Thin film stabilized configuration of multicellular lattice structures and additive manufacturing build method

Abstract

The present application relates to the field of additive manufacturing, more particularly to a thin film stable configuration of a multi-cell lattice structure and an additive manufacturing construction method, comprising a plurality of hollowed-out single-cell lattice structures, a plurality of hollowed-out single-cell lattice structures are symmetrically combined with the outer edge surface of the triangular plate as the mirror surface to form a double-unit hollowed-out single-cell lattice structure and a four-unit hollowed-out single-cell lattice structure, and the four-unit hollowed-out single-cell lattice structure is taken as a basic unit array to form a thin film stable configuration of a multi-cell lattice structure; the method comprises the following steps: S1: constructing an equivalent model of the hollowed-out single-cell lattice structure; S2: taking the equivalent model as the basis to additively manufacture a single-cell lattice structure model; S3: the single-cell lattice structure is subjected to material processing to form the hollowed-out single-cell lattice structure; the structure has better thermodynamic performance, strength performance, lightweight and shock absorption and energy absorption effect compared with the general single-cell lattice structure.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing, and more specifically to multi-cell lattice structures of thin film stable configurations and additive manufacturing methods for constructing them. Background Technology

[0002] In recent years, industry has been committed to enabling metal components to possess characteristics such as lightweight, long lifespan, and high performance. This trend has greatly promoted the application and development of additive manufacturing technology. Laser additive manufacturing technology provides a new technical approach for the design and manufacture of high-performance metal components. The layer-by-layer processing method of additive manufacturing can enhance the design freedom of the internal structure of lattice materials, precisely control the shape and size, and thus better leverage the advantages of different lattice structures.

[0003] Currently, thanks to years of experience in the additive manufacturing field, we have designed and established a performance database of various additive manufacturing lattice units using parametric modeling and simulation systems. This allows us to select appropriate lattice units and corresponding lattice unit design parameters for different applications. Furthermore, we can optimize and combine different lattices based on their performance characteristics and use multiple lattices for splicing design.

[0004] However, currently, no lattice structure has been developed based on the stable configuration of liquid thin films. Therefore, our design will fill the gap in local design in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-cell lattice structure with a stable thin film configuration and an additive manufacturing method for constructing it. This structure has better thermodynamic properties, strength properties, lightweighting and vibration damping and energy absorption effects compared to general single-cell structures.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A multi-cell lattice structure with a thin-film stable configuration includes multiple hollowed-out single-cell cell structures. Each hollowed-out single-cell cell structure includes six triangular plates with identical structures, forming a regular quadrilateral. The six triangular plates are fixedly connected to each other, with the common vertex of the six triangular plates being the center of the regular quadrilateral. Starting from the center, four common sides are formed in the space, evenly distributed around the center. Three triangular plates are evenly distributed around the common sides. The six triangular plates divide the space into four quadrilaterals of equal shape. Each quadrilateral contains a four-sided arc-shaped body, with the sides of the four-sided arc-shaped body extending to adjacent triangular plates. Multiple hollowed-out single-cell cell structures are symmetrically combined with the outer faces of the triangular plates as mirror faces to form a double-unit hollowed-out single-cell cell structure and a four-unit hollowed-out single-cell cell structure. The four-unit hollowed-out single-cell cell structure is used as the basic unit array to form a multi-cell lattice structure with a thin-film stable configuration.

[0008] The triangle is an isosceles triangle;

[0009] Using the center of the arc surface of the four-sided arc body as the shape, make a circle, use the circle as the boundary to process the material, and remove the internal structure of the four-sided arc body to process the four-sided arc body into a perforated arc plate.

[0010] The diameter of the circle is two-thirds of the arc length of the tetrahedral body;

[0011] Construct a tetrahedral solid through the midpoint of the three shared edges within each quadrilateral.

[0012] An additive manufacturing method for constructing multicellular lattice structures with stable thin-film configurations, comprising the following steps:

[0013] S1: Construct an equivalent model of a hollowed-out single-cell crystal structure;

[0014] S2: Additive manufacturing unit cell structure model based on equivalent model;

[0015] S3: Hollowed-out single-cell structure formed by material processing of single-cell structure;

[0016] S4: The outer surfaces of the additively manufactured hollowed-out single-cell structure are symmetrically combined to form a double-unit hollowed-out single-cell structure and a four-unit hollowed-out single-cell structure.

[0017] S5: A multi-cell lattice structure with a thin film stable configuration formed by an array of four-unit hollow single-cell crystal structures as the basic unit array.

[0018] S1 specifically includes the following steps:

[0019] S11: Construct a tetrahedral framework and immerse the tetrahedral framework in foam water;

[0020] S12: Removing the tetrahedral frame will form six triangular liquid films composed of the two endpoints of each edge of the regular tetrahedron and the body center of the regular tetrahedron;

[0021] S13: The tetrahedral frame is immersed in the foam water for the second time. The liquid film will form a four-sided arc-shaped liquid film with the body center of the tetrahedron as the center.

[0022] S14: The four faces of the four-sided arc-shaped liquid film cut the six triangular liquid films, forming six irregular quadrilateral liquid films;

[0023] The structures of the four-sided arc-shaped liquid film and the six-quadrilateral liquid film are extracted to form an equivalent model of the hollowed-out unit cell structure;

[0024] S3 specifically includes the following steps:

[0025] S31: Draw a circle with the center of the arc surface of the tetrahedral body;

[0026] S32: Process the material using a circular boundary and remove the internal structure of the four-sided arc-shaped body;

[0027] S33: The four-sided arc-shaped body is processed into a perforated arc plate, which in turn forms a hollow single-cell crystal structure;

[0028] In S2, laser powder bed cladding additive manufacturing technology is used to manufacture a single-cell crystal structure model.

[0029] The beneficial effects of this invention are as follows:

[0030] The formation mechanism of multi-cell lattice structure with stable thin film configuration involves the competition and coordinated balance between intermolecular forces and surface tension to form a stable configuration with minimum free energy. Therefore, multi-cell lattice structure with stable thin film configuration has better thermodynamic properties than general single-cell structure.

[0031] The multi-cell lattice structure of the thin film stable configuration has a strength that is more than 10% higher than that of the traditional lattice network structure;

[0032] Compared with traditional lattice network structures, the multi-cell lattice structure based on additive manufacturing thin film stabilization is more than 5% lighter.

[0033] The vibration damping and energy absorption effect of the multi-cell lattice structure with thin film stability is improved by more than 8% compared with the traditional lattice network structure. Attached Figure Description

[0034] The present invention will now be described in further detail with reference to the accompanying drawings and specific implementation methods.

[0035] Figure 1 This is a schematic diagram of the multi-cell lattice structure of the thin film stabilization configuration of the present invention;

[0036] Figure 2 This is a schematic diagram of the tetrahedral frame structure of the present invention;

[0037] Figure 3 This is a schematic diagram of the tetrahedral frame and liquid film structure of the present invention;

[0038] Figure 4 This is a schematic diagram of the four-sided arc-shaped liquid film structure of the present invention;

[0039] Figure 5 and 6 This is a schematic diagram of the triangular plate distribution structure of the present invention;

[0040] Figure 7 and 8 This is a schematic diagram of the unit cell structure of the present invention;

[0041] Figure 9 and10 This is a schematic diagram of the hollowed-out single-cell crystal structure combination structure of the present invention;

[0042] Figure 11 This is a schematic diagram of the hollowed-out single-cell crystal structure with a dual-unit combination structure of the present invention;

[0043] Figure 12 This is a schematic diagram of the four-unit combination structure of the hollowed-out single-cell crystal structure of the present invention;

[0044] Figure 13 This is a schematic diagram of the multi-cell lattice structure of the four-unit combined array constituting a thin film stable configuration according to the present invention;

[0045] In the figure: tetrahedral frame 11; liquid film 12; tetrahedral body center 13; tetrahedral arc liquid film 14; quadrilateral liquid film 15; triangle 21; common edge 22; center 23; tetrahedral arc 24; circle 25; perforated arc plate 26. Detailed Implementation

[0046] The present invention will now be described in further detail with reference to the accompanying drawings.

[0047] like Figures 1 to 13 As shown below, the structure and function of the multi-cell lattice structure of the thin film stable configuration will be explained in detail.

[0048] The multi-cell lattice structure of the thin film stable configuration includes multiple hollowed-out single-cell cell structures. Each hollowed-out single-cell cell structure includes six triangular plates 21, which form a regular quadrilateral. The six triangular plates 21 have identical structures and are isosceles triangles. The six triangular plates 21 are fixedly connected to each other. The common vertex of the six triangular plates 21 is the center 23 of the regular quadrilateral. The sides where the triangular plates 21 contact each other are shared sides 22. Four shared sides 22 are formed in space starting from the center 23, and are evenly distributed around the center 23. Three triangular plates 21 surround the center 23. Six triangular plates 21 are evenly distributed around the common side 22, dividing the space into four quadrilaterals of equal shape. Each quadrilateral contains a four-sided arc-shaped body 24. The four-sided arc-shaped body 24 is constructed through the midpoint of the three common sides 22 in each quadrilateral. The side of the four-sided arc-shaped body 24 extends to the adjacent triangular plate 21. A circle 25 is made with the center of the arc surface of the four-sided arc-shaped body 24. The diameter of the circle 25 is two-thirds of the arc length of the four-sided arc-shaped body 24. The material is processed with the circle 25 as the boundary, and the internal structure of the four-sided arc-shaped body 24 is removed to form a perforated arc plate 26.

[0049] Multiple hollowed-out single-cell cell structures are symmetrically combined with the outer face of the triangular plate 21 as a mirror image to form a double-unit hollowed-out single-cell cell structure and a four-unit hollowed-out single-cell cell structure, such as... Figure 11 and 12As shown;

[0050] A multi-cell lattice structure with a thin-film stable configuration is formed by an array of four-unit hollow single-cell crystal structures as the basic unit; such as Figure 13 As shown;

[0051] like Figure 1 As shown, the multi-cell lattice structure with a thin film stable configuration is formed by an array of basic unit cells, namely a hollow single-cell crystal structure and a four-unit hollow single-cell crystal structure.

[0052] The formation mechanism of hollow unit cell structure involves the competition and coordination balance between intermolecular forces and surface tension to form a stable configuration with minimum free energy. Therefore, hollow unit cell structure has better thermodynamic properties than general unit cell structure.

[0053] The diameter of the circle 25 is two-thirds of the arc length of the tetrahedral arc body 24. If the diameter of the through hole in the circle 25 is too large or the position of the perforated arc plate 26 is too close to the side length of the regular tetrahedron, the strength and stiffness of the unit cell structure will be reduced. If the diameter of the through hole in the circle 25 is too small or the position of the perforated arc plate 26 is too close to the body center of the cube, the powder will be difficult to remove and the cleaning efficiency will be low.

[0054] When the hollow unit cell structure is subjected to external loads, the perforated arc plate 26 can stabilize and reinforce the hollow unit cell structure, thereby improving the stability of the hollow unit cell structure. In addition, the hollow unit cell structure is symmetrical, which makes the force in all directions balanced when subjected to external loads, reduces anisotropy, and improves the stability of the hollow unit cell structure.

[0055] An additive manufacturing method for constructing multicellular lattice structures with stable thin-film configurations, comprising the following steps:

[0056] S1: Construct an equivalent model of a hollowed-out single-cell crystal structure;

[0057] S2: Using laser powder bed cladding additive manufacturing technology to manufacture unit cell structure models, and using equivalent models as the basis for additive manufacturing of unit cell structure models;

[0058] S3: Hollowed-out single-cell structure formed by material processing of single-cell structure;

[0059] S4: The outer surfaces of the additively manufactured hollowed-out single-cell structure are symmetrically combined to form a double-unit hollowed-out single-cell structure and a four-unit hollowed-out single-cell structure.

[0060] S5: A multi-cell lattice structure with a thin film stable configuration formed by an array of four-unit hollow single-cell crystal structures as the basic unit array.

[0061] S1 specifically includes the following steps:

[0062] S11: Construct a tetrahedral frame 11 and immerse the tetrahedral frame 11 in foam water;

[0063] S12: Removing the tetrahedral frame 11 will form six triangular liquid films 12, which are formed by the two endpoints of each side of the regular tetrahedron and the body center 13 of the regular tetrahedron.

[0064] S13: The tetrahedral frame 11 is immersed in the foam water for the second time, and the liquid film 12 will form a four-sided arc-shaped liquid film 14 with the tetrahedral body center 13 as the center.

[0065] S14: The four faces of the four-sided arc-shaped liquid film 14 cut the six triangular liquid films 12 to form six irregular quadrilateral liquid films 15.

[0066] The structures of the four-sided arc-shaped liquid film 14 and the six quadrilateral liquid films 15 are extracted to form an equivalent model of the hollowed-out unit cell structure.

[0067] S3 specifically includes the following steps:

[0068] S31: Draw a circle 25 with the center of the arc surface of the four-sided arc body 24;

[0069] S32: Process the material using the circle 25 as the boundary and remove the internal structure of the four-sided arc-shaped body 24;

[0070] S33: The four-sided arc-shaped body 24 is processed into a perforated arc plate 26, thereby forming a hollow single-cell crystal structure;

[0071] Specifically, the following implementation methods are provided and described in detail;

[0072] like Figure 2 and 3 As shown, when a rod-shaped tetrahedral framework 11 is immersed in foamy water, it will form six triangular liquid films 12 when it is first removed from the foamy water. These films are composed of the two endpoints of each side of the regular tetrahedron and the body center 13 of the tetrahedron (ignoring the influence of gravity). In other words, the interior of the tetrahedral framework 11 is divided into four smaller "tetrahedra" by the liquid films 12. It should be noted that this configuration formation mechanism involves the competition and coordinated balance of intermolecular forces and surface tension to form a stable configuration with minimum free energy.

[0073] extract Figure 3 For typical liquid film configurations, we established Figure 5 and Figure 6 The equivalent model shown is . Figure 5 and Figure 6 It is Figure 3 Each face without thickness in the model is given a thickness to form an "interior tetrahedron" structural model, and the face thickness is determined according to the functional requirements and specifications of the part.

[0074] like Figure 4 As shown, when the upper tetrahedral frame 11 is immersed in water again, due to the presence of gas, the liquid film 12 will form a four-sided arc-shaped liquid film 14 with the body center 13 of the tetrahedron as the center. The four sides of the four-sided arc-shaped liquid film 14 cut the six triangular liquid films 12 of the aforementioned "built-in tetrahedron" to form six irregular quadrilateral liquid films 15. The material inside the four-sided arc-shaped liquid film 14 is removed to form a cavity, at which point a single-cell structure with no thickness is formed.

[0075] It should be noted that at different foam water concentrations, the surface tension and viscosity of the fluid vary, resulting in different sizes and proportions of the four-sided arc-shaped body. Then, extraction... Figure 4 A typical liquid film configuration was established. Figure 7 and Figure 8 The equivalent model shown. Figure 7 and Figure 8 It is Figure 4 Each facet in the model, which has no thickness, is given a thickness to form a unit cell structure model. The facet thickness is determined by the functional requirements and specifications of the part.

[0076] To achieve lightweight and impact-resistant applications of single-cell structures, we employ customizable, flexible, and rapid additive manufacturing methods. Selective laser powder bed cladding (SLM) technology is widely used and offers high precision in metal / non-metal additive manufacturing. When manufacturing single-cell structures using SLM, it is essential to ensure the absence of sealed cavities within the structure, allowing for rapid removal of residual powder. When using other manufacturing processes, sealed cavities within the single-cell structure are not a necessary requirement. Therefore, we create a circle 25 at the center of each arc face of the tetrahedral body 24. Material is removed from the tetrahedral body 24 using this circle 25 to obtain a perforated arc plate 26, opening up the previously closed tetrahedral body 24 to remove redundant powder material (affected by additive manufacturing processes), etc. (See [link to relevant documentation]). Figure 9 and 10 This creates a hollowed-out single-cell crystal structure;

[0077] When the hollow unit cell structure is subjected to external loads, the perforated arc plate 26 can stabilize and reinforce the hollow unit cell structure, thereby improving the stability of the hollow unit cell structure. In addition, the hollow unit cell structure is symmetrical, which makes the force in all directions balanced when subjected to external loads, reduces anisotropy, and improves the stability of the hollow unit cell structure.

[0078] The specific cleaning methods for powder residues in the unit cell structure after additive manufacturing can be as follows: high-pressure air gun can be used to blow air out the powder through the through holes; cleaning liquid can be used to flush out the powder; ultrasonic waves can also be used for auxiliary treatment to accelerate the discharge of powder through vibration. The impact of the open structure on the hollow unit cell structure is minimized, thereby ensuring the stability of the unit cell structure.

[0079] In this example, the diameter of the circle 25 removed from the perforated arc plate 26 is approximately 2 / 3 of the arc length of the perforated arc plate 26; the vertex of the perforated arc plate 26 falls at 1 / 2 of the outer vertex of the tetrahedral frame 11.

[0080] If the diameter of the circular 25 through hole is too large or the position of the perforated arc plate 26 is too close to the side length of the regular tetrahedron, the strength and stiffness of the unit cell structure will be reduced. If the diameter of the circular 25 through hole is too small or the position of the perforated arc plate 26 is too close to the body center of the cube, the powder will be difficult to remove and the cleaning efficiency will be low.

[0081] like Figures 11 to 13 As shown, by mirroring and arranging a single-cell structure in three-dimensional space along the front-back, left-right, and up-down directions according to preset requirements, a multi-cell lattice structure (more than two single-cell units) can be obtained. There is more than one method for constructing multi-cell structures;

[0082] Here we use selective laser powder bed cladding (SLM) additive manufacturing technology to fabricate multi-cell lattice structures. First, the chamber of the SLM machine is filled with metal (or nylon, ceramic, etc., metal is used as an example here) powder. Then, this metal powder is distributed in a very thin layer across the entire substrate or laminate by a coating machine blade;

[0083] Then, a high-power laser melts 2D slices of the part by selectively melting the powdered material. A cover plate then descends one layer, and a coater finely spreads another layer of fresh powder across the entire surface. This process is repeated until the multicellular lattice structure is fabricated.

[0084] The entire process is performed in a controlled atmosphere inside the machine. Once the part is made, it can be removed from the machine. The SLM part needs to be removed from the build plate, which is typically done using a band saw.

[0085] Of course, additive manufacturing technology based on direct energy deposition (DED) can also be used to manufacture multi-cell lattice structures. The specific operation process is the same as that of manufacturing parts using DED technology commonly found on the market.

[0086] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A multi-cell lattice structure with a stable thin-film configuration, comprising multiple hollowed-out single-cell crystal structures, characterized in that: The hollow single-cell structure includes six triangular plates (21), which together form a regular quadrilateral. The six triangular plates (21) have the same structure and are fixedly connected to each other. The common vertex of the six triangular plates (21) is the center (23) of the regular quadrilateral. Four common sides (22) are formed in space starting from the center (23). The four common sides (22) are evenly distributed around the center (23), and the three triangular plates (21) are evenly distributed around the common sides (22). Six triangular plates (21) divide the space to form four quadrilaterals of equal shape. Each quadrilateral is provided with a four-sided arc body (24). The sides of the four-sided arc body (24) extend to the adjacent triangular plates (21). Multiple hollow single-cell crystal structures are symmetrically combined with the outer side of the triangular plates (21) as mirror faces to form a double-unit hollow single-cell crystal structure and a four-unit hollow single-cell crystal structure. The four-unit hollow single-cell crystal structure is used as the basic unit array to form a multi-cell lattice structure with a thin film stable configuration. Make a circle (25) with the center of the arc surface of the four-sided arc body (24), process the material with the circle (25) as the boundary, and remove the internal structure of the four-sided arc body (24) to form a perforated arc plate (26). The diameter of the circle (25) is two-thirds of the arc length of the tetrahedral body (24); Construct a tetrahedral solid (24) through the midpoint of the three common edges (22) within each quadrilateral.

2. The multi-cell lattice structure of the thin-film stable configuration according to claim 1, characterized in that: The triangle (21) is an isosceles triangle.

3. An additive manufacturing method for fabricating a multi-cell lattice structure with a thin film stable configuration as described in claim 1 or 2, characterized in that: The method includes the following steps: S1: Construct an equivalent model of a hollowed-out single-cell crystal structure; S2: Additive manufacturing unit cell structure model based on equivalent model; S3: Hollowed-out single-cell structure formed by material processing of single-cell structure; S4: The outer surfaces of the additively manufactured hollowed-out single-cell structure are symmetrically combined to form a double-unit hollowed-out single-cell structure and a four-unit hollowed-out single-cell structure. S5: A multi-cell lattice structure with a thin film stable configuration formed by an array of four-unit hollow single-cell crystal structures as the basic unit array. S1 specifically includes the following steps: S11: Construct a tetrahedral frame (11) and immerse the tetrahedral frame (11) in foam water; S12: Taking out the tetrahedral frame (11) will form six triangular liquid films (12) composed of the two endpoints of each side of the regular tetrahedron and the body center (13) of the regular tetrahedron. S13: The tetrahedral frame (11) is immersed in the foam water for the second time. The triangular liquid film (12) will form a four-sided arc-shaped liquid film (14) with the body center (13) of the regular tetrahedron as the center. S14: The four faces of the four-sided arc liquid film (14) cut the six triangular liquid films (12) to form six irregular quadrilateral liquid films (15).

4. The additive manufacturing method for constructing a multi-cell lattice structure with a thin film stable configuration according to claim 3, characterized in that: The structures of the four-sided arc-shaped liquid film (14) and the six quadrilateral liquid films (15) are extracted to form an equivalent model of the hollowed-out single-cell crystal structure.

5. The additive manufacturing method for constructing a multi-cell lattice structure with a thin film stable configuration according to claim 3, characterized in that: S3 specifically includes the following steps: S31: Draw a circle (25) with the center of the arc surface of the four-sided arc body (24). S32: Process the material using the circle (25) as the boundary and remove the internal structure of the four-sided arc body (24); S33: The four-sided arc body (24) is processed into a perforated arc plate (26), thereby forming a hollow single-cell crystal structure.

6. The additive manufacturing method for constructing a multi-cell lattice structure with a thin-film stable configuration according to claim 3, characterized in that: In S2, laser powder bed cladding additive manufacturing technology is used to manufacture a single-cell crystal structure model.

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