Preparation method and application of 2-3 type piezoelectric composite material

Abstract

This invention relates to a method for preparing and applying a type 2-3 piezoelectric composite material. The invention aims to solve the problems of low electromechanical coupling coefficient and excessively high acoustic impedance in existing traditional 2-2 piezoelectric composite materials, which lead to acoustic impedance mismatch and consequently narrow operating bandwidth and low sensitivity of ultrasonic probes. The method includes: 1. Cutting the piezoelectric material; 2. Preparing a filler epoxy resin material; 3. Casting; 4. Thickness reduction. Application: Used in the fabrication of linear phased array ultrasonic transducers.

Description

Technical Field

[0001] This invention relates to a method for preparing piezoelectric composite materials and their applications. Background Technology

[0002] Phased array ultrasound is an advanced ultrasonic testing technology with advantages such as wide applicability, strong penetration, high sensitivity, portable equipment, and safe operation. It has wide applications in industrial non-destructive testing and biomedical imaging. Compared to single-unit ultrasonic transducers, phased array ultrasonic transducers, with their high frame rate imaging and dynamic focusing capabilities, have become the preferred type of ultrasonic transducer for next-generation non-destructive testing and medical imaging. However, the electromechanical coupling coefficient of currently fabricated traditional 2-2 piezoelectric composite materials is relatively low. Furthermore, because piezoelectric single crystals and piezoelectric ceramics are high-density, high-acoustic impedance (>30 Mrayls) solid materials, they suffer from severe acoustic impedance mismatch with low-acoustic impedance media (~1.5 Mrayls) such as water, air, and the human body. This leads to significant energy loss at the interface during sound wave transmission, resulting in a narrow operating bandwidth for linear phased array (linear array) ultrasonic transducers based on 2-2 piezoelectric composite materials. This makes them unsuitable for scenarios with more complex operating frequencies and higher imaging precision, severely restricting the development and application of linear array ultrasonic transducers.

[0003] Currently, the main optimization method for piezoelectric materials in linear ultrasonic transducers is to replace piezoelectric ceramic materials with piezoelectric single-crystal materials with superior piezoelectric properties, such as relaxor ferroelectric single-crystal materials. However, due to the limitations of the coupled vibration modes in traditional 2-2 piezoelectric composite structures, the excellent piezoelectric properties of relaxor ferroelectric single-crystal materials cannot be fully utilized. This method does not significantly improve the performance of linear ultrasonic transducers and still cannot meet the ever-increasing demands for imaging bandwidth in military, industrial, and medical fields. Therefore, preparing a piezoelectric composite material with pure large vibration modes, high electromechanical coupling coefficient, and low acoustic impedance is the core task and challenge for optimizing the bandwidth, imaging resolution, and other performance characteristics of ultrasonic transducers. Summary of the Invention

[0004] This invention aims to solve the problems of low electromechanical coupling coefficient and excessively high acoustic impedance of existing traditional 2-2 piezoelectric composite materials, which lead to acoustic impedance mismatch and consequently narrow operating bandwidth and low sensitivity of ultrasonic probes. It provides a broadband high-transmission tuning ratio optical switch and its preparation method.

[0005] A method for preparing a type 2-3 piezoelectric composite material, characterized by comprising the following steps:

[0006] I. Cutting of piezoelectric materials:

[0007] The upper surface of the piezoelectric material is cut to obtain multiple rows of vertically intersecting transverse grooves and multiple rows of longitudinal grooves. Then, it is annealed, cleaned and dried to obtain the cut piezoelectric material.

[0008] The multiple rows of transverse grooves are arranged in parallel, with a width of 0.01mm to 0.50mm, a depth of 0.04mm to 2mm, and a spacing of 0.02mm to 1mm between adjacent transverse grooves; the multiple rows of longitudinal grooves are arranged in parallel, with a width of 0.01mm to 0.50mm, a depth 0.02mm to 1mm greater than the depth of the transverse grooves, and a spacing of 0.02mm to 1mm between adjacent longitudinal grooves;

[0009] II. Preparation of filler phase epoxy resin material:

[0010] The epoxy resin is mixed with the curing agent, and then the air bubbles are removed to obtain a filled phase epoxy resin material.

[0011] III. Irrigation:

[0012] The epoxy resin filling material is poured into the transverse and longitudinal grooves of the cut piezoelectric material, and then the air bubbles are removed and cured to obtain the cured composite material.

[0013] IV. Thickness Reduction:

[0014] The lower surface of the cured composite material is thinned and polished until the piezoelectric material at the bottom of the longitudinal groove is removed. The distance between the bottom of the transverse groove and the lower surface is 0.02 mm to 1 mm, thus obtaining the type 2-3 piezoelectric composite material.

[0015] An application of a type 2-3 piezoelectric composite material, which is used in the fabrication of a linear phased array ultrasonic transducer.

[0016] The beneficial effects of this invention are:

[0017] The piezoelectric composite structure of the present invention (types 2-3) has a high electromechanical coupling coefficient, low acoustic impedance, high fabrication success rate, and can effectively improve the bandwidth of linear array ultrasonic transducers.

[0018] 1. It changed the resonant mode k of the traditional 2-2 type piezoelectric composite material. t Type 2-3 piezoelectric composite materials have a higher electromechanical coupling coefficient k3'3 compared to traditional k t The mode was improved, thereby enhancing the performance of the linear array ultrasonic transducer.

[0019] 2. Compared with the traditional 2-2 type piezoelectric composite structure, the 2-3 type piezoelectric composite material reduces the content of the high acoustic impedance (~30Mrayls) piezoelectric phase and increases the content of the low acoustic impedance (~2Mrayls) filling phase, thereby reducing the total acoustic impedance of the piezoelectric composite material, reducing the acoustic energy loss caused by the acoustic impedance mismatch with the target carrier, and improving the sensitivity of the linear array ultrasonic transducer.

[0020] 3. Due to the reduction of high-density piezoelectric phase, the total mass of the type 2-3 piezoelectric composite material is lighter, and its vibration amplitude is larger under the same voltage excitation, thus improving the acoustic emission performance of the linear array ultrasonic transducer.

[0021] 4. The bandwidth of the linear array ultrasonic transducer based on the real 2-3 type piezoelectric composite material can reach 92.1% to 115%.

[0022] This invention relates to a method for preparing and applying a type 2-3 piezoelectric composite material. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating the preparation process of piezoelectric composite materials of type 2-3 in Example 1; the transverse grooves are... Figure 1 In the x-direction, the longitudinal groove is Figure 1 middle y direction;

[0024] Figure 2 The simulation results show the electromechanical coupling performance of type 2-3 piezoelectric composite materials with different transverse groove depths in Examples 1 to 5 and Comparative Experiments 1 to 2.

[0025] Figure 3 The graph shows the electromechanical coupling performance test patterns of type 2-3 piezoelectric composite materials with different transverse groove depths in Examples 1 to 5 and Comparative Experiments 1 to 2.

[0026] Figure 4 This is a schematic diagram of the linear array ultrasonic transducer structure based on the piezoelectric composite materials of types 2-3 in Examples 1 and 6;

[0027] Figure 5 The time-domain and frequency-domain spectra of the 2-3 type linear array ultrasonic transducer are shown. (a) is Example 1, and (b) is Example 6. Detailed Implementation

[0028] Specific Implementation Method 1: This implementation method describes a method for preparing a type 2-3 piezoelectric composite material, which is carried out according to the following steps:

[0029] I. Cutting of piezoelectric materials:

[0030] The upper surface of the piezoelectric material is cut to obtain multiple rows of vertically intersecting transverse grooves and multiple rows of longitudinal grooves. Then, it is annealed, cleaned and dried to obtain the cut piezoelectric material.

[0031] The multiple rows of transverse grooves are arranged in parallel, with a width of 0.01mm to 0.50mm, a depth of 0.04mm to 2mm, and a spacing of 0.02mm to 1mm between adjacent transverse grooves; the multiple rows of longitudinal grooves are arranged in parallel, with a width of 0.01mm to 0.50mm, a depth 0.02mm to 1mm greater than the depth of the transverse grooves, and a spacing of 0.02mm to 1mm between adjacent longitudinal grooves;

[0032] II. Preparation of filler phase epoxy resin material:

[0033] The epoxy resin is mixed with the curing agent, and then the air bubbles are removed to obtain a filled phase epoxy resin material.

[0034] III. Irrigation:

[0035] The epoxy resin filling material is poured into the transverse and longitudinal grooves of the cut piezoelectric material, and then the air bubbles are removed and cured to obtain the cured composite material.

[0036] IV. Thickness Reduction:

[0037] The lower surface of the cured composite material is thinned and polished until the piezoelectric material at the bottom of the longitudinal groove is removed. The distance between the bottom of the transverse groove and the lower surface is 0.02 mm to 1 mm, thus obtaining the type 2-3 piezoelectric composite material.

[0038] In this specific embodiment, the piezoelectric material is first horizontally fixed on a cutting platform. A precision dicing machine is used to cut along one side of the piezoelectric material, followed by a second vertical cut, with the first cut being deeper than the second. The cut piezoelectric material is then annealed at a temperature above its Curie temperature to release the internal stress caused by the cutting and prevent it from affecting its piezoelectric properties.

[0039] Principle: By adjusting the cutting depth, the 2-3 piezoelectric composite material achieves a coupled resonance state and optimal acoustic impedance parameters, resulting in a high electromechanical coupling coefficient. Matching layers and backing layers are bonded to the upper and lower surfaces of the composite material, followed by ultrasonic transducer performance testing. Under the same conditions, the ultrasonic transducer fabricated based on the 2-3 piezoelectric composite structure exhibits a significantly enhanced bandwidth.

[0040] The beneficial effects of this embodiment are:

[0041] The piezoelectric composite structure of Embodiments 2-3 has a high electromechanical coupling coefficient, low acoustic impedance, high fabrication success rate, and can effectively improve the bandwidth of linear array ultrasonic transducers.

[0042] 1. It changed the resonant mode k of the traditional 2-2 type piezoelectric composite material. t Type 2-3 piezoelectric composite materials have a higher electromechanical coupling coefficient k3'3 compared to traditional k t The mode was improved, thereby enhancing the performance of the linear array ultrasonic transducer.

[0043] 2. Compared with the traditional 2-2 type piezoelectric composite structure, the 2-3 type piezoelectric composite material reduces the content of the high acoustic impedance (~30Mrayls) piezoelectric phase and increases the content of the low acoustic impedance (~2Mrayls) filling phase, thereby reducing the total acoustic impedance of the piezoelectric composite material, reducing the acoustic energy loss caused by the acoustic impedance mismatch with the target carrier, and improving the sensitivity of the linear array ultrasonic transducer.

[0044] 3. Due to the reduction of high-density piezoelectric phase, the total mass of the type 2-3 piezoelectric composite material is lighter, and its vibration amplitude is larger under the same voltage excitation, thus improving the acoustic emission performance of the linear array ultrasonic transducer.

[0045] 4. The bandwidth of the linear array ultrasonic transducer based on the real 2-3 type piezoelectric composite material can reach 92.1% to 115%.

[0046] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the piezoelectric material mentioned in step one is a binary relaxor ferroelectric single crystal material, a ternary relaxor ferroelectric single crystal material, a binary relaxor ferroelectric piezoelectric ceramic material, or a ternary relaxor ferroelectric piezoelectric ceramic material. Everything else is the same as in Specific Implementation Method One.

[0047] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that the annealing treatment described in step one is specifically performed at a temperature above the Curie temperature of the piezoelectric material. Everything else is the same as in Specific Implementation Method One or Two.

[0048] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that the epoxy resin mentioned in step two is EPO-TEK 301 or E-51. Everything else is the same as in Specific Implementation Methods One to Three.

[0049] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that the mass ratio of epoxy resin to curing agent in step two is (3-4):1. Everything else is the same as in Specific Implementation Methods One to Four.

[0050] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that: in step two, the environment is placed in a vacuum for 2 to 10 minutes to remove air bubbles; in step three, the environment is placed in a vacuum for 0.5 to 3 hours to remove air bubbles. Everything else is the same as Specific Implementation Methods One to Five.

[0051] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in that the mass percentage of piezoelectric material in the 2-3 type piezoelectric composite material prepared in step four is 40% to 70%. Everything else is the same as in Specific Implementation Methods One to Six.

[0052] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in that: the multiple rows of transverse grooves described in step one are arranged in parallel, and the width of the transverse grooves is 0.10mm to 0.50mm, the depth is 0.10mm to 0.60mm, and the spacing between adjacent transverse grooves is 0.20mm to 1mm. Everything else is the same as in Specific Implementation Methods One to Seven.

[0053] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One to Eight in that: the multiple rows of longitudinal grooves described in step one are arranged in parallel, and the width of the longitudinal grooves is 0.10mm to 0.50mm, the depth of the longitudinal grooves is 0.10mm to 0.50mm greater than the depth of the transverse grooves, and the spacing between adjacent longitudinal grooves is 0.20mm to 1mm. Everything else is the same as in Specific Implementation Methods One to Eight.

[0054] Specific Implementation Method 10: This implementation method describes the application of a type 2-3 piezoelectric composite material, which is used in the fabrication of a linear phased array ultrasonic transducer.

[0055] The beneficial effects of the present invention are verified using the following embodiments:

[0056] Example 1:

[0057] A method for preparing a type 2-3 piezoelectric composite material, comprising the following steps:

[0058] I. Cutting of piezoelectric materials:

[0059] For dimensions of 19.10×10.00×1.00mm 3 The upper surface of the piezoelectric material is cut to obtain multiple rows of transverse grooves and multiple rows of longitudinal grooves that intersect vertically. Then, it is annealed at 300℃ for 12 hours. Finally, it is ultrasonically cleaned and dried in anhydrous ethanol to obtain the cut piezoelectric material.

[0060] The multiple rows of transverse grooves are arranged in parallel, with a width of 0.10 mm, a depth of 0.40 mm, and a spacing of 0.20 mm between adjacent transverse grooves; the multiple rows of longitudinal grooves are arranged in parallel, with a width of 0.10 mm, a depth of 0.60 mm, and a spacing of 0.20 mm between adjacent longitudinal grooves.

[0061] II. Preparation of filler phase epoxy resin material:

[0062] Mix 5.0g of epoxy resin with 1.50g of curing agent, then sonicate, and finally place under a vacuum of 2×10⁻⁶. -1 In a vacuum environment of Pa for 2 minutes, remove air bubbles to obtain a filled phase epoxy resin material;

[0063] III. Irrigation:

[0064] The epoxy resin filling material was poured into the transverse and longitudinal grooves of the cut piezoelectric material, and then placed in a vacuum of 10... -1 The composite material was cured by placing it in a vacuum environment for 3 hours to remove air bubbles, and then allowing it to stand for 24 hours in a dust-free environment at room temperature to obtain the cured composite material.

[0065] IV. Thickness Reduction:

[0066] The lower surface of the cured composite material was thinned and polished until the composite material thickness was 0.60 mm. Then it was immersed in anhydrous ethanol for ultrasonic cleaning to obtain the type 2-3 piezoelectric composite material.

[0067] The piezoelectric material mentioned in step one is PZT-5H piezoelectric ceramic.

[0068] The epoxy resin mentioned in step two is E-51 epoxy resin; the curing agent is the curing agent corresponding to E-51 epoxy resin.

[0069] The volume percentage of piezoelectric material in the type 2-3 piezoelectric composite material prepared in step four is 51%.

[0070] Figure 1 This is a flowchart illustrating the preparation process of piezoelectric composite materials of type 2-3 in Example 1; the transverse grooves are... Figure 1 In the x-direction, the longitudinal groove is Figure 1 Middle y direction.

[0071] Example 2: This comparative experiment differs from Example 1 in that the depth of the transverse groove is 0.1 mm; and the volume percentage of piezoelectric material in the type 2-3 piezoelectric composite material prepared in step four is 63%. Everything else is the same as in Example 1.

[0072] Example 3: This comparative experiment differs from Example 1 in that the depth of the transverse groove is 0.2 mm; and the volume percentage of piezoelectric material in the type 2-3 piezoelectric composite material prepared in step four is 59%. Everything else is the same as in Example 1.

[0073] Example 4: This comparative experiment differs from Example 1 in that the depth of the transverse groove is 0.3 mm; and the volume percentage of piezoelectric material in the type 2-3 piezoelectric composite material prepared in step four is 55%. Everything else is the same as in Example 1.

[0074] Example 5: This comparative experiment differs from Example 1 in that the depth of the transverse groove is 0.5 mm; and the volume percentage of piezoelectric material in the type 2-3 piezoelectric composite material prepared in step four is 48%. Everything else is the same as in Example 1.

[0075] Example 6: This example differs from Example 1 in that the piezoelectric material mentioned in step one is a PMN-PT piezoelectric single crystal material. Everything else is the same as in Example 1.

[0076] Comparative Experiment 1: This comparative experiment differs from Example 1 in that: no transverse groove cutting was performed in the x-direction, resulting in a conventional 2-2 type piezoelectric composite material; the volume percentage of piezoelectric material in the conventional 2-2 type piezoelectric composite material prepared in step four is 66%. Everything else is the same as in Example 1.

[0077] Comparative Experiment 2: This comparative experiment differs from Example 1 in that the depth of the transverse groove is 0.6 mm; and the volume percentage of piezoelectric material in the type 2-3 piezoelectric composite material prepared in step four is 44%. Everything else is the same as in Example 1.

[0078] Gold electrodes with a thickness of 200 nm were deposited on both the upper and lower surfaces of the type 2-3 piezoelectric composite materials obtained in Examples 1 to 5 and Comparative Experiments 1 to 2. Then, they were subjected to DC field polarization processing for 30 min at room temperature and a polarization electric field of 1 kV / mm, and the following performance tests were performed:

[0079] The 2-3 type piezoelectric composite materials obtained in Examples 1 to 5 and Comparative Experiments 1 to 2 were subjected to resonant mode simulation using COMSOL software. The simulated impedance spectra of the 2-3 type piezoelectric composite materials with different transverse groove depths were obtained, and the electromechanical coupling coefficient was calculated. Figure 2 As shown. Figure 2 The figures show the simulation results of the electromechanical coupling performance of type 2-3 piezoelectric composite materials with different transverse groove depths in Examples 1 to 5 and Comparative Experiments 1 to 2. As can be seen from the figures, the electromechanical coupling coefficient reaches its maximum value of 0.68 when the cutting depth d in the x direction is 0.4 mm.

[0080] Impedance spectroscopy tests were performed on the type 2-3 piezoelectric composite materials obtained in Examples 1-5 and Comparative Experiments 1-2 using an impedance analyzer. The electromechanical coupling coefficient behavior matched the simulation behavior. Figure 3 As shown. Figure 3 The graph shows the electromechanical coupling performance test results of the 2-3 type piezoelectric composite materials with different transverse groove depths in Examples 1 to 5 and Comparative Experiments 1 to 2. As can be seen from the graph, compared with the 0.595 of the traditional 2-2 type piezoelectric composite material in Comparative Experiment 1, the electromechanical coupling coefficient of the 2-3 type piezoelectric composite material in Example 1 is 0.645, which is 8.4% higher. This is more conducive to improving the bandwidth of the linear array ultrasonic transducer.

[0081] The piezoelectric composite materials of types 2-3 obtained in Examples 1 and 6 were used to fabricate a 64-element linear array ultrasonic transducer with a working frequency of 3MHz, such as... Figure 4 As shown, Figure 4 This is a schematic diagram of the linear array ultrasonic transducer structure based on the type 2-3 piezoelectric composite material in Examples 1 and 6. The acoustic matching layer is obtained by mixing alumina powder with a particle size of 1 μm and epoxy resin E-51 at a mass ratio of 1:1, with a thickness of 0.2 mm; the backing layer is obtained by mixing tungsten powder with a particle size of 500 nm and epoxy resin E-51 at a mass ratio of 10:1, with a thickness of 30 mm. The pulse-echo method was used to measure the time-domain and frequency-domain spectra of the type 2-3 linear array ultrasonic transducers prepared in Examples 1 and 6, respectively. Figure 5 As shown, Figure 5 The time-domain and frequency-domain spectra of the type 2-3 linear array ultrasonic transducer are shown in Figures (a) and (b) respectively. As can be seen from the figures, the bandwidth of the linear array ultrasonic transducer based on the type 2-3 piezoelectric composite material obtained in Example 1 can reach 92.1%, and the bandwidth of the linear array ultrasonic transducer based on the type 2-3 piezoelectric composite material obtained in Example 6 can reach 115%. This represents a 20% increase in bandwidth compared to the type 2-2 linear array ultrasonic transducer under the same conditions.

[0082]

[0083] Where acoustic impedance = longitudinal sound velocity * density

[0084]

Claims

1. A method for preparing a type 2-3 piezoelectric composite material, characterized in that... It is done in the following steps: I. Cutting of piezoelectric materials: The upper surface of the piezoelectric material is cut to obtain multiple rows of vertically intersecting transverse grooves and multiple rows of longitudinal grooves. Then, it is annealed, cleaned and dried to obtain the cut piezoelectric material. The multiple rows of transverse grooves are arranged in parallel, with a width of 0.01mm to 0.50mm, a depth of 0.04mm to 2mm, and a spacing of 0.02mm to 1mm between adjacent transverse grooves; the multiple rows of longitudinal grooves are arranged in parallel, with a width of 0.01mm to 0.50mm, a depth 0.02mm to 1mm greater than the depth of the transverse grooves, and a spacing of 0.02mm to 1mm between adjacent longitudinal grooves; II. Preparation of filler phase epoxy resin material: The epoxy resin is mixed with the curing agent, and then the air bubbles are removed to obtain a filled phase epoxy resin material. III. Irrigation: The epoxy resin filling material is poured into the transverse and longitudinal grooves of the cut piezoelectric material, and then the air bubbles are removed and cured to obtain the cured composite material. IV. Thickness Reduction: The lower surface of the cured composite material is thinned and polished until the piezoelectric material at the bottom of the longitudinal groove is removed. The distance between the bottom of the transverse groove and the lower surface is 0.02 mm to 1 mm, thus obtaining the type 2-3 piezoelectric composite material.

2. The method for preparing a type 2-3 piezoelectric composite material according to claim 1, characterized in that... The piezoelectric material mentioned in step one is a binary relaxor ferroelectric single crystal material, a ternary relaxor ferroelectric single crystal material, a binary relaxor ferroelectric piezoelectric ceramic material, or a ternary relaxor ferroelectric piezoelectric ceramic material.

3. The method for preparing a type 2-3 piezoelectric composite material according to claim 2, characterized in that... The annealing process described in step one is specifically annealing at a temperature above the Curie temperature of the piezoelectric material.

4. The method for preparing a type 2-3 piezoelectric composite material according to claim 1, characterized in that... The epoxy resin mentioned in step two is EPO-TEK 301 or E-51.

5. The method for preparing a type 2-3 piezoelectric composite material according to claim 4, characterized in that... The mass ratio of epoxy resin to curing agent in step two is (3-4):

1.

6. The method for preparing a type 2-3 piezoelectric composite material according to claim 1, characterized in that... In step two, place the container in a vacuum environment for 2 to 10 minutes to remove air bubbles; in step three, place the container in a vacuum environment for 0.5 to 3 hours to remove air bubbles.

7. The method for preparing a type 2-3 piezoelectric composite material according to claim 1, characterized in that... In the type 2-3 piezoelectric composite material prepared in step four, the volume percentage of piezoelectric material is 40% to 70%.

8. The method for preparing a type 2-3 piezoelectric composite material according to claim 1, characterized in that... The multiple rows of transverse grooves mentioned in step one are arranged in parallel, and the width of the transverse grooves is 0.10mm to 0.50mm, the depth is 0.10mm to 0.60mm, and the spacing between adjacent transverse grooves is 0.20mm to 1mm.

9. The method for preparing a type 2-3 piezoelectric composite material according to claim 8, characterized in that... The multiple longitudinal grooves mentioned in step one are arranged in parallel, and the width of the longitudinal grooves is 0.10mm to 0.50mm, the depth of the longitudinal grooves is 0.10mm to 0.50mm greater than the depth of the transverse grooves, and the spacing between adjacent longitudinal grooves is 0.20mm to 1mm.

10. The application of a type 2-3 piezoelectric composite material prepared by the preparation method according to claim 1, characterized in that... Type 2-3 piezoelectric composite materials are used in the fabrication of linear phased array ultrasonic transducers.

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