High Energy Absorption Rate TPMS Porous Alloy Energy Absorber and Its Preparation Method

Abstract

This invention provides a high-energy-absorption-rate TPMS porous alloy energy-absorbing box and its preparation method. The TPMS porous alloy energy-absorbing box uses an AlSi10Mg alloy for the outer frame and TPMS porous structural units, giving the product lightweight, high load-bearing capacity, and resistance to stress concentration. Under impact loads, it can achieve uniform deformation and gradual collapse, forming a stable plateau stress zone, significantly improving overall energy absorption efficiency and structural stability. By controlling the relative density and topology of the TPMS structural units and optimizing the preparation process parameters, this invention achieves a maximum compressive strength of 127.5 MPa, a maximum elastic modulus of 4.48 GPa, and a maximum volumetric energy absorption of 13.01 kJ / cm². 3 It is applicable to aerospace, automotive anti-collision structures, and various protective equipment fields.

Description

Technical Field

[0001] This invention relates to the field of porous metal structures and energy absorption devices, specifically to a TPMS porous alloy energy-absorbing box with high energy absorption rate and its preparation method, which is applicable to fields such as aerospace, automobile manufacturing, and rail transportation that have stringent requirements for lightweighting and energy absorption performance. Background Technology

[0002] With the rapid development of modern industrial technology, aerospace, rail transportation, automotive engineering, and protective equipment fields have placed increasingly stringent comprehensive performance requirements on structural materials, especially in the synergistic improvement of lightweight, high strength, and efficient energy absorption. In practical engineering applications, key structural components not only need sufficient static load-bearing capacity to support daily operating conditions, but also need to efficiently dissipate energy through controlled plastic deformation when subjected to unexpected impacts or collision loads, thereby effectively reducing the damage to the main structure and personnel caused by impact loads. Therefore, the design and manufacture of high-performance energy-absorbing structures has become one of the important research directions in the interdisciplinary field of engineering mechanics and materials science.

[0003] To meet the stringent comprehensive performance requirements, porous materials have gradually become a core technological approach to improve energy absorption performance, thanks to continuous advancements in materials science and structural design methods. Porous structures, by introducing a large number of controllable pores within the material, achieve significant weight reduction while absorbing substantial impact energy during loading through various mechanisms such as pore wall buckling and plastic collapse, thereby significantly improving the material's specific energy absorption performance. Among these, periodic porous structures have become a research hotspot in the field of energy-absorbing materials due to their advantages such as regular structure, quantifiable controllable geometric parameters, and predictable mechanical properties. Among the many types of periodic porous structures, the Triply Periodic Minimal Surface (TPMS) structure has attracted widespread attention from academia and industry due to its unique geometric and topological characteristics. TPMS structures are a type of continuous curved surface that extends periodically in three-dimensional space, with a constant average curvature, and inherent characteristics of being non-self-intersecting and having a smooth, continuous surface. Compared to traditional truss structures or honeycomb structures, TPMS structures do not have obvious node connections, effectively avoiding stress concentration problems and thus improving the overall mechanical performance of the structure. In addition, the TPMS structure has a natural three-dimensional interconnected pore network, which enables it to achieve a more uniform stress distribution and a more stable deformation mode during compression.

[0004] Based on these superior geometric and mechanical properties, TPMS structures typically exhibit a distinct three-stage mechanical response under compressive loads: an initial elastic deformation stage, a long stable plateau stage, and a final densification stage. The plateau stage corresponds to the continuous plastic collapse of the structure and the absorption of energy; the stability of the plateau stress and the length of the plateau interval are core indicators for evaluating energy absorption performance. Compared to traditional porous structures, TPMS porous structures often possess longer and more stable plateau intervals, maintaining a constant energy absorption capacity over a larger deformation range, thus significantly improving overall energy absorption efficiency. Although TPMS structures have demonstrated excellent energy absorption performance in both theoretical analysis and experimental research, several key challenges remain to be addressed in transitioning from the laboratory to practical engineering applications.

[0005] First, the geometry of TPMS structures is extremely complex, making it difficult for traditional manufacturing processes (such as casting and machining) to achieve high-precision machining of their complex surfaces, and easily leading to internal defects, which severely limits their engineering applications. Second, different TPMS topologies and key geometric parameters (such as wall thickness, periodic dimensions, and relative density) significantly affect the mechanical properties of the structure, but existing research mostly focuses on the uniform density design of single topologies, lacking systematic research on advanced design methods such as multi-topology combinations and gradient densities. Furthermore, how to achieve ideal progressive collapse deformation through structural design under actual complex impact load conditions, rather than sudden overall shear failure, still requires further in-depth research.

[0006] In summary, existing technologies for the design and manufacturing of porous energy-absorbing structures still suffer from systemic problems such as limited structural forms, manufacturing processes, insufficient performance control, and unstable deformation modes. There is an urgent need to develop a novel, high-performance, and easily engineered TPMS porous metal energy-absorbing box to comprehensively improve overall energy absorption efficiency and further expand its engineering applications in key fields such as aerospace and rail transportation. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to address the above-mentioned deficiencies in the prior art by providing a high-energy-absorption-rate TPMS porous alloy energy-absorbing box and its preparation method, so as to solve the technical problems of low energy absorption efficiency and unstable structure of porous alloy materials in the prior art.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a high energy absorption rate TPMS porous alloy energy-absorbing box, including an outer frame body and a TPMS porous structure unit filled inside the outer frame body. Both the outer frame body and the TPMS porous structure unit are made of AlSi10Mg alloy. The outer frame is a square or rectangular hollow frame used to constrain the deformation mode of the TPMS porous structural unit. The TPMS porous structural unit is a three-period minimal surface configuration, forming a continuous porous network inside.

[0009] Specifically, the aforementioned TPMS porous alloy energy-absorbing box adopts a composite design combining an AlSi10Mg alloy (Si content approximately 10wt%) with an outer frame and TPMS porous structural units. The high specific strength and corrosion resistance of the AlSi10Mg alloy enable lightweighting. The square or rectangular outer frame constrains the lateral expansion of the internal TPMS porous structural units, preventing unexpected shear failure and improving energy absorption stability. The TPMS three-period minimal curved surface configuration has no stress concentration nodes, and combined with a continuous through-pore network, it can achieve uniform stress distribution, thereby achieving efficient and stable energy absorption.

[0010] Preferably, the TPMS porous structural unit is selected from one or more of the following: Gyroid structure (helical icosahedron), Diamond structure (Schwarz diamond surface), and Primitive structure (Schwarz P surface).

[0011] Specifically, the above-mentioned multi-structure combination design can further expand the range of energy absorption performance control and adapt to diverse engineering needs: the Gyroid structure has good isotropy and excellent energy absorption; the Diamond structure has high specific strength; and the Primitive structure has good manufacturability.

[0012] Preferably, the relative density of the TPMS porous structural unit is 10% to 60%.

[0013] Specifically, this range ensures that the energy-absorbing box achieves optimal specific energy absorption performance while meeting load-bearing requirements: when the relative density is below 10%, the structural strength is insufficient and it is prone to brittle fracture; when the relative density is above 60%, the lightweight advantage is lost and the deformation is unstable.

[0014] Preferably, the porosity of the TPMS porous structural unit can be adjusted to 10%–60% by adjusting the structural parameters, and the unit size is 30–50 mm.

[0015] Specifically, the porosity can be adjusted from 10% to 60% through structural parameters (TPMS cell wall thickness, relative density, topology type and cell size), achieving precise customization of energy absorption performance and matching different impact load conditions; the 30-50mm unit size is suitable for standard installation space in aerospace, rail transportation and other fields, significantly improving the product's versatility and interchangeability.

[0016] Preferably, the TPMS porous structural units are arranged periodically along the pressure direction, and the unit size is 2 to 10 mm.

[0017] Specifically, the TPMS structure is arranged periodically along the compression direction, which ensures the uniformity and predictability of compression deformation and avoids premature local failure; the unit size of 2 to 10 mm not only meets the forming accuracy requirements of selective laser melting technology, but also ensures that the hole wall has sufficient load-bearing capacity.

[0018] Preferably, the TPMS porous structure unit is a non-porous structure, or it has a through hole at its center; the through hole is a circular through hole or a square through hole.

[0019] Specifically, the non-perforated structure has good overall continuity and does not have the problem of local stress concentration caused by openings, resulting in excellent structural integrity and fatigue resistance; opening circular through holes can optimize the load transfer path and effectively improve the peak load capacity, compressive stability and energy absorption efficiency of the structure; opening square through holes can meet the usage requirements of special assembly and installation conditions.

[0020] Preferably, both the outer frame body and the TPMS porous structure unit are provided with gradient wall thickness regions. The gradient wall thickness regions are divided into continuous and discrete types, and their wall thickness increases or decreases sequentially along the loading direction.

[0021] Specifically, by adopting continuous or discrete gradient wall thicknesses and making the wall thickness change in an orderly manner along the loading direction, the stress characteristics of compressive loads can be matched, the structural mechanical response can be directionally controlled, and local instability can be delayed. The gradient wall thicknesses of the outer frame and the internal units are set synchronously, which can achieve coordinated deformation and effectively improve the structural load-bearing stability and energy absorption efficiency.

[0022] Preferably, the TPMS porous alloy energy-absorbing box is integrally formed using selective laser melting technology.

[0023] Specifically, selective laser melting technology enables seamless connection between the outer frame and the TPMS porous structural unit, avoiding stress concentration and connection failure caused by welding or bonding; at the same time, it solves the problem that traditional processes cannot manufacture complex TPMS curved surface structures with high precision, greatly improving the overall structure and manufacturing accuracy.

[0024] Preferably, the density of the outer frame body is gradient-distributed along the loading direction to improve energy absorption efficiency.

[0025] Specifically, the above design enables the TPMS porous alloy energy-absorbing box to undergo orderly and gradual deformation from the low-density end to the high-density end during compression, avoiding the overall sudden shear failure that is prone to occur in uniform density structures, thereby significantly improving the overall energy absorption efficiency.

[0026] Preferably, the TPMS porous structural unit has a compressive strength ≤127.5MPa, an elastic modulus ≤4.48GPa, and a volumetric energy absorption ≤13.01kJ / cm³. 3 .

[0027] Specifically, the aforementioned superior performance indicators make the TPMS porous alloy energy-absorbing box less prone to damage under load conditions, while it can stably perform its energy-absorbing function, effectively adapting to various impact protection scenarios and ensuring stable and reliable product performance.

[0028] Preferably, the TPMS porous structural unit undergoes progressive collapse under compressive load, resulting in a stable plateau stress zone forming the entire TPMS porous alloy energy-absorbing box.

[0029] Specifically, the above design enables the TPMS porous alloy energy-absorbing box to form a stable platform stress zone, which can continuously and uniformly dissipate impact energy within a large deformation range, avoiding the violent impact caused by the instantaneous release of energy and minimizing damage to the main structure and personnel.

[0030] Accordingly, the present invention also provides a method for preparing a high-energy-absorption-rate TPMS porous alloy energy absorber as described in any of the above claims. The method employs powder bed melt molding technology and uses AlSi10Mg alloy powder as raw material to prepare the TPMS porous alloy energy absorber, specifically including the following steps: S10: A three-dimensional structural model of the TPMS porous alloy energy-absorbing box was designed and constructed using computer-aided design software, and then sliced ​​and layered. S20: Import the three-dimensional slice data corresponding to the three-dimensional structural model into the powder bed melting molding equipment, and use AlSi10Mg alloy powder as raw material to print the material layer by layer according to the preset process parameters. The preset process parameters are: laser power of 100-300W, scanning distance of 50-300μm, layer thickness of 30-60μm, and scanning speed of 600-1500mm / s.

[0031] Specifically, this invention employs a powder bed fusion molding process with AlSi10Mg alloy powder. First, computer-aided design is used to complete model building and slicing. Then, relying on equipment, the model is printed layer by layer according to process parameters such as limited laser power, scanning spacing, layer thickness, and scanning speed. The entire process can complete the integrated fabrication of complex TPMS porous energy-absorbing boxes in one go. The optimized process parameters can ensure that the alloy powder is fully melted and the interlayer bonding is tight, effectively improving the density, dimensional accuracy, and mechanical uniformity of the formed components. This not only overcomes the problem of traditional processes being unable to process complex curved porous structures, but also enables stable mass production, taking into account molding quality, production efficiency, and engineering practicality.

[0032] The present invention first provides a high energy absorption rate TPMS porous alloy energy absorption box, including an outer frame body and TPMS porous structural units filled inside the outer frame body. Both the outer frame body and the TPMS porous structural units are made of AlSi10Mg alloy. The outer frame is a square or rectangular hollow frame used to constrain the deformation mode of the TPMS porous structural unit. The TPMS porous structural unit is a three-period minimal surface configuration, forming a continuous porous network inside.

[0033] The beneficial effects of this invention are as follows: Unlike existing technologies, this invention provides a high-energy-absorption-rate TPMS porous alloy energy-absorbing box and its preparation method. The aforementioned TPMS porous alloy energy-absorbing box uses an AlSi10Mg alloy to make the outer frame and TPMS porous structural units. The outer frame constrains the deformation of the internal structure, and combined with a three-period minimal curved surface porous configuration with adjustable parameters, the product simultaneously possesses the characteristics of lightweight, high load-bearing capacity, and resistance to stress concentration. Under impact loads, it can achieve uniform deformation and gradual collapse, forming a stable plateau stress zone, significantly improving the overall energy absorption efficiency and structural stability, effectively reducing impact damage, and is suitable for use in multiple fields such as aerospace, rail transportation, automobiles, and protective equipment. By controlling the relative density and topology of the TPMS structural units and optimizing the preparation process parameters, this invention achieves a maximum compressive strength of 127.5 MPa, a maximum elastic modulus of 4.48 GPa, and a maximum volumetric energy absorption of 13.01 kJ / cm². 3 It also possesses excellent mechanical isotropy and lightweight advantages. The overall structure has a high level of lightweight, excellent specific energy absorption performance, stable mechanical properties and strong designability, making it particularly suitable for aerospace, automotive anti-collision structures and various protective equipment fields. Attached Figure Description

[0034] Figure 1 The scanning strategy for AlSi10Mg alloy powder in the L-PBF process.

[0035] Figure 2 CAD model of TPMS porous AlSi10Mg energy-absorbing box mesh with different wall thicknesses and a porosity of 30%.

[0036] Figure 3 Sample models of porous AlSi10Mg energy-absorbing cells in TPMS with different wall thicknesses and a porosity of 30%.

[0037] Figure 4 Stress-strain curves of porous AlSi10Mg energy-absorbing cells with different wall thicknesses and a porosity of 30% using TPMS.

[0038] Figure 5 Mechanical properties of TPMS porous AlSi10Mg energy-absorbing cells with different wall thicknesses and a porosity of 30%: (a) Normalized Young's modulus E * (b) The normalized initial peak value should be σ p* (c) Normalized energy absorption W V * .

[0039] Figure 6 A CAD model of a TPMS porous AlSi10Mg energy-absorbing box mesh with the same wall thickness and a porosity of 37.5%, with holes of different shapes removed in the middle.

[0040] Figure 7 Sample models of TPMS porous AlSi10Mg energy-absorbing boxes with the same wall thickness and a porosity of 37.5%, with different shaped holes removed in the middle.

[0041] Figure 8 Stress-strain curves of TPMS porous AlSi10Mg energy-absorbing boxes with the same wall thickness and a porosity of 37.5%, with different shaped holes removed in the middle.

[0042] Figure 9 Mechanical properties of TPMS porous AlSi10Mg energy-absorbing boxes with the same wall thickness and a porosity of 37.5%, but with pores of different shapes removed from the center: (a) Normalized Young's modulus (b) Normalized initial peak value (c) Normalized energy absorption .

[0043] Figure 10 A CAD model of a TPMS porous AlSi10Mg energy-absorbing box mesh with varying wall thickness and a porosity of 37.5%.

[0044] Figure 11 Sample models of TPMS porous AlSi10Mg energy-absorbing cells with different wall thicknesses and a porosity of 37.5%.

[0045] Figure 12 Stress-strain curves of TPMS porous AlSi10Mg energy-absorbing cells with different wall thicknesses and a porosity of 37.5%.

[0046] Figure 13 Mechanical properties of TPMS porous AlSi10Mg energy-absorbing cells with different wall thicknesses and a porosity of 37.5%: (a) Normalized Young's modulus (b) Normalized initial peak value (c) Normalized energy absorption .

[0047] Figure 14 The deformation process of porous AlSi10Mg energy-absorbing structures with different shapes in TPMS. Detailed Implementation

[0048] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0049] To address the aforementioned shortcomings of existing technologies, this invention, after reviewing existing technologies and conducting in-depth research, has found that common three-period minimal surface structures include Gyroid, Diamond, and Primitive structures. Among these, the Gyroid structure, with its excellent mechanical isotropy and superior mechanical response characteristics, stands out as the type of TPMS structure with the most outstanding comprehensive application potential. With the continuous development of additive manufacturing technology, Selective Laser Melting (SLM) technology has gradually matured, providing a new solution for manufacturing porous structures with complex geometries. This technology achieves the integrated forming of complex three-dimensional structures by melting metal powder layer by layer, possessing advantages such as high forming accuracy and high design freedom, and can fully meet the processing and manufacturing requirements of TPMS structures.

[0050] Among various metallic materials compatible with SLM (Silicon-Metal-Alloyed) processes, AlSi10Mg alloy possesses excellent formability, high specific strength, and outstanding corrosion resistance, making it one of the most widely used materials in this process system. AlSi10Mg structural components prepared using SLM technology can form a fine-grained, strengthened microstructure, exhibiting significantly superior overall mechanical properties compared to traditionally cast components. In practical engineering applications, energy-absorbing structures are mostly arranged in the form of energy-absorbing boxes. These structures rely on an external frame to constrain the internal energy-absorbing units, thereby controlling the overall deformation mode and further improving energy absorption efficiency and structural stability. Based on this, combining TPMS porous structures with energy-absorbing box structures and achieving synergistic optimization through rational design has become a key research direction in this field.

[0051] Therefore, developing a novel high-performance energy-absorbing structure is of paramount engineering necessity. This invention organically combines the excellent mechanical properties of TPMS porous structures with the lightweight advantages of AlSi10Mg alloys. Relying on a comprehensive structural design and supporting manufacturing process, it achieves a balance between high energy absorption rate and structural stability. Simultaneously, it introduces gradient design and multi-parameter optimization methods, ensuring that the structure maintains excellent energy absorption performance at different deformation stages, fully meeting the engineering needs under various complex working conditions.

[0052] Specifically, this invention discloses a TPMS porous alloy energy-absorbing box with high energy absorption rate. The TPMS porous alloy energy-absorbing box is fabricated using laser powder bed melting (L-PBF) technology. Its alloy structure is constructed through software collaborative modeling. Specifically, the TPMS lattice structure is first modeled and designed using MATLAB software, and then the square box structure is drawn and designed using CAD software. Finally, the TPMS lattice model and the square box model are combined to obtain the overall structure of the energy-absorbing box.

[0053] This invention also discloses a method for preparing the aforementioned high-energy-absorption-rate TPMS porous alloy energy-absorbing box. This method uses AlSi10Mg alloy powder as raw material and employs powder bed fusion molding technology to prepare porous alloy components. The specific preparation steps are as follows: First, the overall structural model design of the TPMS porous alloy energy-absorbing box is completed using CAD software. Then, the designed structural model data is imported into the powder bed fusion molding equipment. Using AlSi10Mg alloy powder as the molding raw material, porous AlSi10Mg alloy material is prepared by layer-by-layer printing using preset process parameters. Specifically, the molding process parameters are set as follows: laser power of 100–300 W, scanning spacing of 50–300 μm, layer thickness of 30–60 μm, and scanning speed of 600–1500 mm / s.

[0054] Performance tests have verified that the TPMS porous alloy energy absorber prepared in this invention possesses excellent energy absorption performance. Compared to the traditional hollow cubic frame structure, the energy absorption performance of this TPMS porous alloy energy absorber is improved by 560% in the Z-axis direction. Furthermore, by matching different types of TPMS topologies and adopting a high-regularity structural design, the energy absorption effect in the Z-axis direction of the component can be further optimized. In addition, the normalized Young's modulus of the TPMS porous AlSi10Mg energy absorber of this invention is increased by 7%, and the anisotropy of energy absorption performance is improved by 5%, effectively optimizing the overall mechanical properties and energy absorption stability of the component.

[0055] The technical solution of the present invention will now be further described with reference to specific embodiments.

[0056] In each embodiment of this invention, professional CAD modeling software is used to construct TPMS porous alloy energy-absorbing box models with different structures. MATLAB software is used to verify the mechanical parameters of the models, ensuring that the shape design of each grid unit matches the stress buckling component ratio of the corresponding embodiment. All samples are prepared using L-PBF (selective laser melting) process, using AlSi10Mg alloy powder as raw material and EOS M290 selective laser melting equipment for processing. By adjusting the forming process parameters and structural configuration, gradient porous AlSi10Mg energy-absorbing boxes with different porosities, wall thickness gradients, and opening forms are prepared, systematically verifying the feasibility and performance advantages of the technical solution of this invention.

[0057] Please see Figure 1 , Figure 1 This is a schematic diagram of the scanning strategy for AlSi10Mg alloy powder during the L-PBF forming process; where, Figure 1 The stacked structure of three consecutive printed layers (Layer N, Layer N+1, Layer N+2) is shown from bottom to top. The vertical distance between adjacent printed layers is 50 μm, and the spacing between laser scanning lines within the same printed layer is uniformly 60 μm. The three printed layers adopt a layer-by-layer orthogonal scanning path: the scanning lines of the lower layer Layer N are arranged along the X-axis, and the scanning direction (left and right direction of the Y-axis) alternates back and forth; the scanning lines of the middle layer Layer N+1 are arranged along the Y-axis, forming an orthogonal structure with the lower layer Layer N, and the scanning direction (up and down direction of the X-axis) alternates back and forth; the scanning lines of the upper layer Layer N+2 are again arranged along the X-axis, forming an orthogonal structure with the middle layer Layer N+1, and the scanning direction (left and right direction of the Y-axis) alternates back and forth.

[0058] Example 1 (Porous AlSi10Mg energy-absorbing box with different wall thickness gradients and 30% porosity using TPMS): In this embodiment 1, a porous AlSi10Mg energy-absorbing box with a porosity of 30% and different wall thickness gradient structures was designed and prepared. The overall model size is 40mm×40mm×40mm. The model is divided into two parts: the outer part is a hollow cube frame with different wall thicknesses, and the inner part is a Gyroid-type porous TPMS lattice structure with different gradient levels.

[0059] The CAD mesh model of this embodiment 1 is as follows: Figure 2 As shown: Figure 2The CAD models of porous AlSi10Mg energy absorbers with different wall thicknesses and TPMS (Temperature Transformation Matrix) with a porosity of 30% are shown from left to right: a hollow cube without a core (HSC), an energy absorber filled with a single-thickness TPMS lattice (1HSC-TC), an energy absorber filled with two-thickness TPMS lattices (2HSC-TC), and an energy absorber filled with three-thickness TPMS lattices (3HSC-TC). The latter three are all filled with Gyroid-type three-period minimal surface porous lattices. They are all box structures constrained by a square frame. As the model number increases, the wall thickness gradient levels of the internal TPMS lattice increase, forming a comparative design sequence from hollow structure to single-level, two-level, and three-level wall thickness gradient TPMS cores. This is used to study the influence of different wall thickness TPMS cores on the performance of the energy absorber.

[0060] In this embodiment, region division is based on the height direction (Z-axis direction) of the cube, and the overall porosity of all samples remains constant at 30%. 1HSC-TC does not perform region division; both the outer frame and the internal TPMS lattice use a single wall thickness, forming a single-level wall thickness structure. 2HSC-TC divides the cube vertically into upper and lower regions. The outer hollow frame is also divided into upper and lower segments, each with two different wall thicknesses. The internal Gyroid-type TPMS lattice is simultaneously divided into upper and lower regions, each with two different wall thicknesses. The outer frame and lattice partitions match, thus forming a two-level wall thickness gradient structure. 3HSC-TC divides the cube vertically into upper, middle, and lower regions. The outer frame and internal lattice are configured with three different wall thicknesses, forming a three-level wall thickness gradient structure. This design only limits the wall thickness partitioning form and gradient levels, without restricting the specific dimensions of the wall thickness at each location. Under the premise of meeting the porosity requirements, those skilled in the art can adjust the specific wall thickness parameters according to actual operating conditions.

[0061] In this embodiment 1, the L-PBF process was used to prepare the samples. The specific process parameters were: laser power 150W, scanning spacing 100μm, layer thickness 50μm, and scanning speed 1200mm / s. The physical samples prepared by the above process are shown below. Figure 3 As shown. Figure 3These are physical samples of porous AlSi10Mg energy-absorbing cells with different wall thickness gradients and a porosity of 30%, prepared using the L-PBF process. From left to right, they are: a hollow square cell without an inner core (HSC), an energy-absorbing cell filled with a single-wall-thickness TPMS lattice (1HSC-TC), an energy-absorbing cell filled with a two-level wall thickness gradient TPMS lattice (2HSC-TC), and an energy-absorbing cell filled with a three-level wall thickness gradient TPMS lattice (3HSC-TC). The HSC is only a frame structure with a hollow interior, while the latter three are box structures with a square frame constraining an internal Gyroid-type porous TPMS lattice. Furthermore, as the sample number increases, the wall thickness gradient levels of the internal TPMS lattice increase sequentially. Figure 2 The CAD models correspond one-to-one, intuitively presenting the actual molding effect of TPMS core structures with different wall thickness gradients, and verifying the feasibility and molding accuracy of L-PBF process for manufacturing complex porous structures.

[0062] To test the mechanical and energy absorption properties of each structure in Example 1, quasi-static compression tests were conducted, and the compressive stress-strain curves of different structures were obtained as follows: Figure 4 As shown. Figure 4 The compressive stress-strain curves of four TPMS porous AlSi10Mg energy-absorbing cells (HSC, 1HSC-TC, 2HSC-TC, and 3HSC-TC) with different wall thicknesses and a porosity of 30% are shown. The horizontal axis represents compressive strain ε (%, ranging from 0% to 60%), and the vertical axis represents compressive stress σ (MPa, ranging from 0% to 200MPa). HSC (black curve) rises rapidly after the elastic stage (strain approximately 0% to 5%), with a significant stress drop at approximately 13% strain, a short plateau period, and drastic stress fluctuations. 1HSC-TC (red curve) enters a stable stress plateau period after the elastic stage, with the plateau stress maintained in the 80-100MPa range, exhibiting small fluctuations, and the stress continues to rise even at 60% strain. 2HSC-TC (blue curve) shows a more stable stress plateau period after the elastic stage. The peak stress of the 1HSC-TC structure reaches approximately 110 MPa at about 30% strain. Although there are fluctuations afterward, the overall plateau period is relatively long, and the stress is still about 95 MPa at 60% strain. The 3HSC-TC structure (green curve) reaches a peak stress of about 105 MPa at about 10% strain. After that, the stress gradually decreases with increasing strain, and the stress drops to about 40-60 MPa when the strain is 50%-60%. Overall, the three structures with TPMS cores have a longer stress plateau stage than the hollow HSC structure. Different wall thickness gradient designs correspond to different mechanical responses. The 1HSC-TC structure has the best plateau stability, the 2HSC-TC structure has the highest peak stress, and the 3HSC-TC structure exhibits gradient yield characteristics. This clearly demonstrates the significant influence of wall thickness gradient on the compressive mechanical properties and plateau stress stability of the energy-absorbing box.

[0063] The quantitative comparison results of the key mechanical properties of each structure in Example 1 are as follows: Figure 5 As shown. Figure 5 A comparison of key mechanical properties of porous AlSi10Mg energy-absorbing cells with different wall thickness gradients and a porosity of 30% (HSC, 1HSC-TG, 2HSC-TG, 3HSC-TG), including (a) normalized Young's modulus. (Vertical axis unit GPa, value range 0-10), (b) Normalized initial peak intensity (Vertical axis unit MPa, value range 75-80) (c) Normalized energy absorption (Vertical axis unit: J / mm) 3 The values ​​range from 0 to 15. Three subplots are shown, with the horizontal axis representing sample type. Error bars are labeled on all data points to indicate test repeatability. In (a), the normalized Young's modulus of HSC is 4.09 GPa, while 1HSC-TG, 2HSC-TG, and 3HSC-TG are 4.14 GPa, 4.36 GPa, and 4.39 GPa, respectively, showing a monotonically increasing trend with increasing wall thickness gradient levels. In (b), the normalized initial peak intensity of HSC is 76.58 MPa, while 1HSC-TG, 2HSC-TG, and 3HSC-TG are 77.46 MPa, 77.64 MPa, and 78.06 MPa, respectively, also gradually increasing with increasing gradient levels. In (c), the normalized energy absorption of HSC... Only 2.32J / mm 3 The 1HSC-TG, 2HSC-TG, and 3HSC-TG concentrations reached 9.59 J / mm². 3 9.41 J / mm 3 8.44J / mm 3 The energy absorption performance of the 1HSC-TG structure with a single gradient is more than 3 times that of the hollow structure, and the energy absorption performance first increases and then decreases with the increase of the gradient level. The single-level gradient structure has the best energy absorption performance. Overall, it shows that the structure with the TPMS core has significant improvements in stiffness, load-bearing strength and energy absorption capacity compared with the hollow HSC. The distribution of error bars also verifies the stability of the test results. The wall thickness gradient design can effectively control the mechanical properties. Among them, the single-level gradient structure performs well in energy absorption, while the multi-level gradient structure is more conducive to improving the structural stiffness and peak load-bearing strength.

[0064] In summary, this embodiment 1 effectively optimizes the mechanical defects of the hollow cube frame structure by introducing a Gyroid-type TPMS core structure with different wall thickness gradients. Compared to a pure hollow cube frame, the TPMS porous AlSi10Mg energy-absorbing box of this embodiment 1 can enhance energy absorption by up to 310% in the Z-axis direction. The introduction of the TPMS porous structure significantly enhances the structural stability of the energy-absorbing box and expands its functional versatility. This structural design has unique application advantages in the field of additive manufacturing.

[0065] Example 2 (Porous AlSi10Mg energy-absorbing box with different center openings and 37.5% porosity using TPMS): In Example 2, a porous AlSi10Mg energy-absorbing box with a porosity of 37.5%, the same wall thickness, and different central opening configurations was designed and prepared. The overall size of the model is 40mm×40mm×40mm. The model also adopts a two-layer structure of outer frame + inner TPMS lattice. By setting different central opening configurations, the control law of opening form on structural mechanics and energy absorption performance was explored.

[0066] The CAD mesh model of this embodiment 2 is as follows: Figure 6 As shown. Figure 6 The CAD models of porous AlSi10Mg energy absorbers with the same wall thickness and porosity of 37.5% are presented from left to right as follows: a hollow square box without an inner core (HSC); an energy absorber filled with a Gyroid-type TPMS lattice with a circular through-hole removed from the center (CCH-TG); an energy absorber filled with a Gyroid-type TPMS lattice with a square through-hole removed from the center (CSH-TG); and an energy absorber filled with a two-level wall thickness gradient TPMS lattice without a central opening (2HSC-TC). All models adopt a square outer frame constraint structure. HSC is only an outer frame structure with a hollow interior. CCH-TG and CSH-TG have circular and square central openings respectively on the basis of filling TPMS lattice. 2HSC-TC is a complete two-level wall thickness gradient TPMS inner core structure without openings. The models show the influence of the shape of the central opening (circular / square) and the absence of openings on the structural form of porous TPMS energy absorbers, providing a basic model for subsequent comparison of the mechanical and energy absorption performance under different opening forms.

[0067] In Example 2, the sample was prepared using the same L-PBF process parameters as in Example 1: laser power 150W, scanning spacing 100μm, layer thickness 50μm, and scanning speed 1200mm / s. The resulting physical sample is shown below. Figure 7 As shown. Figure 7These are physical samples of porous AlSi10Mg energy absorbers with different central openings, all with the same wall thickness and porosity of 37.5%, prepared using the L-PBF process. From left to right: a hollow square box without an inner core (HSC); an energy absorber filled with a Gyroid-type TPMS lattice and with a circular through-hole removed from the center (CCH-TG); an energy absorber filled with a Gyroid-type TPMS lattice and with a square through-hole removed from the center (CSH-TG); and an energy absorber filled with a two-level wall thickness gradient TPMS lattice without a central opening (2HSC-TG). All samples have a square outer frame constraint structure. HSC is only the outer frame structure with a hollow interior. CCH-TG and CSH-TG have circular and square through-holes formed in the center of their TPMS cores, respectively. 2HSC-TG has a complete TPMS lattice core without any openings. Figure 6 The CAD models correspond one-to-one, intuitively presenting the actual molding effect of different center opening shapes (circular / square) and no opening design, verifying the manufacturing feasibility and molding accuracy of L-PBF process for complex TPMS porous structures with center openings, and clearly showing the internal structural characteristics under different opening forms.

[0068] The mechanical response of each structure was tested through quasi-static compression tests, and the compressive stress-strain curves were obtained as follows: Figure 8 As shown. Figure 8The figures show the compressive stress-strain curves of TPMS porous AlSi10Mg energy absorbers (HSC, CCH-TG, CSH-TG, and 2HSC-TG) with the same wall thickness and porosity of 37.5% but different centrally vented forms. The horizontal axis represents compressive strain ε (%, ranging from 0% to 60%), and the vertical axis represents compressive stress σ (MPa, ranging from 0% to 200MPa). HSC (black curve) shows a rapid increase in strain during the elastic stage (approximately 0% to 5%), followed by a sharp stress drop at approximately 15% strain, with a very short plateau period and significant fluctuations. CCH-TG (red curve, with a circular central vent) exhibits slight stress fluctuations after the elastic stage, but reaches a peak stress of approximately 120MPa at approximately 35% strain, subsequently maintaining a stable plateau range of 90% to 110MPa. At 60% strain, the stress remains at approximately 110MPa, demonstrating a long plateau period and excellent stability. CSH-TG (blue curve, with a square central vent) shows a different elastic stage. The stress fluctuations after the strain stage are relatively large, with two significant stress drops (lowest at about 45 MPa) occurring at approximately 10% strain. The stress then gradually recovers, maintaining a plateau stress range of 75–95 MPa. At 60% strain, the stress is approximately 110 MPa, indicating slightly lower stability than the circular perforated structure. The 2HSC-TG (purple curve, two-stage gradient structure without perforations) reaches an initial peak stress of approximately 105 MPa at approximately 8% strain. Subsequently, the stress fluctuates and decreases multiple times. After 35% strain, the plateau stress drops to approximately 65–75 MPa. Although there is a later recovery, the overall plateau stress is lower than that of the perforated structure. Overall, all three structures filled with TPMS cores have a longer stress plateau stage than the hollow HSC. The central perforation form (especially the circular perforation) effectively optimizes the stress fluctuation characteristics, improves plateau stability and peak load capacity, and directly demonstrates the significant regulatory effect of the central perforation shape on the compressive mechanical response and energy absorption characteristics of the energy-absorbing box.

[0069] The quantitative comparison results of the key mechanical properties of each structure in Example 2 are as follows: Figure 9 As shown. Figure 9 A comparison of key mechanical properties of TPMS porous AlSi10Mg energy absorbers (HSC, CCH-TG, CSH-TG, 2HSC-TG) with different center-aperture configurations and the same wall thickness and porosity of 37.5%, including (a) normalized Young's modulus. (Vertical axis unit GPa, range 0~10), (b) Normalized initial peak intensity (Vertical axis unit MPa, range 75–85) (c) Normalized energy absorption (Vertical axis unit: J / mm) 3The data points are divided into three subplots (range 0–15), with the horizontal axis representing sample type. Error bars are marked on all data points to indicate test repeatability. In (a), the normalized Young's modulus of HSC is 4.09 GPa, while that of CCH-TG, CSH-TG, and 2HSC-TG are 4.43 GPa, 4.45 GPa, and 4.36 GPa, respectively. The Young's modulus of the TPMS-filled core structure is higher than that of the hollow HSC, with the square-aperture CSH-TG having the highest modulus. In (b), the normalized initial peak intensity of HSC is 76.98 MPa, while that of CCH-TG and CSH-TG are 82.11 MPa and 81.72 MPa, respectively, both significantly higher than that of HSC and the non-aperture 2HSC-TG (77.64 MPa). The peak intensity of the circular-aperture CCH-TG is the highest. In (c), the normalized energy absorption of HSC is only 2.53 J / mm². 3 CCH-TG, CSH-TG, and 2HSC-TG reached 9.62 J / mm², respectively. 3 8.67J / mm 3 9.41 J / mm 3 The energy absorption performance of the CCH-TG structure with a circular opening is more than 3 times that of the hollow structure. The CSH-TG structure with a circular opening has the best energy absorption performance, while the CSH-TG structure with a square opening is slightly lower. Overall, it shows that the central opening design (especially the circular opening) significantly improves the initial peak strength and energy absorption capacity while ensuring stiffness. The distribution of the error bars verifies the stability of the test results and intuitively reflects the significant control effect of the central opening shape on the mechanical properties of the TPMS porous energy absorber.

[0070] Compared to traditional hollow cubic frame structures, the porous AlSi10Mg energy absorber with a central opening and TPMS lattice designed in Example 2 can enhance energy absorption in the Z-axis direction by up to 315%. The composite structure of the central opening and TPMS lattice can effectively avoid the defects of stress concentration and buckling instability in hollow structures, further enhancing structural stability and mechanical isotropy, greatly expanding the functional versatility of porous energy absorbers, and possessing significant application advantages in the fields of high-end additive manufacturing equipment and lightweight protective structures.

[0071] Example 3 (Porous AlSi10Mg energy-absorbing box with different wall thickness distributions and 37.5% porosity using TPMS): In this embodiment 3, based on a porosity of 37.5%, a porous AlSi10Mg energy absorber with different wall thickness distribution strategies was designed. It includes two types of wall thickness distribution structures: uniform gradient and asymmetric gradient. The overall size of the model is uniformly 40mm×40mm×40mm. The outer frame is a standard hollow cube structure, and the interior is filled with Gyroid-type TPMS lattices with different wall thickness distributions. The focus is on exploring the effect of wall thickness distribution on the energy absorption limit and mechanical stability of the energy absorber.

[0072] The CAD mesh model in this embodiment 3 is as follows: Figure 10 As shown. Figure 10 The CAD models of porous AlSi10Mg TPMS energy absorbers with a porosity of 37.5% and different wall thickness distributions are shown from left to right: 3HSC-TG (TPMS core with three-level uniform wall thickness gradient), OAF1313-TG (TPMS core with a specific asymmetric wall thickness distribution), AF1333-TG (TPMS core with another type of asymmetric wall thickness distribution), and 1HSC-TG (TPMS core with a single-level uniform wall thickness). All models are box structures with a square outer frame constraining the internal Gyroid-type porous TPMS lattice. Different numbers correspond to different wall thickness distribution strategies, intuitively presenting the differences in TPMS lattice morphology under different wall thickness designs such as uniform gradient and asymmetric gradient. This provides a basic model for subsequent comparison of the effects of different wall thickness distributions on the mechanical and energy absorption performance of the energy absorber.

[0073] In this embodiment 3, the outer frame wall thickness remains uniform and the overall porosity is kept constant at 37.5%. Only the wall thickness distribution of the internal Gyroid-type TPMS lattice is designed. 1HSC-TG is a single-level uniform structure with the same wall thickness throughout the internal lattice. 3HSC-TG is a three-level uniform symmetrical gradient structure, equally divided into upper, middle, and lower regions along the vertical height of the cube. The lattice wall thickness in each region gradually changes according to a fixed pattern, and both the partition size and wall thickness arrangement are symmetrical. OAF1313-TG and AF1333-TG represent two types of asymmetrical wall thickness distribution structures, both breaking the symmetrical design rules of uniform gradients: OAF1313-TG is divided into multiple regions of unequal size along the height direction, and the lattice wall thickness in each region no longer changes in an orderly gradient; the partition length and wall thickness values ​​are asymmetrical. AF1333-TG can adopt an equal partition form, but the lattice wall thickness in each partition breaks the gradual change pattern, and the wall thicknesses of the upper and lower regions have no symmetrical correspondence, forming another type of asymmetrical wall thickness arrangement. Under the premise of keeping the porosity constant, the two types of asymmetric structures form different spatial distributions of wall thickness.

[0074] This Example 3 continues the unified L-PBF preparation process: AlSi10Mg alloy powder is used as raw material, and it is processed using an EOS M290 selective laser melting machine with a laser power of 150W, a scanning spacing of 100μm, a layer thickness of 50μm, and a scanning speed of 1200mm / s. The resulting physical sample is shown below. Figure 11 As shown. Figure 11These are physical samples of porous AlSi10Mg energy-absorbing cells with TPMS, all with a porosity of 37.5% and different wall thickness distributions, prepared using the L-PBF process. From left to right, they are 3HSC-TG (three-level uniform wall thickness gradient TPMS core), OAF1313-TG (asymmetric wall thickness distribution TPMS core), AF1333-TG (another type of asymmetric wall thickness distribution TPMS core), and 1HSC-TG (single-level uniform wall thickness TPMS core). All samples are box-like structures with a square outer frame constraining an internal Gyroid-type TPMS porous lattice. Different numbers correspond to different wall thickness distribution strategies. Figure 10 The CAD models correspond one-to-one, intuitively presenting the actual molding effect under different wall thickness designs such as uniform gradient and asymmetric gradient, clearly demonstrating the differences in TPMS lattice morphology with different wall thickness distributions, and verifying the feasibility and molding accuracy of L-PBF process for manufacturing complex wall thickness gradient porous structures.

[0075] Example 3: Test results of the compressive mechanical response of each structure are as follows Figure 12 As shown. Figure 12The figures show the compressive stress-strain curves of four TPMS porous AlSi10Mg energy-absorbing cells (3HSC-TG, OAF1313-TG, AF1333-TG, and 1HSC-TG), all with a porosity of 37.5% and different wall thickness distributions. The horizontal axis represents compressive strain ε (%, ranging from 0% to 60%), and the vertical axis represents compressive stress σ (MPa, ranging from 0% to 200MPa). Among them, 3HSC-TG (blue curve, three-level uniform gradient) exhibits multiple stress fluctuations after the elastic stage, with the stress continuously decreasing after approximately 25% strain. During the plateau period, the stress significantly decreases with increasing strain, dropping to approximately 65MPa at 60% strain. OAF1313-TG (green curve, asymmetric gradient) shows a stress peak of approximately 125MPa at approximately 10% strain. Although there are subsequent fluctuations, it maintains a high plateau stress region of 125–140MPa in the strain range of 30%–50%. After 0% strain, the stress decreases rapidly, resulting in the best overall peak stress and plateau stability. AF1333-TG (red curve, another type of asymmetric gradient) exhibits smaller stress fluctuations after the elastic stage, maintaining a stable plateau of 100–115 MPa in the 30%–50% strain range, with a slight decrease in stress in the later stages of strain. 1HSC-TG (purple curve, single-stage uniform wall thickness) shows a gradual increase in stress after the elastic stage, with the plateau stress maintained in the 80–100 MPa range, exhibiting the lowest overall stress level but with minimal fluctuations. Overall, different wall thickness distributions significantly affect the peak stress, plateau stability, and later stress decay characteristics of the energy absorber. Asymmetric gradient design (especially OAF1313-TG) can significantly improve the plateau stress level and stability, while a three-stage uniform gradient is prone to later stress decay, directly demonstrating the regulatory effect of wall thickness distribution strategies on the compressive mechanical response and energy absorption performance of the TPMS porous energy absorber.

[0076] The key mechanical performance quantitative data of each structure in this embodiment 3 are as follows: Figure 13 As shown. Figure 13 A comparison of key mechanical properties of TPMS porous AlSi10Mg energy absorbers (3HSC-TG, OAF1313-TG, AF1333-TG, and 1HSC-TG) with the same porosity of 37.5% but different wall thickness distributions, including (a) normalized Young's modulus. (Vertical axis unit GPa, range 0–10), (b) Normalized initial peak intensity (Vertical axis unit MPa, range 75–80), (c) Normalized energy absorption (Vertical axis unit: J / mm) 3The three subplots (range 0-20) show the sample type on the horizontal axis, and all data points are labeled with error bars to reflect test repeatability. In (a), the normalized Young's moduli of each structure are: 3HSC-TG (4.17 GPa), OAF1313-TG (4.19 GPa), AF1333-TG (4.17 GPa), and 1HSC-TG (4.14 GPa). Different wall thickness distributions have little effect on Young's moduli, and the numerical differences are not significant. In (b), the normalized Young's moduli are... The initial peak intensities were: 3HSC-TG (78.06 MPa), OAF1313-TG (77.75 MPa), AF1333-TG (77.89 MPa), and 1HSC-TG (77.46 MPa). The 3HSC-TG with a three-level uniform gradient had the highest peak intensity, while the 1HSC-TG with a single-level uniform wall thickness had the lowest. (c) The normalized energy absorption performance showed significant differences, with OAF1313-TG (13.01 J / mm²) showing the highest. 3 The highest was AF1333-TG (11.24 J / mm), followed by AF1333-TG (11.24 J / mm). 3 ) and 1HSC-TG (9.59J / mm 3 ), 3HSC-TG (8.64J / mm 3 The results showed that the wall thickness distribution had little effect on the Young's modulus of the TPMS porous energy absorber, but it had a significant regulatory effect on the initial peak intensity, especially the energy absorption performance. The asymmetric gradient design (OAF1313-TG) achieved the optimal energy absorption effect while ensuring a high peak intensity. The distribution of the error bars also verified the stability of the test results.

[0077] This embodiment 3, through an innovative asymmetric wall thickness gradient distribution design, significantly breaks through the energy absorption limit of traditional uniform gradient porous structures. Compared with the hollow cube frame structure, the energy absorption performance of the optimal structure in this embodiment 3 can be enhanced by up to 560% in the Z-axis direction, demonstrating a significant performance improvement. This wall thickness distribution control strategy effectively solves the problems of limited energy absorption and severe mechanical attenuation in traditional porous energy-absorbing structures, further improving the structural mechanical isotropy and adaptability to operating conditions.

[0078] Analysis of the overall deformation mechanism: To reveal the toughening and energy absorption mechanism of various TPMS porous energy-absorbing boxes in this invention, deformation process observations were conducted on all configuration structures under Z-axis compressive loading. The deformation comparison results are as follows: Figure 14 As shown. Figure 14To compare the deformation processes of porous AlSi10Mg energy-absorbing cells with different TPMS configurations under compressive loading along the Z-axis, the figures are divided into two groups, left and right. Each group shows the deformation states at two stages: 5% strain and 10% strain, with the loading direction parallel to the Z-axis. The left group includes four structures: HSC (hollow square box), CCH-TG (central circular opening), CSH-TG (central square opening), and 3HSC-TG (three-level wall thickness gradient). The right group includes four TPMS structures with different wall thickness distributions: 2HSC-TG, AF1333-TG, OAF1313-TG, and 1HSC-TG. Samples at 10% strain are marked with red diagonal lines to indicate the direction of shear deformation band development. At the 5% strain stage, only the outer frame of the HSC exhibits slight buckling. The lattice of the remaining TPMS core structure did not show significant damage during the buckling deformation. When the strain was increased to 10%, the HSC outer frame underwent significant overall buckling. Local crushing occurred at the central opening of CCH-TG and CSH-TG, and shear bands were formed along the diagonal direction. 3HSC-TG, 2HSC-TG, AF1333-TG, OAF1313-TG, and 1HSC-TG showed different lattice crushing modes, and the shear bands extended along the diagonal direction. TPMS structures with different wall thickness distributions showed different deformation uniformity and shear band development trends, which intuitively reflected the differences in the deformation mechanism of hollow structures and energy-absorbing boxes with different TPMS configurations, wall thickness distributions, and opening forms during the compression process, providing direct evidence of the deformation process for analyzing their energy absorption characteristics.

[0079] A comprehensive comparative analysis of Examples 1 to 3 reveals that all TPMS structures without openings exhibit stable load transfer and no risk of localized stress concentration due to their uniform lattice arrangement. Opening-free designs with varying wall thickness gradients and distributions significantly enhance the stiffness, load-bearing capacity, and energy absorption capacity of the hollow cube, resulting in high structural reliability and a wide range of applicable working conditions. In the centrally opened configuration, the circular opening optimizes the force flow transmission path, further improving the peak load-bearing capacity and energy absorption effect. It also guides the orderly expansion of shear deformation bands, ensuring a stable stress plateau throughout compression and achieving optimal overall mechanical performance. The square opening, however, suffers from stress concentration at corners, leading to sudden stress drops during loading, large stress fluctuations, and decreased energy absorption performance, resulting in poorer overall performance. In conclusion, in practical applications, circular centrally opened TPMS structures are preferred when high energy absorption, high load-bearing capacity, and compressive stability are sought. When structural integrity, fatigue performance, and adaptability to complex loads are paramount, TPMS structures without openings are preferred. The square centrally opened configuration has significant performance defects and is not recommended for engineering applications.

[0080] In summary, the present invention has the following significant technical advantages compared to the prior art: (1) The preparation process is controllable and suitable for large-scale production. The present invention uses selective laser melting forming technology to prepare porous AlSi10Mg energy-absorbing boxes with a porosity of 20% to 40%. It can precisely control the product's appearance size, porosity, pore size and internal lattice structure, and can complete personalized customization according to different engineering conditions. The overall preparation process is simple and the processing cost is low, which can realize the batch preparation of large-size porous AlSi10Mg alloy components and is fully suitable for industrial-scale production needs.

[0081] (2) Precisely controllable structural performance and wide range of applications. This invention achieves precise control over the stiffness, peak strength, energy absorption capacity, and mechanical isotropy of the porous energy-absorbing box through multiple innovative structural optimizations such as outer wall gradient design, central opening configuration design, and asymmetric wall thickness distribution design, combined with precise additive manufacturing parameter control. This effectively overcomes the shortcomings of traditional porous AlSi10Mg alloy structures, such as low energy absorption efficiency, poor stability, and limited performance. The technical solution of this invention provides a new approach to the structural design and performance optimization of high-performance porous metal materials, and can be widely applied in high-performance fields such as aerospace lightweight protection, biomedical load-bearing, and high-end equipment vibration damping and energy absorption.

[0082] It should be noted that all the above embodiments belong to the same inventive concept, and the descriptions of each embodiment have different focuses. Where the description in a particular embodiment is not detailed, please refer to the description in other embodiments.

[0083] The above embodiments merely illustrate implementation methods of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A high-energy-absorption-rate TPMS porous alloy energy-absorbing box, characterized in that, It includes an outer frame body and a TPMS porous structure unit filled inside the outer frame body, both of which are made of AlSi10Mg alloy. The outer frame is a square or rectangular hollow frame used to constrain the deformation mode of the TPMS porous structure unit. The TPMS porous structure unit is a three-period minimal surface configuration, forming a continuous porous network inside.

2. The high energy absorption rate TPMS porous alloy energy-absorbing box according to claim 1, characterized in that, The TPMS porous structural unit is selected from one or more of the Gyroid structure, Diamond structure, and Primitive structure.

3. The high energy absorption rate TPMS porous alloy energy-absorbing box according to claim 2, characterized in that, The relative density of the TPMS porous structural unit is 10% to 60%.

4. The high energy absorption rate TPMS porous alloy energy-absorbing box according to claim 2, characterized in that, The porosity of the TPMS porous structure unit is 10% to 60%, and the unit size is 30 to 50 mm.

5. The high energy absorption rate TPMS porous alloy energy-absorbing box according to claim 2, characterized in that, The TPMS porous structure units are arranged periodically along the pressure direction, and the unit size is 2 to 10 mm.

6. The high energy absorption rate TPMS porous alloy energy-absorbing box according to claim 1, characterized in that, The TPMS porous structure unit is a non-porous structure, or it has a through hole at its center; the through hole is a circular through hole or a square through hole.

7. The high energy absorption rate TPMS porous alloy energy-absorbing box according to claim 1, characterized in that, Both the outer frame and the TPMS porous structure unit are provided with gradient wall thickness regions. The gradient wall thickness regions are divided into continuous and discrete types, and their wall thickness increases or decreases sequentially along the loading direction.

8. The high energy absorption rate TPMS porous alloy energy-absorbing box according to claim 1, characterized in that, The TPMS porous structural unit has a compressive strength ≤127.5MPa, an elastic modulus ≤4.48GPa, and a volumetric energy absorption ≤13.01kJ / cm³. 3 .

9. The high energy absorption rate TPMS porous alloy energy absorber according to any one of claims 1 to 8, characterized in that, The TPMS porous structural unit undergoes progressive collapse under compressive load, resulting in a stable plateau stress zone formed by the TPMS porous alloy energy-absorbing box as a whole.

10. A method for preparing a high-energy-absorption-rate TPMS porous alloy energy-absorbing cell as described in any one of claims 1 to 9, characterized in that, The TPMS porous alloy energy-absorbing box is integrally formed using selective laser melting technology, specifically including the following steps: S10, A three-dimensional structural model of the TPMS porous alloy energy-absorbing box is designed and constructed using computer-aided design software, and then sliced ​​and layered. S20, the three-dimensional slice data corresponding to the three-dimensional structural model is imported into the powder bed melting molding equipment, and AlSi10Mg alloy powder is used as raw material to print the material layer by layer according to the preset process parameters. The preset process parameters are: laser power of 100-300W, scanning spacing of 50-300μm, layer thickness of 30-60μm, and scanning speed of 600-1500mm / s.

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