CN115069524B - 1-3 Composite piezoelectric material for high-frequency ultrasonic transducer and preparation method thereof - Google Patents

Abstract

The invention relates to a piezoelectric material, in particular to a 1-3 composite piezoelectric material for a high-frequency ultrasonic transducer and a preparation method thereof, comprising the following steps: s1: preparing a soft template containing micropores by an etching technology; s2: filling micropores in the soft template obtained in the step S1 with piezoelectric ceramic powder; s3: performing high-temperature sintering on the product obtained in the step S2 to remove the soft template, so as to obtain a piezoelectric ceramic column array; s4: filling and curing the piezoelectric ceramic column array obtained in the step S3 by using a high polymer to obtain a semi-finished product; s5: and (3) grinding and thinning the semi-finished product obtained in the step (S4), plating electrodes and polarizing to obtain the 1-3 composite piezoelectric material. Compared with the prior art, the preparation method provided by the invention has the advantages that the preparation process is simplified and efficient, and meanwhile, the prepared 1-3 composite piezoelectric material has excellent piezoelectric performance in a high-frequency ultrasonic range (30-50 MHz).

Description

A 1-3 composite piezoelectric material for high-frequency ultrasonic transducer and a preparation method thereof

Technical Field

The invention relates to a piezoelectric material, in particular to a 1-3 composite piezoelectric material for a high-frequency ultrasonic transducer and a preparation method thereof.

Background technique

High-frequency medical ultrasound imaging and industrial non-destructive testing can use ultrasonic transducers to perform microstructure ultrasound imaging and detection of human tissue and important micro-industrial parts with micron-level resolution. This technology belongs to the next generation of high-end medical and industrial equipment and is one of the key research areas. The ultra-high spatial resolution of high-frequency ultrasonic transducers requires them to have high sensitivity and bandwidth, but the higher the frequency of ultrasonic emission and reception, the lower the electromechanical coupling coefficient that determines its electromechanical conversion efficiency. Therefore, it is necessary to use a piezoelectric material that still has a high electromechanical coupling coefficient in the high-frequency ultrasonic frequency band for ultrasonic imaging, detection and identification.

Compared with traditional single-phase piezoelectric materials (such as PZT ceramics, PMNT single crystals, etc.), 1-3 composite materials have a higher electromechanical coupling coefficient on the one hand, which can greatly increase the sensitivity of the ultrasonic transducer echo signal. On the other hand, it has a lower acoustic impedance than single-phase materials, which makes it easy to achieve impedance matching with human tissue and plastic parts, and can increase the sensitivity of high-frequency ultrasonic transducers while reducing the difficulty of transducer preparation processes. Especially in the high-frequency ultrasonic stage of 30 to 50 MHz, 1-3 composite materials still have a high electromechanical coupling coefficient, and are necessary materials for high-performance medical high-frequency ultrasonic imaging and high-frequency non-destructive testing.

The 1-3 composite material used for high-frequency ultrasound imaging is different from the piezoelectric materials generally used in medium and low frequencies. Due to the need for longitudinal vibration modes, its piezoelectric phase microstructure is required to still have a large aspect ratio, small column spacing and high piezoelectric performance at the micrometer scale. However, for the tens of micrometer-level piezoelectric microstructures used in high-frequency ultrasound applications, traditional 1-3 composite material preparation methods such as mechanical cutting-filling method and plasma etching method require large precision equipment, are time-consuming, and have a small piezoelectric filling ratio, which cannot meet the industrial production of high-frequency composite materials. In addition, the traditional silicon template method uses a photolithographic silicon wafer as a template, injects PZT nanopowder into micropores, and uses hot isostatic pressing to prepare a piezoelectric column array, but the incompressibility of the silicon template makes the sintering density of the ceramic microcolumns low, making it difficult to obtain high piezoelectric performance.

Summary of the invention

The purpose of the present invention is to solve at least one of the above problems and to provide a 1-3 composite piezoelectric material for a high-frequency ultrasonic transducer and a preparation method thereof, thereby simplifying and improving the preparation process. At the same time, the prepared 1-3 composite piezoelectric material has excellent piezoelectric properties within the high-frequency ultrasonic range (30-50MHz).

The purpose of the present invention is achieved through the following technical solutions:

The first aspect of the present invention discloses a method for preparing a 1-3 composite piezoelectric material for a high-frequency ultrasonic transducer, comprising the following steps:

S1: Prepare soft templates containing micropores by etching technology;

S2: filling the micropores in the soft template obtained in step S1 with piezoelectric ceramic powder;

S3: sintering the product obtained in step S2 at a high temperature to remove the soft template, thereby obtaining a piezoelectric ceramic column array;

S4: filling and curing the piezoelectric ceramic column array obtained in step S3 with a high molecular polymer to obtain a semi-finished product;

S5: Grind and thin the semi-finished product obtained in step S4, plate electrodes and polarize it to obtain the 1-3 composite piezoelectric material.

Preferably, in step S1, the etching technology is one of laser etching, plasma etching and chemical etching; the material of the soft template is rosin; the diameter of the micropores is 25-150 μm, and the length does not exceed 200 μm; the density of the micropores on the soft template is 400-1000/ ^mm2 . Through the design of the template micropores, the diameter, spacing and arrangement of the piezoelectric columns (microcolumns) in the prepared product can be controlled to achieve microstructure regulation; and the use of the template enables the product to be prepared and produced on a large scale.

Preferably, in step S2, the piezoelectric ceramic powder is a perovskite structure ferroelectric powder.

Preferably, the piezoelectric ceramic powder is one or more of lead zirconate titanate (PZT), lead magnesium niobate titanate (PMN-PT), lead indium magnesium niobate titanate (PIN-PMN-PT, i.e. lead indium niobate-lead magnesium niobate-lead titanate), sodium potassium niobate (KNN) and sodium bismuth titanate-barium titanate (NBT-BT).

Preferably, in step S2, the filling comprises the following steps:

S21: dispersing piezoelectric ceramic powder in a binder to form a slurry;

S22: vacuum-infusing the slurry obtained in step S21 into the micropores in the soft template obtained in step S1, and then drying under normal pressure to form a microcolumn precursor with a relatively high density;

S23: applying pressure perpendicular to the surface to the microcolumn precursor obtained in step S22.

Preferably, in step S21, the adhesive is acrylamide.

Preferably, in step S23, the pressure is 6.0 MPa and the maintenance time is 30 min.

Preferably, in step S3, the high temperature sintering is unidirectional hot pressing sintering, comprising the following steps: heating the soft template to 500-530°C at a heating rate of 50°C/h and keeping it warm for 2-3h, then heating it to 1150-1200°C at the same heating rate and keeping it warm for 1.5-2h. The main advantage of using unidirectional hot pressing sintering in the present invention is that, first of all, the equipment requirements are not as high as isostatic hot pressing sintering (another hot pressing sintering method), the process is simple, the cost is low, and the effect of sintering densification can be achieved. In addition, because the soft template is pressurized, unidirectional hot pressing sintering can keep the sample flat after burning, while isostatic pressing will press the template into an irregular shape and cannot be used.

The high-temperature sintering in step S3 has three functions: first, to remove the soft template; second, to make the sintered piezoelectric microcolumns stand upright on the substrate to form a piezoelectric ceramic microcolumn array; third, the substrate will shrink during the sintering process, which is used to reduce the spacing between the piezoelectric microcolumns, make the arrangement more compact, and increase the filling ratio of the piezoelectric phase.

Preferably, in step S4, the high molecular polymer is epoxy resin, and the filling and curing is performed under vacuum conditions. Epoxy curing under vacuum conditions can eliminate bubbles in the gaps between ceramic micro-pillars.

Preferably, in step S5, the upper and lower surfaces of the cured composite material are thinned by grinding to keep them parallel, and the substrate also needs to be removed by grinding and thinning; according to the requirements of the transducer frequency, the composite material is ground and thinned to the required thickness, and electrodes are plated on the upper and lower surfaces by magnetron sputtering; the sample is polarized, and the polarization is carried out under silicone oil and room temperature conditions, the applied electric field is 3 kV/mm, and the polarization time is 30 minutes.

The second aspect of the present invention discloses a 1-3 composite piezoelectric material for a high-frequency ultrasonic transducer, which is prepared by any of the above methods for preparing a 1-3 composite piezoelectric material for a high-frequency ultrasonic transducer.

Compared with the prior art, the present invention has the following beneficial effects:

1. In terms of preparation, this method is a new and effective method for preparing high-frequency 1-3 composite piezoelectric materials. It has high preparation efficiency and low cost, and is conducive to the industrial preparation and application of 1-3 composite piezoelectric materials in the field of high-frequency ultrasonic technology.

2. The piezoelectric ceramic microcolumns prepared by the present invention have uniform radial distribution of element content, simple phase structure and relatively complete lattice. Comprehensive performance tests show that the high-frequency 1-3 composite piezoelectric material prepared by the present invention has excellent piezoelectric properties in the high-frequency ultrasonic range (30-50MHz), especially the electromechanical coupling coefficient can reach more than 61.5%, which is greatly improved compared with the single-phase PZT ceramics with the same components.

3. The composite piezoelectric material provided by the present invention is composed of two parts, and the main function is the piezoelectric phase (piezoelectric column), so 1) the higher the piezoelectric performance of the piezoelectric column material itself, the greater the piezoelectric response of the composite material. The piezoelectric constant _d33 of commonly used piezoelectric materials is between 600 and 1300pC/N. 2) The aspect ratio (cylindrical), that is, the usual "width-to-height ratio" (long strip), is between 1.2 and 5 in the present invention, belonging to the longitudinal vibration mode, and has a higher electromechanical coupling coefficient (>60%), while the aspect ratio of non-composite materials is ~0.1, such as a single piece of PZT ceramic, and the electromechanical coupling coefficient is only 50%. 3) For example, the spacing between the columns of the composite material prepared by the cutting and filling method is generally >12μm, and the preparation method of the present invention can achieve >3μm, and the column spacing is smaller. Compared with the two, the piezoelectric constant of the composite material can be increased by 30%.

4. The present invention uses a soft template for preparation, so that the prepared composite piezoelectric material has the following advantages:

1) Diameter: The diameter can be made very small, with a minimum of 25 microns. While maintaining a large aspect ratio (1.2-5), the smaller the diameter, the smaller the column length (composite material thickness) can be. The smaller the thickness and the higher the frequency, the higher the resonant frequency of the composite material, which can increase the material and ultrasonic transducer frequency to a high frequency (30-50MHz). High frequency can only be achieved when the diameter is small enough. For example, when using the traditional cutting and filling method, the column will fall if it is too thin, and the maximum can only reach 10MHz, which cannot meet the high frequency requirements.

2) Spacing: When the spacing is small, the proportion of the piezoelectric phase can be high, and the overall piezoelectric response of the composite material is large, or the piezoelectric performance is good, and the piezoelectric coefficient is large. The minimum spacing that can be obtained by the traditional method is 12 microns, while the minimum spacing of this method is 3 microns, which can increase the piezoelectric constant of the composite material by 30% to 40% compared with the traditional method.

3) Arrangement: Uniform and random arrangement can suppress the vibration mode between the pillars, making the vibration mode of the overall composite material purer and the piezoelectric response signal purer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic flow diagram of the preparation method of the present invention;

FIG2 is a microstructure diagram of the 1-3 composite piezoelectric material prepared in Example 1;

FIG. 3 is a graph showing the impedance performance and resonance/anti-resonance frequency of the 1-3 composite piezoelectric material prepared in Example 1.

Detailed ways

The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

In the following examples, if the reagents used are not specifically described, commercial products that can be routinely obtained by those skilled in the art can be used. In the following examples, if the methods used are not specifically described, methods that can be routinely understood and used by those skilled in the art can be used.

A method for preparing a 1-3 composite piezoelectric material for a high-frequency ultrasonic transducer, as shown in FIG1 , comprises the following steps:

S1: Preparation of soft templates containing micropores by laser etching;

S2: filling the micropores in the soft template obtained in step S1 with piezoelectric ceramic powder;

S3: sintering the product obtained in step S2 at a high temperature to remove the soft template, thereby obtaining a piezoelectric ceramic column array;

S4: filling and curing the piezoelectric ceramic column array obtained in step S3 with a high molecular polymer to obtain a semi-finished product;

S5: Grind and thin the semi-finished product obtained in step S4, plate electrodes and polarize it to obtain 1-3 composite piezoelectric material.

Wherein, in step S1, the material of the soft template is rosin with a thickness of 0.5±0.2 mm; the diameter of the micropores is 25-70 μm and the length is not more than 200 μm; the density of the micropores on the soft template is 400-1000 micropores/mm ² .

Among them, in step S2, the piezoelectric ceramic powder is a perovskite structure ferroelectric powder, which can specifically be one or more of lead zirconate titanate (PZT), lead magnesium niobate titanate (PMN-PT), lead indium magnesium niobate titanate (PIN-PMN-PT), sodium potassium niobate (KNN) and sodium bismuth titanate-barium titanate (NBBT).

The filling in step S2 includes the following sub-steps:

S21: dispersing piezoelectric ceramic powder with a particle size of 1-3 μm in a binder to form a slurry;

S22: vacuum-infusing the slurry obtained in step S21 into the micropores in the soft template obtained in step S1, and then drying under normal pressure to form a microcolumn precursor with a relatively high density;

S23: Apply a pressure of 6.0 MPa perpendicular to the surface to the microcolumn precursor obtained in step S22 and maintain it for 30 minutes.

Among them, in step S3, the high temperature sintering is unidirectional hot pressing sintering, including the following steps: heating the soft template to 500-530°C at a heating rate of 50°C/h and keeping it warm for 2-3h, and then heating it to 1150-1200°C at the same heating rate and keeping it warm for 1.5-2h.

Wherein, in step S4, the high molecular polymer is epoxy resin; and the filling and curing are performed under vacuum conditions.

Among them, in step S5, the upper and lower surfaces of the cured composite material are thinned by grinding to keep them parallel, and the substrate also needs to be removed by grinding and thinning; according to the requirements of the transducer frequency, the composite material is ground and thinned to the required thickness, and electrodes are plated on the upper and lower surfaces by magnetron sputtering; the sample is polarized, and the polarization is carried out under silicone oil and room temperature conditions, the applied electric field is 3kV/mm, and the polarization time is 30 minutes.

Example 1

Preparation of high uniformity 1-3 composite piezoelectric material with micro-pillar diameter of 25 μm:

In this embodiment, lead zirconate titanate (PZT) nanopowder with a morphotropic phase boundary component is selected as the piezoelectric phase, and the average particle size of PZT is 500 nm; and epoxy resin (Epo-Tek 301-2) is selected as the polymer matrix.

S1: A soft template is prepared by laser etching a plastic sheet, as shown in Figure 1. The thickness of the soft template is 0.5±0.2 mm, and the diameter of the micropore is 25 μm.

S2, using PZT-5H component powder to fill the template micropores.

1) PZT powder with a particle size of 1 to 3 μm is dispersed in a binder solution to form a PZT slurry.

2) The slurry is poured into the micropores of the plastic sheet under a vacuum environment and dried under normal pressure to volatilize the flux, thereby forming a microcolumn precursor with a higher density.

3) The template filled with PZT powder is subjected to a pressure of 6.0 MPa perpendicular to the surface and maintained for 30 minutes.

S3: The soft template is heated to 500°C at a heating rate of 50°C/h, kept at this temperature for 3 hours, and then continued to be heated to 1200°C at the same heating rate, kept at this temperature for 2 hours, to sinter the PZT ceramic microcolumns.

S4: Epoxy resin polymer (Epo-Tek 301-2) is used for filling and curing to obtain a 1-3 type piezoelectric composite material, as shown in Figure 1. PZT powder pressed tablets are selected as the micro-pillar array substrate, the density of the pressed tablets is 3.52g/ ^cm3 , the diameter of the pressed tablets is 10mm, and the thickness is 1mm. The pressed tablets shrink during the sintering process, which can significantly reduce the spacing between the PZT piezoelectric micro-pillars on them, making them more closely arranged. As shown in Figure 2.

S5: The sample is ground and thinned by a cutting machine. Specifically, a mechanical grinder is used to thin the solidified 1-3 composite piezoelectric material. A 1000 mesh diamond grinding disc is used for rough grinding, and then an alumina template is used for fine grinding. Finally, a 1-3 composite piezoelectric material sheet with a thickness of 50 μm is obtained. Then, gold electrodes are plated on the upper and lower surfaces of the sample by magnetron sputtering, as shown in Figure 1. The specific operation is as follows: The wafer is ultrasonically cleaned in alcohol, acetone, and deionized water for 15 minutes using an ultrasonic cleaning machine, and then dried at 50°C. Then, magnetron sputtering is used to coat the upper and lower surfaces of the sample with multiple layers of composite electrodes. In this example, a nickel electrode is sputtered first, and then a layer of chromium electrode is sputtered as a transition electrode, and its thickness can be controlled between 900-1500nm. Then a layer of gold electrode is sputtered, and its thickness can be controlled between 1-2μm. The sputtering time for each layer of electrode is 10 minutes, and the surface temperature of the sample is kept below 80°C.

S6: The sample is polarized in silicone oil at room temperature with an applied electric field of 3 kV/mm for 30 minutes.

The microstructure of the prepared 1-3 composite material was observed using an optical microscope at a magnification of 1000 times, as shown in Figure 2. The piezoelectric columns are arranged neatly and evenly, and the diameter of a single piezoelectric column is small, reaching 25μm. The average spacing between ceramic microcolumns is small, reaching 3μm.

The shape and size of the piezoelectric column directly determine the piezoelectric constant of the material and the vibration mode of the material, while the vibration mode determines the electromechanical coupling performance. Therefore, the neatness and uniformity of the piezoelectric column can prevent the interference of the vibration modes between the columns, making the vibration mode purer and enhancing the purity of the piezoelectric signal generated and received. In addition, the column has a small diameter, so the sample can be made thinner while maintaining a certain aspect ratio (which determines the size of the electromechanical coupling performance), and the frequency can be made higher to achieve high frequency. The smaller average spacing can increase the proportion of the piezoelectric phase and obtain a larger piezoelectric constant, that is, a higher piezoelectric response.

Impedance spectrum test, according to "Piezoelectric ceramic material performance test method - Determination of performance parameters" (GB/T3389-2008), the product's impedance-frequency spectrum and loss-frequency spectrum are measured using a precision LCR analyzer HP4284A. The measurement temperature is room temperature and the test frequency range is 20-60MHz, as shown in Figure 3.

As can be seen from FIG3 , the resonant frequency of the high-frequency 1-3 composite piezoelectric material of this embodiment is 37.4 MHz, and the anti-resonant frequency is 46.1 MHz. According to the "Test Methods for Performance of Piezoelectric Ceramic Materials - Determination of Performance Parameters" (GB/T 3389-2008), its electromechanical coupling coefficient is calculated to be 62.4%, which is significantly higher than that of the PZT single-phase ceramic sheet (k _t ~50%).

Embodiment 2-5

The preparation process is basically the same as that of Example 1, except for the design size of the micropores in step S1. The specific data are shown in Table 1.

The performance testing method is the same as that in Example 1.

Example 6

S1, soft templates with different thicknesses and different micropore diameters were prepared by laser etching plastic sheets of different thicknesses, as shown in Figure 1. The thickness of the soft template was 0.5±0.2 mm, and the diameter of the micropore was 120 μm.

S2, using PZT-5H component powder to fill the template micropores.

1) PZT powder with a particle size of 1 to 3 μm is dispersed in a binder solution to form a PZT slurry.

2) The slurry is poured into the micropores of the plastic sheet under a vacuum environment and dried under normal pressure to volatilize the flux, thereby forming a microcolumn precursor with a higher density.

3) The template filled with PZT powder is subjected to a pressure of 6 MPa perpendicular to the surface and maintained for 30 minutes.

S3, heating the soft template to 530°C at a heating rate of 50°C/h, keeping the temperature for 2h, and then continuing to heat to 1200°C at the same heating rate, keeping the temperature for 2h, to sinter the PZT ceramic microcolumns.

S4, epoxy resin polymer (Epo-Tek 301-2) is used for filling and curing to obtain a 1-3 type piezoelectric composite material, as shown in Figure 1. PZT powder pressed tablets are selected as micropillar array substrates, the density of the pressed tablets is 3.52g/ ^cm3 , the diameter of the pressed tablets is 10mm, and the thickness is 1mm.

S5, cutting the sample into different thicknesses by a cutting machine, and plating gold electrodes on the upper and lower surfaces of the sample by magnetron sputtering, as shown in FIG1. This process is consistent with step S5 in Example 1.

S6, polarizing the sample. The polarization is carried out in silicone oil at room temperature. The applied electric field is 3 kV/mm and the polarization time is 30 minutes.

The performance test method is the same as that in Example 1, and the results are shown in Table 1.

Table 1 Data summary of Examples 1-6

In Table 1, sample number 1# corresponds to the sample prepared in Example 1, sample number 2# corresponds to the sample prepared in Example 2, and so on.

The microstructures of the six 1-3 composite piezoelectric material samples prepared were further observed using a scanning electron microscope (SEM). For example, microstructure information such as microcolumn diameter d, microcolumn spacing s, and microcolumn length h were obtained, as shown in Table 1. It can be seen that this preparation method can prepare samples with any microcolumn diameter between 25μm and 120μm for PZT ceramic microcolumns; the available ceramic microcolumn spacing range is 3 to 10μm; the available PZT ceramic microcolumn length range is 40 to 100μm; the available 1-3 composite piezoelectric material ceramic phase ratio range is 43 to 55%; the achievable resonant frequency can be higher than 35MHz, and the maximum anti-resonance frequency in the sample reaches 46.1MHz. After the composite material is used to make an ultrasonic transducer, an important parameter of the transducer is the center frequency, which is jointly determined by the resonant frequency and anti-resonance frequency of the composite material. The higher the resonance and anti-resonance frequencies of the material, the higher the center frequency of the transducer. Combined with the test data in Table 1, it can be seen that the center frequency of the material prepared by the method provided by the present invention can reach high frequency after being further made into an ultrasonic transducer.

In addition, it can be seen from Table 1 that the electromechanical coupling coefficient is distributed between 61% and 71% at high frequency (~40MHz), which is much higher than the 50% to 55% of the PZT ceramic monolith, showing a large electromechanical coupling performance advantage, which is beneficial to improving the performance of high-frequency ultrasonic transducers.

The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims (8)

1. The preparation method of the 1-3 composite piezoelectric material for the high-frequency ultrasonic transducer is characterized by comprising the following steps of:

s1: preparing a soft template containing micropores by an etching technology;

s2: filling micropores in the soft template obtained in the step S1 with piezoelectric ceramic powder;

s3: performing high-temperature sintering on the product obtained in the step S2 to remove the soft template, so as to obtain a piezoelectric ceramic column array; the high-temperature sintering is unidirectional hot-pressing sintering, and the product obtained in the step S2 is pressed and sintered to shrink in the sintering process;

S4: filling and curing the piezoelectric ceramic column array obtained in the step S3 by using a high polymer to obtain a semi-finished product;

S5: grinding and thinning the semi-finished product obtained in the step S4, plating electrodes and polarizing to obtain the 1-3 composite piezoelectric material;

In the step S1, the etching technology is one of laser etching, plasma etching and chemical etching; the soft template is made of rosin; the diameter of the micropores is 25-150 μm, and the length is not more than 200 μm; the density of micropores on the soft template is 400-1000 micropores/mm ²;

In step S3, the high temperature sintering includes the following steps: the soft template is heated to 500-530 ℃ at the heating rate of 50 ℃/h and is kept for 2-3h, and then heated to 1150-1200 ℃ at the same heating rate and is kept for 1.5-2h.

2. The method for preparing a 1-3 composite piezoelectric material for a high-frequency ultrasonic transducer according to claim 1, wherein in step S2, the piezoelectric ceramic powder is perovskite structure ferroelectric powder.

3. The method for preparing a 1-3 composite piezoelectric material for a high-frequency ultrasonic transducer according to claim 2, wherein the piezoelectric ceramic powder is one or more of lead zirconate titanate, lead magnesium niobate titanate, lead indium magnesium niobate titanate, potassium sodium niobate and bismuth sodium titanate-barium titanate.

4. The method for preparing a 1-3 composite piezoelectric material for a high frequency ultrasonic transducer according to claim 1, wherein in step S2, the filling comprises the steps of:

S21: dispersing piezoelectric ceramic powder in an adhesive to form slurry;

s22: vacuum pouring the slurry obtained in the step S21 into micropores in the soft template obtained in the step S1, and then drying under normal pressure to form a microcolumn precursor;

s23: and (2) applying pressure vertical to the surface to the micro-column precursor obtained in the step S22.

5. The method of manufacturing a 1-3 composite piezoelectric material for a high frequency ultrasonic transducer according to claim 4, wherein in step S21, the adhesive is acrylamide.

6. The method of manufacturing a 1-3 composite piezoelectric material for a high frequency ultrasonic transducer according to claim 4, wherein in step S23, the pressure is 6.0MPa and the holding time is 30min.

7. The method for preparing a 1-3 composite piezoelectric material for a high-frequency ultrasonic transducer according to claim 1, wherein in step S4, the high-molecular polymer is epoxy resin; the filling and curing are carried out under vacuum.

8. A 1-3 composite piezoelectric material for a high-frequency ultrasonic transducer, which is prepared by the preparation method of the 1-3 composite piezoelectric material for the high-frequency ultrasonic transducer according to any one of claims 1-7.