezoelectric ceramic material, characterized in that, The chemical formula of the piezoelectric ceramic material is (1- x Pb(Mg) 1 / 3 Nb 2 / 3 O3- x PbTiO3: y (La2O3+SrCO3), where x =0.32, 0.00 < y ≤0.03, x and y The piezoelectric properties of piezoelectric ceramic materials are enhanced by introducing La2O3 and SrCO3 at a molar ratio of 1.

2. The piezoelectric ceramic material according to claim 1, characterized in that, The chemical formula of the piezoelectric ceramic material is 0.68Pb(Mg) 1 / 3 Nb 2 / 3 O3-0.32PbTiO3: y (La2O3+SrCO3), where 0.01≤ y ≤0.03, y It is a molar ratio.

3. A method for preparing a piezoelectric ceramic material, characterized in that, Includes the following steps: According to the stoichiometric ratio of MgNb2O6, MgO powder and Nb2O5 powder are mixed evenly, dried and sintered to obtain precursor MgNb2O6 powder. According to (1- x Pb(Mg) 1 / 3 Nb 2 / 3 O3- x The stoichiometry of PbTiO3, among which x =0.32, x The MgNb2O6 powder, Pb3O4 powder, and TiO2 powder were mixed evenly in a molar ratio, dried, and then sintered to obtain (1- x Pb(Mg) 1 / 3 Nb 2 / 3 O3- x PbTiO3 powder; According to (1- x Pb(Mg) 1 / 3 Nb 2 / 3 O3- x PbTiO3: y The stoichiometric ratio of (La₂O₃+SrCO₃), where x =0.32, 0.00 < y ≤0.03, x and y To enhance the piezoelectric properties of piezoelectric ceramic materials by introducing La2O3 and SrCO3 at a molar ratio; the (1- x Pb(Mg) 1 / 3 Nb 2 / 3 O3- x PbTiO3 powder, La2O3 powder, and SrCO3 powder are mixed evenly, dried, and then mixed with a binder. After pressing and molding, they are sintered to obtain piezoelectric ceramic materials.

4. The method for preparing piezoelectric ceramic materials according to claim 3, characterized in that, In the process of mixing MgO powder and Nb2O5 powder evenly, drying and then sintering, the sintering temperature is 1100°C to 1200°C, the sintering time is 4 hours to 5 hours, and the heating and cooling rates are both 5°C / min to 10°C / min.

5. The method for preparing piezoelectric ceramic materials according to claim 3, characterized in that, In the process of uniformly mixing the MgNb2O6 powder, Pb3O4 powder, and TiO2 powder, the excess amount of Pb3O4 is 2 mol% to 5 mol%.

6. The method for preparing piezoelectric ceramic materials according to claim 3, characterized in that, In the process of mixing the MgNb2O6 powder, Pb3O4 powder, and TiO2 powder evenly, drying, and then sintering, the sintering temperature is 850°C to 950°C, the sintering time is 2 hours to 4 hours, and the heating and cooling rates are both 5°C / min to 10°C / min.

7. The method for preparing piezoelectric ceramic materials according to claim 3, characterized in that, The adhesive is an aqueous solution of polyvinyl alcohol, and the concentration of the aqueous solution of polyvinyl alcohol is 5wt%~10wt%.

8. The method for preparing piezoelectric ceramic materials according to claim 3, characterized in that, The (1- x Pb(Mg) 1 / 3Nb 2 / 3 O3- x The PbTiO3 powder, La2O3 powder, and SrCO3 powder are mixed evenly, dried, and then mixed with a binder. After pressing and molding, the mixture is sintered at a temperature of 1150°C to 1250°C for 1 hour to 3 hours, with heating and cooling rates of 5°C / min to 10°C / min.

9. The method for preparing piezoelectric ceramic materials according to claim 3, characterized in that, The powder is mixed evenly by ball milling, with a ball-to-material ratio of 20:1 to 30:1, a ball mill speed of 250 rpm to 350 rpm, and a milling time of 20 to 30 hours. The uniformly mixed powder is dried at a temperature of 80°C to 100°C for 8 to 10 hours.

10. A piezoelectric device, characterized in that, Includes the piezoelectric ceramic material as described in claim 1 or 2.

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