Structure, design method, printing equipment and printing method of pillar lattice

Abstract

The invention provides a pillar lattice structure which comprises an outer supporting portion and an inner supporting portion, the outer supporting portion comprises four supporting faces and four supporting pillars, and the four supporting faces are arranged in a square shape and define a square ring; each supporting surface comprises a left supporting part and a right supporting part, and the left supporting part and the right supporting part are both of a V-shaped structure; the V-shaped connecting ends of the left supporting part and the right supporting part are connected with each other, so that an X-shaped structure is formed after the left supporting part and the right supporting part are connected; the V-shaped extending ends of the left supporting part and the right supporting part are connected with the adjacent supporting surfaces; the four supporting columns are arranged at the four prisms of the square ring; the two ends of the supporting column are connected with the two ends of the left supporting part and the two ends of the right supporting part of the two adjacent supporting faces respectively. The structural design of the pillar lattice provided by the invention has remarkable advantages in improvement of the structural specific strength and light weight, and shows excellent deformation stability under a compression load in a specific load direction, and the advantage can be embodied through structural stability and mechanical properties.

Description

Technical Field

[0001] The invention relates to the technical field of laser selective melting, and in particular to a structure, a design method, a printing device and a printing method of a pillar lattice. Background Art

[0002] Metal lattice metamaterials are porous materials composed of interconnected pillars, plates, shells or their mixtures, usually organized in repeating unit cells with pore sizes ranging from millimeters to sub-millimeter. They have found important applications in various fields such as aerospace. Hollow pillar lattice metamaterials, as the name suggests, consist of interconnected hollow pillars instead of solid pillars. Initially, hollow pillar lattices (HSL) were manufactured in a multi-step method using lattice topological polymer templates coated with metal or ceramic before the template was etched to leave the hollow topology. However, this multi-step method is inefficient and geometrically limited. With the maturity of laser selective melting technology, Ti-6Al-4V hollow pillar lattice (HSL) metamaterials have been successful, and the development of this structure has become rapid, but because the material is relatively expensive, it needs to be replaced with some cheaper and more affordable materials to reduce costs while still providing high corrosion resistance. Summary of the invention

[0003] The object of the present invention is to provide a pillar lattice structure, design method, printing device and printing method to solve at least one technical problem existing in the prior art.

[0004] In order to solve the above technical problems, the present invention provides a pillar lattice structure, including an outer support portion, the outer support portion includes four support surfaces and four support columns, the four support surfaces are arranged in a square and form a square ring; Each supporting surface includes a left supporting portion and a right supporting portion, and both the left supporting portion and the right supporting portion are V-shaped structures; The V-shaped connecting ends of the left supporting part and the right supporting part are connected to each other, so that the left supporting part and the right supporting part are connected to form an X-shaped structure; The V-shaped outwardly extending ends of the left supporting portion and the right supporting portion are connected to adjacent supporting surfaces; Four support columns are arranged at four prisms of the square ring; The two ends of the support column are respectively connected to the two end portions of the left support portion and the right support portion of the two adjacent support surfaces.

[0005] Furthermore, the structure of the pillar lattice also includes an inner support portion; the inner support portion includes four support rods, both ends of the four support rods are respectively connected to the eight vertices of the square ring, and the centers of the four support rods intersect at the center of the square ring.

[0006] In a second aspect, the present application also discloses a method for designing a pillar lattice structure, comprising the steps of: A1: Establish an accurate XYZ three-dimensional coordinate system in three-dimensional space as the basic framework for building the lattice structure; A2: Determine the size and number of reciprocal lattice vectors required for reciprocal space construction according to the requirements of the target lattice structure; A3: Use Fourier transform to map the reciprocal lattice vector from the abstract reciprocal space to the actual real space, and derive the mathematical expression of the target superlattice polarization pattern; A4: Based on the expression obtained in step A3, use computing software to draw a corresponding graph to intuitively understand the shape and characteristics of the polarization pattern; A5: Customize the shape and size of the polarization pattern in the Y-axis direction according to actual needs (such as specific physical properties or application scenarios); A6: Designing a specific pattern of the target superlattice polarization pattern according to the shape and size of step A5; A7: The nonlinear coefficient is calculated to evaluate its influence on material properties; A8: Multiple designed polarization pattern fragments are combined together by flipping and splicing to form a basic unit with specific periodicity and symmetry; A9: The basic units constructed according to step A8 are replicated and arranged to construct the entire target superlattice polarization pattern.

[0007] In a third aspect, the present application also discloses a pillar lattice printing device, comprising a molding plane, a first laser, a second laser, a first galvanometer device, and a second galvanometer device; AlSi10Mg alloy powder is arranged on the molding plane; The first laser and the second laser cooperate with the first galvanometer device and the second galvanometer device respectively, and are used to perform 3D printing on the molding plane by laser selective melting.

[0008] Furthermore, the diameter of the laser generated by the first laser is 3 microns.

[0009] Furthermore, the laser amplitude distribution expression generated by the first laser is: .

[0010] Furthermore, a beam expander is provided between the first laser and the first galvanometer device.

[0011] Furthermore, a lens is arranged between the first galvanometer device and the molding plane.

[0012] Furthermore, a shaping lens is arranged between the beam expander and the first galvanometer device.

[0013] In a fourth aspect, the present application also discloses a method for printing a pillar lattice structure, comprising the steps of: S1: Determine the structural parameters of the pillar lattice; S2: pre-printing processing; S3: Setting laser parameters; S4: The first laser prints the inner and outer diameters; S5: The second laser prints the intermediate body; S6: Repeat S4 and S5 until printing is completed.

[0014] By adopting the above technical solution, the present invention has the following beneficial effects: (1) By adopting a design in which four supporting surfaces are arranged in a square shape and combining the left and right supporting parts of a V-shaped structure, the pillar lattice structure has excellent stability in multiple directions. This design can effectively resist external pressure or vibration and improve the stability of the overall structure.

[0015] (2) The X-shaped structure formed by the left and right support parts, as well as the connection method between the V-shaped protruding ends and the adjacent support surfaces, make the structure of the pillar lattice maximize the use of space while maintaining stability, thereby improving the compactness and efficiency of the structure.

[0016] Customized design flexibility: The unit cell size, lattice size, and the size of each support part and support column in this technical solution can be customized according to actual needs. This flexibility enables the structure of the pillar lattice to be suitable for different application scenarios and printing requirements, and has a wide range of applicability.

[0017] (3) The support column structure selected in the design and the connection method between the support column and the two ends of the V-shaped structure not only enhance the stability of the structure, but also improve the feasibility of the printing process. This design can ensure that the structure of the pillar lattice is not easily deformed or damaged during the laser printing process, thereby improving the printing success rate and product quality.

[0018] (4) Since the structure of the pillar lattice reduces unnecessary material usage through optimized design while maintaining strength and stability, effective material savings are achieved. This helps to reduce production costs and improve economic benefits.

[0019] (5) The structure of the pillar lattice has excellent stability, space utilization efficiency and printing feasibility, so it has broad application prospects in the field of laser 3D printing. It can be used to manufacture various parts and molds with complex structures, providing strong support for industrial design, aerospace, biomedicine and other fields.

[0020] (6) The accuracy of the design is ensured by constructing a precise XYZ three-dimensional coordinate system and designing the lattice structure on it. At the same time, the polarization pattern curve is drawn using computing software, making the design process more intuitive and easier to understand and adjust.

[0021] (7) The shape and size of the polarization pattern in the Y-axis direction can be customized according to actual needs, making the design highly flexible and able to meet the needs of different physical properties or application scenarios.

[0022] (8) By calculating the nonlinear coefficient, the impact of the design on material properties can be evaluated, so that necessary optimization adjustments can be made. This helps to foresee possible problems in the early stages of the design and make timely modifications.

[0023] (9) Multiple polarization pattern fragments are combined into a basic unit by flipping and splicing, ensuring the periodicity and symmetry of the entire lattice structure. This is crucial to improving the stability and performance of the material.

[0024] (10) The entire target superlattice polarization pattern is constructed by replicating and arranging, making the design process both efficient and scalable. This method can quickly generate complex lattice structures and adapt to design requirements of different scales and complexities.

[0025] (11) This technical solution applies mathematical methods such as Fourier transform to the actual design process, realizing the transformation from abstract theory to concrete practice. This not only improves the scientific nature of the design, but also provides a solid theoretical foundation for subsequent experiments and applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 A structural diagram of the structure of the pillar lattice; Figure 2 A partial cross-sectional view of the structure of a pillar lattice; Figure 3 This is a schematic diagram of the 3D printing sequence; Figure 4 A schematic diagram of the dual laser structure of the printing device for the pillar lattice; Figure 5 A schematic structural diagram of a first preferred embodiment of a printing device for a pillar lattice; Figure 6A schematic diagram of the structure of a second preferred embodiment of a printing device for a pillar lattice; Figure 7 A detailed flow chart of the structural design method for the pillar lattice; Figure 8 A detailed flow chart of a method for printing a structure of a hollow pillar lattice; Fig. 9 for Figure 8 Detailed flow chart of step S2 in FIG. Fig.10 for Figure 8 Detailed flow chart of step S3 in FIG. Fig.11 for Figure 8 Detailed flow chart of step S4; Fig.12 It is a structural schematic diagram of a melting printing device; Fig.13 It is a structural schematic diagram of a laser printing device; Fig.14 It is a schematic diagram of the three-dimensional structure of the powder absorbing device; Fig.15 for Fig.14 A partial cross-sectional view of Fig.16 for Fig.14 Schematic diagram of the plan structure of the injection pipe location.

[0028] Reference numerals: 1-left support part; 2-right support part; 3-support column; 4-molding plane; 5-first laser; 6-second laser; 7-first galvanometer device; 8-second galvanometer device; 9-beam expander; 10-lens; 11-shaping lens; 12-powder storage bin; 13-lifting part; 14-powder scraper; 15-laser; 16-scanner; 17-jet head; 18-suction device; 19-jet device; 20-printing nozzle; 21-wire feed guide wheel; 22-printing wire; 23-heating part; 24-lifting platform; 25-external support part; 26-internal support part. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] The present invention is further explained below in conjunction with specific implementation modes.

[0033] Embodiment 1: like Figure 1-2 As shown, the structure of a pillar lattice provided in this embodiment includes an outer support portion 25 and an inner support portion 26. The outer support portion 25 includes four support surfaces and four support columns 3. The four support surfaces are arranged in a square and form a square ring. Each support surface includes a left support portion 1 and a right support portion 2, and both the left support portion 1 and the right support portion 2 are V-shaped structures; The V-shaped connecting ends of the left supporting part 1 and the right supporting part 2 are connected to each other, so that the left supporting part 1 and the right supporting part 2 are connected to form an X-shaped structure; The V-shaped outwardly extending ends of the left supporting part 1 and the right supporting part 2 are connected to adjacent supporting surfaces; Four support columns 3 are arranged at the four prisms of the square ring; Both ends of the support column 3 are respectively connected to both ends of the left support portion 1 and the right support portion 2 of two adjacent support surfaces.

[0034] The inner support portion 26 includes four support rods, both ends of which are respectively connected to eight vertices of the square ring (the two ends of the four support columns 3), and the centers of the four support rods intersect at the center of the square ring.

[0035] As a further implementation of this embodiment, the unit cell of this structure is composed of a pillar part and a support column. The pillar part or the support column can be a hollow pillar or a solid pillar, and its outer diameter (d) is 1.5 mm. The unit cell size is 5×5×5 mm. 3 Since the minimum width of conventional lasers is 0.24 mm, the method in this paper can be used to print FCC and FCCZ lattices with a wall thickness greater than 0.24 mm.

[0036] Unit cell Figure 1-2 As shown, it is the smallest unit of the lattice structure. In the research in this field, 6 pixels are set in each direction as the average number of pixels used by researchers. In this application, the unit cell size is 5×5×5mm 3 For the lattice structure with 6 x 6 x 6 elements in the x, y and z directions, the lattice size is 31.5 x 31.5 x 31.5 mm. 3 .

[0037] By adopting the above technical solution, the present invention has the following beneficial effects: (1) By adopting a design in which four supporting surfaces are arranged in a square shape and combining the left supporting part 1 and the right supporting part 2 of the V-shaped structure, the structure of the pillar lattice has excellent stability in multiple directions. This design can effectively resist external pressure or vibration and improve the stability of the overall structure.

[0038] (2) The X-shaped structure formed by the left support part 1 and the right support part 2, and the connection method between the V-shaped protruding end and the adjacent support surface, make the structure of the pillar lattice maximize the use of space while maintaining stability, thereby improving the compactness and efficiency of the structure.

[0039] Customized design flexibility: The unit cell size, lattice size, each support part, the outer diameter and aperture of the support column in this technical solution can be customized according to actual needs. This flexibility makes the structure of the pillar lattice suitable for different application scenarios and printing requirements, and has a wide range of applicability.

[0040] (3) The support column 3 structure selected in the design, as well as the connection method between the support column 3 and the two ends of the V-shaped structure, not only enhances the stability of the structure, but also improves the feasibility of the printing process. This design can ensure that the structure of the pillar lattice is not easily deformed or damaged during the laser printing process, thereby improving the printing success rate and product quality.

[0041] (4) Since the structure of the pillar lattice reduces unnecessary material usage through optimized design while maintaining strength and stability, effective material savings are achieved. This helps to reduce production costs and improve economic benefits.

[0042] This structure overcomes the relatively low strength of BCC (body-centered cubic) or FCC (face-centered cubic) structures under compressive loads. The hollow pillars can show good deformation stability under compressive loads in the z-axis direction. By adjusting the topological layout and size design of the lattice structure, its mechanical properties can be further optimized to meet different design requirements. This optimization method based on structural customization provides flexibility and efficiency for structural applications under different working conditions.

[0043] Compared with a solid structure, each support part is a hollow structure in the middle, which significantly reduces the structural weight and material usage while maintaining the same strength and stiffness. By adjusting the internal hollow design, the structure can increase the elastic modulus, improve the Poisson's ratio, and achieve isotropic elasticity.

[0044] The structural design of the pillar lattice provided by the present invention has significant advantages in improving the structural specific strength and lightness, and exhibits excellent deformation stability under a compressive load in a specific load direction. This advantage can be reflected in the structural stability and mechanical properties: 1) In terms of structural stability, the Maxwell number is effectively improved M , thereby transforming the original lattice structure from a bending-dominated type to a tension-compression-dominated type, which greatly improves the stiffness of the lattice structure and thus improves its stability.

[0045] 2) In terms of mechanical properties, the structure of the pillar lattice has lower compliance (less stiffness) and higher load-bearing capacity in theory compared with the traditional body-centered cubic or face-centered cubic lattice, and there is Vertical (z direction) direction of the support column, so in Should The compressive strength and stiffness in the direction are high, and the remaining pillars are x Higher stiffness and deformation resistance in the y and y directions (5) The structure of the pillar lattice has excellent stability, space utilization efficiency and printing feasibility, so it has broad application prospects in the field of laser 3D printing. It can be used to manufacture various parts and molds with complex structures, providing strong support for industrial design, aerospace, biomedicine and other fields.

[0046] Embodiment 2: like Figure 7 The second embodiment of the present application is shown, which discloses a method for designing a pillar lattice structure, comprising the steps of: A1: Establish an accurate XYZ three-dimensional coordinate system in three-dimensional space as the basic framework for building the lattice structure; A2: Determine the size and number of reciprocal lattice vectors required for reciprocal space construction according to the requirements of the target lattice structure; A3: Use Fourier transform to map the reciprocal lattice vector from the abstract reciprocal space to the actual real space, and derive the mathematical expression of the target superlattice polarization pattern; A4: Based on the expression obtained in step A3, use computing software to draw a corresponding graph to intuitively understand the shape and characteristics of the polarization pattern; A5: Customize the shape and size of the polarization pattern in the Y-axis direction according to actual needs (such as specific physical properties or application scenarios); A6: Designing a specific pattern of the target superlattice polarization pattern according to the shape and size of step A5; A7: The nonlinear coefficient is calculated to evaluate its influence on material properties; A8: Multiple designed polarization pattern fragments are combined together by flipping and splicing to form a basic unit with specific periodicity and symmetry; A9: The basic units constructed according to step A8 are replicated and arranged to construct the entire target superlattice polarization pattern.

[0047] By adopting the above technical solution, the present invention has the following beneficial effects: (1) The accuracy of the design is ensured by constructing a precise XYZ three-dimensional coordinate system and designing the lattice structure on it. At the same time, the polarization pattern curve is drawn using computing software, making the design process more intuitive and easier to understand and adjust.

[0048] (2) The shape and size of the polarization pattern in the Y-axis direction can be customized according to actual needs, making the design highly flexible and able to meet the needs of different physical properties or application scenarios.

[0049] (3) By calculating the nonlinear coefficient, the impact of the design on material properties can be evaluated, so that necessary optimization adjustments can be made. This helps to foresee possible problems in the early stages of the design and make timely modifications.

[0050] (4) Multiple polarization pattern fragments are combined into a basic unit by flipping and splicing, ensuring the periodicity and symmetry of the entire lattice structure. This is crucial to improving the stability and performance of the material.

[0051] (5) The entire target superlattice polarization pattern is constructed by replicating and arranging, making the design process both efficient and scalable. This method can quickly generate complex lattice structures and adapt to design requirements of different scales and complexities.

[0052] (6) This technical solution applies mathematical methods such as Fourier transform to the actual design process, realizing the transformation from abstract theory to concrete practice. This not only improves the scientific nature of the design, but also provides a solid theoretical foundation for subsequent experiments and applications.

[0053] Embodiment 3: like Figure 3-6 The third embodiment of the present application is shown, which discloses a pillar lattice printing device, including a molding plane 4, a first laser 5, a second laser 6, a first galvanometer device 7 and a second galvanometer device 8; AlSi10Mg alloy powder is arranged on the molding plane 4; The first laser 5 and the second laser 6 cooperate with the first galvanometer device 7 and the second galvanometer device 8 respectively, and are used to perform 3D printing on the molding plane 4 by laser selective melting.

[0054] The diameter of the laser generated by the first laser 5 is 3 microns.

[0055] The laser amplitude distribution expression generated by the first laser 5 is: .

[0056] The laser generated by the first laser 5 is a high-precision laser with a small spot size of about 3 microns. Since the laser amplitude distribution expression of the high-precision laser is , The inner circle has high energy and the outer circle has low energy. The laser has strong focusing ability, high peak power and short duration, which can make the laser irradiated part reach about one thousand degrees, and the molten pool width is about 0.03mm, which can quickly melt the powder of the thin-walled part to achieve the effect of rapid molding.

[0057] Aluminum alloys have high reflectivity and thermal conductivity. The thermal conductivity of AlSi10Mg is about 103-173W / m in the horizontal direction and about 119-173W / m in the vertical direction. The reflectivity of aluminum powder itself is not high, but the laser reflectivity of aluminum powder after melting is about 91%, resulting in most of the laser energy being reflected and quickly conducting heat away from the molten pool. These characteristics require higher laser energy to achieve optimal powder melting and stable molten pool formation, but therefore, under equivalent energy input, the molten pool trajectory using aluminum powder will be much wider than that using titanium powder, because the heat will disperse and melt nearby powders. When the same wall thickness range as the successful SLM printing of Ti-6Al-4V is used, the forming effect of aluminum is worse, so high-energy small spot laser printing is also required.

[0058] As a further implementation of this embodiment, a beam expander 9 is further provided between the first laser 5 and the first galvanometer device 7 .

[0059] A lens 10 is further disposed between the first galvanometer device 7 and the molding plane 4 .

[0060] A shaping lens 11 is also provided between the beam expander 9 and the first galvanometer device 7 for focusing the energy distribution of the laser again, so that the laser spot becomes smaller and the energy is concentrated.

[0061] The lens 10 is an F-theta lens or an F-θ lens.

[0062] AlSi10Mg (557°C) has a low liquidus temperature compared to the high liquidus temperature of Ti-6Al-4V (1605±10°C). As a result, AlSi10Mg alloy powders tend to sinter and / or melt in hollow channels and external unit cell contours even at temperatures below 500°C (low-silicon commercial aluminum alloys are typically sintered at temperatures close to 600°C). As a result, powder occlusion in these narrow hollow channels is prone to occur, and external powder adhesion also develops easily as powder gathers in the corners of the unit cell topology. This is further exacerbated by the poor powder flowability commonly observed with aluminum powders compared to titanium powders. Therefore, SLM manufacturing of complex AlSi10Mg HSLs requires consideration of method design, including laser scanning strategies. High-precision laser scanning of the inner and outer walls can address this problem by improving the surface quality of the inner and outer walls.

[0063] So the molding surface after high-precision laser printing is smooth enough, there is no powder occlusion in the internal channels, and the pillars are well connected through each node. In addition, the small amount of powder adhering to the top of each external node now seems negligible. Since there are no deep surface cavities, the outer surface of each hollow pillar will appear smoother.

[0064] The generation of high-precision lasers relies on lasers with higher energy density and power than traditional fiber lasers. With a dedicated galvanometer system, the focused spot of the laser beam can be made smaller. A beam shaping lens 11 is added before scanning. The function of the lens is to focus the energy distribution of the laser again, making the laser spot smaller, the energy more concentrated, and the effect in printing better.

[0065] By adopting the above technical solution, the present invention has the following beneficial effects: (1) Using a high-precision laser with a diameter of 3 microns, combined with a specific laser amplitude distribution expression, the laser has strong focusing ability and high peak power, which can quickly melt the powder in the thin-walled part and achieve high-precision printing. This high-precision printing can ensure the surface quality of the inner and outer walls of the pillar lattice structure and improve the smoothness of the molding surface.

[0066] (2) In view of the characteristics of AlSi10Mg alloy powder, such as high reflectivity and thermal conductivity, high-precision laser printing can effectively avoid the occlusion problem of powder on the hollow channels and external unit cell contours, reduce the adhesion of external powder, and make the outer surface of each hollow pillar look smoother.

[0067] (3) 3D printing through laser selective melting, combined with the rapid melting capability of high-precision lasers, can significantly improve printing efficiency and shorten production cycles.

[0068] (4) Although this technical solution is optimized for AlSi10Mg alloy powder, its high-precision laser printing principle is also applicable to other metal materials with similar properties, improving the material applicability of the printing equipment.

[0069] (5) The first laser 5 and the second laser 6 equipped in the device can be controlled independently. By cooperating with different galvanometer devices, the printing of pillar lattice structures with different structures and complexities can be realized, which has high flexibility.

[0070] (6) By adding optical elements such as a beam expander 9, a lens 10 and a shaping lens 11, the focusing performance of the laser beam and the printing accuracy are further improved, thereby ensuring the stability and reliability of the printing process.

[0071] Embodiment 4: like Figure 8 The third embodiment of the present application is shown, which discloses a method for printing a hollow pillar lattice structure, comprising the steps of: S1: Determine the structural parameters of the pillar lattice; S2: pre-printing processing; S3: Setting laser parameters; S4: The first laser prints the inner and outer diameters; S5: The second laser prints the intermediate body; S6: Repeat S4 and S5 until printing is completed.

[0072] As a further implementation of this embodiment, step S1 is specifically: The unit cell size of the structure is fixed at 5×5×5mm 3 , set the outer diameter of the pillar to 1.5mm.

[0073] like Fig. 9 FIG. 2 is a further implementation of this embodiment, in which step S2 is specifically as follows: S21: Confirm that the laser printing area is consistent with the preset drawing, and check whether there is no slag, oxide, oil stain or other excess on the substrate surface; S22: Add AlSi10Mg powder so that the volume of the added powder is greater than twice the volume of the printed workpiece; S23: Confirm that the hard disk of the industrial computer of the equipment has sufficient storage space to prevent data loss during processing due to insufficient storage space; S24: Inject inert gas to ensure stable oxygen content in the construction environment during processing; S25: Check that the ambient temperature of the space where the equipment is located is maintained between 15-30°C and the humidity is less than 50% to prevent the powder from getting damp and the device from being damaged; S26: Check whether the water circuit, electrical circuit and anti-static device are normal.

[0074] like Fig.10 It is shown as a further implementation of this embodiment, and step S3 is specifically: S31: setting the sizes of the lasers finally emitted by the first laser and the second laser, wherein the laser of the first laser is 3 microns, and the laser of the second laser is larger than 3 microns; S32: Setting the printing paths of the two lasers.

[0075] like Fig.11 It is shown as a further implementation of this embodiment, and step S4 is specifically: S41: Identify and determine the area that needs to be printed with dual lasers; S42: Turn on the first laser to scan the outer wall, and turn off the first laser after the scanning is completed; S43: Turn on the first laser to scan the inner wall, and turn off the first laser after the scanning is completed; S44: Detect oxygen content, ambient temperature, environmental suitability, equipment powder surface flatness, and remaining powder amount through sensors; S45: If the oxygen content is less than 500ppm, the ambient temperature is between 20-35°C, the humidity is less than 90, the powder surface of the equipment is flat, and the powder is sufficient, then implement step S5, otherwise activate the alarm system.

[0076] The oxygen content is usually kept below 1000ppm during printing, but because high-precision lasers are used in this patent, the spot size is smaller and the energy density is higher, and the requirements for preventing oxidation are higher. Therefore, it is best to keep the oxygen content below 500ppm to achieve better molding effects and meet higher requirements.

[0077] By adopting the above technical solution, the present invention has the following beneficial effects: (1) By setting the specific outer diameters of the left, right, and inner support parts and the outer diameters of the support columns, the apertures, and other parameters, the structure of the hollow pillar lattice can be precisely controlled to meet the size and accuracy requirements of specific applications.

[0078] By setting specific parameters such as unit cell size, pore size and outer diameter of support pillar 3, the structure of the hollow pillar lattice can be precisely controlled to meet the size and precision requirements of specific applications.

[0079] (2) The first laser 5 and the second laser 6 are used to print the inner and outer diameters and the middle body respectively. This dual laser printing technology improves the printing efficiency and accuracy, and ensures the quality of the inner and outer walls of the hollow pillar lattice structure.

[0080] (3) Through strict preparation and processing before printing, including confirming the printing area, checking the substrate surface, adding powder, checking environmental parameters, etc., various potential problems in the printing process are effectively avoided, ensuring the smooth progress of the printing process and the printing quality.

[0081] (4) During the printing process, the stability of the processing environment is ensured by injecting inert gas and controlling the ambient temperature and humidity, thereby reducing the impact of the environment on the printing quality.

[0082] (5) Sensors are used to monitor parameters such as oxygen content, ambient temperature, humidity, powder surface flatness, and the amount of remaining powder in real time, and an alarm system is activated when the parameters do not meet the requirements, ensuring the safety and reliability of the printing process.

[0083] (6) By precisely controlling printing parameters and optimizing the printing process, material waste can be reduced and printing efficiency can be improved, thereby reducing costs and improving production benefits.

[0084] Embodiment 5: like Figure 12-16 As shown in the figure, this embodiment discloses a device suitable for laser 3D printing, including a powder storage bin 12, a lifting part 13, a powder scraper 14, a lifting platform 24, a laser 15, a scanner 16, an air jet 17, an air suction device 18, an air jet device 19, a printing nozzle 20, a wire feed guide wheel 21, a printing wire 22 made of a second material and a heating part 23.

[0085] The powder storage bin 12 is filled with metal powder made of a specific first material. The powder is strictly screened to ensure that its quality and performance meet the processing requirements.

[0086] The first material has a melting point lower than that of the second material.

[0087] A lifting part 13 is provided at the bottom of the powder storage bin 12. The lifting part 13 is precisely designed, and through precise mechanical operation, the metal powder in the powder storage bin 12 can be gradually ejected to ensure the thickness and uniformity of the powder layer.

[0088] The top of the lifting platform 24 and the top of the powder storage bin 12 are on the same horizontal plane.

[0089] As the lifting part 13 is lifted, the protruding metal powder is pushed by the powder scraper 14. The powder scraper 14 is carefully designed and adjusted, and its shape and angle can ensure that the metal powder is evenly spread on the lifting platform 24 during the pushing process to form a flat powder bed.

[0090] The laser 15 is responsible for emitting laser light and transmitting the laser light to the scanner 16. The laser 15 has stable output performance and a precise control system to ensure the quality and stability of the laser beam.

[0091] The scanner 16 receives the laser beam from the laser 15 and changes the path of the laser through the built-in galvanometer technology. This technology allows the emission direction, speed and energy density of the laser beam to be precisely controlled to meet different processing requirements.

[0092] The diameter of the nozzle 17 is precisely controlled to ensure that it is smaller than the inner diameter of the outer wall of the pillar, so that it can smoothly enter and operate inside the pillar. The nozzle 17 is further divided into an outer package area and an inner package tube. The outer package area is arranged outside the inner package tube, providing additional structure and function for the nozzle 17.

[0093] The inner tube, as a tube body, is directly connected to the air suction device 18. This design enables the inner tube to quickly and effectively suck air or gas when needed, providing power for subsequent jet operation.

[0094] The outer package area is connected to the jet device 19 through a specific pipeline. This connection mode ensures the stable flow of gas and, when necessary, quickly transmits the gas to the outer package area through the jet device 19.

[0095] One or more circles of jet holes are arranged circumferentially on the side wall of the outer package area. The design of these jet holes allows the gas to be uniformly and widely ejected, thereby effectively interacting with the powder layer to achieve absorption or dispersion of the powder layer.

[0096] The printing wire 22, as a manufacturing raw material, is stably delivered to the printing nozzle 20 through the rotation drive of the wire feed guide wheel 21. The precise control of the wire feed guide wheel 21 ensures the continuity and stability of the wire, providing a basis for the subsequent melting process.

[0097] A heating unit 23 is provided on the print head 20. The main function of the heating unit 23 is to heat and melt the printing wire 22 entering the print head. By precisely controlling the temperature of the heating unit 23, the printing wire 22 can be uniformly heated to above the melting point inside the print head, thereby transforming into a molten state, ready for the subsequent deposition process.

[0098] The controller, as the brain of the fused deposition device, is responsible for controlling the movement and printing of the print head 20 according to a preset program. It can accurately control the movement trajectory of the print head according to the parameters set by the user, such as printing speed, printing path, etc., to ensure the accuracy and efficiency of the printing process.

[0099] In order to monitor the temperature of the molten material in real time during the printing process, the device is provided with a temperature sensor on the print head 20. The sensor can detect the temperature of the molten material at the print head in real time and feed the data back to the controller. By analyzing the data, the controller can adjust the temperature of the heating part 23 in time to ensure that the temperature of the molten material is stable within a suitable range.

[0100] In addition, the device is also equipped with a temperature measuring device, namely an infrared thermometer. The thermometer is set on the printing platform to detect the temperature of the pillar lattice structure on the printing platform. Through infrared technology, the thermometer can measure the temperature of the lattice structure non-contactly, providing an important reference for temperature control during the printing process.

[0101] The temperature sensor and the temperature measuring device are both electrically connected to the controller. When the temperature measuring device detects that the structure of the pillar lattice on the printing platform cools to a preset temperature range, the print head 20 starts to work. This electrical connection method ensures the accuracy and real-time nature of the data, so that the controller can make accurate judgments and decisions based on the data to further optimize the printing process.

[0102] By adopting the above technical solution, the present invention has the following beneficial effects: (1) Through the precise control of the laser 15 and the scanner 16, the emission direction, speed and energy density of the laser beam can be accurately adjusted, thereby ensuring high-precision processing during the printing process and meeting the fine manufacturing requirements of complex structures.

[0103] (2) The synergistic effect of the lifting part 13 and the powder scraper 14 enables the metal powder to be evenly spread on the lifting platform to form a flat powder bed. This uniformity is crucial to ensure the surface quality and uniformity of the internal structure of the printed part.

[0104] (3) The design of the air jet head 17 and the air suction device 18 enables the gas to be precisely controlled as needed to interact with the powder layer to achieve absorption or dispersion of the powder layer. This flexibility facilitates gas management during the printing process.

[0105] (4) The precise control of the wire feed guide wheel 21 ensures the stable delivery of the printing wire 22, providing a reliable basis for the subsequent melting process. This helps to reduce the failure rate during the printing process and improve printing efficiency.

[0106] (5) The cooperation between the heating unit 23 and the temperature sensor can detect and adjust the temperature of the molten material in real time to ensure that it works stably within a suitable range. This helps to ensure the quality and performance of the printed part.

[0107] (6) The setting of infrared thermometer can measure the temperature of the pillar lattice structure on the printing platform in a non-contact manner, providing an important reference for temperature control during the printing process. This monitoring method is not only accurate, but also does not cause damage to the printed parts.

[0108] (7) The controller, as the core of the device, can accurately control the movement and printing of the print head 20 according to the preset program and the parameters set by the user, thus realizing an intelligent and automated printing process. This helps to improve printing efficiency and reduce the difficulty of operation.

[0109] Embodiment 6: The sixth embodiment of the present application discloses a printing method for a hollow pillar lattice structure based on the fourth embodiment, comprising the steps of: B1: Laying metal powder through powder storage bin, lifting part and powder scraper; B2: Print the outer wall of the pillar by laser and scanner; B3: The metal powder inside the outer wall of the pillar is sucked out at a fixed point through the air jet head, the air suction device and the air jet device; B4: Heat and pre-melt the outer wall of the pillar; B5: Filling the molten material into the area inside the outer wall of the pillar through the printing nozzle, the wire guide wheel, the printing wire and the heating part; B6: Repeat steps B1-B5 until printing is completed.

[0110] As a further implementation of this embodiment, step B1 is specifically as follows: B11: The metal powder in the powder storage bin is lifted to the height of the printing platform through the lifting part; B12: The powder scraper spreads the metal powder on the printing platform to form a powder bed; As a further implementation of this embodiment, step B3 is specifically as follows: B31: Move the jet head to the outer wall of the pillar and turn on the suction device; B32: After the air suction device is turned on for 1 second, the air suction device is turned off and the air injection device is turned on; B33: 0.1s after the jet device is turned on, the suction device is turned on; B34: The suction device is turned on for 0.5-1s and then turned off, and the suction device and the jet device are turned off at the same time; B35: Return the nozzle to its initial position.

[0111] During the metal 3D printing process, metal powders tend to accumulate easily in the hollow area of ​​the outer wall of the pillar. In order to effectively remove these powders, the suction device 18 is first started, which can suck away most of the metal powders in the hollow of the outer wall of the pillar. However, due to the complexity of the structural design and the particularity of the corner area, a small amount of powder will still remain in the corner. In order to achieve a better cleaning effect, after the suction operation lasts for 1 second, the suction device 18 is turned off and the jet device 19 is started instead. The opening of the jet device 19 will disturb the remaining powder in the corner, making it no longer close to the wall surface. Then, within 0.1 seconds after the jet device 19 is turned on, the suction device 18 is started again. This operation not only increases the disturbance of the powder, making it easier to float, but also effectively sucks the powder floating in the air into the suction device 18 by forming an air circulation in the hollow of the outer wall of the pillar. If the time interval between the opening of the jet device 19 and the opening of the second air suction device 18 is set too large, the powder in the hollow of the outer wall of the pillar may be scattered into the environment due to too long a time. Although this can also reduce the powder residue on the outer wall of the pillar to a certain extent, there are several significant disadvantages in doing so. First, the powder that could have been recycled and reused by the air suction device 18 will be difficult to recycle once it is scattered into the environment, resulting in a waste of resources. Second, after the printing is completed, when the equipment seal is opened, these scattered metal powders may pose health or safety risks to the experimenters. Based on the above considerations, as well as the empirical data obtained by the inventor through multiple experiments, it was finally determined that the time interval between the opening of the jet device 19 and the opening of the second air suction device 18 is 0.1 seconds. The selection of this time interval can not only ensure that the powder is fully disturbed and floated, but also effectively avoid the occurrence of the above-mentioned disadvantages, achieving dual optimization of cleaning effect and resource utilization.

[0112] As a further implementation of this embodiment, step B4 is specifically as follows: B41: Reduce the laser power to 90-95% of the original power; B42: Scan along the inner side of the outer wall of the pillar using a laser and a scanner.

[0113] A key step in optimizing the material processing process is to achieve precise heating of specific material areas by accurately controlling the laser power. Specifically, when the inner side of the pillar outer wall is scanned with a laser at 90% to 95% of the original power, this area can quickly reach a specific temperature range, that is, 75% to 90% of the melting point. This precise temperature control ensures that the heating process will neither cause excessive melting of the material due to excessive heating nor fail to achieve the expected melting effect due to insufficient temperature. After the inner side of the pillar outer wall reaches the predetermined temperature, the molten second material begins to play its role. Due to the heat conduction effect, the second material can effectively transfer heat to the inner side of the pillar outer wall made of the first material, further promoting the temperature rise of this area. As the temperature continues to rise, the inner wall of the pillar outer wall gradually reaches a molten state. At this time, the inner side of the pillar outer wall and the molten second material interpenetrate each other, and the two materials fuse with each other at the molecular level. This interpenetration process not only strengthens the bonding force between the two materials, but also forms a more uniform and stable structure at the interface of the materials. When the entire system is cooled, the mechanical properties of the interface between the two materials are significantly improved. This optimized processing flow not only improves the overall performance of the material, but also ensures the stability and reliability of product quality.

[0114] As a further implementation of this embodiment, step B5 is specifically as follows: B51: Move the print head to the top of the hollow space on the outer wall of the pillar; B52: The printing filament is driven by the filament guide wheel to enter the printing nozzle, and the heating part is turned on to melt the printing filament; B53: The print head fills the molten printing filament into the hollow position of the outer wall of the pillar; B54: Return the print head to its initial position.

[0115] By adopting the above technical solution, the present invention has the following beneficial effects: (1) Compared with traditional solid or hollow pillar lattice metamaterials, the lattice composite metamaterial structure shows significant superiority in performance. This advantage is mainly due to its unique manufacturing method, which allows us to achieve customized regulation of various properties such as structural toughness, conductivity, stiffness, etc. by selectively filling molten materials with different properties according to needs. This flexibility enables the lattice composite metamaterial to be widely used in different fields and meet the specific needs of different application scenarios.

[0116] (2) During the manufacturing process, by precisely setting the printing parameters and pre-processing the printing environment, combined with the application of laser melting technology, we successfully achieved high-precision printing of the outer wall of the pillar. This not only ensures the accuracy of the structure, but also ensures the uniformity and consistency of the material. In addition, in order to further improve the quality of the molten deposition process, we used a powder layer absorption device to remove the residual metal powder in the outer wall of the pillar. This measure effectively reduced the impact of impurities on the structural performance, thereby obtaining a higher quality composite metamaterial structure.

[0117] (3) The powder layer absorption device plays a key role in the manufacturing process. It can effectively remove the metal powder remaining in the outer wall of the pillar to prevent the powder from adversely affecting the structural performance. At the same time, the removed powder can be recycled and reused, which not only improves the utilization rate of materials but also reduces production costs. This recycling method helps to achieve sustainable utilization of resources and is in line with the green development concept of modern manufacturing.

[0118] (4) During the manufacturing process, the dispersion of metal powder is an issue that needs attention. In order to prevent the metal powder from scattering into the environment and causing adverse effects on equipment and personnel, we adopted a combined control method of the jet device 19 and the suction device 18. By accurately controlling the working sequence of the two devices, we successfully achieved effective control of the metal powder. This control method not only improves the recycling rate of the powder, but also reduces the impact on the environment and personnel, and meets the requirements of environmental protection and safe production.

[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pillar lattice structure, characterized in that: The outer support part includes four support surfaces and four support columns, and the four support surfaces are arranged in a square and form a square ring; Each supporting surface includes a left supporting portion and a right supporting portion, and both the left supporting portion and the right supporting portion are V-shaped structures; The V-shaped connecting ends of the left supporting part and the right supporting part are connected to each other, so that the left supporting part and the right supporting part are connected to form an X-shaped structure; The V-shaped outwardly extending ends of the left supporting portion and the right supporting portion are connected to adjacent supporting surfaces; Four support columns are arranged at four prisms of the square ring; The two ends of the support column are respectively connected to the two end portions of the left support portion and the right support portion of the two adjacent support surfaces.

2. The pillar lattice structure according to claim 1, characterized in that: The structure of the pillar lattice also includes an inner support portion; the inner support portion includes four support rods, both ends of the four support rods are respectively connected to the eight vertices of the square ring, and the centers of the four support rods intersect at the center of the square ring.

3. A method for designing a pillar lattice structure, comprising the steps of: A1: Establish an accurate XYZ three-dimensional coordinate system in three-dimensional space as the basic framework for building the lattice structure; A2: Determine the size and number of reciprocal lattice vectors required for reciprocal space construction according to the requirements of the target lattice structure; A3: Use Fourier transform to map the reciprocal lattice vector from the abstract reciprocal space to the actual real space, and derive the mathematical expression of the target superlattice polarization pattern; A4: Based on the expression obtained in step A3, use computing software to draw a corresponding graph to intuitively understand the shape and characteristics of the polarization pattern; A5: Customize the shape and size of the polarization pattern in the Y-axis direction according to actual needs (such as specific physical properties or application scenarios); A6: Designing a specific pattern of the target superlattice polarization pattern according to the shape and size of step A5; A7: The nonlinear coefficient is calculated to evaluate its influence on material properties; A8: Multiple designed polarization pattern fragments are combined together by flipping and splicing to form a basic unit with specific periodicity and symmetry; A9: The basic units constructed according to step A8 are replicated and arranged to construct the entire target superlattice polarization pattern.

4. A printing device for the pillar lattice according to any one of claims 1 to 2, comprising a molding plane, a first laser, a second laser, a first galvanometer device and a second galvanometer device; AlSi10Mg alloy powder is arranged on the molding plane; The first laser and the second laser cooperate with the first galvanometer device and the second galvanometer device respectively, and are used to perform 3D printing on the molding plane by laser selective melting.

5. The printing device according to claim 4, characterized in that: The laser generated by the first laser has a diameter of 3 microns.

6. The printing device according to claim 4, characterized in that: The laser amplitude distribution expression generated by the first laser is: 。 7. The printing device according to claim 4, characterized in that: A beam expander is also provided between the first laser and the first galvanometer device.

8. The printing device according to claim 7, characterized in that: An F-theta lens or an F-θ lens is also arranged between the first galvanometer device and the molding plane.

9. The printing device according to claim 8, characterized in that: A shaping lens is also provided between the beam expander and the first galvanometer device for focusing the energy distribution of the laser again, so that the laser spot becomes smaller and the energy is concentrated.

10. A method for printing a pillar lattice structure, comprising the steps of: S1: Determine the structural parameters of the pillar lattice; S2: pre-printing processing; S3: Setting laser parameters; S4: The first laser prints the inner and outer diameters; S5: The second laser prints the intermediate body; S6: Repeat S4 and S5 until printing is completed.

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