Intelligent damping material prepared from piezoelectric ceramic complex and preparation method of intelligent damping material

Abstract

The invention discloses an intelligent damping material prepared from a piezoelectric ceramic complex and a preparation method of the intelligent damping material, and belongs to the technical field of vibration control materials. The material is of a three-layer composite structure including an elastic matrix layer, a piezoelectric ceramic composite layer and a restraint layer, wherein the piezoelectric ceramic composite layer is formed by compounding 30%-50% of piezoelectric ceramic particles, 5%-15% of conductive filler and 35%-65% of a polymer binder; the shore hardness of the elastic matrix layer is 30D-60D, and the elastic modulus of the restraint layer is 20GPa-80GPa. The preparation method comprises the key steps of piezoelectric ceramic particle silane coupling agent modification, composite slurry high-speed mixing, elastic matrix layer vulcanization molding, matrix surface plasma treatment, gradient hot-pressing composite curing and the like. Through interface modification and three-dimensional conductive network construction, the interface bonding strength and energy dissipation efficiency are greatly improved, the damping loss factor tan delta of the material is larger than or equal to 0.3 in the wide temperature range of-50 DEG C to 150 DEG C, the vibration attenuation rate of the material is larger than or equal to 40%, the material is suitable for vibration control of aerospace, rail transit and precision machinery, the preparation process is simple and convenient, and large-scale production is easy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of intelligent damping and vibration control materials, in particular to a multi-field coupling intelligent damping material based on piezoelectric ceramic composite material and a large-scale preparation method thereof. The material can be directly integrated in cabin structures of aerospace vehicles, bogie damping systems of high-speed rail vehicles and bed vibration isolation components of precision CNC machine tools, and is particularly suitable for vibration control requirements under the working conditions of a wide temperature range of-50℃ to 150℃ and high-frequency vibration (100Hz to 5000Hz). BACKGROUND

[0002] In the field of industrial equipment and high-end manufacturing, vibration is the core inducement of equipment precision attenuation and structural fatigue failure. For example, the high-frequency vibration generated during the operation of an aero-engine accessory case can cause the loosening of pipe joints; the vibration of a high-speed train bogie directly affects the ride comfort and the service life of the track. Traditional damping materials are mainly divided into two categories: one is passive damping material, such as nitrile rubber and asphalt-based composite material, which has a damping loss factor (tan δ) usually lower than 0.2 and a performance that decreases rapidly when the temperature exceeds 80℃, and cannot meet the requirements of wide temperature range working conditions; the other is traditional piezoelectric damping material, which has the ability of mechanical energy-electric energy conversion, but generally has three technical bottlenecks: first, poor dispersion of piezoelectric phase, such as directly mixing piezoelectric ceramic particles into the polymer matrix, which easily causes agglomeration, resulting in uneven electric field distribution in the material; second, low interfacial bonding strength, the thermal expansion coefficients of piezoelectric ceramics and polymers are quite different (about 10×10 -6 / ℃ for piezoelectric ceramics and about 100×10 -6 / ℃ for polymers), which easily causes interfacial peeling after cold and hot cycles; third, low energy dissipation efficiency, lack of efficient conductive network to convert the electric energy generated by piezoelectric conversion into heat energy dissipation, resulting in a vibration attenuation rate lower than 30%.

[0003] Existing technologies have failed to overcome the aforementioned bottlenecks in improving piezoelectric ceramic composite damping materials. For example, Chinese patent CN112321876A discloses a "multilayer piezoelectric damping composite material" using an alternating layer structure of PZT piezoelectric ceramic sheets and rubber. While this improves damping performance, the rigidity of the piezoelectric ceramic sheets results in insufficient material flexibility, making it unsuitable for curved surfaces. Chinese patent CN113861245B discloses a "method for preparing piezoelectric composite materials," which disperses piezoelectric particles via solvent evaporation. However, this method requires three steps: solvent dissolution, coating, and evaporation, resulting in a production cycle of over 8 hours, and solvent residue reduces the interfacial bonding strength. Chinese patent CN114574236A proposes using a coupling agent to modify piezoelectric particles, but the mechanism of action and optimal dosage of the coupling agent are not clearly defined, leading to significant fluctuations in modification effects in practical applications. Therefore, developing a smart damping material that combines uniform piezoelectric phase dispersion, strong interfacial bonding, and high preparation efficiency has become an urgent need in this field.

[0004] Therefore, developing a smart damping material with uniform piezoelectric phase dispersion, strong interfacial bonding, simple preparation process, and excellent damping performance has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] Addressing the core deficiencies of existing technologies, the core objective of this invention is to provide a smart damping material prepared using a piezoelectric ceramic composite and its preparation method. Specific objectives include: 1) solving the problem of piezoelectric ceramic particle agglomeration through chemical modification of a silane coupling agent and a high-speed shear mixing process, thereby improving particle dispersion uniformity in the matrix by over 60%; 2) increasing the interfacial peel strength to over 8 MPa through plasma treatment of the elastic matrix surface and gradient hot pressing, a 50% improvement compared to traditional processes; 3) constructing a three-dimensional conductive network through a conductive filler composite design, thereby improving energy dissipation efficiency by 40% and achieving a vibration attenuation rate of over 45%; 4) optimizing the preparation process, shortening the production cycle to less than 2 hours, and enabling large-scale production. This invention, through the synergistic effect of structural design and process innovation, ultimately achieves stable damping performance of the material within a wide temperature range of -50℃ to 150℃.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A smart damping material prepared using a piezoelectric ceramic composite and its preparation method are disclosed. The smart damping material of this invention adopts a sandwich-style three-layer composite structure of "elastic matrix layer - piezoelectric ceramic composite layer - constraint layer". Each layer achieves molecular-level bonding through an interface modification process to form a synergistic damping system. The structural design principle is as follows: Elastic matrix layer: As the initial receiver and carrier of vibration energy, the key reason for controlling its Shore hardness between 30D and 60D is that: below 30D, the material is too soft and cannot effectively transmit vibration to the piezoelectric composite layer; above 60D, the material is too rigid and its own deformation capacity is insufficient, limiting the piezoelectric effect. Nitrile rubber (excellent oil resistance), chloroprene rubber (outstanding weather resistance), or hydrogenated nitrile rubber (good high-temperature resistance) are preferred, with 1%-3% of nano-silica reinforcing agent dispersed internally—nano-silica with a particle size of 50nm-100nm can fill the gaps between rubber molecules, increasing the tensile strength of the matrix layer by 20%-30% without affecting its damping performance.

[0007] Piezoelectric ceramic composite layer: The core functional layer, whose component ratios were optimized through orthogonal experiments: piezoelectric ceramic particles 30%-50%—below 30%, piezoelectric conversion efficiency is insufficient; above 50%, particles are prone to agglomeration; conductive filler 5%-15%—below 5%, a continuous conductive network cannot be formed; above 15%, the material's flexibility is reduced; polymer binder 35%-65%—serves as a dispersion carrier, ensuring uniform distribution of each component. Its damping mechanism is a dual mechanism of "piezoelectric conversion-energy dissipation": when the material is subjected to vibration, the piezoelectric ceramic particles generate polarized charges due to the positive piezoelectric effect; the three-dimensional network constructed by the conductive filler rapidly transfers the charges and dissipates them through the Joule heating effect; simultaneously, the viscoelastic deformation of the polymer binder also dissipates some vibrational energy. The synergistic effect of these two mechanisms significantly improves damping performance.

[0008] Constraint Layer: Based on the "constraint damping principle," its elastic modulus is controlled between 20GPa and 80GPa. Below 20GPa, the rigidity is insufficient, failing to effectively constrain the lateral deformation of the piezoelectric composite layer; above 80GPa, the material is too heavy, unsuitable for lightweight applications. Aluminum alloy (density 2.7g / cm³) is selected. 3 Low cost), stainless steel (good corrosion resistance) or carbon fiber composite material (density 1.6g / cm³). 3 With high specific strength, the design with a thickness of 0.1mm-1mm balances rigidity requirements with lightweight goals. For example, carbon fiber composites are preferred in aerospace applications, while aluminum alloys are preferred in rail transportation applications.

[0009] The selection of key components must match functional requirements: 1) Piezoelectric ceramic particles: PZT piezoelectric ceramics (piezoelectric constant d33=300pC / N-500pC / N, suitable for medium and high frequency vibration), BaTiO3 piezoelectric ceramics (low cost, suitable for civilian applications) or PMN-PT piezoelectric ceramics (piezoelectric constant d33>1000pC / N, suitable for high precision control), particle size 5μm-50μm—particles that are too small (<5μm) are prone to agglomeration, while those that are too large (>50μm) will reduce the interfacial bonding strength; the mechanism of action of silane coupling agents (KH550, KH560, etc.) is that the functional groups at both ends of their molecules react with the hydroxyl groups (-OH) on the surface of the piezoelectric ceramics and the active groups of the polymer binder, respectively, to form chemical bridges. The addition amount is 0.5%-2% of the particle mass—the modification is insufficient when it is less than 0.5%, and agglomeration of the coupling agent will occur when it is more than 2%.

[0010] 2) Conductive filler: When graphene (sheet structure, excellent conductivity) and carbon nanotubes (one-dimensional structure, easy to form network) are combined, a mass ratio of 1:2-2:1 can realize a three-dimensional conductive network of "sheet-tube interweaving", which improves the conductivity efficiency by 30% compared with a single filler.

[0011] 3) Polymer binder: Bisphenol A type epoxy resin (epoxy value 0.48-0.54eq / 100g) is combined with amine curing agent (such as ethylenediamine, diethylenetriamine) at a mass ratio of 1:5-1:10. This ratio can ensure that the epoxy resin is fully cured and the degree of crosslinking reaches more than 85%, so that the temperature resistance and structural strength of the composite layer meet the requirements.

[0012] The preparation method of this intelligent damping material adopts a "segmented molding-interface strengthening" process route. The process parameters of each step have been optimized through multi-factor experiments. The core lies in solving two key problems: component dispersion and interfacial bonding. The specific process is as follows: Preparation of piezoelectric ceramic composite slurry: Pretreated piezoelectric ceramic particles, conductive fillers, and polymer binders are added to a high-speed mixer (model SHR-10A). The temperature is controlled at 80℃-120℃—this temperature range reduces the viscosity of the polymer binder, facilitating dispersion; the rotation speed is 500r / min-1500r / min—the low-speed (500r / min-800r / min) stage achieves initial mixing of components, while the high-speed (1200r / min-1500r / min) stage breaks up particle agglomerations through shear force; the mixing time is 20min-60min—adjusted according to the filler content. When the filler content is high, the mixing time is extended to 60min to ensure uniform dispersion of components. The dispersion uniformity is verified by scanning electron microscopy (SEM), and the particle agglomerate size must be less than 50μm. Elastic matrix layer molding: The elastic matrix raw materials (raw rubber, nano silica, vulcanizing agent, etc.) are mixed in proportion and then added to a flat vulcanizing machine (model XLB-D500×500). The temperature is controlled at 150℃-180℃—vulcanization is insufficient below 150℃, and rubber is prone to aging above 180℃; the pressure is 10MPa-20MPa—to ensure tight bonding of the raw materials and avoid internal pores; the vulcanization time is 10min-30min—adjusted according to the matrix thickness, 20min is sufficient for a 2mm thickness. After molding, the hardness is tested using a Shore hardness tester (model LX-D) to ensure it is within the range of 30D-60D. Composite Molding: First, a doctor blade coater is used to coat the composite slurry onto the surface of the pretreated elastic matrix layer, with a coating thickness of 0.2mm-1mm. Too thin a coating results in insufficient piezoelectric conversion area, while too thick a coating easily leads to cracking. Then, the constraint layer is manually bonded to ensure no air bubbles remain. The composite preform is placed in an autoclave (model GY-100), with the temperature controlled at 120℃-160℃—this temperature range promotes the curing of the polymer binder while preventing aging of the elastic matrix layer; the pressure is 5MPa-15MPa—ensuring tight bonding between layers and improving interfacial bonding strength; the temperature and pressure are maintained for 30min-90min—ensuring full cross-linking of the binder. Natural cooling is used during the cooling stage, with a cooling rate not exceeding 3℃ / min to avoid thermal stress within the material due to excessive temperature differences, ultimately yielding the finished product.

[0013] The present invention has the following beneficial effects: This invention achieves a significant improvement in damping performance and engineering application value through synergistic innovation in structure, composition, and process. The specific effects of the invention are reflected in the following four aspects: 1. Structural Innovation: The three-layer structure of "elastic matrix - piezoelectric composite - constraint layer" forms a complete chain of "vibration reception - energy conversion - energy dissipation", which improves the vibration attenuation rate by more than 50% compared with traditional single-layer piezoelectric composite materials; 2. Component optimization: Silane coupling agent modification solved the problem of piezoelectric particle agglomeration, and compound conductive filler constructed a highly efficient conductive network, enabling the material to maintain a tanδ of above 0.35 in a wide temperature range of -50℃ to 150℃, overcoming the defect of poor temperature stability of traditional materials; 3. Technological breakthrough: The "high-speed mixing-plasma modification-gradient hot pressing" process shortens the production cycle to less than 2 hours and increases the interfacial peel strength to 8MPa-10MPa, solving the problems of low preparation efficiency and weak interfacial bonding in existing technologies. 4. Application Expansion: The oil-resistant material and the lightweight high-temperature resistant material are respectively adapted to the specific needs of the rail transportation and aerospace fields. Compared with existing commercial damping materials (such as 3M Scotch-Weld™ damping adhesive), the vibration attenuation rate of this invention is increased by 40% and the cost is reduced by 30% at the same thickness. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the intelligent damping material structure of the present invention.

[0015] Figure 2 This is a flowchart of the preparation method of the present invention. Detailed Implementation

[0016] The present invention will be further described in detail below with reference to two parallel embodiments. Embodiment 1 addresses the oil resistance requirements in the rail transit field, while Embodiment 2 addresses the lightweight and high-temperature resistance requirements in the aerospace field. The specific parameters of the raw materials used in each embodiment are as follows: PZT piezoelectric ceramic particles (model PZT-5H, particle size 20μm, piezoelectric constant d33=450pC / N); PMN-PT piezoelectric ceramic particles (model PMN-PT-32, particle size 10μm, piezoelectric constant d33=1200pC / N); graphene (3-5 layers, sheet diameter 1μm-5μm, resistivity 1×10⁻⁶). -6 Ω·m); carbon nanotubes (diameter 5nm-10nm, length 1μm-5μm, resistivity 5×10 Ω·m); -5 Ω·m); Bisphenol A type epoxy resin (model E-51, epoxy value 0.48-0.54eq / 100g); Amine curing agent (model T31, active hydrogen equivalent 45g / eq); Polyurethane (model PU-100, Shore hardness 50D, glass transition temperature -40℃); Acrylonitrile rubber (model N41, acrylonitrile content 31%); Hydrogenated nitrile rubber (model HNBR-40, saturation 98%, high temperature resistance 150℃); Nano silica (model A200, particle size 12nm, specific surface area 200m²). 2 / g); Silane coupling agent KH550 (molecular formula C8H) 19 NO3Si); ​​silane coupling agent KH560 (molecular formula C9H) 20 O5Si). The scope of protection of this invention is not limited to the following embodiments; all equivalent modifications based on the technical solution of this invention are within the scope of protection.

[0017] Example 1: Material composition (by mass percentage) This embodiment provides a smart damping material prepared using a piezoelectric ceramic composite and its preparation method: Piezoelectric ceramic composite layer: 40% PZT piezoelectric ceramic particles (particle size 20μm), 5% graphene (3-5 layers), 55% bisphenol A type epoxy resin (model E-51), amine curing agent (model T31, mass ratio of epoxy resin 1:8). Under this ratio, the piezoelectric constant d33 of the composite layer reaches 180pC / N, while the tensile strength is ≥5MPa. Elastic matrix layer: 98% nitrile rubber (model N41) and 2% nano silica (model A200). After molding, the Shore hardness is 45D, the tensile strength is ≥8MPa, and the elongation at break is ≥300%, which meets the oil resistance and mechanical requirements of the rail transit field. Constraint layer: 6061 aluminum alloy (thickness 0.5mm, elastic modulus 70GPa, density 2.7g / cm³) 3 It has low cost and good processing performance, making it suitable for large-scale applications.

[0018] The preparation steps are as follows: Pretreatment of piezoelectric ceramic particles: PZT particles were placed in anhydrous ethanol (99.7% purity) and ultrasonically cleaned for 30 minutes using an ultrasonic cleaner (200W power, 40kHz frequency) to remove surface oil and impurities. They were then placed in a vacuum drying oven (model DZF-6050) and dried at 80℃ for 2 hours to remove surface moisture. The dried particles were then added to a 3% (w / w) KH550 silane coupling agent ethanol dilution (95% ethanol purity) and reacted for 1.5 hours at 70℃ and 300 rpm in a constant temperature stirrer. KH550 molecules reacted with the hydroxyl groups on the PZT surface and the epoxy resin through their two end functional groups, forming chemical bridges. After the reaction, the particles were filtered, and then dried in a 100℃ vacuum drying oven for 1 hour. The silane coupling agent addition was 1% of the particle mass. This dosage, as verified by experiments, improved the dispersion uniformity of the particles in the epoxy resin by 60%. Preparation of composite slurry: Pretreated PZT particles, graphene, and epoxy resin (model E-51) were added to a high-speed mixer (model SHR-10A). The temperature was set at 100℃ and the rotation speed at 1000 r / min, and the mixture was mixed for 40 min. The high-speed shear force broke up the particle agglomeration. Then, an amine curing agent (model T31) was added, and the mixture was mixed for another 10 min to ensure that the curing agent was evenly dispersed, resulting in a composite slurry with no agglomeration and good flowability (viscosity 5000 mPa·s-8000 mPa·s). Elastic matrix layer molding: Nitrile rubber (model N41), nano silica (model A200) and vulcanizing agent (sulfur, added at 1.5% of the rubber mass) were mixed in proportion and then added to a flat vulcanizing machine (model XLB-D500×500). The temperature was set at 160℃ and the pressure at 15MPa, and vulcanization was carried out for 20 minutes. The vulcanization curve test showed that the degree of crosslinking of the rubber reached 85% under these conditions. After vulcanization, the mixture was taken out and cooled to room temperature to obtain an elastic matrix layer with a thickness of 3mm. The Shore hardness test showed that it was 45D. Elastic substrate surface treatment: The surface of the elastic substrate layer was roughened by sanding with sandpaper (800# grit) to remove the surface oxide layer. After roughening, the surface roughness was tested using a surface roughness tester (model TR200), and the surface roughness Ra=1μm. This roughness can increase the contact area with the composite slurry. Subsequently, the substrate layer was placed in a plasma treatment machine (model PT-300) with a power of 200W and an argon flow rate of 10L / min for 10 minutes. The plasma bombardment caused active groups such as hydroxyl and carboxyl groups to be generated on the substrate surface, which improved the interfacial bonding energy by 40%. Composite molding: A doctor blade coater (model XB-1200) is used to coat the composite slurry onto the surface of the treated elastic substrate layer. The coating thickness is 0.5 mm, and the coating speed is 50 mm / s to ensure a uniform coating without bubbles. Then, the 6061 aluminum alloy constraint layer is manually attached, and a rubber roller is used to roll and remove interface bubbles. The composite preform is placed in an autoclave (model GY-100), and the heating rate is set to 3℃ / min. The temperature is raised to 140℃, the pressure is 10 MPa, and the temperature and pressure are maintained for 60 min. Under these conditions, the epoxy resin is fully cured, and the crosslinking degree reaches 88%. After the heat preservation is completed, the heating device is turned off, and the material is allowed to cool naturally to room temperature (cooling rate 2℃ / min) to avoid thermal stress. Finally, a smart damping material with dimensions of 200 mm × 100 mm × 3.5 mm is obtained.

[0019] Performance testing: The product of Example 1 was tested for performance according to the following criteria: 1) Damping loss factor tanδ: The dynamic mechanical analyzer (DMA, model TA Q800) was used. The test temperature was -50℃ to 150℃, the frequency was 1Hz, and the strain was 0.1%. The results showed that tanδ was 0.35-0.42, and the maximum value of 0.42 was reached at 25℃. 2) Vibration attenuation rate: Using a vibration testing system (model B&K 4808), the test frequency was 100Hz-5000Hz, and the excitation force was 10N. The results showed that the vibration attenuation rate was 45%, which is 125% higher than that of traditional nitrile rubber damping materials (attenuation rate of 20%). 3) Interfacial peel strength: Tested using a universal testing machine (Instron 5969) according to GB / T 2790-1995 standard, the result was 8 MPa, which is 60% higher than that of the unmodified material (5 MPa); 4) Thermal cycling performance: After 500 cycles of thermal cycling (-50℃ for 2 hours → 150℃ for 2 hours, heating / cooling rate 5℃ / min) in a high and low temperature test chamber (model GDW-100), the tanδ value was 0.33-0.40 after cycling, the performance retention rate was 92%, and there was no interface peeling phenomenon. 5) Oil resistance: When the material is immersed in No. 10 aviation hydraulic oil at 25°C for 72 hours, the volume change rate is ≤5%, which meets the requirements of the hydraulic system of rail transit.

[0020] Example 2, Material Composition (by mass percentage) This embodiment provides a smart damping material prepared using a piezoelectric ceramic composite and its preparation method: Piezoelectric ceramic composite layer: 35% PMN-PT piezoelectric ceramic particles (particle size 10μm, piezoelectric constant d33=1200pC / N), 10% graphene / carbon nanotube composite conductive filler (mass ratio 1:1, number of graphene layers 3-5, carbon nanotube diameter 5nm-10nm), and 55% polyurethane (model PU-100). Under this ratio, the piezoelectric constant d33 of the composite layer reaches 350pC / N, while exhibiting excellent high-temperature resistance. Elastic matrix layer: 97% hydrogenated nitrile rubber (model HNBR-40), 3% nano silica (model A200), Shore hardness 55D after molding, tensile strength ≥12MPa, elongation at break ≥250%, high temperature resistance 150℃, meeting the environmental requirements of the aerospace field. Constraint layer: Carbon fiber composite material (T300 carbon fiber / epoxy resin matrix, thickness 0.3 mm, elastic modulus 65 GPa, density 1.6 g / cm³) 3 It has high strength and can achieve lightweight design.

[0021] The specific preparation steps are as follows: Pretreatment of piezoelectric ceramic particles: PMN-PT particles were placed in anhydrous ethanol (99.7% purity) and ultrasonically cleaned for 25 minutes using an ultrasonic cleaner (200W power, 40kHz frequency) to remove surface impurities; then placed in a vacuum drying oven and dried at 80℃ for 2 hours; the dried particles were added to a 2% (w / w) KH560 silane coupling agent ethanol dilution (95% ethanol purity) and stirred at 65℃ and 300r / min for 2 hours. The epoxy groups of KH560 can react with the hydroxyl groups of polyurethane to improve the interfacial bonding force; after the reaction, the particles were filtered and vacuum dried at 100℃ for 1 hour for later use. The amount of silane coupling agent added was 1.5% of the particle mass, which can achieve the best dispersion uniformity of the particles in polyurethane. Composite slurry preparation: Pretreated PMN-PT particles, composite conductive filler (graphene / carbon nanotubes 1:1), and polyurethane (model PU-100) were added to a high-speed mixer. The temperature was set at 90℃ and the rotation speed at 1200 r / min. The mixture was mixed for 30 min. The high-speed shear force caused the conductive filler to form a three-dimensional network, resulting in a composite slurry with no agglomeration and a viscosity of 6000 mPa·s-9000 mPa·s. Elastic matrix layer molding: Hydrogenated nitrile butadiene rubber (model HNBR-40), nano silica (model A200) and vulcanizing agent (diisopropylbenzene peroxide, added at 2% of the rubber mass) are mixed and added to a flat vulcanizing machine. The temperature is set at 170℃ and the pressure at 12MPa, and vulcanization is carried out for 25 minutes. Under these conditions, the crosslinking degree of hydrogenated nitrile butadiene rubber reaches 90%. After vulcanization, the mixture is cooled to room temperature to obtain an elastic matrix layer with a thickness of 2mm and a Shore hardness of 55D. Elastic substrate surface treatment: The surface of the elastic substrate layer was roughened by sanding with sandpaper (1000# grit), and the surface roughness tester showed Ra=1.5μm; then it was placed in a plasma treatment machine with a power of 150W and a nitrogen flow rate of 8L / min for 15min. The nitrogen plasma can introduce amino groups into the substrate surface, which can enhance the chemical bonding with polyurethane. Composite molding: A composite slurry is applied using a doctor blade coater to a thickness of 0.8 mm at a coating speed of 40 mm / s; a carbon fiber composite constraint layer is then bonded, and a rubber roller is used to remove bubbles; the composite preform is placed in an autoclave, heated at a rate of 4℃ / min to 130℃, and held at a pressure of 8 MPa for 80 min to allow the polyurethane to fully cure; it is then allowed to cool naturally to room temperature (cooling rate 1.5℃ / min) to obtain a smart damping material with dimensions of 200 mm × 100 mm × 2.8 mm and an overall density of 1.8 g / cm³. 3 Compared to the material in Example 1 (density 2.3 g / cm³), 3 Lightweight by 21.7%.

[0022] Performance testing: The product of Example 2 was tested for performance using the same standards as in Example 1, and the results are as follows: 1) Damping loss factor tanδ: DMA test showed it to be 0.38-0.45, reaching a maximum value of 0.45 at 50℃, and its wide temperature range stability was better than that of Example 1; 2) Vibration attenuation rate: The vibration test system measured 48%, which is 6.7% higher than that of Example 1. This is mainly due to the higher piezoelectric conversion efficiency of PMN-PT piezoelectric ceramic. 3) Interface peel strength: The universal testing machine test result was 10 MPa, which is 25% higher than that of Example 1. This is attributed to the excellent reactivity of KH560 coupling agent with polyurethane. 4) Thermal cycling performance: After 500 thermal cycles, tanδ is 0.36-0.43, performance retention rate is 92%, and there is no structural damage; 5) High temperature resistance: After being kept at 150℃ for 1000h, the tanδ test result is 0.37-0.44, and the performance retention rate is 95%, which is far superior to the material in Example 1 (performance retention rate of 85% after being kept at 150℃ for 1000h). 6) Lightweight performance: density 1.8g / cm³ 3 It meets the lightweight requirements of the aerospace industry and can be used in the shock absorption structure of helicopter cabins.

[0023] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art can make conventional adjustments within the scope of the technical solution of the present invention, specifically including: 1) Component adjustment: Piezoelectric ceramic particles can be replaced with ZnO piezoelectric ceramics, LiNbO3 piezoelectric ceramics, etc., conductive fillers can be replaced with flake silver powder (suitable for high conductivity requirements) and conductive carbon black (suitable for low cost requirements), and polymer binders can be replaced with polyimide (suitable for ultra-high temperature requirements). 2) Adjustment of process parameters: The mixing temperature can be adjusted according to the viscosity of the adhesive (e.g., polyimide adhesive needs to be increased to 150℃), and the hot pressing pressure can be adjusted according to the material thickness (it can be increased to 20MPa when the thickness is greater than 5mm). 3) Structural adjustment: A metal mesh conductive layer can be added to the piezoelectric ceramic composite layer to further improve the energy dissipation efficiency.

[0024] As long as it does not deviate from the core damping mechanism of "piezoelectric conversion-energy dissipation" and the structural concept of "three-layer composite" of this invention, it falls within the protection scope of this invention.

[0025] Finally, the following points should be noted: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection", and "linkage" should be interpreted broadly, and can be mechanical or electrical connections, or internal connections between two components, or direct connections. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change. Secondly: The accompanying drawings of the embodiments disclosed in this invention only involve the structures that are relevant to the implementation of this disclosure. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this invention can be combined with each other. In conclusion, the above description is merely an embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A smart damping material prepared by using a piezoelectric ceramic composite, characterized in that, The smart damping material comprises, from inside to outside, an elastic matrix layer, a piezoelectric ceramic composite layer and a constraint layer; the piezoelectric ceramic composite layer is composed of piezoelectric ceramic particles, conductive fillers and a polymer binder, and the components are 30%-50% of piezoelectric ceramic particles, 5%-15% of conductive fillers and 35%-65% of the polymer binder in terms of mass percentage; the Shore hardness of the elastic matrix layer is 30D-60D, and the elastic modulus of the constraint layer is 20GPa-80GPa.

2. The smart damping material prepared by piezoelectric ceramic composite according to claim 1, characterized in that, The piezoelectric ceramic particles are one or more of PZT piezoelectric ceramic, BaTiO3 piezoelectric ceramic or PMN-PT piezoelectric ceramic, the particle size is 5μm-50μm, and the particles are subjected to surface modification treatment with a silane coupling agent, and the addition amount of the silane coupling agent is 0.5%-2% of the mass of the piezoelectric ceramic particles.

3. The smart damping material prepared by piezoelectric ceramic composite according to claim 1, characterized in that, The conductive fillers are one or more of graphene, carbon nanotubes, flaky silver powder or conductive carbon black; when graphene and carbon nanotubes are used in combination, the mass ratio of the two is 1:2-2:

1.

4. The smart damping material prepared by piezoelectric ceramic composite according to claim 1, characterized in that, The polymer binder is one or more of epoxy resin, polyurethane, polyimide or acrylate, wherein the epoxy resin is bisphenol A type epoxy resin, and is used in combination with an amine curing agent, and the mass ratio of the curing agent to the epoxy resin is 1:5-1:

10.

5. The smart damping material prepared by piezoelectric ceramic composite according to claim 1, characterized in that, The elastic matrix layer is made of nitrile rubber, chlorobutyl rubber or hydrogenated nitrile rubber, and uniformly dispersed inside are nano-silicon dioxide reinforcing agents with a mass fraction of 1%-3%; the constraint layer is an aluminum alloy, stainless steel or carbon fiber composite material, and has a thickness of 0.1mm-1mm.

6. The smart damping material prepared by piezoelectric ceramic composite according to claim 1, characterized in that, The method comprises the following steps: Step 1: preparing a piezoelectric ceramic composite slurry, adding piezoelectric ceramic particles, conductive fillers and a polymer binder into a high-speed mixer, mixing at 80℃-120℃ and a rotation speed of 500r / min-1500r / min for 20min-60min to obtain a uniform slurry; Step 2: forming an elastic matrix layer, adding elastic matrix raw materials into a vulcanizing machine, vulcanizing at 150℃-180℃ and a pressure of 10MPa-20MPa for 10min-30min to obtain the elastic matrix layer; Step 3: composite forming, coating the slurry obtained in Step 1 on the surface of the elastic matrix layer, the coating thickness being 0.2mm-1mm, and then adhering the constraint layer to the surface of the slurry, placing the constraint layer into a hot press tank, and heat pressing at 120℃-160℃ and a pressure of 5MPa-15MPa for 30min-90min, and then cooling to room temperature to obtain the smart damping material.

7. The smart damping material prepared by piezoelectric ceramic composite according to claim 6, characterized in that, The piezoelectric ceramic particles in Step 1 need to be pretreated before use: placing the piezoelectric ceramic particles into an ethanol solution, ultrasonic cleaning for 20min-40min, drying, adding an ethanol dilution of a silane coupling agent, stirring and reacting at 60℃-80℃ for 1h-2h, filtering and drying, and then being ready for use, and the mass concentration of the ethanol dilution of the silane coupling agent is 1%-5%.

8. The smart damping material prepared by piezoelectric ceramic composite according to claim 6, characterized in that, Before coating the slurry in step 3, the surface of the elastic matrix layer needs to be polished and roughened, and the roughness Ra of the roughened surface is 0.5-2 microns, and then plasma treatment is performed for 5-15 minutes, and the plasma treatment power is 100-300 W.

9. The smart damping material prepared by piezoelectric ceramic composite according to claim 6, characterized in that, The heating rate of the autoclave in step 3 is 2-5℃ / min, and after the holding is completed, the natural cooling method is used, and the cooling rate is not more than 3℃ / min, so as to avoid stress in the material.

10. The smart damping material prepared by piezoelectric ceramic composite according to claim 1, characterized in that, The intelligent damping material is used for vibration control components of aerospace equipment, rail transit vehicles or precision machinery, and the damping loss factor tan delta is greater than or equal to 0.3 and the vibration attenuation rate is greater than or equal to 40% in the temperature range of-50-150℃.

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