A preparation method for a multifunctional vibration-damping shell lattice structure

Abstract

This invention discloses a method for fabricating a multifunctional vibration-damping shell lattice structure, belonging to the field of shipbuilding and submarine technology. This invention biomimetically designs a bull horn structure and applies it to submarine hull protection. Drawing inspiration from the macro- and micro-scale characteristics of yak horns commonly found in nature, three bull horn lattice structures were established, combining the porous cavity characteristics of the horn core with the corrugated structure at the cross-section of the bull horn sheath. These three bull horn lattice structures were then constructed into a biomimetic bull horn gradient structure with a honeycomb-like negative gradient change. Compared to traditional lattice structures, this structure exhibits superior mechanical load-bearing performance and a more stable deformation mode upon impact. The TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic bull horn structure, prepared using pressureless infiltration technology, not only significantly improves the energy dispersion area of ​​the shell at the point of impact, but its built-in aluminum foam material also provides excellent sound insulation and noise reduction.

Description

Technical Field

[0001] This invention belongs to the field of ship and submersible technology, and more specifically, relates to a method for preparing a multifunctional vibration-damping shell lattice structure. Background Technology

[0002] Existing submarine hulls still have significant shortcomings in acoustic stealth and vibration and noise reduction, severely restricting the submarine's stealth operations and service endurance. Traditional steel hulls have limited effectiveness in suppressing mechanical vibrations and propeller noise. Structural sound waves generated by internal equipment operation can easily radiate into the water through the hull, forming obvious acoustic signatures. Simultaneously, existing hull materials have insufficient absorption and scattering properties for active sonar waves, making it easier for enemy detection systems to pinpoint the submarine's location. Furthermore, it is difficult to balance pressure resistance and lightweight design with traditional hulls; at high diving depths, hull thickness often needs to be increased, which exacerbates weight and hydrodynamic noise. Therefore, there is an urgent need to develop a new submarine hull structure that, while ensuring mechanical strength, significantly improves acoustic stealth performance, reduces vibration transmission efficiency, and optimizes hydrodynamic noise characteristics, effectively enhancing the submarine's battlefield survivability and tactical stealth.

[0003] TC4 titanium alloy belongs to the α+β type titanium alloy, which combines the advantages of α phase (stable and resistant to high temperature) and β phase (high strength and heat-treatable). TC4 has a density of only 4.43 g / cm³ (about 60% of that of steel), but its tensile strength can reach 900-1100 MPa. Its specific strength (strength / density ratio) far exceeds that of steel and aluminum alloys. At the same time, its corrosion resistance is excellent. It hardly corrodes in seawater and acid and alkaline environments, so it is one of the ideal materials for manufacturing submarine hulls.

[0004] In recent years, due to the demand for lightweighting, additive manufacturing TC4 lattice structures have been widely used in the field of submarine protection. However, traditional additive manufacturing TC4 lattice structures, such as pyramid and BCC types, mostly have defects and shortcomings. After being subjected to periodic fluid pressure or explosive shock waves, the energy absorption efficiency of these traditional lattice structures will decrease significantly, and their blast resistance performance is even inferior to that of traditional stiffened plate structures.

[0005] Meanwhile, the cavity structure of the TC4 lattice is insufficient in absorbing low-frequency (<500Hz) mechanical vibrations and sonar waves, and the shell radiated noise can still reach over 90dB, making it easily detectable by modern passive sonar (such as towed array sonar). Aluminum foam itself is lightweight and high-strength, and its porous structure can effectively absorb mid-to-high frequency sound waves. Furthermore, closed-cell aluminum foam can achieve a shielding effectiveness of over 75dB against high-frequency electromagnetic waves (0.015kHz–1.5GHz). However, although the porous structure of aluminum foam can absorb impact energy, it is prone to plastic deformation under high loads, leading to structural failure. In addition, due to the nature of its porous structure, aluminum foam is prone to fracture under shear forces, limiting its application in load-bearing structures.

[0006] If the mechanical properties of the TC4 lattice structure and the filtering and noise reduction capabilities of aluminum foam can be combined, the performance advantages of the two materials can be combined to make up for the shortcomings of a single material, and a submarine hull lattice structure that can efficiently reduce vibration and effectively filter noise can be designed, which can greatly improve the safety of the submarine during its service. Summary of the Invention

[0007] To address the aforementioned problems in the existing technology, the present invention aims to provide a method for preparing a multifunctional vibration-damping shell lattice structure.

[0008] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0009] A method for fabricating a multifunctional vibration-damping shell lattice structure includes the following steps:

[0010] Step 1: Based on 3D modeling software, the biomimetic bull horn gradient structure is established. The biomimetic bull horn gradient structure includes three different bull horn lattice structures obtained from the cross-section of the bull horn core. Then, a composite surface structure composed of the three different bull horn lattice structures is established. Subsequently, the wall thickness of the surface layer composed of each cavity structure is adjusted in a gradient manner to finally obtain the biomimetic bull horn gradient structure.

[0011] Step 2: Import the biomimetic bull horn gradient structure designed in Step 1 into Magics software, and print TC4 titanium alloy powder into a biomimetic bull horn gradient structure based on selective laser melting technology.

[0012] Step 3: The biomimetic horn gradient structure of TC4 material is prepared into a TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic horn heterostructure using a pressureless impregnation method.

[0013] Step four involves applying two multifunctional composite coatings to the TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic bull horn heterostructure obtained in step three using electrochemical deposition and dip-coating techniques.

[0014] Preferably, the three types of bullhorn lattice structures in step one have the same cross-sectional dimensions and aspect ratios.

[0015] Preferably, in the composite surface structure of step one, each of the horn lattice structures is coupled and spliced ​​to form a single-layer surface structure, and the surface structure composed of multiple cavity structures is coupled and spliced ​​to form a multi-layer composite structure.

[0016] Preferably, the three types of horn-shaped lattice structures in step one are all implemented by equation-driven curve commands, surface scanning commands, and solid thickening commands. The equations used in the equation-driven curve commands include the involute equation, the Archimedes spiral equation, and the cycloid equation.

[0017] Preferably, the construction method of one of the three horn-shaped lattice structures is as follows:

[0018] Using the previous reference plane as the reference, the involute parametric equation is used as the sketch outline: X: m*(cos(t)+t*sin(t)), Y: m*(sin(t)-t*cos(t)), where t ranges from 0 to 3 / 2 Pi, where m is a constant and t is a variable. At the same time, a vertical line segment of length n is drawn on the right reference plane as a path sketch.

[0019] The surface scanning operation is performed, the contour orientation changes with the path, the contour twisting method is selected with a specified twist angle, the twisting control is controlled by the number of turns, the beginning and end points of the scanned surface are marked as A and B respectively, and then the scanned surface is thickened.

[0020] Perform linear array solid operation along the AB direction, and then perform mirror solid operation on the arrayed structure with the front reference plane as the reference to obtain the bull horn lattice structure unit.

[0021] Finally, the individual units of the bull horn lattice structure are arrayed along the x, y, and z axes to obtain the bull horn lattice structure.

[0022] Preferably, the construction method of one of the three horn-shaped lattice structures is as follows:

[0023] Using the previous reference plane as the reference, the gradient line parameterization equation is used as the sketch outline X:o*t*cos(t), Y:o*t*sin(t), where t ranges from 0 to 2Pi, o is a constant and t is a variable. At the same time, a vertical line segment of length n is drawn on the right reference plane as the path sketch.

[0024] The surface scanning operation is performed while keeping the normal of the contour orientation unchanged. The contour twisting method is selected with a specified twist value, and the twisting control is carried out using degree control. The first and last endpoints of the scanned surface are marked as C and D, respectively. Then, the scanned surface is thickened.

[0025] Establish a reference axis with point C and the top view reference plane as references, then perform a circular array along the reference axis, then establish a reference plane with point D and the right view reference plane as references, and perform a mirror solid operation with the reference plane as references to obtain the horn lattice structure unit.

[0026] Finally, the individual units of the bull horn lattice structure are arrayed along the x, y, and z axes to obtain the bull horn lattice structure.

[0027] Preferably, the construction method of one of the three horn-shaped lattice structures is as follows:

[0028] Using the previous reference plane as the reference, the gradient line parameterization equation is used as the sketch outline X: p*(t - sin(t)), Y: p*(1 - cos(t)), where the range of t is Pi / 3-Pi, where p is a constant and t is a variable. At the same time, a vertical line segment of length n is drawn on the right reference plane as the path sketch.

[0029] Then, a surface scanning operation is performed. The contour orientation changes with the path. The contour twisting method is selected with a specified twist value. The twisting control is done with radian control. The first and last endpoints of the scanned surface are marked as E and F, respectively. Then, the scanned surface is thickened.

[0030] A reference axis is established based on point F and the front reference plane, and a circular array solid command is performed. Then, a mirror solid command is performed based on the front reference plane to obtain the horn lattice structure unit.

[0031] Finally, the individual units of the bull horn lattice structure are arrayed along the x, y, and z axes to obtain the bull horn lattice structure.

[0032] Preferably, the specific implementation steps of the pressureless impregnation method in step three are as follows:

[0033] The aluminum foam board is placed on the biomimetic bull horn gradient structure prepared in step two, and heated to 900℃ at 5℃ / min in an argon atmosphere. After reaching the temperature, it is held for 1 hour and then cooled with the furnace. At this time, the aluminum foam material is allowed to deposit into the biomimetic bull horn gradient structure under its own gravity, so that it can be fully impregnated.

[0034] Preferably, the specific method for adding two additional multifunctional composite coatings in step four is as follows:

[0035] First, an electrochemical deposition method is used to deposit a corrosion-resistant zinc-nickel alloy coating;

[0036] Electrochemical deposition employs a three-electrode system, in which a TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic bull horn heterostructure is used as the working electrode, a platinum sheet is used as the counter electrode, and a saturated calomel electrode is used as the reference electrode. The selected deposition solution consists of sodium citrate, citric acid, nickel sulfate, zinc sulfate, and deionized water.

[0037] The electrodeposition process was carried out in constant potential mode, with a deposition potential of -1.1 to -1.25 V, a deposition time of 10 to 30 min, and a solution temperature of 25 ℃.

[0038] Subsequently, the electromagnetic shielding coating was prepared on the outside of the zinc-nickel alloy coating by dip-coating.

[0039] The TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic bull horn heterostructure coated with zinc-nickel alloy was immersed in Mxene solution at a speed of 10 mm / min. After the TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic bull horn heterostructure was completely submerged in Mxene solution, it was pulled out at the same speed. This process was repeated 5-10 times. Then the TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic bull horn heterostructure was removed and the electromagnetic shielding coating was allowed to solidify.

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0041] This invention applies a biomimetic design of the horn structure to the field of submarine hull protection. Drawing on the macro- and micro-scale features of yak horns commonly found in nature, three horn lattice structures were established that combine the porous cavity features of the horn core with the corrugated structure at the cross-section of the horn sheath. Furthermore, these three horn lattice structures were constructed into a biomimetic horn gradient structure with a honeycomb-like negative gradient change. Compared with traditional lattice structures, this structure exhibits superior mechanical load-bearing performance and a more stable deformation mode when subjected to impact damage.

[0042] The TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic bull horn heterostructure prepared by pressureless infiltration further improves the mechanical properties and deformation modes of the gradient biomimetic bull horn lattice structure. Simultaneously, the interpenetrating phase material significantly increases the impact area, mitigating stress concentration during explosions and further enhancing the submarine's operational stability. Furthermore, the introduction of aluminum foam effectively addresses the insufficient sound absorption and noise reduction capabilities of the TC4 titanium alloy lattice structure, preventing sonar detection of the submarine and further improving its stealth performance.

[0043] The combined process of electrochemical deposition and dip-coating offers advantages such as precise thickness control, strong adhesion, functional gradation, and low cost, making it particularly suitable for the multifunctional coating requirements of submarine lattice structures. By employing electrochemical deposition and dip-coating to deposit a multifunctional chemical coating on the periphery of the lattice structure, the electromagnetic shielding capability and corrosion resistance of the hull structure are further enhanced. This prevents excessive electromagnetic waves from disrupting the normal operation of high-precision instruments inside the hull, significantly improving the safety of the submarine hull during operation. Attached Figure Description

[0044] Figure 1 A schematic diagram illustrating the sampling of yak horns in nature and the electronic characterization of the horn sheath and core.

[0045] Figure 2 Schematic diagrams of three types of horn lattice structures and a biomimetic horn gradient structure designed based on the macro- and micro-features of yak horn.

[0046] Figure 3 A schematic diagram of the biomimetic J-shaped horn-shaped corrugated structure BJHWPS designed for this invention;

[0047] Figure 4 A schematic diagram of the biomimetic A-type horn-shaped corrugated structure BAHWPS designed for this invention;

[0048] Figure 5 A schematic diagram of the biomimetic B-type horn-shaped corrugated structure BBHWPS designed for this invention;

[0049] Figure 6 A schematic diagram of the biomimetic bull horn gradient structure BHGS;

[0050] Figure 7 To prepare a biomimetic bull horn heterostructure of TC4 titanium alloy-aluminum foam interpenetrating phase based on pressureless infiltration method;

[0051] Figure 8 To prepare a multi-layered TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic horn heterostructure with a multifunctional coating by electrodeposition and dip-coating methods.

[0052] Figure 9 This is a schematic diagram illustrating the working principle of a multi-level TC4 titanium alloy-aluminum foam interpenetrating biomimetic heterostructure.

[0053] In the figure: 11, biomimetic J-shaped bull horn corrugated structure; 110, biomimetic J-shaped bull horn corrugated structure unit; 12, biomimetic A-shaped bull horn corrugated structure; 120, biomimetic A-shaped bull horn corrugated structure unit; 13, biomimetic B-shaped bull horn corrugated structure; 130, biomimetic B-shaped bull horn corrugated structure unit; 2, biomimetic bull horn gradient structure; 3, TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic bull horn heterostructure; 4, multi-level TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic heterostructure. Detailed Implementation

[0054] The present invention will be further described below with reference to specific embodiments.

[0055] This design is based on the microstructure of yak horns found in nature. Yak horns possess excellent resistance to impact deformation, and their unique structure and material properties enable them to maintain stability under severe collisions or stress. Figure 1 As shown, yak horn has a typical cave-like structure, consisting of an outer keratinous sheath (horn sheath) and an inner horn core (bone core). The longitudinal SEM characterization of the polished horn sheath is shown below. Figure 1 As shown on the left, its surface is grayish-black, and its microstructure exhibits a unique wavy, layered structure.

[0056] These wavy, layered structures have the following typical characteristics: low peak values, smooth peak shapes, and separation between waves. The wavy, cracked, layered structure of the horn-shaped sheath effectively resists impact and absorbs energy through mechanisms such as crack deflection, interlaminar slip, and shear band formation. Meanwhile, as... Figure 1 As shown on the right, the core material observed along the horn axis exhibits a loose, porous morphology with a disordered arrangement. As a lightweight porous material, the core material's low density and large specific area enhance the impact mechanical properties of the horn. Furthermore, the macroscopic gradient morphology of the yak horn is reflected in the gradual changes in its structure, composition, and mechanical properties from the base to the tip. This multi-scale gradient design also gives it excellent comprehensive mechanical properties.

[0057] First, the microstructure of yak horn in nature was observed using a micro-electron microscope. The observed microstructure of yak horn included the cavity structure features observed in the cross-section of the horn core and the wavy structure features observed in the longitudinal part of the horn sheath.

[0058] like Figure 2As shown, structural design was carried out based on the key features of the yak horn microstructure. Three horn lattice structures were extracted from the yak horn microstructure, including a biomimetic J-shaped horn wave pattern structure 11 (abbreviated as BJHWPS), a biomimetic A-shaped horn wave pattern structure 12 (abbreviated as BAHWPS), and a biomimetic B-shaped horn wave pattern structure 13 (abbreviated as BBHWPS). The three horn lattice structures all exhibit different wave characteristics and cavity structures. At the same time, based on the macro-gradient strategy of horn, the three horn lattice structures were constructed into a honeycomb-shaped negative gradient overall structure, establishing a biomimetic horn gradient structure 2 (abbreviated as BHGS). BHGS exhibits a negative gradient strategy, that is, the wall thickness increases sequentially from top to bottom. The shell structure constructed using this negative gradient strategy can further improve the vibration reduction performance of the shell structure.

[0059] The overall impact resistance of yak horn relies on the synergistic effect mechanism between the horn sheath and the core: the horn sheath withstands tensile and shear forces under load, resisting surface cracks through its fiber-reinforced structure, while the core absorbs energy through pore collapse, preventing internal stress from being transmitted to the horn sheath. Three horn lattice structures, BJHWPS, BAHWPS, and BBHWPS, simultaneously possess corrugated features and cavity structures in both the longitudinal and axial directions, and each exhibits different corrugated characteristics and cavity structures. The biomimetic horn gradient structure 2 possesses negative gradient characteristics; this strategy has been proven in studies of honeycomb lattice structures to significantly improve the impact resistance of structures.

[0060] After designing the overall structure of the biomimetic bull horn gradient structure 2, the vibration-damping shell based on this structure can be manufactured. The specific fabrication method is as follows:

[0061] Step 1: Based on 3D modeling software, the biomimetic bull horn gradient structure 2 is established. The biomimetic bull horn gradient structure 2 includes three different bull horn lattice structures obtained from the cross-section of the bull horn core. A composite surface layer structure composed of the three different bull horn lattice structures is established. Then, the wall thickness of the surface layer composed of each bull horn lattice structure is adjusted in a gradient to finally obtain the biomimetic bull horn gradient structure 2.

[0062] Step 2: Convert the biomimetic bull horn gradient structure 2 designed in Step 2 into an STL format file and import it into Magics software. Based on the selective laser melting (SLM) technology, print TC4 titanium alloy powder into a biomimetic bull horn gradient structure 2.

[0063] Step 3: The biomimetic bull horn gradient structure 2 of TC4 material is prepared into a TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic bull horn heterostructure 3 using a pressureless impregnation method.

[0064] Step 4: Two multi-functional coatings are deposited on the outside of the TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic bull horn heterostructure 3 using electrochemical deposition and dip-coating methods to further prepare the multi-layered TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic bull horn heterostructure 3, in order to solve the problems of insufficient corrosion resistance of traditional shell structures and electromagnetic interference encountered during service.

[0065] like Figure 3 As shown, the design steps of the biomimetic J-shaped bullhorn corrugated structure 11 are as follows: First, using the front-view reference plane as a reference, the equation-driven curve is used: The involute parameterized equation is used as the sketch outline: X: m*(cos(t)+t*sin(t)), Y: m*(sin(t)-t*cos(t)), where t ranges from 0 to 3 / 2. Pi (m is a constant, t is a variable) is drawn on the right reference plane as a path sketch, and a vertical line segment of length n is drawn as a path sketch. Next, a surface scanning operation is performed, with the contour orientation changing with the path. The contour twisting method is selected with a specified twist angle, and the twisting control is controlled by the number of turns and the arc is 1.5 turns. The beginning and end endpoints of the scanned surface (consistent with the path direction) are marked as A and B, respectively. Then, a thickening operation is performed with a thickness of t1. Next, a linear array solid operation is performed along the AB direction, with an array solid quantity of 1. Then, a mirror solid operation is performed with the front reference plane (sketching contour reference plane) as the reference to construct a biomimetic J-shaped bullhorn corrugated structure 110 with dimensions a1*b1*c1. Finally, array solid operations are performed along the x-axis, y-axis and z-axis respectively, with an array number of 2, to form a biomimetic J-shaped bullhorn corrugated structure 11.

[0066] like Figure 4As shown, the design steps of the biomimetic A-type horn-shaped corrugated structure 12 are as follows: First, using the front-view reference plane as a reference, the equation-driven curve is used: the gradient line parameterized equation (corresponding to the Archimedes spiral equation) is used as the sketch outline: X: o*t*cos(t), Y: o*t*sin(t), where t ranges from 0 to 2. Pi (o is a constant, t is a variable) is drawn on the right-view reference plane as a path sketch. Next, a surface scanning operation is performed, keeping the normal of the contour orientation unchanged. The contour twisting method is selected with a specified twist value, and the twisting control is set to 60 degrees. The beginning and end points of the scanned surface are marked as C and D, respectively. Then, a thickening operation is performed with a thickness of t2. Next, a reference axis 1 is established with point C and the upper reference plane as the reference, and then a circular array is performed with an array count of 4. Then, a reference plane 1 is established with point D and the right-view reference plane as the reference, and a mirror solid operation is performed with reference plane 1 as the reference. At this time, a biomimetic A-type horn corrugated structure 120 with dimensions of a2*b2*c2 is formed. At the same time, according to the top view, the corresponding A-type cavity feature is still in the open state. Finally, array solid operations are performed along the x-axis, y-axis and z-axis directions, with an array count of 2, to form a biomimetic A-type horn corrugated structure 12.

[0067] like Figure 5 As shown, the design steps of the biomimetic B-type bullhorn corrugated structure 13 are as follows: First, using the front-view reference plane as the reference, the equation-driven curves are: using the gradient line parameterized equation (corresponding to the cycloid equation) as the sketch outline X: p*(t- sin(t)), Y: p*(1 - cos(t)), where t ranges from Pi / 3 to Pi (p is a constant and t is a variable). Simultaneously, a vertical line segment of length n is drawn on the right-view reference plane as a path sketch. Next, a surface scanning operation is performed, with the contour orientation changing with the path. The contour twisting method is selected with a specified twist value, and the twisting control uses radian control with the radian set to 5 rad. The beginning and end endpoints of the scanned surface are marked as E and F, respectively. Then, a thickening operation is performed with the thickness set to t3. A reference axis 2 is established based on point F and the front-view reference plane, and a circular array solid command is performed with an array count of 4. At this point, the top view shows that the A-type cavity features a lotus-like cavity shape. Then, a mirror solid command is performed based on the front-view reference plane (the reference plane on which the original contour curve was drawn) to obtain a biomimetic B-type horn-shaped corrugated structure unit 130 with dimensions a3*b3*c3. Finally, an array solid operation is performed along the x-axis, y-axis, and z-axis directions with an array count of 2 to obtain the biomimetic B-type horn-shaped corrugated structure 13.

[0068] like Figure 6As shown, the biomimetic bull horn gradient structure 2 is designed by coupling and splicing three biomimetic bull horn lattice structures: BJHWPS, BAHWPS, and BBHWPS. In the surface layer composed of these three different biomimetic bull horn lattice structures, the cross-sectional dimensions and aspect ratios of the different types of bull horn lattice structures are the same, meaning that the planar proportions of different types of bull horn lattice structures are the same in the same surface layer. In the multi-layered composite surface layer, the wall thickness of each bull horn lattice structure is adjusted in a gradient manner. The wall thickness gradually increases from top to bottom (corresponding to the outside to the inside in the actual ship hull), which is a negative gradient strategy. This negative gradient strategy is consistent with the macroscopic gradient strategy of the bull horn. The coupling method is inspired by the interlocking interfaces present in horn and hoof structures, allowing the lattice structure to achieve a coupling reinforcement effect when subjected to impact.

[0069] The biomimetic bull horn gradient structure 2 was manufactured using selective laser melting technology. The laser power was 180W, the laser scanning rate was 800mm / s, the single-layer printing thickness was 20μm, and the laser scanning spacing was 60μm. In order to ensure the bonding effect of the coupling interface, the overlapping areas between different bull horn lattice structures were remelted 2-3 times during the printing process.

[0070] For the process of preparing the TC4 titanium alloy-aluminum foam interpenetrating biomimetic bull horn heterostructure, please refer to [reference needed]. Figure 7 As shown, the steps for preparing the TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic bull's horn heterostructure 3 using the pressureless infiltration method are as follows: A commercially available aluminum foam board is placed on the prepared biomimetic bull's horn gradient structure 2, and the temperature is raised to 900℃ at a rate of 5℃ / min under argon protection. After holding at this temperature for 1 hour, it is cooled with the furnace. When the temperature exceeds the melting point of the aluminum foam, the molten aluminum foam gradually infiltrates into the biomimetic bull's horn gradient structure 2 under the action of gravity. To promote the infiltration effect, a counterweight can be applied above the aluminum foam and the biomimetic bull's horn gradient structure 2 to ensure that the molten aluminum fully fills the structural voids.

[0071] See the image for an effect diagram of the multi-level TC4 titanium alloy-aluminum foam interpenetrating biomimetic heterostructure prepared by deposition coating. Figure 8As shown, the process of preparing the multilayered TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic heterostructure 4 using electrochemical deposition and dip-coating methods is as follows: First, a corrosion-resistant zinc-nickel alloy coating is prepared on the surface of the TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic horn heterostructure 3 substrate using electrochemical deposition. Using the TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic horn heterostructure 3 as the working electrode, a platinum sheet as the counter electrode, and a saturated calomel electrode (SCE) as the reference electrode, deposition is performed in an electrolyte containing sodium citrate (66.15 g / L), citric acid (43.2 g / L), nickel sulfate (78.75 g / L), zinc sulfate (43.2 g / L), and deionized water, under constant potential mode (-1.1~-1.25 V vs. SCE) for 10~30 minutes, with the temperature controlled at 25 ℃. Subsequently, an MXene electromagnetic shielding layer is coated on the zinc-nickel alloy coating using the dip-coating method. The sample was immersed in the MXene solution at a speed of 10 mm / min, and after complete immersion, it was pulled up at the same speed. This process was repeated 5-10 times, and after curing, a composite functional coating was formed. The MXene solution in the dip-coating method was prepared by hydrofluoric acid (HF) etching: MAX phase materials such as Ti3AlC2 were immersed in 45% HF, stirred at 40 °C for 36 hours, centrifuged and washed until neutral, and then ultrasonically exfoliated for 45 minutes to obtain a monolayer MXene dispersion.

[0072] The working principle diagram of this patent can be found in [reference]. Figure 9 As shown: First, when the submarine hull generates vibration noise, the aluminum foam in the multi-layered TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic heterostructure 4 absorbs sound waves, resulting in a good noise reduction effect and further reducing the detection range of enemy sonar. Second, when enemy detection ships use magnetic detection equipment to detect targets, the outer electromagnetic shielding coating in the multi-layered TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic heterostructure 4 can effectively reflect and absorb incident waves, thereby reducing its own electromagnetic characteristics and interfering with or evading enemy detection signals. Based on this, the submarine's "stealth performance" during service can be further improved. In addition, when the submarine is detected and attacked, the TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic horn heterostructure 3 within the multi-layered TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic heterostructure 4, due to the rigid-flexible coupling concept and biomimetic gradient structure design, has the advantages of increased explosion point area and good load-bearing effect compared to the traditional pyramid lattice structure. Therefore, its ability to resist explosion damage and impact deformation will be greatly improved.

Claims

1. A method for fabricating a multifunctional vibration-damping shell lattice structure, characterized in that, Includes the following steps: Step 1: Based on 3D modeling software, the biomimetic bull horn gradient structure is established. The biomimetic bull horn gradient structure includes three different bull horn lattice structures obtained from the cross-section of the bull horn core. Then, a composite surface layer structure composed of the three different bull horn lattice structures is established. Subsequently, the wall thickness of the surface layer composed of each bull horn lattice structure is adjusted in a gradient manner to finally obtain the biomimetic bull horn gradient structure. Step 2: Import the biomimetic bull horn gradient structure designed in Step 1 into Magics software, and print TC4 titanium alloy powder into a biomimetic bull horn gradient structure based on selective laser melting technology. Step 3: The biomimetic horn gradient structure of TC4 material is prepared into a TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic horn heterostructure using a pressureless impregnation method. Step four involves applying two multifunctional composite coatings to the TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic bull horn heterostructure obtained in step three using electrochemical deposition and dip-coating techniques.

2. The method for preparing a multifunctional vibration-damping shell lattice structure according to claim 1, characterized in that, The three types of bullhorn lattice structures in step one have the same cross-sectional dimensions and aspect ratios.

3. The method for preparing a multifunctional vibration-damping shell lattice structure according to claim 1, characterized in that, In step one, the composite surface structure consists of a single-layer surface structure formed by coupling and splicing each type of horn lattice structure, and a multi-layer composite structure formed by coupling and splicing multiple horn lattice structures.

4. The method for preparing a multifunctional vibration-damping shell lattice structure according to claim 1, characterized in that, In step one, the three types of horn-shaped lattice structures are all implemented using equation-driven curve commands, surface scanning commands, and solid thickening commands. The equations used in the equation-driven curve commands include the involute equation, the Archimedes spiral equation, and the cycloid equation.

5. The method for preparing a multifunctional vibration-damping shell lattice structure according to claim 4, characterized in that, The construction method of one of the three horn-shaped lattice structures is as follows: Using the previous reference plane as the reference, the involute parametric equation is used as the sketch outline: X: m*(cos(t)+t*sin(t)), Y: m*(sin(t)-t*cos(t)), where t ranges from 0 to 3 / 2 Pi, where m is a constant and t is a variable. At the same time, a vertical line segment of length n is drawn on the right reference plane as a path sketch. The surface scanning operation is performed, the contour orientation changes with the path, the contour twisting method is selected with a specified twist angle, the twisting control is controlled by the number of turns, the beginning and end points of the scanned surface are marked as A and B respectively, and then the scanned surface is thickened. Perform linear array solid operation along the AB direction, and then perform mirror solid operation on the arrayed structure with the front reference plane as the reference to obtain the bull horn lattice structure unit. Finally, the individual units of the bull horn lattice structure are arrayed along the x, y, and z axes to obtain the bull horn lattice structure.

6. The method for preparing a multifunctional vibration-damping shell lattice structure according to claim 4, characterized in that, The construction method of one of the three horn-shaped lattice structures is as follows: Using the previous reference plane as the reference, the gradient line parameterization equation is used as the sketch outline X:o*t*cos(t), Y:o*t*sin(t), where t ranges from 0 to 2Pi, o is a constant and t is a variable. At the same time, a vertical line segment of length n is drawn on the right reference plane as the path sketch. The surface scanning operation is performed while keeping the normal of the contour orientation unchanged. The contour twisting method is selected with a specified twist value, and the twisting control is carried out using degree control. The first and last endpoints of the scanned surface are marked as C and D, respectively. Then, the scanned surface is thickened. Establish a reference axis with point C and the top view reference plane as references, then perform a circular array along the reference axis, then establish a reference plane with point D and the right view reference plane as references, and perform a mirror solid operation with the reference plane as references to obtain the horn lattice structure unit. Finally, the individual units of the bull horn lattice structure are arrayed along the x, y, and z axes to obtain the bull horn lattice structure.

7. The method for preparing a multifunctional vibration-damping shell lattice structure according to claim 4, characterized in that, The construction method of one of the three horn-shaped lattice structures is as follows: Using the previous reference plane as the reference, the gradient line parameterization equation is used as the sketch outline X: p*(t - sin(t)), Y: p*(1 - cos(t)), where the range of t is Pi / 3-Pi, where p is a constant and t is a variable. At the same time, a vertical line segment of length n is drawn on the right reference plane as the path sketch. Then, a surface scanning operation is performed. The contour orientation changes with the path. The contour twisting method is selected with a specified twist value. The twisting control is done with radian control. The first and last endpoints of the scanned surface are marked as E and F, respectively. Then, the scanned surface is thickened. A reference axis is established based on point F and the front reference plane, and a circular array solid command is performed. Then, a mirror solid command is performed based on the front reference plane to obtain the horn lattice structure unit. Finally, the individual units of the bull horn lattice structure are arrayed along the x, y, and z axes to obtain the bull horn lattice structure.

8. The method for preparing a multifunctional vibration-damping shell lattice structure according to claim 1, characterized in that, The specific implementation steps of the pressureless impregnation method in step three are as follows: The aluminum foam board is placed on the biomimetic bull horn gradient structure prepared in step two, and heated to 900℃ at 5℃ / min in an argon atmosphere. After reaching the temperature, it is held for 1 hour and then cooled with the furnace. At this time, the aluminum foam material is allowed to deposit into the biomimetic bull horn gradient structure under its own gravity, so that it can be fully impregnated.

9. The method for preparing a multifunctional vibration-damping shell lattice structure according to claim 1, characterized in that, The specific method for adding two additional multifunctional composite coatings in step four is as follows: First, an electrochemical deposition method is used to deposit a corrosion-resistant zinc-nickel alloy coating; Electrochemical deposition employs a three-electrode system, in which a TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic bull horn heterostructure is used as the working electrode, a platinum sheet is used as the counter electrode, and a saturated calomel electrode is used as the reference electrode. The selected deposition solution consists of sodium citrate, citric acid, nickel sulfate, zinc sulfate, and deionized water. The electrodeposition process was carried out in constant potential mode, with a deposition potential of -1.1 to -1.25 V, a deposition time of 10 to 30 min, and a solution temperature of 25 ℃. Subsequently, the electromagnetic shielding coating was prepared on the outside of the zinc-nickel alloy coating by dip-coating. The TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic bull horn heterostructure coated with zinc-nickel alloy was immersed in Mxene solution at a speed of 10 mm / min. After the TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic bull horn heterostructure was completely submerged in Mxene solution, it was pulled out at the same speed. This process was repeated 5-10 times. Then the TC4 titanium alloy-aluminum foam interpenetrating phase biomimetic bull horn heterostructure was removed and the electromagnetic shielding coating was allowed to solidify.

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