Meso-scale modeling of multiple-layer fabrication process in Selective Electron Beam Melting: Inter-layer/track voids formation
Meso-scale modeling of multiple-layer fabrication process in Selective Electron Beam Melting: Inter-layer/track voids formation
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DOI：
10.1016/j.matdes.2017.12.031
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发表时间：
2018-03
影响因子：
8.4
通讯作者：
Wentao Yan;Ya Qian;W. Ge;Stephen Lin;Wing Kam Liu;F. Lin;G. Wagner
中科院分区：
文献类型：
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作者：
Wentao Yan;Ya Qian;W. Ge;Stephen Lin;Wing Kam Liu;F. Lin;G. Wagner
选择性电子束熔炼(SEBM)是一种很有前途的粉末基金属添加剂制造技术。然而，大多数粉末尺度的建模工作仅限于单道过程，同时也很难从实验上观察道与层之间的相互作用。在这项研究中，我们开发了一个集成的建模框架来研究多轨道、多层的SEBM过程。该方法由粉末扩散的离散元模型和粉末熔化的计算流体动力学(CFD)模型组成。这两个模型以循环的形式交换3D几何数据，以再现在多个粉末层中沿不同扫描路径的多个轨迹的制造过程。这种集成的建模方法能够进一步理解当前轨道和层如何与导致轨道/层间空隙的先前轨道和层相互作用。它还融入了更多的影响因素，特别是逐层扫描策略。根据我们的模拟结果，系统地讨论了由于未融合而产生的层/道间空洞，这与文献中的实验观测结果定性地一致。
Selective Electron Beam Melting (SEBM) is a promising powder-based metallic Additive Manufacturing (AM) technology. However, most powder-scale modeling efforts are limited to single track process, while it is also difficult to experimentally observe the interaction between tracks and layers. In this study, we develop an integrated modeling framework to investigate the SEBM process of multiple tracks and multiple layers. This approach consists of a Discrete Element model of powder spreading and a Computational Fluid Dynamics (CFD) model of powder melting. These two models exchange 3D geometrical data as a cycle to reproduce the manufacturing process of multiple tracks along various scan paths in multiple powder layers. This integrated modeling approach enables further understanding of how current tracks and layers interact with previous ones leading to inter-track/layer voids. It also incorporates more influential factors, particularly the layer-wise scan strategy. The inter-layer/track voids due to the lack of fusion are systematically discussed in light of our simulation results which qualitatively agree with experimental observations in literature.