1-3 piezoelectric ceramic composite material, preparation method and application thereof

Abstract

A 1-3 type piezoelectric ceramic composite material, a preparation method and applications thereof, the composite material comprising an array formed by ceramic columns and polymers, that is, the periphery of the ceramic columns is sequentially provided with an epoxy resin layer and a silica gel layer, the epoxy resin layer and the silica gel layer form a soft and hard polymer, the thickness vibration mode and the transverse vibration mode are regulated through the soft and hard polymer, the thickness vibration mode and the transverse vibration mode are coupled and the electromechanical coupling coefficient is improved; the preparation method adopts a cutting filling method: the ceramic is first cut into a ceramic framework, the epoxy resin is poured into the first cutting gap, the second cutting is performed in the first cutting gap, the silica gel is poured into the second cutting gap, and the ceramic phase is polished after solidification; the composite material can be applied to a water acoustic transducer, and the performance parameters of bandwidth expansion and resolution improvement; the present application breaks through the limitation of the longitudinal electromechanical coupling coefficient k 33 of the piezoelectric phase, can effectively improve the thickness electromechanical coupling coefficient, is simple to prepare, can be mass-produced, is not prone to deformation, and is stable in performance.

Description

Technical Field

[0001] This invention relates to the field of electromechanical coupling technology of piezoelectric composite materials, specifically to a type 1-3 piezoelectric ceramic composite material, its preparation method, and its application. Background Technology

[0002] Piezoelectric transducers are widely used in underwater detection, identification, communication, biomedicine, and non-destructive testing. The electromechanical properties of the piezoelectric material play a crucial role and are key to the transducer's excellent performance. The bandwidth and energy conversion efficiency of a piezoelectric transducer mainly depend on the electromechanical coupling coefficient (k) of the piezoelectric material. t ), that is, k t The higher the value, the wider the bandwidth and the better the sensitivity.

[0003] Type 1-3 piezoelectric composites (the first number represents the connectivity of the piezoelectric phase, and the second number represents the connectivity of the polymer phase; 1 represents one-dimensional connectivity, i.e., connectivity in only one direction, generally linear; 3 represents three-dimensional connectivity, generally continuous in three directions) have a relatively high electromechanical coupling coefficient k. t With its low acoustic impedance Z and controllable piezoelectric phase distribution, it is widely used in the transducer field. As the requirements for transducer sensitivity and resolution increase, exploring type 1-3 piezoelectric composite materials with higher electromechanical coupling performance is of great significance.

[0004] The methods to improve the electromechanical coupling coefficient of 1–3 piezoelectric composites typically include: 1. Changing the shape of the piezoelectric phase, such as making it circular, square, or triangular (Hayward G, BJ, Assessing the influence of pillar aspectratio on the behavior of 1–3 connectivity composite transducers. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 1996. 1(43): p. 98-108.); 2. Reducing the Poisson's ratio of the polymer to allow the piezoelectric phase to vibrate more freely (A, SW, Optimizing electromechanical coupling in piezocomposites using polymers with negative Poisson's ratio. 1991, IEEE: IEEE 1991 Ultrasonics Symposium. p. 661-666.); 3. Changing the periodic structure of the piezoelectric composite, such as changing it from a traditional periodic structure to a Gaussian distribution (Xu, D., et al., Design and properties of Gaussian-type 1–3 piezoelectric). composites.Composite Structures, 2016. 140: p. 213-216.).

[0005] However, the above-mentioned existing technologies have the following drawbacks: 1) Changes in the shape of the piezoelectric phase cannot effectively improve the electromechanical coupling coefficient; 2) Composite materials of low Poisson's ratio polymers are prone to deformation, reducing performance stability; 3) The preparation of aperiodic structural composite materials is complex and difficult to mass-produce; 4) The thickness electromechanical coupling performance of type 1-3 composite materials is affected by the longitudinal electromechanical coupling coefficient k of the piezoelectric phase. 33 Restrictions. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the present invention aims to provide a type 1-3 piezoelectric ceramic composite material, its preparation method, and its application. The prepared composite material overcomes the limitations of the longitudinal electromechanical coupling coefficient k of the piezoelectric phase. 33 The limitations of this method can effectively improve the electromechanical coupling coefficient of thickness. It is simple to prepare, can be mass-produced, is not easily deformed, and has stable performance. It can be used in the production and manufacturing of underwater acoustic transducers.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A type 1-3 piezoelectric ceramic composite material includes an array formed by ceramic pillars and polymers. An epoxy resin layer and a silicone layer are sequentially disposed around the periphery of the ceramic pillars, and the epoxy resin layer and silicone layer form a soft and hard polymer.

[0008] The epoxy resin accounts for 90%-10% of the volume fraction of the polymer; the silicone accounts for 10%-90% of the volume fraction of the polymer.

[0009] A method for preparing a type 1-3 piezoelectric ceramic composite material includes the following steps: Step 1, one-time cutting: Use a dicing machine to cut the ceramic into a ceramic column array to form a ceramic column skeleton. After cutting, the array is ultrasonically cleaned and dried. Step 2, one-time potting: First, mix epoxy resin and the corresponding type and amount of curing agent evenly to obtain epoxy resin colloid, and then vacuum to remove air bubbles; then pour the epoxy resin colloid into the ceramic column array prepared in Step 1 to fill the cut gaps once; vacuum again to remove air bubbles and then cure at room temperature; grind the upper surface of the cured ceramic epoxy resin composite material to remove excess epoxy resin and expose the ceramic columns. Step 3, secondary cutting: The ceramic epoxy resin composite material prepared in step 2 is cut a second time using a dicing machine, and the width of the secondary cutting gap is smaller than that of the primary cutting gap, forming a composite material array of epoxy resin-encapsulated ceramic pillars; ultrasonic cleaning and drying; Step 4, Secondary potting: Pour silicone into the composite material array of epoxy resin-coated ceramic pillars prepared in Step 3, fill the secondary cutting gaps, and form a composite material array in which epoxy resin layer and silicone layer are successively wrapped around the ceramic pillars. After vacuuming to remove air bubbles from the silicone, it is cured at room temperature. Step 5, Grinding: Grind the composite material array that is wrapped with epoxy resin layer and silicone layer in step 4 to remove excess silicone and ceramic substrate on the upper and lower surfaces to expose the ceramic column. Step 6: The ceramic piezoelectric composite material obtained in Step 5 is ultrasonically cleaned and dried, and a gold electrode is magnetron sputtered to obtain the type 1-3 piezoelectric ceramic composite material.

[0010] The center of the secondary cutting slit should be aligned as closely as possible with the center of the primary cutting slit filled with epoxy resin.

[0011] The sum of the width of the ceramic column and the width of the first cut gap is the transverse periodic dimension of the composite material. The final thickness of the ceramic composite material after grinding in step 5 is comparable to the transverse periodic dimension, i.e., thickness / transverse period < 3.

[0012] A type 1-3 piezoelectric ceramic composite material is used to prepare underwater acoustic transducers.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: 1) The piezoelectric ceramic composite material of type 1-3 prepared by the present invention effectively improves the electromechanical coupling performance. When applied to devices such as underwater acoustic transducers, the improved energy conversion efficiency and the widening of the resonant frequency and anti-resonant frequency range are beneficial to expanding the bandwidth of the transducer. The increase in bandwidth is beneficial to improving performance parameters such as resolution and sensitivity.

[0014] 2) Compared with changing the arrangement of the periodicity, the preparation method of the piezoelectric ceramic composite material of type 1-3 prepared by the present invention adopts the cutting and filling method, which has a simple process, the cutting parameters can be precisely controlled, the process stability is high, and the repeatability of the finished product is good.

[0015] 3) The polymer phase of the type 1-3 piezoelectric ceramic composite material prepared by this invention includes two polymers: soft (silicone) and hard (epoxy resin). The epoxy resin can serve as a supporting structure to prevent deformation of the piezoelectric ceramic composite material. 4) This invention utilizes a method of modulating soft and hard polymer phases, unlike previous methods that relied on pure thickness vibration modes to increase the thickness electromechanical coupling coefficient to the longitudinal electromechanical coupling coefficient (k). 33 This innovative method couples transverse vibration modes with thickness vibration modes to form a merged vibration mode, broadening the range between resonant and anti-resonant frequencies and increasing the electromechanical coupling coefficient k. t Breakthrough in the longitudinal electromechanical coupling coefficient k of piezoelectric phase 33 Restrictions.

[0016] In summary, compared with the prior art, this invention adopts the traditional cutting and filling method to innovatively combine soft and hard polymers, regulate the vibration mode of the piezoelectric ceramic composite material, significantly improve the electromechanical coupling performance of the material, and break through the limitations of the piezoelectric properties of the piezoelectric phase itself. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the piezoelectric ceramic composite material of types 1-3 of the present invention.

[0018] Figure 2 This is a flowchart of the preparation method of the present invention.

[0019] Figure 3 Optical images of piezoelectric ceramic composite materials for comparative examples and Examples 1-3.

[0020] Figure 4 To compare the piezoelectric strain constant d of the piezoelectric ceramic composite materials in Examples 1-3 33 Comparison chart.

[0021] Figure 5 Impedance spectra of piezoelectric ceramic composite materials for comparison with Examples 1-3.

[0022] Figure 6 To compare the resonant frequency, anti-resonant frequency, and electromechanical coupling coefficient k of the piezoelectric ceramic composite materials in Examples 1-3. t Comparison chart.

[0023] Figure 7 The diagram shows a comparison of the acoustic impedance Z of the piezoelectric ceramic composite material with that of Examples 2-3. Detailed Implementation

[0024] The technical solution of the present invention is illustrated below through embodiments. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic solution of the present invention. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0025] Example 1, referring to Figure 1 A type 1-3 piezoelectric ceramic composite material is composed of an array of ceramic pillars and polymers. An epoxy resin layer and a silicone layer are sequentially arranged around the ceramic pillars. The epoxy resin layer and the silicone layer form a soft and hard polymer. The thickness vibration mode and the transverse vibration mode are controlled by the soft and hard polymers, so that the vibration modes are coupled and the electromechanical coupling coefficient is improved. The epoxy resin accounts for 70% of the volume fraction of the polymer.

[0026] The silicone accounts for 30% of the volume fraction of the polymer.

[0027] Reference Figure 2 The preparation method of the type 1-3 piezoelectric ceramic composite material includes the following steps: Step 1, One-time cutting: Use a dicing machine to cut the PZT-4 ceramic into pieces with a single-cut kerf width of 1.03mm and ceramic pillar width of 1.01*1.01mm. 2 The ceramic column array, with a transverse period of 2.04 mm, forms a ceramic skeleton. After cutting, it is ultrasonically cleaned, arranged, and dried. Step 2, one-time potting: First, mix the A phase resin and B phase curing agent of Epo-Tek 301 two-component epoxy resin evenly in a mass ratio of 4:1 to obtain epoxy resin colloid, and then vacuum to remove air bubbles; then pour the epoxy resin colloid into the ceramic column array prepared in Step 1 to fill the cut gaps; after vacuuming to remove air bubbles, cure at room temperature for 24 hours, grind the upper surface of the cured ceramic composite array, remove excess epoxy resin, and expose the ceramic columns; Step 3, secondary cutting: The ceramic epoxy resin composite material prepared in step 2 is cut a second time using a dicing machine. The width of the secondary cutting gap is 0.25mm. The center of the secondary cutting gap is aligned with the center of the primary cutting gap filled with epoxy resin as much as possible to form a composite material array of epoxy resin-encapsulated ceramic pillars; ultrasonic cleaning and drying. Step 4, secondary potting: Pour silicone into the composite material array of epoxy resin-coated ceramic pillars prepared in Step 3, fill the secondary cutting gaps, and form a composite material array in which epoxy resin layer and silicone layer are successively wrapped around the ceramic pillars. After vacuuming to remove air bubbles, cure at room temperature for 24 hours; wherein epoxy resin and silicone account for 70% and 30% of the polymer volume fraction, respectively.

[0028] Step 5, Grinding: Grind the composite material array that is wrapped with epoxy resin layer and silicone layer in step 4. Grind away the excess silicone and ceramic substrate on the upper and lower surfaces to expose the ceramic column; the thickness after grinding is 2.8mm; the final thickness of the ceramic composite material after grinding is comparable to the transverse period dimension, that is, thickness / transverse period < 3. Step 6: The ceramic piezoelectric composite material obtained in Step 5 is ultrasonically cleaned and dried, and a gold electrode is magnetron sputtered to obtain the type 1-3 piezoelectric ceramic composite material.

[0029] Comparative Example: Type 1-3 piezoelectric ceramic composites with the same transverse period and thickness were prepared as a control. The specific method is as follows: Step 1, Cutting: Use a dicing machine to cut the PZT-4 ceramic into pieces with a kerf width of 1.03mm and ceramic pillars with a width of 1.01*1.01mm. 2 The ceramic column array has a transverse period of 2.04 mm, forming a ceramic column skeleton. After cutting, it is ultrasonically cleaned, arranged, and dried. Step 2, potting: First, mix the A phase resin and B phase curing agent of Epo-Tek 301 two-component epoxy resin evenly in a mass ratio of 4:1 to obtain epoxy resin colloid, and then vacuum to remove air bubbles; then pour the epoxy resin colloid into the ceramic column array prepared in Step 1 to fill the cut gaps; after vacuuming to remove air bubbles, cure at room temperature for 24 hours, grind the upper and lower surfaces of the cured ceramic composite array, remove excess epoxy resin and ceramic substrate, and expose the ceramic columns; Step 3: The ceramic epoxy resin composite material prepared in Step 2 is ultrasonically cleaned and dried, and then a gold electrode is magnetron sputtered.

[0030] Comparative examples and optical diagrams of piezoelectric ceramic composite materials from Example 1 are shown below. Figure 3 As shown, the comparative example polymers are different from those in Example 1, which contains two polymers, with white silicone surrounding epoxy resin.

[0031] Using quasi-static d 33 The measuring instrument (ZJ-6A, Chinese Academy of Sciences, China) measured the piezoelectric coefficient (d) of the piezoelectric ceramic composite materials prepared in the comparative example and Example 1. 33 The value was calculated by averaging 20 random points, and the results showed that d in Example 1 was... 33The comparison ratio increased by approximately 30.3%, from 143.9 pC / N to 187.5 pC / N. Figure 4 As shown, this is because the silicone is soft, which reduces the clamping effect of the polymer on the piezoelectric ceramic pillar.

[0032] Impedance spectra of the piezoelectric ceramic composite materials prepared in the comparative example and Example 1 were measured using an impedance analyzer (E4990a, Agilent, USA). The electromechanical coupling coefficient of the tested embodiment can be calculated. Figure 5 In the impedance spectrum, three resonant peaks appear in the comparative example, with the lowest frequency peak corresponding to the thickness resonant frequency. f r =500.5 kHz, f r1 = 586 kHz corresponds to the first transverse resonant frequency. f r2 = 748 kHz corresponds to the second transverse resonant frequency, meaning that the first and second transverse vibration modes appear near the thickness vibration; through the modulation of soft and hard polymers, the peak of the second transverse vibration mode disappears, but the interference of the first transverse vibration mode still exists, refer to Figure 6 ,in f r = 472.5 kHz, f a = 565.7 kHz, and its electromechanical coupling coefficient is calculated to be 0.59, while in the comparative example, due to the interference of the transverse vibration mode, its electromechanical coupling coefficient is 0.39. It can be seen that the addition of silicone reduces the interference of the second transverse mode, and the electromechanical coupling coefficient is slightly improved. Specific data are shown in Table 1.

[0033] Table 1 Comparative Example 500.5 536.5 586 676 748 793 0.39 Example 1 472.5 565.7 624.3 703.8 / / 0.59 In Example 2, the volume fractions of epoxy resin and silicone in the polymer were both changed to 50% in Example 1; the width of the secondary cutting slit in step 3 of the preparation method was 0.43 mm.

[0034] The beneficial effects of this embodiment are as follows: the optical diagrams of the piezoelectric ceramic composite materials in the comparative example and Example 2 are shown below. Figure 3 As shown, the white silica gel content in Example 2 is higher than that in Example 1. The piezoelectric coefficient d was randomly measured at 20 points. 33 The values, and their average values ​​compared to the comparative results, show that Example 2 showed an improvement of approximately 42% compared to the comparative example, increasing from 143.9 pC / N to 205.4 pC / N. Figure 4 As shown in Table 2.

[0035] Table 2 Comparative Example 143.9 2706.5 2803.2 7.6 Example 2 205.4 2631.6 2785.7 7.4 Figure 5 In the impedance spectrum, the thickness vibration peak and the first transverse vibration mode in Example 2 merge into a broadened impedance peak; refer to Figure 6 In Example 2, the distance between the resonant frequency and the anti-resonant frequency increases, wherein... f r = 480 kHz, f a = 726 kHz, and its electromechanical coupling coefficient is calculated to be 0.78. Furthermore, it is worth noting the k-value of the PZT-4 piezoelectric ceramic. 33 The value is 0.69. In this embodiment 2, the coupling of thickness vibration and first transverse vibration overcomes the influence of the piezoelectric ceramic's own properties, providing a possibility for achieving high electromechanical performance in piezoelectric materials with low electromechanical properties. Specific data are shown in Table 3.

[0036] Table 3 Comparative Example 500.5 536.5 586 676 748 793 0.39 Example 2 480 726 / / / / 0.78 By measuring the longitudinal wave acoustic waves of the comparative example and Example 2 v l The results showed that the longitudinal wave velocities of the two were not significantly different, but the density of silicone was lower than that of epoxy resin, and the acoustic impedance in Example 2 was slightly lower than that in the comparative example. Figure 7 As shown in Table 2, the specific data is as follows.

[0037] In Example 3, the volume fractions of epoxy resin and silicone in the polymer in Example 1 were changed to 30% and 70%, respectively; the width of the secondary cutting slit in step 3 of the preparation method was 0.64 mm.

[0038] The beneficial effects of this embodiment are as follows: The optical diagrams of the piezoelectric ceramic composite materials in the comparative example and Example 3 are shown below. Figure 3 As shown, the white silica gel content in Example 3 is higher than that in Example 2 and Example 1.

[0039] The piezoelectric coefficient d was randomly measured at 20 points. 33 The values, and their average values ​​compared to the comparative results, show that Example 3 improved by approximately 64.56% compared to the comparative example, increasing from 143.9 pC / N to 236.8 pC / N. Figure 4 As shown in Table 4.

[0040] Table 4 Comparative Example 143.9 2706.5 2803.2 7.6 Example 3 236.8 2601.4 2552.7 6.7 like Figure 5 As shown, the impedance spectrum peaks of the piezoelectric ceramic composite material in Example 3 become sharper; refer to Figure 6 In Example 3, the resonant frequency remains essentially unchanged, while the anti-resonant frequency is lower than that in Examples 1 and 2. f r = 481 kHz, fa = 624.4kHz, and its electromechanical coupling coefficient is calculated to be 0.68, which is close to the k-value of PZT-4 piezoelectric ceramic. 33 The increased amount of 0.69.704 silica gel causes the piezoelectric phase to tend towards free vibration, hence the piezoelectric coefficient d 33 and electromechanical coupling coefficient k t The performance of these materials is close to that of the piezoelectric ceramic column itself. Specific data are shown in Table 5.

[0041] Table 5 Comparative Example 500.5 536.5 586 676 748 793 0.39 Example 3 481 624.4 / / / / 0.68 Example 3: The increased silica content resulted in increased longitudinal acoustic waves. v l Both the density and the acoustic impedance are lower than the comparative example, and the calculated acoustic impedance is 11.8% lower than that of the comparative example. Figure 7 As shown in Table 4, the specific data is as follows.

[0042] In Example 4, the volume fractions of epoxy resin and silicone in the polymer in Example 1 were changed to 90% and 10%, respectively; the width of the secondary cutting slit in step 3 of the preparation method was 0.08 mm.

[0043] In Example 5, the volume fractions of epoxy resin and silicone in the polymer in Example 1 were changed to 10% and 90%, respectively; the width of the secondary cutting slit in step 3 of the preparation method was 0.89 mm.

[0044] Example 6: The ceramic phase in Example 1 was replaced with PZT-5 ceramic, and the volume fractions of epoxy resin and silicone were 50% and 50% of the polymer, respectively. This embodiment describes a method for preparing a type 1-3 piezoelectric ceramic composite material, comprising the following steps: Step 1, One-time cutting: Use a dicing machine to cut the PZT-5 ceramic into pieces with a 2mm wide kerf and a ceramic column width of 2*2mm. 2 The ceramic column array, with a transverse period of 4mm, forms a ceramic skeleton. After cutting, it is ultrasonically cleaned, arranged, and dried. Step 2, one-time potting: First, mix E-51 epoxy resin and the corresponding type of curing agent at a mass ratio of 6:1 to obtain epoxy resin colloid, and then vacuum to remove air bubbles; then pour the epoxy resin colloid into the ceramic column array prepared in Step 1 to fill the cut gaps once; vacuum again to remove air bubbles and then cure at room temperature; grind the upper surface of the cured ceramic epoxy resin composite material to remove excess epoxy resin and expose the ceramic columns. Step 3, secondary cutting: The ceramic epoxy resin composite material prepared in step 2 is cut a second time using a dicing machine. The width of the secondary cutting slit is 0.85 mm. The center of the secondary cutting slit is aligned with the center of the primary cutting slit filled with epoxy resin as much as possible to form a composite material array of epoxy resin-encapsulated ceramic pillars; ultrasonic cleaning and drying. Step 4, Secondary potting: Pour silicone into the composite material array of epoxy resin-coated ceramic pillars prepared in Step 3, fill the secondary cutting gaps, and form a composite material array in which epoxy resin layer and silicone layer are successively wrapped around the ceramic pillars. After vacuuming to remove air bubbles in the silicone, it is cured at room temperature; wherein epoxy resin and silicone each account for 50% of the polymer volume fraction.

[0045] Step 5, Grinding: Grind the composite material array that is wrapped with epoxy resin layer and silicone layer in step 4. Grind away the excess silicone and ceramic substrate on the upper and lower surfaces to expose the ceramic column. The final thickness of the ceramic composite material after grinding is 5.6 mm, which is comparable to the transverse periodic structure, and the thickness / transverse period is <3. Step 6: The ceramic piezoelectric composite material obtained in Step 5 is ultrasonically cleaned and dried, and a gold electrode is magnetron sputtered to obtain the type 1-3 piezoelectric ceramic composite material.

[0046] Example 7: The ceramic phase of Example 1 was replaced with PIN-PMN-PT ceramic, and the volume fractions of epoxy resin and silicone were 50% and 50% of the polymer, respectively. This embodiment describes a method for preparing a type 1-3 piezoelectric ceramic composite material, comprising the following steps: Step 1, One-time cutting: Use a dicing machine to cut the PIN-PMN-PT ceramic into pieces with a single-cut kerf width of 0.74mm and a ceramic column width of 0.6*0.6mm. 2 The ceramic column array, with a transverse period of 1.34 mm, forms a ceramic skeleton. After cutting, it is ultrasonically cleaned, arranged, and dried. Step 2, one-time potting: First, mix E-44 epoxy resin and the corresponding type of curing agent at a 1:1 mass ratio to obtain epoxy resin colloid, and then vacuum to remove air bubbles; then pour the epoxy resin colloid into the ceramic column array prepared in Step 1 to fill the cut gaps; vacuum again to remove air bubbles and then cure at room temperature; grind the upper surface of the cured ceramic epoxy resin composite material to remove excess epoxy resin and expose the ceramic columns. Step 3, secondary cutting: The ceramic epoxy resin composite material prepared in step 2 is cut a second time using a dicing machine. The width of the secondary cutting slit is 0.3 mm. The center of the secondary cutting slit is aligned with the center of the primary cutting slit filled with epoxy resin as much as possible to form a composite material array of epoxy resin-encapsulated ceramic pillars; ultrasonic cleaning and drying. Step 4, Secondary potting: Pour silicone into the composite material array of epoxy resin-coated ceramic pillars prepared in Step 3, fill the secondary cutting gaps, and form a composite material array in which epoxy resin layer and silicone layer are successively wrapped around the ceramic pillars. After vacuuming to remove air bubbles in the silicone, it is cured at room temperature; wherein epoxy resin and silicone each account for 50% of the polymer volume fraction.

[0047] Step 5, Grinding: Grind the composite material array that is wrapped with epoxy resin layer and silicone layer in step 4. Grind away the excess silicone and ceramic substrate on the upper and lower surfaces to expose the ceramic column. The final thickness of the ceramic composite material after grinding is 3.06 mm, which is comparable to the transverse periodic structure, and the thickness / transverse period is <3. Step 6: The ceramic piezoelectric composite material obtained in Step 5 is ultrasonically cleaned and dried, and a gold electrode is magnetron sputtered to obtain the type 1-3 piezoelectric ceramic composite material.

[0048] The application of the type 1-3 piezoelectric ceramic composite material described in Examples 1-7 to underwater acoustic transducers is beneficial for expanding the bandwidth and improving the resolution and other performance parameters of underwater acoustic transducers.

Claims

1. A method for preparing a type 1-3 piezoelectric ceramic composite material, characterized in that: The aforementioned type 1-3 piezoelectric ceramic composite material comprises an array of ceramic pillars and polymers. Specifically, an epoxy resin layer and a silicone layer are sequentially disposed around the periphery of the ceramic pillars, forming a soft and hard polymer. The epoxy resin accounts for 10%-90% of the volume fraction of the polymer, and the silicone accounts for 10%-90% of the volume fraction of the polymer. The method for preparing a type 1-3 piezoelectric ceramic composite material includes the following steps: Step 1, one-time cutting: Use a dicing machine to cut the ceramic into a ceramic column array to form a ceramic column skeleton. After cutting, ultrasonically clean, arrange and dry. Step 2, one-time potting: First, mix epoxy resin and the corresponding type and amount of curing agent evenly to obtain epoxy resin colloid, and then vacuum to remove air bubbles; then pour the epoxy resin colloid into the ceramic column array prepared in Step 1 to fill the cut gaps once; vacuum again to remove air bubbles and then cure at room temperature; grind the upper surface of the cured ceramic epoxy resin composite material to remove excess epoxy resin and expose the ceramic columns. Step 3, secondary cutting: The ceramic epoxy resin composite material prepared in step 2 is cut a second time using a dicing machine, and the width of the secondary cutting gap is smaller than that of the primary cutting gap, forming a composite material array of epoxy resin-encapsulated ceramic pillars; ultrasonic cleaning and drying; Step 4, Secondary potting: Pour silicone into the composite material array of epoxy resin-coated ceramic pillars prepared in Step 3, fill the secondary cutting gaps, and form a composite material array in which epoxy resin layer and silicone layer are successively wrapped around the ceramic pillars. After vacuuming to remove air bubbles from the silicone, it is cured at room temperature. Step 5, Grinding: Grind the composite material array that is wrapped with epoxy resin layer and silicone layer in step 4 to remove excess silicone and ceramic substrate on the upper and lower surfaces to expose the ceramic column. Step 6: The ceramic piezoelectric composite material obtained in Step 5 is ultrasonically cleaned and dried, and a gold electrode is magnetron sputtered to obtain the type 1-3 piezoelectric ceramic composite material.

2. The method according to claim 1, characterized in that: The center of the secondary cutting slit is aligned with the center of the primary cutting slit filled with epoxy resin.

3. The method according to claim 1, characterized in that: The sum of the width of the ceramic column and the width of the first cut gap is the transverse periodic dimension of the composite material. The final thickness of the ceramic composite material after grinding in step 5 is comparable to the transverse periodic dimension, i.e., thickness / transverse period < 3.

4. The method for preparing a type 1-3 piezoelectric ceramic composite material according to claim 1, characterized in that: The aforementioned type 1-3 piezoelectric ceramic composite material consists of an array of ceramic pillars and polymers. An epoxy resin layer and a silicone layer are sequentially arranged around the ceramic pillars. The epoxy resin layer and the silicone layer form a soft and hard polymer. The soft and hard polymers are used to regulate the thickness vibration mode and the transverse vibration mode, thereby coupling the vibration modes and improving the electromechanical coupling coefficient. The epoxy resin accounts for 50% of the volume fraction of the polymer; The silica gel accounts for 50% of the volume fraction of the polymer.

5. The method for preparing a type 1-3 piezoelectric ceramic composite material according to claim 4, characterized in that, Includes the following steps: Step 1, One-time cutting: Use a dicing machine to cut the PZT-4 ceramic into pieces with a single-cut kerf width of 1.03mm and ceramic pillar width of 1.01*1.01mm. 2 The ceramic column array, with a transverse period of 2.04 mm, forms a ceramic skeleton. After cutting, it is ultrasonically cleaned, arranged, and dried. Step 2, one-time potting: First, mix the A phase resin and B phase curing agent of Epo-Tek 301 two-component epoxy resin evenly in a mass ratio of 4:1 to obtain epoxy resin colloid, and then vacuum to remove air bubbles; then pour the epoxy resin colloid into the ceramic column array prepared in Step 1 to fill the cut gaps; after vacuuming to remove air bubbles, cure at room temperature for 24 hours, grind the upper surface of the cured ceramic composite array, remove excess epoxy resin, and expose the ceramic columns; Step 3, secondary cutting: The ceramic epoxy resin composite material prepared in step 2 is cut a second time using a dicing machine. The width of the secondary cutting gap is 0.43 mm. The center of the secondary cutting blade is aligned with the center of the primary cutting gap filled with epoxy resin to form a composite material array of epoxy resin-encapsulated ceramic pillars; ultrasonic cleaning and drying. Step 4, Secondary potting: Pour silicone into the composite material array of epoxy resin-coated ceramic pillars prepared in Step 3, filling the secondary cutting gaps, forming a composite material array with epoxy resin layers and silicone layers sequentially wrapped around the ceramic pillars. After vacuuming to remove air bubbles, cure at room temperature for 24 hours; wherein epoxy resin and silicone each account for 50% and 50% of the polymer volume fraction, respectively. Step 5, Grinding: Grind the composite material array that is wrapped with epoxy resin layer and silicone layer in step 4. Grind away the excess silicone and ceramic substrate on the upper and lower surfaces to expose the ceramic column; the thickness after grinding is 2.8mm; the final thickness of the ceramic composite material after grinding is comparable to the transverse period dimension, that is, thickness / transverse period < 3. Step 6: The ceramic piezoelectric composite material obtained in Step 5 is ultrasonically cleaned and dried, and a gold electrode is magnetron sputtered to obtain the type 1-3 piezoelectric ceramic composite material.

6. A type 1-3 piezoelectric ceramic composite material prepared by the preparation method according to any one of claims 1-5, characterized in that, Used to manufacture underwater acoustic transducers.

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