Study on the Quasistatic Compression Performance of Arch Microstrut Lattice Structure by Selective Laser Melting

Abstract

In recent years, lattice structures have been widely used in aerospace, automobile, biomedicine, and other fields. Lattice structures are porous structures composed of repeating cellular units. Because of their high-porosity spatial structure and low density, lattice structures have high specific strength, high specific stiffness, good energy absorption ability, excellent thermal and acoustic insulation properties, and so on. [1][2][3][4][5][6] The properties of the lattice structures are defined by the cell structure, cell size, base material properties, and relative densities of the cellular unit.Because of the highly complex spatial structure of lattice structures, it is difficult to manufacture the lattice structures with the traditional manufacturing process. Recently, the development of the additive manufacturing (AM) technologies has made the manufacturing of lattice structures easier. Based on ASTM standard, [3] AM is defined as a process of joining materials to make parts from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing and formative manufacturing methodologies. As a member of the AM, selective laser melting (SLM) has been successfully used to fabricate intricate lattice structures for various applications. [7][8][9][10][11][12][13] However, the lattice structure prepared by SLM usually has errors with the original design. Although the manufacturing error can be reduced by optimizing the processing parameters, the manufacturing error cannot be completely eliminated due to the inherent characteristics of SLM. SLM is a forming method based on multilayer accumulation. During manufacturing, the transition between layers is discontinuous, so it will produce step effect. At the same time, the thermal diffusion in the laser processing area will lead to incomplete melting of the powder in the adjacent area, and the incomplete melting metal powder will adhere to the struts' surface, which will affect the manufacturing accuracy and mechanical property of the lattice structure. Further development on the manufacturing technology of lattice structures and improving the machining accuracy and quality are also the focus of future research.At present, the most common lattice structures include microstrut lattice structure (composed of straight struts and nodes), triply periodic minimal surfaces' lattice structure (consists of several smooth surfaces), and the structure derived from them. The microstrut lattice structures include body-centered cubic (BCC), face-centered cubic (FCC), rhombic dodecahedron (RD), et al. and the triply periodic minimal surfaces' lattice structures include Gyroid cellular (GC), Schoen Gyroid (SG), et al. Because of its simple structure and convenient manufacture, BCC lattice structures been widely studied and applied. [7][8][9] SLM technique offers a viable method for manufacturing highperformance BCC lattice structures, which have good property in absorbing energy, and the Gibson-Ashby model could be adapted to predict BCC lattice mechanical properties fo...

Compression and energy absorption properties of the truss-like lightweight materials based on symmetric groups

“…According to the analysis of finite element simulations, it was found that the novel hexagonal prism TLM had excellent energy absorption capacity. The impact resistance and energy absorption properties were measured using two important indicators: specific energy absorption (SEA) and ideal energy absorption efficiency [24,25]. The energy absorbed per unit mass was defined as SEA, which could be expressed as follows: Where s was the stress of the hexagonal prism TLM's meso-structures, e was the strain of the structures, r* was the relative density of the structures, and r was the density of the A1Si10Mg alloy.…”

“…Zhang et al [23] designed enhanced pyramidal TLM through node optimization design. Ding and Yao et al [24,25] fabricated ARCH TLM by optimizing the center line of BCC strut. Wang et al [13] modified the traditional FCC TLM by adding a cross-rod at the center of its RVU.…”

Compression and energy absorption properties of the novel truss-like lightweight material based on space group P6mm

“…Zhang et al [20] designed enhanced pyramidal unit cell through node optimization design. Ding and Yao et al [21,22] fabricated ARCH unit cell by optimizing the center line of BCC strut. Wang et al [12] modi ed the traditional FCC TLM by adding a cross-rod at the center of the unit cell.…”

On the Technological Feasibility of Additively Manufactured Self‐Supporting AlSi10Mg Lattice Structures

“…[20] At the design stage, difficulties include the choice of the unit cell and its repetition in order to fill a defined design space while obtaining a computer-aided design (CAD) model that can be easily handled and modified. [21] New approaches are proposing the adoption of neural networks that allow tuning the desired mechanical response in much shorter computational times. [22] Simulation is addressed in many studies today [10,18,[23][24][25] with a special attention to the development of plastic and damage models.…”

“…[26] Particularly in the automotive field, PBF-LB/M of aluminum alloys is certainly the most promising solution and cubic unit cells are widely adopted owing to the relative ease of design and modeling. [15,21,27] In spite of that, PBF-LB/M processes are not totally free from manufacturing boundaries, the major ones being the minimum size of features that can be built and the maximum overhang length. [27,28] The ASTM standard "Additive manufacturing -Design -Part 1: Laser-based powder bed fusion of metals" provides insightful definitions of the minimum size of features such as gaps, holes, channels, walls, and beams, as a function of the width of the melt pool.…”