A modeling method of controllable toughening heterogeneous composite material

Abstract

The application is a modeling method of controllable strong and tough heterogeneous composite material, relates to the field of composite material modeling and preparation, and comprises the following steps: step 1: establishing a diamond unit cell and a graphene unit cell; step 2: establishing a matrix structure; cloning the diamond unit cell and the graphene unit cell structure to obtain a cloned unit cell structure, and then stacking to obtain a diamond structure matrix structure and a graphene structure matrix structure; step 3: connecting the diamond and graphene matrix structures; taking the diamond matrix structure as a reference, after the two edges of the graphene rings coincide with each other, the other two vertices extended from the coinciding vertices are connected with the two vertices of the same edge of the diamond, to form a matched diamond and graphene matrix structure; the modeling method of the application is suitable for application scenarios requiring both high strength and high toughness.

Description

Technical Field

[0001] This invention relates to the field of laser additive manufacturing of composite materials, and specifically to a modeling method for tunable high-strength and high-toughness heterogeneous composite materials. Background Technology

[0002] Ordinary materials can no longer meet current production and processing needs, leading to the development of composite materials. The purpose of composite materials is to leverage the strengths of two or more constituent materials while overcoming their inherent weaknesses to a certain extent, thereby improving the performance of the composite material. The concept of heterogeneous materials was first proposed in 2015 by Professor Zhu Yuntian and Professor Wu Xiaolei of the Institute of Mechanics, Chinese Academy of Sciences. Heterogeneity refers to a microstructure characterized by its multi-level, multi-scale, ordered construction across three-dimensional space, including grains, crystal defects, and phase composition. This field has rapidly developed into a sizable international materials research area in recent years. Furthermore, the organic combination of heterogeneous materials using laser additive manufacturing technology can improve their controllability and optimize their performance.

[0003] Laser additive manufacturing technology, also known as laser 3D printing, is a computer-aided manufacturing technology based on the discrete-stacking principle. It involves slicing a three-dimensional solid model into two-dimensional layers, then discretizing these layers into one-dimensional lines, and finally stacking them point-by-point using laser cladding technology to create the final three-dimensional solid part. Based on different classification principles and understandings, additive manufacturing technology also has various other names such as rapid prototyping, rapid forming, rapid manufacturing, and 3D printing. Its connotation is constantly being deepened, and its scope is continuously expanding.

[0004] The design and manufacturing methods for achieving a balance between strength and toughness through the construction of heterogeneous metallic materials have become a cutting-edge research area and hot topic in mechanical engineering and materials science. Zhang Xiancheng et al. studied the theoretical basis and common manufacturing processes for the microstructure control of heterogeneous metallic materials in recent years, finding that the construction of heterogeneous microstructures can be used as an independent method or a synergistic alloying strategy to further break through the traditional inverse relationship between strength and toughness in metallic materials. However, the heterogeneity of the material's microstructure does not always lead to an improvement in strength and toughness, and current research in the field of heterogeneous metallic materials focuses on the matching of strength and toughness. Liu Pei et al. invented a multi-level layered heterogeneous copper-aluminum composite material and its preparation method, which can improve the strength of the composite material while maintaining a certain level of plasticity and toughness. However, it cannot control the strength and toughness of the heterogeneous material according to production needs. Our research method can effectively solve this problem by controlling the structural ratio of the diamond matrix structure and the graphene matrix structure, thereby obtaining heterogeneous models with different strengths and toughnesses.

[0005] Yuan Yuxuan et al. summarized the research progress of heterogeneous metallic materials with matching strength and toughness, and analyzed the mechanical properties, microstructure and deformation mechanism of heterogeneous metallic materials. They found that most heterogeneous metallic materials are currently obtained by relying on traditional processing methods and empirical design, which restricts the forming and performance improvement of such complex structures. The method we studied is to prepare heterogeneous composite materials by using laser selective melting technology, which can complete the forming of complex structures at low cost and high efficiency.

[0006] Geng Lin et al. studied the progress in the configurational strengthening and toughening of metal matrix composites, finding that the composite design of metal structural materials can fully utilize the designability of the distribution and content of each component phase, potentially leading to breakthroughs in the high strength and toughness of metal structural materials. Professor Zhang Di et al. from Shanghai Jiao Tong University proposed controlling the distribution of each component phase through composite configuration design, achieving "configurational strengthening and toughening" of metal structural materials. Domestic and international materials scientists have conducted some exploratory research on strengthening and toughening metal structural materials through composite material configuration design, finding that composite materials with network, double-connected, layered, or gradient distributions of reinforcement or component phases can fully utilize the performance potential of metal composite materials and achieve optimal configuration of performance indicators. However, previous studies have not proposed relevant theories for controllable strength and toughness heterogeneous composite materials. Our research proposes a novel method from this perspective to adapt to different requirements under different production conditions.

[0007] Currently, no structure can simultaneously achieve both high strength and high toughness, and its strength and toughness can be controlled by changing the ratio. However, the combination of the high strength of diamond structure and the high stiffness of graphene structure provides a concept for heterogeneous toughness design. This invention achieves toughness by combining diamond structure and graphene structure. By changing the ratio of diamond structure and graphene structure, a gradient is formed to control the strength and toughness of heterogeneous materials, so that they can be applied to occasions with different strength and toughness requirements. Summary of the Invention

[0008] The purpose of this invention is to provide a method for controlling the strength and toughness of heterogeneous composite materials.

[0009] The technical solution adopted to achieve the purpose of this invention is: a modeling method for adjustable high-toughness heterogeneous composite materials, comprising the following steps:

[0010] Step 1: Construct diamond and graphene unit cells: Select the lattice constant of the material and the crystal orientation corresponding to the x, y, and z directions. Construct a diamond unit cell with a sphere radius: prism radius: prism length of 7:5:35. A diamond unit cell with a lattice constant of 46 is constructed. Use polygonal topology to create a regular hexagonal graphene unit cell structure with a sphere radius: prism radius: prism length of 7:5:40.

[0011] Step 2: Establish the matrix structure: The diamond cell and graphene cell structures are cloned to obtain the cloned cell structures, and then stacked to obtain the diamond matrix structure and the graphene matrix structure, respectively.

[0012] Step 3: Connecting the diamond and graphene matrix structures: Based on the diamond matrix structure, after one side of the two graphene rings overlaps with each other, the other two vertices extended from the overlapping vertex are connected to the two vertices on the same side of the diamond. The angle between the diamond cell and the graphene cell is 30°, and the length of the third side after the two hexagonal graphene monomer structures are combined is exactly equal to the lattice parameter of the diamond cell to ensure a tight connection and form a matching diamond and graphene matrix structure.

[0013] Step 4: Model Gradient Construction: The constructed diamond matrix structure and graphene matrix structure are alternately arranged laterally with different cell ratios to form a gradient model. The gradient ratio of the diamond matrix can be arbitrary, while the gradient ratio of the graphene matrix is ​​an odd number. One diamond matrix structure can connect 2-3 graphene matrix structures, ensuring the same interlayer spacing. When connecting two graphene layers, they are located at the upper and lower lattice vertices of the diamond cell, respectively. When connecting three graphene layers, they are located at the upper and lower lattice vertices and the face center of the diamond cell, respectively. The connection angle between the diamond matrix structure and the graphene sheet structure can range from 0° to 45°.

[0014] Compared with the prior art, the advantage of this invention lies in the development of a modeling method for tunable high-toughness heterogeneous composite materials. By adjusting the structural ratio of diamond matrix structure and graphene matrix structure, heterogeneous models with different strengths and toughnesses can be obtained. Attached Figure Description

[0015] Figure 1 It has a diamond and graphene unit cell structure.

[0016] Figure 2 The basic model is based on a 1:1 ratio of diamond sheets to graphene sheets.

[0017] Figure 3 This is a graphene gradient model.

[0018] Figure 4 This is the diamond gradient model.

[0019] Figure 5 This is a standard tensile model. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings.

[0021] A modeling method for tunable high-toughness heterogeneous composite materials, the specific steps of which are as follows:

[0022] Step 1: Establish diamond and graphene unit cells: Select the lattice constant of the material and the crystal orientations corresponding to the x, y, and z directions. Establish a diamond unit cell with a sphere radius of 7, a cylinder radius of 5, a length of 35, and a lattice constant of 46 using the ball-and-stick model method. Create a graphene unit cell structure with a sphere radius of 7, a length of 40, and a cylinder radius of 5 using polygonal topology.

[0023] Step 2: Establish the matrix structure: The diamond cell and graphene cell structures are cloned to obtain the cloned cell structures, and then stacked to obtain the diamond matrix structure and the graphene matrix structure, respectively.

[0024] Step 3: Connecting the diamond and graphene matrix structures: Using the diamond matrix structure as a reference, after one side of the two graphene rings overlaps with each other, the other two vertices extending from the overlapping vertex are connected to the two vertices on the same side of the diamond, forming a matched diamond and graphene matrix structure.

[0025] Step 4: Model Gradient Construction: Construct the basic model by alternating diamond and graphene sheets in a 1:1 ratio laterally (e.g., Figure 2 As shown), secondly, keeping the proportion of diamond sheets unchanged on the original basic model, the graphene sheets are arranged in a ratio of 1:3:5:... and so on to obtain the graphene gradient structure (as shown). Figure 3 As shown), furthermore, while maintaining the graphene ratio unchanged on the original basic model, the diamond layers are arranged in a ratio of 1:2:3... and so on to obtain the diamond gradient structure (as shown). Figure 4 (As shown).

[0026] After establishing the material model, simulations of heterogeneous composite materials with controllable strength and toughness are performed, including the following steps:

[0027] Step 1: Construct a heterogeneous composite material model based on the method described in claim 1 to obtain a tensile model;

[0028] Step 2: Read the stretching model and set the X, Y, and Z directions of the model region as periodic boundary conditions; define variables and calculate the required physical quantities;

[0029] Step 3: Select a potential function that can describe the interatomic interaction forces in the heterogeneous composite material system.

[0030] Step 4: Energy Minimization

[0031] Step 5: Perform relaxation to obtain the relaxation model;

[0032] Step 6: Limit simulation parameters and perform simulation: stretch at a constant speed and output the information after stretching;

[0033] Step 7: Data processing and visualization analysis.

[0034] Following simulation, the heterogeneous composite material model is prepared by laser selective melting, including the following steps:

[0035] Step 1: Import the model. Convert the model file to STL format and import it into the slicing software.

[0036] Step 2: Model slicing. Set process parameters, support parameters, and model placement orientation in the slicing software.

[0037] Step 3: Laser additive manufacturing. The laser scans the composite material powder pre-placed in the powder applicator along a given path. The left forming cylinder descends by one step (one layer thickness), while the right material cylinder rises by one step. The scraper pushes the composite material powder to the forming area for uniform layering. After preheating, the laser scans and melts the powder again, layer by layer, until the laser additive manufacturing of the entire component is completed.

[0038] Step 4: Component processing. After the laser additive manufacturing is completed, the component is removed, the supporting surface of the component is removed and polished, and the component is subjected to subsequent processing such as UV curing and stress relief annealing.

[0039] Step 5: Determine the strength and toughness of the component. The middle part of the standard tensile model is a structural component with a thickness of 3mm, and the clamping end is a solid sample.

Claims

1. A modeling method for tunable high-toughness heterogeneous composite materials, characterized in that: Includes the following steps: Step 1: Establish diamond and graphene unit cells: Select the lattice constants of the materials and the crystal orientations corresponding to the x, y, and z directions, establish the diamond unit cell using the ball-and-stick model method, and create the graphene unit cell structure using polygonal topology; Step 2: Establishing the matrix structure: The diamond cell and graphene cell structures are cloned to obtain the cloned cell structures, and then stacked to obtain the diamond matrix structure and the graphene matrix structure, respectively. Step 3: Connecting the diamond and graphene matrix structures: Using the diamond matrix structure as a reference, after one side of each of the two graphene rings overlaps, the other two vertices extending from the overlapping vertex are connected to the two vertices on the same side of the diamond, forming a matched diamond and graphene matrix structure; when connecting the diamond matrix structure and the graphene matrix structure, the angle between the diamond cell and the graphene cell is 30°; the length of the third side after the two hexagonal graphene monomer structures are combined is exactly equal to the lattice parameter of the diamond cell to ensure a tight connection. Step 4: Model gradient construction: The constructed diamond matrix structure and graphene matrix structure are alternately arranged laterally with different cell ratios to form a gradient model.

2. The method according to claim 1, characterized in that: The constructed diamond unit cell has a sphere radius: prism radius: prism length ratio of 7:5:35, and a lattice constant of 46.

3. The method according to claim 1, characterized in that: The constructed polygonal topology creates a regular hexagonal graphene cell structure with a sphere radius: cylinder radius: cylinder length ratio of 7:5:

40.

4. The method according to claim 1, characterized in that: A diamond matrix structure can connect 2 to 3 layers of graphene matrix structure.

5. The method according to claim 1, characterized in that: The graphene matrix structure is connected to the upper and lower lattice vertices or face centers of the diamond unit cell to ensure that the graphene interlayer spacing is the same.

6. The method according to claim 1, characterized in that: The graphene matrix structure can be connected at the upper and lower lattice vertices or face centers of the diamond unit cell.

7. The method according to claim 1, characterized in that: The connection angle between the diamond matrix structure and the graphene sheet structure can range from 0° to 45°.

8. The method according to claim 1, characterized in that: The gradient ratio of the diamond matrix can be arbitrary, while the gradient ratio of the graphene matrix is ​​an odd number, to ensure that the diamond matrix and the graphene matrix form a lattice-matched structure.

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