Powder-scale multi-physics modeling of multi-layer multi-track selective laser melting with sharp interface capturing method
Powder-scale multi-physics modeling of multi-layer multi-track selective laser melting with sharp interface capturing method
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DOI：
10.1007/s00466-018-1614-5
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发表时间：
2018-08
影响因子：
4.1
通讯作者：
Zekun Wang;Wentao Yan;Wing Kam Liu;Moubin Liu
中科院分区：
文献类型：
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作者：
Zekun Wang;Wentao Yan;Wing Kam Liu;Moubin Liu
选择性激光熔化（SLM）作为一种很有前途的粉末基增材制造技术，近年来得到了广泛的应用。然而，熔化和凝固过程的实验观察是非常具有挑战性的。这阻碍了对SLM中飞溅和成球效应等各种现象背后的物理机制的研究，并进一步对产品的质量控制提出了挑战。粉末级计算模型可以再现SLM的多物理过程。在这项研究中，我们耦合有限体积法（FVM）和离散元法来模拟粉末颗粒的沉积，并使用FVM来模拟熔化过程，都与环境空气。特别是，尖端的尖锐表面捕捉技术（iso-Advector）被纳入到流体模型的体积，以重建在熔化过程中不同阶段之间的界面。然后使用Iso-Advector捕获和重建熔融材料与环境空气之间的界面，该界面进一步用作散布下一个粉末层的固体边界。因此，3D几何数据在这两个阶段之间反复交换，以再现SLM的粉末扩散-熔化过程，该过程在多个粉末层上结合了不同的扫描路径。为了证明粉末级多物理场建模框架的有效性，模拟了具有不同制造参数（Ti-6Al-4V粉末）的典型场景，并与文献中的实验观察结果进行了比较。
As a promising powder-based additive manufacturing technology, selective laser melting (SLM) has gained great popularity in recent years. However, experimental observation of the melting and solidification process is very challenging. This hinders the study of the physical mechanisms behind a variety of phenomena in SLM such as splashing and balling effects, and further poses challenges to the quality control of the products. Powder-scale computational models can reproduce the multi-physics process of SLM. In this study, we couple the Finite Volume Method (FVM) and Discrete Element Method to model the deposition of powder particles, and use the FVM to model the melting process, both with ambient air. In particular, a cutting-edge sharp surface capturing technique (iso-Advector) is incorporated into the Volume of Fluid Model to reconstruct the interface between different phases during the melting process. Iso-Advector is then used to capture and reconstruct the interface between molten material and ambient air, which is further used as a solid boundary for spreading the next powder layer. As such, 3D geometrical data is exchanged between these two stages repeatedly to reproduce the powder spreading-melting process of SLM incorporating different scan paths on multiple powder layers. To demonstrate the effectiveness of the powder-scale multi-physics modeling framework, typical scenarios with different fabrication parameters (Ti–6Al–4V powder) are simulated and compared with experimental observations available in literature.