A method for preparing a light-weight load-bearing and laser-protecting hyperstructure

Abstract

The application discloses a preparation method of a force-thermal superstructure with light load bearing and laser protection, adopts a double-point lattice structure design of light metal skeleton lattice and ablation type resin matrix composite lattice nested with each other, utilizes a 3D printing forming process, combines new technical advantages of selective forming of various materials, and realizes integrated high-precision forming of the force-thermal superstructure with light load bearing and laser protection by means of finite element numerical simulation and calculation optimization. The superstructure prepared by the method improves the specific strength and specific stiffness of the structure within the design range, and simultaneously has the laser protection function, so that the method has important significance for overall weight reduction and protection.

Description

Technical Field

[0001] This invention relates to a method for preparing a thermo-mechanical superstructure that combines lightweight load-bearing capacity with laser protection, belonging to the field of metamaterial design and multi-material 3D printing technology. Background Technology

[0002] Lattice superstructures are low-density structures with excellent mechanical properties, including high specific strength, specific stiffness, impact energy absorption, and vibration and noise reduction. Compared to traditional solid materials, lattice structures with the same performance can reduce weight by more than 70%, making them widely used in aerospace equipment such as rockets, satellites, and hypersonic vehicles. Aerospace equipment experiences complex dynamic loads during service, and the resulting vibrations and heat concentrations can severely interfere with the operational accuracy of internal components, even leading to failure. However, limitations imposed by launch or payload capacity, and the difficulty in dissipating heat from components, mean that simply increasing the thickness or size of traditional metal materials cannot meet practical requirements. Therefore, higher demands are placed on the research and development of lattice structures under different service conditions.

[0003] Furthermore, laser-guided energy weapons are increasingly being used in military operations, but hollow lattice structures offer limited protection against lasers. Laser weapon defense primarily relies on energy dissipation through reflection and absorption ablation, thereby protecting internal components. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a method for preparing a mechanothermal superstructure that combines lightweight load-bearing and laser protection, thereby realizing the integrated design and molding of a lightweight load-bearing and laser-protected superstructure.

[0005] The technical solution of this invention is:

[0006] A method for fabricating a mechanothermal superstructure that combines lightweight load-bearing capacity with laser protection includes:

[0007] Using aluminum alloy as the raw material, an octahedral load-bearing structure lattice unit was designed.

[0008] The lattice unit is simulated and modeled. Based on the deformation and heat transfer of the lattice unit under excitation, the size and density of the individual cells of the lattice structure are adjusted and optimized to achieve the matching of structural density and load-bearing capacity, so as to obtain a metal skeleton lattice that meets the requirements of use.

[0009] A laser-protected superstructure filled with ablation-type resin-based material is designed in the hollow region of the metal skeleton lattice to form a double-fold lattice structure in which the metal skeleton lattice and the ablation-type resin-based composite material lattice are nested together; a gap is left between the two lattices to serve as a gap in the molding process and a channel for the volatilization of ablation components.

[0010] An ablation-type printable resin-based slurry was prepared and a dual-point array structure was 3D printed on a panel to obtain a thermo-mechanical superstructure that combines lightweight load-bearing capacity with laser protection.

[0011] Preferably, the metal skeleton octahedral lattice unit is composed of eight isosceles triangles. An ablation-type resin-based filling material laser protection superstructure is designed in the hollow area of ​​the metal skeleton lattice. The design method is as follows: take the midpoint of the three sides of each isosceles triangle as a node, and extend outward in the opposite direction to form three arms. The intersection of the three arms is the geometric center of the gap between multiple octahedral cells. Continue to extend outward from the intersection to form a fourth arm. This arm has the same angle and length as the previous three arms. The structure formed is a line connecting the geometric center of a tetrahedron to its four vertices.

[0012] Preferably, the entire superstructure is 3D printed on the panel. The specific method is as follows: a dual-nozzle metal-resin integrated 3D printer is used to print the dual-point matrix structure layer by layer on the formed panel. The printing sequence of each layer is as follows: first, the metal material is printed by powder feeding laser sintering, and then the resin material is selected and cured by extrusion ultraviolet light. The last layer fills all the gaps with resin material to form a complete plane with a surface roughness of less than or equal to 6.4.

[0013] Preferably, the panel is a laser-cut aluminum alloy plate with the same grade as the 3D printed load-bearing lattice superstructure aluminum alloy and a thickness of 0.5 to 1.5 mm.

[0014] Preferably, the size and density of individual cells in the lattice structure are adjusted and optimized to achieve a match between structural density and load-bearing capacity. This allows the bipolar lattice structure to reduce its structural density to 1 g / cm³ while meeting the service requirements of not exceeding 20 GPa overload and 100 MPa surface load. 3 the following.

[0015] Preferably, the method for preparing ablation-resistant printable resin-based slurry is as follows: ceramic particles are added after the resin and catalyst are mixed for ablation resistance enhancement. The particle size of the ceramic particles is 50-150 μm, and the mass ratio of ceramic particles to resin is 1:2. The ceramic particles include SiO2, Al2O3, and BN.

[0016] Preferably, the resin is a modified phenolic resin or a modified phthalonitrile resin.

[0017] Preferably, the modification method of the modified phenolic resin or modified phthalonitrile resin is as follows: a photosensitive functional group is added to the phenolic resin or phthalonitrile resin, so that the phenolic resin or phthalonitrile resin is rapidly cured within 10 seconds under ultraviolet light irradiation at 60-80°C.

[0018] Preferably, the relative node spacing of the metal skeleton lattice cells is controlled at 0.1 to 0.5 mm, which achieves weight reduction while serving as a gap in the molding process and a channel for the volatilization of ablation components.

[0019] Preferably, the lattice elements of the load-bearing structure are simulated and modeled. A multi-branch model is used to characterize the load-bearing capacity and heat transfer capacity of the lightweight high-strength aluminum alloy structure. The stress-strain relationship is calculated. The elastic body is characterized by a linear elastic model. A simulation model of the lattice structure is established based on the material constitutive relation. The deformation and heat transfer of the structure under excitation are calculated. The relationship between structural deformation and structural shape, material properties, and stress distribution is analyzed. The size and dimensions of the lattice structure are optimized based on the simulation results.

[0020] The advantages of this invention compared to the prior art are:

[0021] (1) The dual-material lattice superstructure design proposed in this invention uses a lightweight aluminum alloy lattice skeleton as the structural support and a lattice resin-based ablation structure in the hollow part to achieve laser protection. Compared with the traditional method, it significantly reduces the overall structural surface density and significantly improves the weight reduction effect while taking into account both structure and functionality.

[0022] (2) This invention utilizes 3D printing molding process, combined with the novel technical advantages of selective molding of multiple materials, and optimizes by finite element numerical simulation calculation to achieve high-precision integrated molding of complex entangled double-key matrix superstructure, avoiding the shape and position deviations caused by multiple process flows such as molding, assembly, welding, and spraying in traditional processes.

[0023] (3) The present invention adopts the 3D printing direct sealing method. After the last layer of the aluminum alloy skeleton is printed, the adhesiveness of the resin and the strengthening effect of the ceramic particle structure are used to directly print and fill all the gaps. The traditional two-layer panel structure is no longer used. While ensuring the surface roughness, the weight reduction target is further achieved. Attached Figure Description

[0024] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0025] Figure 1 This is a schematic diagram of a single cell of a lattice superstructure according to an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of multiple cell combinations in a lattice superstructure according to an embodiment of the present invention. Detailed Implementation

[0027] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0028] This invention proposes a method for fabricating a mechanothermal superstructure that combines lightweight load-bearing capacity with laser protection, comprising:

[0029] 1) Lightweight metal load-bearing lattice structure design

[0030] Taking a typical lattice octahedral structure as an example, the lattice unit of the load-bearing structure is designed, such as... Figure 1 As shown, a metal skeleton lattice structure 1 is constructed using lightweight, high-strength aluminum alloy as the raw material.

[0031] 2) Numerical simulation and optimization of lattice superstructures

[0032] A simulation model of a lightweight load-bearing octahedral lattice structure was developed. A multi-branch model was used to characterize the load-bearing capacity and heat transfer capacity of the lightweight high-strength aluminum alloy structure. The stress-strain relationship was calculated, and the elastic body was characterized using a linear elastic model. A simulation model of the lattice structure was established based on the material constitutive relation. The deformation and heat transfer of the structure under excitation were calculated, and the relationship between structural deformation and structural shape, material properties, and stress distribution was analyzed. By analyzing the stress and overload conditions during actual service, the size and dimensions of individual cells in the lattice structure were adjusted and optimized to achieve a reasonable match between structural density and load-bearing capacity, ultimately obtaining a metal skeleton lattice that meets the service requirements.

[0033] 3) Laser-protected superstructure design using ablation-type resin-based filler materials

[0034] Using the optimized load-bearing lattice structure from step 2) as a reference, a reverse support lattice structure is designed in the hollow region to form an ablation-type resin-based filled material laser protection superstructure 2. The design concept is to use the center of the aluminum alloy support skeleton as a node, extending outwards in a reverse direction. The outer nodes are the geometric centers of the gaps between cells. A distance of 0.1–0.5 mm must be maintained between two relative nodes of a single cell as a molding process gap to prevent the heat-affected zone generated during aluminum alloy molding from interfering with the curing of the resin-based composite material. This also serves as a channel for component volatilization during the ablation process in service.

[0035] 4) Preparation of ablation-type printable resin-based paste

[0036] The resin-based material can be modified phenolic resin or modified phthalonitrile resin. The modification method involves adding photosensitive functional groups to the phenolic resin or phthalonitrile resin, enabling it to cure rapidly within 10 seconds under ultraviolet light irradiation at 60–80°C. When preparing the printing paste, SiO2, Al2O3, and BN ceramic particles are added after mixing the components and catalyst to enhance ablation resistance. The particle size of the ceramic particles is 50–150 μm, and the mass ratio of ceramic powder to resin is 1:2.

[0037] 5) Complete the 3D printing of the heterogeneous material monolithic superstructure on the panel to obtain a thermo-mechanical superstructure that combines lightweight load-bearing capacity with laser protection.

[0038] The panel is made of laser-cut aluminum alloy sheet, with the same grade as the aluminum alloy used in the 3D printed load-bearing lattice superstructure, and a thickness of 0.5–1.5 mm. A dual-nozzle metal-resin integrated 3D printer is used to print the optimized nested lattice superstructure, composed of two materials, layer by layer on the panel. The printing sequence for each layer is as follows: first, the metal material is printed using a powder-feed laser sintering method, followed by the resin material being selected and cured using an extrusion-type ultraviolet light method. The final layer fills all gaps with resin material, forming a complete plane with a final surface roughness of less than or equal to 6.4.

[0039] Compared to existing laser protection structure designs using lattice frameworks with ablation-type filling and multi-layer structures with layers, the mechanical-thermal superstructure designed and manufactured in this invention improves the specific strength and specific stiffness of the structure within the design range, such as... Figure 2 As shown, it also possesses laser protection capabilities, which is of great significance for overall weight reduction and protection. Furthermore, this method involves integrated fabrication, with the molding process completed in a single step, avoiding errors caused by assembly, welding, and filling processes, thus significantly improving efficiency and precision.

[0040] Example 1: A method for forming a titanium alloy lattice superstructure hollow sealed panel, comprising the following steps:

[0041] Step 1: Lightweight Metal Load-Bearing Lattice Structure Design: Taking a typical octahedral lattice structure as an example, design the lattice unit of the load-bearing structure. Lightweight, high-strength aluminum alloy is used as the raw material to construct the basic structural components;

[0042] Step 2: Numerical Simulation and Optimization of the Lattice Superstructure: A simulation model of the lightweight load-bearing lattice structure is performed. A multi-branch model is used to characterize the load-bearing capacity and heat transfer capacity of the lightweight high-strength aluminum alloy structure. The stress-strain relationship is calculated. The elastic body is represented using a linear elastic model. A simulation model of the lattice structure is established based on the material constitutive relation. The deformation and heat transfer of the structure under excitation are calculated, and the relationship between structural deformation and structural shape, material properties, stress distribution, etc., is analyzed. Based on the simulation results, detailed optimizations are made to variables such as the size and density of the lattice structure.

[0043] Step 3: Design of protective superstructure for ablation-type resin-based protective filler material: Taking the optimized load-bearing lattice structure in step 2) as a reference, a reverse lattice structure is designed in the hollow area. A 0.1mm gap is left between the relative nodes of a single lattice cell as a molding process gap and a channel for the volatilization of ablation components. At this time, the overall surface density is the largest and the molding accuracy requirement is 0.02mm.

[0044] Step 4: Preparation of ablation-type printable resin-based slurry: Modified phenolic resin is selected as the resin-based material. When preparing the printing slurry, SiO2, Al2O3 and BN ceramic particles with a mass ratio of 1:1:1 are added after the components and catalyst are mixed to enhance ablation resistance. The particle size of the ceramic particles is 50-70μm and the mass ratio of ceramic powder to resin is 1:2.

[0045] Step 5: An AlSi10Mg aluminum alloy sheet is laser-cut into a 300×300mm panel with a thickness of 0.8mm. A dual-nozzle integrated 3D printer is used to print a lattice superstructure layer by layer onto the panel. The printing sequence is as follows: first, powder-fed laser sintering prints the aluminum alloy material, followed by extrusion-based UV curing of the resin material. The final layer fills all voids with resin material to form a complete plane. The final surface roughness is measured to be 3.2.

[0046] Example 2: A method for forming a titanium alloy lattice superstructure hollow sealed panel, comprising the following steps:

[0047] Step 1: Lightweight Metal Load-Bearing Lattice Structure Design: Taking a typical octahedral lattice structure as an example, design the lattice unit of the load-bearing structure. Lightweight, high-strength aluminum alloy is used as the raw material to construct the basic structural components;

[0048] Step 2: Numerical Simulation and Optimization of the Lattice Superstructure: A simulation model of the lightweight load-bearing lattice structure is performed. A multi-branch model is used to characterize the load-bearing capacity and heat transfer capacity of the lightweight high-strength aluminum alloy structure. The stress-strain relationship is calculated. The elastic body is represented using a linear elastic model. A simulation model of the lattice structure is established based on the material constitutive relation. The deformation and heat transfer of the structure under excitation are calculated, and the relationship between structural deformation and structural shape, material properties, stress distribution, etc., is analyzed. Based on the simulation results, detailed optimizations are made to variables such as the size and density of the lattice structure.

[0049] Step 3: Design of protective superstructure for ablation-type resin-based protective filler material: Taking the optimized load-bearing lattice structure in step 2) as a reference, a reverse lattice structure is designed in the hollow area. A 0.5mm gap is left between the relative nodes of a single lattice cell as a molding process gap and a channel for the volatilization of ablation components. At this time, the overall surface density is the minimum and the molding accuracy requirement is 0.02mm.

[0050] Step 4: Preparation of ablation-type printable resin-based slurry: Modified phenolic resin is selected as the resin-based material. When preparing the printing slurry, SiO2, Al2O3 and BN ceramic particles with a mass ratio of 1:2:2 are added after the components and catalyst are mixed to enhance ablation resistance. The particle size of the ceramic particles is 100-150μm and the mass ratio of ceramic powder to resin is 1:2.

[0051] Step 5: An AlSi10Mg aluminum alloy sheet is laser-cut into a 300×300mm panel with a thickness of 1.2mm. A dual-nozzle integrated 3D printer is used to print a lattice superstructure layer by layer onto the panel. The printing sequence is as follows: first, powder-fed laser sintering prints the aluminum alloy material, followed by extrusion-based UV curing of the resin material. The final layer fills all voids with resin material to form a complete plane. The final surface roughness is measured to be 3.2.

[0052] The embodiments described above are merely preferred embodiments of the present invention. Ordinary variations and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for fabricating a mechanothermal superstructure that combines lightweight load-bearing capacity with laser protection, characterized in that, include: Using aluminum alloy as the raw material, an octahedral load-bearing structure lattice unit was designed. The lattice unit is simulated and modeled. Based on the deformation and heat transfer of the lattice unit under excitation, the size and density of a single cell of the lattice unit are adjusted and optimized to achieve a match between structural density and load-bearing capacity, thereby obtaining a metal skeleton lattice that meets the requirements of use. A laser-protected superstructure filled with ablation-type resin-based material is designed in the hollow region of the metal skeleton lattice to form a double-fold lattice structure in which the metal skeleton lattice and the ablation-type resin-based composite material lattice are nested together; a gap is left between the two lattices to serve as a gap in the molding process and a channel for the volatilization of ablation components. Ablative printable resin-based slurry was prepared and a dual-point array structure was 3D printed on a panel to obtain a mechanothermal superstructure that combines lightweight load-bearing and laser protection. The metal skeleton octahedral lattice unit is composed of eight isosceles triangles. An ablation-type resin-based filling material laser-protected superstructure is designed in the hollow area of ​​the metal skeleton lattice. The design method is as follows: take the midpoint of the three sides of each isosceles triangle as a node, and extend outward in the opposite direction to form three arms. The intersection of the three arms is the geometric center of the gap between multiple octahedral cells. Continue to extend outward from the intersection to form a fourth arm. The angle between the fourth arm and the first three arms is equal and the length is equal. The structure formed is a line connecting the geometric center of a tetrahedron to its four vertices.

2. The method for preparing a mechanothermal superstructure according to claim 1, characterized in that, The entire superstructure is 3D printed on the panel. The specific method is as follows: a dual-nozzle metal-resin integrated 3D printer is used to print the dual-point matrix structure layer by layer on the formed panel. The printing sequence of each layer is as follows: first, the metal material is printed by powder feeding laser sintering, and then the resin material is selected and cured by extrusion ultraviolet light. The last layer fills all the gaps with resin material to form a complete plane with a surface roughness of less than or equal to 6.

4.

3. The method for preparing a mechanothermal superstructure according to claim 2, characterized in that, The panel is made of laser-cut aluminum alloy plate, with the same grade as the 3D printed load-bearing lattice superstructure aluminum alloy, and a thickness of 0.5~1.5mm.

4. The method for preparing a mechanothermal superstructure according to claim 1, characterized in that, By adjusting and optimizing the size and density of individual cells in the lattice unit, a match between structural density and load-bearing capacity is achieved. This allows the bipolar lattice structure to reduce its structural density to 1 g / cm³ while meeting the service requirements of not exceeding 20 GPa overload and 100 MPa surface load. 3 the following.

5. The method for preparing a mechanothermal superstructure according to claim 1, characterized in that, The method for preparing ablation-resistant printable resin-based slurry is as follows: ceramic particles are added after the resin and catalyst are mixed to enhance ablation resistance. The particle size of the ceramic particles is 50~150μm, and the mass ratio of ceramic particles to resin is 1:

2. The ceramic particles include SiO2, Al2O3 or BN.

6. The method for preparing a mechanothermal superstructure according to claim 5, characterized in that, The resin is selected from modified phenolic resin or modified phthalonitrile resin.

7. The method for preparing a mechanothermal superstructure according to claim 6, characterized in that, The modification method for modified phenolic resin or modified phthalonitrile resin is as follows: photosensitive functional groups are added to the phenolic resin or phthalonitrile resin, so that the phenolic resin or phthalonitrile resin is rapidly cured within 10 seconds under ultraviolet light irradiation at 60~80℃.

8. The method for preparing a mechanothermal superstructure according to claim 1, characterized in that, The relative node spacing of the metal skeleton lattice cells is controlled at 0.1~0.5mm, which not only reduces weight but also serves as a gap in the molding process and a channel for the volatilization of ablation components.

9. The method for preparing a mechanothermal superstructure according to claim 1, characterized in that, Simulation modeling of the lattice unit of the load-bearing structure is carried out. A multi-branch model is used to characterize the load-bearing capacity and heat transfer capacity of the lightweight high-strength aluminum alloy structure. The stress-strain relationship is calculated. The elastic body is characterized by a linear elastic model. A simulation model of the lattice structure is established based on the material constitutive relation. The deformation and heat transfer of the structure under excitation are calculated. The relationship between structural deformation and structural shape, material properties and stress distribution is analyzed. The size and dimensions of the lattice structure are optimized based on the simulation results.

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