李琦, 吴新星, 杜侣, 江五贵. Ti-6Al-4V晶格结构选区激光熔化的有限元模拟与验证[J]. 失效分析与预防, 2023, 18(4): 213-221. DOI: 10.3969/j.issn.1673-6214.2023.04.001
    引用本文: 李琦, 吴新星, 杜侣, 江五贵. Ti-6Al-4V晶格结构选区激光熔化的有限元模拟与验证[J]. 失效分析与预防, 2023, 18(4): 213-221. DOI: 10.3969/j.issn.1673-6214.2023.04.001
    LI Qi, WU Xin-xing, DU Lv, JIANG Wu-gui. Finite Element Simulation and Experimental Verification of Selective Laser Melting Process of Ti-6Al-4V Lattice Structures[J]. Failure Analysis and Prevention, 2023, 18(4): 213-221. DOI: 10.3969/j.issn.1673-6214.2023.04.001
    Citation: LI Qi, WU Xin-xing, DU Lv, JIANG Wu-gui. Finite Element Simulation and Experimental Verification of Selective Laser Melting Process of Ti-6Al-4V Lattice Structures[J]. Failure Analysis and Prevention, 2023, 18(4): 213-221. DOI: 10.3969/j.issn.1673-6214.2023.04.001

    Ti-6Al-4V晶格结构选区激光熔化的有限元模拟与验证

    Finite Element Simulation and Experimental Verification of Selective Laser Melting Process of Ti-6Al-4V Lattice Structures

    • 摘要: 为探究晶格结构激光选区熔化(SLM)成形过程,建立了晶格结构SLM成形工艺的有限元(FE)模型,模拟了SLM成形Ti-6Al-4V合金晶格结构的过程。首先运用Slic3r软件从CAD文件中生成包括扫描间距、激光功率、层厚和扫描速度的G代码,然后将其转换为一系列路径信息并导入到有限元模型中用以控制“单元生死”,从而模拟SLM工艺的逐层沉积过程。在该技术中,打印层单元随着铺粉的进行被逐层激活并参与有限元计算。基于发展的FE模型,提出适应晶格结构的扫描路径策略并进行相应的实验验证。结果表明:随着成形高度的增加,转角处的温度不断积累,导致该处热应力增加从而增加破裂风险。相比于默认扫描策略,提出的优化扫描策略可以减少零件的热累积,从而减小转角处的应力集中。本研究可为金属晶格构件SLM工艺提供优化指导。

       

      Abstract: In order to investigate selective laser melting (SLM) processes of lattice structures, a finite element (FE) model concerning SLM forming process was established, which was employed to simulate the SLM process of Ti-6Al-4V lattice structure. First, Slic3r software was used to generate G-codes from CAD files, including hatch spacing, laser power, layer thickness, and scanning speed, which were then converted into a series of toolpath information and imported into the FE model to control the “element birth and death”, thus simulate the layer-by-layer deposition process of the SLM process. With this technique, the printed layers are activated one by one as the powders spread, and participate in the FE calculations. Based on the proposed FE model, a scanning path strategy adapted to the lattice structure was proposed and verified. The results show that as the forming height increases, the heat at the corner accumulates, leading to an increase in thermal stresses there and thereby aggravating the risk of rupture. Compared to the default strategy, the proposed optimized scanning strategy can reduce the stress concentration at the corner due to the decreased thermal accumulation of the part. Therefore, this study can provide optimization guidance for SLM process of metallic lattice components.

       

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