Preparation method for and use of manganese dioxide doped PZT piezoelectric ceramic

Abstract

A preparation method for and use of a manganese dioxide doped PZT piezoelectric ceramic. The method comprises: putting PZT and oxide into a ball mill jar, and carrying out wet ball milling on a raw material, alcohol and zirconium balls in proportion for 24 h; placing, in a drying oven for heating, a wet material obtained after ball milling; grinding dry powder, putting the ground dry powder into a corundum crucible with a cover, and pre-sintering same at 850°C for 2 h; carrying out ball milling on the pre-sintered powder for 12 h, drying, granulating with PVA, carrying out dry pressing molding to prepare a disc sample, and removing a binder at 500°C; and sealingly sintering the prepared sample at 850°C-1300°C for 2 h. By using the method, the sintering temperature can be reduced, and the high dielectric properties can be considered.

Description

Preparation method and application of manganese dioxide-doped PZT piezoelectric ceramics Technical Field

[0001] The present invention belongs to the technical field of piezoelectric ceramic materials, and in particular relates to a preparation method and application of manganese dioxide-doped PZT piezoelectric ceramics. Background Art

[0002] Piezoelectric ceramics are ferroelectric ceramic materials that exhibit a piezoelectric effect when polarized with high-voltage direct current. In the more than 50 years since the discovery of the piezoelectric properties of BaTiO₃ in 1947, piezoelectric ceramics and piezoelectric ceramic devices made from them have made significant progress. Compared to piezoelectric single crystals, piezoelectric ceramics offer advantages such as a high electromechanical coupling coefficient, ease of forming complex shapes, low cost, and ease of mass production. Therefore, they are widely used in the manufacture of piezoelectric transformers, ultrasonic transducers, piezoelectric buzzers, filters, and more.

[0003] With the rapid development of electronic information technology, electronic transformers have been widely used, and various forms of electronic transformers have continued to emerge. Piezoelectric ceramic transformers, as a new type of electronic transformer, have also gradually developed. Piezoelectric ceramic transformers are an integrated solid-state transformer made of piezoelectric ceramics. Compared with traditional wire-wound transformers, piezoelectric ceramic transformers have excellent properties such as high step-up ratio, high conversion efficiency, resistance to high voltage and high temperature, short-circuit burnout, moisture resistance, electromagnetic interference resistance, conservation of non-ferrous metals, small size, and light weight. They are particularly well-suited to the trend of electronic circuits toward integration and chip-based development. Currently, piezoelectric ceramic transformers are widely used in electronic information products such as laptops, digital cameras, PDAs, mobile phones, fax machines, and copiers. As electronic products develop towards intelligence, miniaturization, office automation, and energy conservation, the application areas of this product will further expand.

[0004] The structure of a multilayer piezoelectric ceramic transformer is similar to that of a multilayer ceramic capacitor (MLCC). Its step-up ratio is much greater than that of a general monolithic piezoelectric ceramic transformer, making it a more ideal form of piezoelectric transformer. However, ordinary piezoelectric ceramic materials have disadvantages such as high sintering temperature (1300~1350℃), the need for expensive platinum and germanium metals as internal electrodes, and high cost, making them unsuitable as materials for multilayer piezoelectric transformers. Therefore, in order to make piezoelectric ceramics obtain practical engineering applications, it is necessary to modify existing materials, further reduce the sintering temperature, and take into account high performance to meet the needs of multilayer piezoelectric ceramic transformers (MPT). Since the 1980s, research on multilayer piezoelectric ceramic transformer materials has been widely carried out at home and abroad, mainly by adding glass phase or oxidized ferrite as a sintering aid to the matrix material (such as PZT, PNN-PZT, etc.) to reduce the sintering temperature. Although the addition of glass phase can significantly reduce the sintering temperature, it often deteriorates the piezoelectric properties; and although the addition of oxidation pot achieves the "dual effect" of lowering the sintering temperature and improving the piezoelectric properties, it is highly toxic and has been banned in the ceramic industry in many countries in the world in recent years. Technical issues

[0005] Through the above analysis, the problems and defects of the existing technology are: the existing piezoelectric ceramic materials cannot achieve high performance on the basis of low sintering temperature to meet the needs of multilayer piezoelectric ceramic transformers (MPT). Technical Solutions

[0006] In view of the problems existing in the prior art, the present invention provides a preparation method and application of manganese dioxide-doped PZT piezoelectric ceramics.

[0007] The present invention is achieved by providing a method for preparing a manganese dioxide-doped PZT piezoelectric ceramic, wherein the method comprises the following steps:

[0008] Step 1: Place PZT and oxide in a ball mill and wet-mill the raw materials, alcohol, and zirconium balls in proportion for 24 h.

[0009] Step 2: The wet material after ball milling is placed in a drying oven for heating;

[0010] Step 3: Grind the dry powder into powder, place it in a corundum crucible with a lid, and pre-calcine it at 850°C for 2 hours;

[0011] Step 4: The pre-calcined powder was ball-milled again for 12 hours, dried, granulated with PVA, dry-pressed to form a disc sample, and the binder was removed at 500°C;

[0012] Step 5: The prepared sample was sintered at 1050°C~1250°C for 2 h.

[0013] Furthermore, the step monoxide is manganese dioxide.

[0014] Furthermore, in step 1, the ratio of raw materials: alcohol: zirconium balls is 1:1.2:5.

[0015] Furthermore, in step 2, the heating temperature is about 100° C. and the heating time is 5 h.

[0016] Furthermore, in step 4, 5% polyvinyl alcohol (PVA) is added for granulation.

[0017] Furthermore, in step 4, the ceramic sheet is pressed into a size of 10 mm×1 mm.

[0018] Furthermore, in step five, the disc sample is directly placed in a single-layer crucible for sintering.

[0019] Furthermore, the fired sample was ground and polished, and then coated with silver paste on the upper and lower surfaces. The silver electrode was fired at 560° C. for 20 minutes, and the sample was subjected to high-voltage polarization in silicone oil.

[0020] Furthermore, the polarization of the sample was carried out in methyl silicone oil at a temperature of 120°C, a polarization voltage of 3 KV / mm, and a polarization time of 30 min.

[0021] Another object of the present invention is to provide a method for preparing manganese dioxide-doped PZT piezoelectric ceramics and use the piezoelectric ceramic material prepared in a piezoelectric transformer. Beneficial effects

[0022] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0023] First, the present invention adopts a MnO2-doped PZT system with a "dual role", which can serve as both a sintering aid and a modifier, to obtain a ceramic material that can be sintered at a temperature of 1200°C and has excellent piezoelectric properties, which fully meets the needs of MPT and well solves the problem of how to modify existing materials to further lower the sintering temperature while taking into account high performance to meet the needs of multilayer piezoelectric ceramic transformers (MPT).

[0024] The present invention adopts an improved solid-solid synthesis method, uses a lower synthesis temperature and a shorter ball milling time to synthesize PZT powder during the synthesis process, and obtains a ceramic material that can be sintered at a low temperature and has excellent piezoelectric properties, which fully meets the requirements of MPT.

[0025] Second, the expected benefits and commercial value of the technical solution of the present invention after transformation are as follows: piezoelectric material is a kind of intelligent material that can convert mechanical energy into electrical energy. It has now formed a huge industry with a market size of nearly 10 billion US dollars per year. Its application range ranges from home electronic products such as mobile phones to aerospace, ship sonar, high-speed trains and other fields.

[0026] The technical solution of this invention overcomes the common belief that piezoelectric ceramics sintered at low temperatures often have lower piezoelectric performance. By utilizing a MnO2-doped PZT system, which has a dual function as both a sintering aid and a modifier, this invention achieves a ceramic material that can be sintered at 1200°C and exhibits excellent piezoelectric properties, fully meeting the requirements of MPT and incorporating innovative and groundbreaking thinking to overcome these limitations.

[0027] Third, the method for preparing the manganese dioxide-doped PZT piezoelectric ceramic provided by the embodiment of the present invention has achieved significant technical advances including:

[0028] 1) Enhanced piezoelectric performance: By doping PZT (lead zirconate titanate) ceramics with manganese dioxide, the electrical properties of piezoelectric ceramics are improved. This doping can optimize the material's crystal structure and electrode properties, thereby enhancing its piezoelectric response.

[0029] 2) Improved sintering properties: The sintering temperature range (1050°C–1250°C) and conditions (sintering in a single-layer crucible) facilitate a more uniform and dense ceramic structure. This approach reduces porosity and defects in the ceramic, improving its mechanical strength and stability.

[0030] 3) Process Optimization: The combined steps of wet ball milling, pre-calcination, re-milling, and high-temperature sintering described in the examples provide an efficient process for preparing high-performance piezoelectric ceramics. In particular, the use of alcohol as the milling medium effectively controls the particle size and distribution of the powder, thereby impacting the quality of the final product.

[0031] 4) Improved polarization efficiency: The high-temperature polarization process (120°C, 3 kV / mm, 30 minutes) in methyl silicone oil more effectively polarizes the ceramic material, thereby improving its piezoelectric properties. This poling method helps form a stable electric dipole moment alignment within the ceramic, enhancing its piezoelectric effect.

[0032] 5) Improved electrode manufacturing process: The electrodes are prepared by silver paste coating and sintering, which not only improves the contact performance between the electrode and ceramic, but also enhances the stability and durability of the overall structure.

[0033] The technological advancement of the present invention not only improves the performance of piezoelectric ceramics, but also optimizes their preparation process, making the material more suitable for various high-performance piezoelectric applications such as sensors, transducers and precision control devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0035] FIG1 is a flow chart of a method for preparing a manganese dioxide-doped PZT piezoelectric ceramic provided in an embodiment of the present invention.

[0036] Figure 2 shows the change of dielectric constant of PZT ceramics under different MnO2 doping amounts.

[0037] Figure 3 Variation of the piezoelectric constant of PZT ceramics under different MnO2 doping amounts. Modes for Carrying Out the Invention

[0038] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0039] In view of the problems existing in the prior art, the present invention provides a preparation method and application of manganese dioxide-doped PZT piezoelectric ceramics.

[0040] The present invention provides a method for preparing a manganese dioxide-doped PZT piezoelectric ceramic. The following are two specific embodiments and implementation schemes thereof:

[0041] Example 1: High-Performance Piezoelectric Sensor

[0042] 1) Material preparation: According to the method you described, PZT powder doped with manganese dioxide was prepared by wet ball milling, drying, pre-calcination, secondary ball milling and drying.

[0043] 2) Molding and sintering: The prepared powder is pressed into 10 mm × 1 mm ceramic sheets and then sealed and sintered at a temperature of 1050°C to 1250°C.

[0044] 3) Electrode Fabrication and Polarization: The fired ceramic sheets are ground and polished, then coated with silver paste on both the upper and lower surfaces and infiltrated to form electrodes. Finally, high-voltage polarization is performed in methyl silicone oil at 120°C and 3 kV / mm for 30 minutes.

[0045] 4) Sensor assembly: Assemble the polarized ceramic sheet into the sensor housing and connect the circuit and output interface.

[0046] 5) Performance test: Perform performance test on the completed piezoelectric sensor to ensure that its sensitivity, frequency response and stability meet the design requirements.

[0047] Example 2: Piezoelectric Energy Harvester

[0048] 1) Material preparation: Following the steps mentioned above, manganese dioxide-doped PZT piezoelectric ceramic material was prepared.

[0049] 2) Molding and sintering: The powder is formed into a shape and size suitable for the energy harvester design through a dry pressing process, and then sintered.

[0050] 3) Electrode preparation and polarization: After the surface of the finished ceramic body is polished, silver paste is coated to make electrodes, and polarization treatment is performed under controlled conditions.

[0051] 4) Energy harvester assembly: Integrate the processed ceramic body into the energy harvester frame and connect the necessary circuits and energy storage elements.

[0052] 5) Performance Verification: Test the efficiency of the energy harvester in the actual application environment (such as vehicle vibration, mechanical movement, etc.) and adjust the design to optimize performance.

[0053] The two embodiments provided by the present invention respectively demonstrate the application potential of manganese dioxide-doped PZT piezoelectric ceramics in high-performance sensors and energy harvesters, especially in enhancing the piezoelectric effect of the material and improving its working stability.

[0054] As shown in FIG1 , a method for preparing a manganese dioxide-doped PZT piezoelectric ceramic provided in an embodiment of the present invention includes the following steps:

[0055] Step 1: Place PZT and oxide in a ball mill and wet-mill the raw materials, alcohol, and zirconium balls in proportion for 24 h.

[0056] Step 2: The wet material after ball milling is placed in a drying oven for heating;

[0057] Step 3: Grind the dry powder into powder, place it in a corundum crucible with a lid, and pre-calcine it at 850°C for 2 hours;

[0058] Step 4: The pre-calcined powder was ball-milled again for 12 hours, dried, granulated with PVA, dry-pressed to form a disc sample, and the binder was removed at 500°C;

[0059] Step 5: The prepared sample is sealed and sintered at a temperature of 1050℃~1250℃ for 2 h.

[0060] Furthermore, the step monoxide is manganese dioxide.

[0061] Furthermore, in step 1, the ratio of raw materials: alcohol: zirconium balls is 1:1.2:5.

[0062] Furthermore, in step 2, the heating temperature is about 100° C. and the heating time is 5 h.

[0063] Furthermore, in step 4, 5% polyvinyl alcohol (PVA) is added for granulation.

[0064] Furthermore, in step 4, the ceramic sheet is pressed into a size of 10 mm×1 mm.

[0065] Furthermore, in step five, the disc sample is directly placed in a single-layer crucible for sintering.

[0066] Furthermore, the fired sample was ground and polished, and then coated with silver paste on the upper and lower surfaces. The silver electrode was fired at 560° C. for 20 minutes, and the sample was subjected to high-voltage polarization in silicone oil.

[0067] Furthermore, the polarization of the sample was carried out in methyl silicone oil at a temperature of 120°C, a polarization voltage of 3 KV / mm, and a polarization time of 30 min.

[0068] Example 1

[0069] Step 1: According to the general formula PbZr 0.53 Ti 0.47 Weigh the raw materials as represented by O3(PZT)+xMnO2 (x=0.1wt%). Place the PZT and oxide in a ball mill and wet-mill the raw materials, alcohol, and zirconium balls in the appropriate proportions for 24 hours.

[0070] Step 2: The wet material after ball milling is placed in a drying oven for heating;

[0071] Step 3: Grind the dry powder into powder, place it in a corundum crucible with a lid, and pre-calcine it at 850°C for 2 hours;

[0072] Step 4: The pre-calcined powder was ball-milled again for 12 hours, dried, granulated with PVA, dry-pressed to form a disc sample, and the binder was removed at 500°C;

[0073] Step 5: The prepared sample was sealed and sintered at 1250 °C for 2 h.

[0074] Furthermore, the step monoxide is manganese dioxide.

[0075] Furthermore, in step 1, the ratio of raw materials: alcohol: zirconium balls is 1:1.2:5.

[0076] Furthermore, in step 2, the heating temperature is about 100° C. and the heating time is 5 h.

[0077] Furthermore, in step 4, 5% polyvinyl alcohol (PVA) is added for granulation.

[0078] Furthermore, in step 4, the ceramic sheet is pressed into a size of 10 mm×1 mm.

[0079] Furthermore, in step five, the disc sample is directly placed in a single-layer crucible for sintering.

[0080] Furthermore, the fired sample was ground and polished, and then coated with silver paste on the upper and lower surfaces. The silver electrode was fired at 560° C. for 20 minutes, and the sample was subjected to high-voltage polarization in silicone oil.

[0081] Furthermore, the polarization of the sample was carried out in methyl silicone oil at a temperature of 120°C, a polarization voltage of 3 KV / mm, and a polarization time of 30 min.

[0082] Example 2

[0083] Step 1: According to the general formula PbZr 0.53 Ti 0.47 Weigh the raw materials as represented by O3(PZT)+xMnO2 (x=0.3wt%). Place the PZT and oxide in a ball mill and wet-mill the raw materials, alcohol, and zirconium balls in the appropriate proportions for 24 hours.

[0084] Step 2: The wet material after ball milling is placed in a drying oven for heating;

[0085] Step 3: Grind the dry powder into powder, place it in a corundum crucible with a lid, and pre-calcine it at 850°C for 2 hours;

[0086] Step 4: The pre-calcined powder was ball-milled again for 12 hours, dried, granulated with PVA, dry-pressed to form a disc sample, and the binder was removed at 500°C;

[0087] Step 5: The prepared sample was sealed and sintered at 1200°C for 2 h.

[0088] Furthermore, the step monoxide is manganese dioxide.

[0089] Furthermore, in step 1, the ratio of raw materials: alcohol: zirconium balls is 1:1.2:5.

[0090] Furthermore, in step 2, the heating temperature is about 100° C. and the heating time is 5 h.

[0091] Furthermore, in step 4, 5% polyvinyl alcohol (PVA) is added for granulation.

[0092] Furthermore, in step 4, the ceramic sheet is pressed into a size of 10 mm×1 mm.

[0093] Furthermore, in step five, the disc sample is directly placed in a single-layer crucible for sintering.

[0094] Furthermore, the fired sample was ground and polished, and then coated with silver paste on the upper and lower surfaces. The silver electrode was fired at 560° C. for 20 minutes, and the sample was subjected to high-voltage polarization in silicone oil.

[0095] Furthermore, the polarization of the sample was carried out in methyl silicone oil at a temperature of 120°C, a polarization voltage of 3 KV / mm, and a polarization time of 30 min.

[0096] Example 3

[0097] Step 1: According to the general formula PbZr 0.53 Ti 0.47 Weigh the raw materials (expressed as O3(PZT)+xMnO2, where x = 0.5 wt%). Place the PZT and oxide in a ball mill and wet-mill the raw materials, alcohol, and zirconium balls in the appropriate proportions for 24 h.

[0098] Step 2: The wet material after ball milling is placed in a drying oven for heating;

[0099] Step 3: Grind the dry powder into powder, place it in a corundum crucible with a lid, and pre-calcine it at 850°C for 2 hours;

[0100] Step 4: The pre-calcined powder was ball-milled again for 12 hours, dried, granulated with PVA, dry-pressed to form a disc sample, and the binder was removed at 500°C;

[0101] Step 5: The prepared sample was sealed and sintered at 1150 °C for 2 h.

[0102] Furthermore, the step monoxide is manganese dioxide.

[0103] Furthermore, in step 1, the ratio of raw materials: alcohol: zirconium balls is 1:1.2:5.

[0104] Furthermore, in step 2, the heating temperature is about 100° C. and the heating time is 5 h.

[0105] Furthermore, in step 4, 5% polyvinyl alcohol (PVA) is added for granulation.

[0106] Furthermore, in step 4, the ceramic sheet is pressed into a size of 10 mm×1 mm.

[0107] Furthermore, in step five, the disc sample is directly placed in a single-layer crucible for sintering.

[0108] Furthermore, the fired sample was ground and polished, and then coated with silver paste on the upper and lower surfaces. The silver electrode was fired at 560° C. for 20 minutes, and the sample was subjected to high-voltage polarization in silicone oil.

[0109] Furthermore, the polarization of the sample was carried out in methyl silicone oil at a temperature of 120°C, a polarization voltage of 3 KV / mm, and a polarization time of 30 min.

[0110] Example 4

[0111] Step 1: According to the general formula PbZr 0.53 Ti 0.47 Weigh the raw materials (expressed as O3(PZT)+xMnO2, where x = 0.7 wt%). Place the PZT and oxide in a ball mill and wet-mill the raw materials, alcohol, and zirconium balls in the appropriate proportions for 24 h.

[0112] Step 2: The wet material after ball milling is placed in a drying oven for heating;

[0113] Step 3: Grind the dry powder into powder, place it in a corundum crucible with a lid, and pre-calcine it at 850°C for 2 hours;

[0114] Step 4: The pre-calcined powder was ball-milled again for 12 hours, dried, granulated with PVA, dry-pressed to form a disc sample, and the binder was removed at 500°C;

[0115] Step 5: The prepared sample was sealed and sintered at 1100°C for 2 h.

[0116] Furthermore, the step monoxide is manganese dioxide.

[0117] Furthermore, in step 1, the ratio of raw materials: alcohol: zirconium balls is 1:1.2:5.

[0118] Furthermore, in step 2, the heating temperature is about 100° C. and the heating time is 5 h.

[0119] Furthermore, in step 4, 5% polyvinyl alcohol (PVA) is added for granulation.

[0120] Furthermore, in step 4, the ceramic sheet is pressed into a size of 10 mm×1 mm.

[0121] Furthermore, in step five, the disc sample is directly placed in a single-layer crucible for sintering.

[0122] Furthermore, the fired sample was ground and polished, and then coated with silver paste on the upper and lower surfaces. The silver electrode was fired at 560° C. for 20 minutes, and the sample was subjected to high-voltage polarization in silicone oil.

[0123] Furthermore, the polarization of the sample was carried out in methyl silicone oil at a temperature of 120°C, a polarization voltage of 3 KV / mm, and a polarization time of 30 min.

[0124] Example 5

[0125] Step 1: According to the general formula PbZr 0.53 Ti 0.47 Weigh the raw materials as represented by O3(PZT)+xMnO2 (x=0.9wt%). Place the PZT and oxide in a ball mill and wet-mill the raw materials, alcohol, and zirconium balls in the appropriate proportions for 24 hours.

[0126] Step 2: The wet material after ball milling is placed in a drying oven for heating;

[0127] Step 3: Grind the dry powder into powder, place it in a corundum crucible with a lid, and pre-calcine it at 850°C for 2 hours;

[0128] Step 4: The pre-calcined powder was ball-milled again for 12 hours, dried, granulated with PVA, dry-pressed to form a disc sample, and the binder was removed at 500°C;

[0129] Step 5: The prepared sample was sealed and sintered at 1050 °C for 2 h.

[0130] Furthermore, the step monoxide is manganese dioxide.

[0131] Furthermore, in step 1, the ratio of raw materials: alcohol: zirconium balls is 1:1.2:5.

[0132] Furthermore, in step 2, the heating temperature is about 100° C. and the heating time is 5 h.

[0133] Furthermore, in step 4, 5% polyvinyl alcohol (PVA) is added for granulation.

[0134] Furthermore, in step 4, the ceramic sheet is pressed into a size of 10 mm×1 mm.

[0135] Furthermore, in step five, the disc sample is directly placed in a single-layer crucible for sintering.

[0136] Furthermore, the fired sample was ground and polished, and then coated with silver paste on the upper and lower surfaces. The silver electrode was fired at 560° C. for 20 minutes, and the sample was subjected to high-voltage polarization in silicone oil.

[0137] Furthermore, the polarization of the sample was carried out in methyl silicone oil at a temperature of 120°C, a polarization voltage of 3 KV / mm, and a polarization time of 30 min.

[0138] The embodiments of the present invention have achieved some positive results during the development or use process and indeed have great advantages over the prior art. The following content describes them in conjunction with data, charts, etc. from the experimental process.

[0139] (1) Example 1

[0140] The dielectric constant was measured using an Agilent 4980A precision impedance meter. The dielectric constant of the sample was 1745 as shown in Figure 2. The ZJ-3 quasi-static d 33 The piezoelectric coefficient d 33 See Figure 3, which is 185 pC / N.

[0141] (2) Example 2

[0142] The dielectric constant was measured using an Agilent 4980A precision impedance meter. The dielectric constant of the sample was 1985 as shown in Figure 2. The ZJ-3 quasi-static d 33 The piezoelectric coefficient d 33 See Figure 3, which is 250 pC / N.

[0143] (3) Example 3

[0144] The dielectric constant was measured using an Agilent 4980A precision impedance meter. The dielectric constant of the sample was 2170 as shown in Figure 2. The ZJ-3 quasi-static d 33 The piezoelectric coefficient d 33 See Figure 3, which is 243 pC / N.

[0145] (4) Example 4

[0146] The dielectric constant was measured using an Agilent 4980A precision impedance meter. The dielectric constant of the sample was 1750 as shown in Figure 2. The ZJ-3 quasi-static d 33 The piezoelectric coefficient d 33 See Figure 3, which is 165 pC / N.

[0147] (5) Example 5

[0148] The dielectric constant was measured using an Agilent 4980A precision impedance meter. The dielectric constant of the sample was 1850 as shown in Figure 2. The ZJ-3 quasi-static d 33 The piezoelectric coefficient d 33 See Figure 3, which is 173 pC / N.

[0149] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with this technical field within the technical scope disclosed by the present invention and within the spirit and principles of the present invention should be covered by the scope of protection of the present invention.

Claims

1. A preparation method of manganese dioxide doped PZT piezoelectric ceramics, characterized in that, it comprises the following steps: Step 1, put PZT and oxide into a ball milling tank, and wet ball mill the raw materials: alcohol: zirconia balls in proportion for 24 h; Step 2, place the wet material after ball milling in a drying oven for heating; Step 3, after grinding the dry powder finely, place it in a covered corundum crucible and pre-burn it at 850 °C for 2 h; Step 4, ball mill the pre-burned powder again for 12 h, dry it, granulate it with PVA, dry press it into a disc sample, and remove the binder at 500 °C; Step 5, sinter the prepared sample hermetically at a temperature of 850 °C to 1300 °C for 2 h.

2. The preparation method of manganese dioxide doped PZT piezoelectric ceramics according to claim 1, characterized in that, the oxide in Step 1 is manganese dioxide.

3. The preparation method of manganese dioxide doped PZT piezoelectric ceramics according to claim 1, characterized in that, the ratio of raw materials: alcohol: zirconia balls in Step 1 is 1:1.2:

5.

4. The preparation method of manganese dioxide doped PZT piezoelectric ceramics according to claim 1, characterized in that, the heating temperature in Step 2 is about 100 °C and the time is 5 h.

5. The preparation method of manganese dioxide doped PZT piezoelectric ceramics according to claim 1, characterized in that, add 5% polyvinyl alcohol for granulation in Step 4.

6. The preparation method of manganese dioxide doped PZT piezoelectric ceramics according to claim 1, characterized in that, press it into a ceramic sheet of 10 mm × 1 mm in Step 4.

7. The preparation method of manganese dioxide doped PZT piezoelectric ceramics according to claim 1, characterized in that, in Step 5, directly place the disc sample in a single-layer crucible for sintering.

8. The preparation method of manganese dioxide doped PZT piezoelectric ceramics according to claim 1, characterized in that, after the fired sample is polished, silver paste is coated on the upper and lower surfaces, sintered and infiltrated with silver electrodes at 560 °C for 20 min, and the sample is subjected to high-voltage polarization in silicone oil.

9. The preparation method of manganese dioxide doped PZT piezoelectric ceramics according to claim 8, characterized in that, the polarization of the sample is carried out in methyl silicone oil, the temperature is 120 °C, the polarization voltage is 3 KV / mm, and the polarization time is 30 min.

10. Application of the piezoelectric ceramic material prepared by the preparation method of a manganese dioxide doped PZT piezoelectric ceramic according to any one of claims 1 to 9 in a piezoelectric transformer.

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