Multi-layer thermo-fluid modeling of powder bed fusion (PBF) process
Multi-layer thermo-fluid modeling of powder bed fusion (PBF) process
复制标题
粉末床熔融 (PBF) 过程的多层热流体建模
DOI：
10.1016/j.jmapro.2022.09.003
复制
发表时间：
2022
影响因子：
6.2
通讯作者：
Chou, Kevin
中科院分区：
文献类型：
--
作者：
Fotovvati, Behzad;Chou, Kevin
在这项研究中，三维热流体计算方法已被开发和用于模拟激光粉末床熔合（PBF）过程。特别的目标是证明多层模拟的激光PBF过程的可行性，并讨论这种方法的潜力和挑战。该方法包括使用离散元法（DEM）来模拟颗粒在粉末床上的扩散，以及计算流体动力学（CFD）和传热来模拟激光-粉末/物质的相互作用，以顺序的方式仅用小的扫描区域来模拟大约10层，受到当前可用计算能力的限制。模拟结果可以提供洞察力，如熔池形状和尺寸，也凝固表面形态沿着不同的构建层。该模型还包括一个表面跟踪算法，以解释空隙和缺乏融合孔的形成。除了实现本研究的主要目标，即，在该计算过程的可行性论证中，还注意到，对于所研究的情况，由于从后续层的激光扫描接收到的额外热能，在前一层中的缺陷可能缩小，甚至消失。这项研究已经成功地证明了一个离散元方法和热流体模型之间的顺序链接在多层沉积的方式和实验验证将在未来的工作。随着未来计算能力的显著提高，所开发的方法可能被用作理解物理现象和选择小特征PBF制造的关键工艺参数的手段。
In this study, a 3D thermo-fluid computational method has been developed and employed to simulate the laser powder bed fusion (PBF) process. The particular objective is to demonstrate the feasibility of multi-layer simulations of the laser PBF process and to discuss the potential and challenges of this approach. The approach includes using the discrete element method (DEM) to simulate particle spreading on a powder bed, as well as computational fluid dynamics (CFD) and heat transfer to simulate laser-powder/matter interactions, in a sequential manner to about 10 layers only with a small scan area, limited by currently available computational power. The simulation results can offer insight such as melt pool shapes and sizes, also solidified surface morphology along different build layers. The model also includes a surface tracking algorithm to account for the formation of voids and lack-of-fusion pores. In addition to achieving the main objective of this study, i.e., feasibility demonstration of this computational process, it is also noted that, for the case studied, the defects in a former layer may shrink, or even vanish, due to the extra thermal energy received from laser scanning of subsequent layers. This study has successfully demonstrated the sequential linkage between a discrete element method and a thermo-fluid model in a multi-layer deposition fashion and the experimental validation will be performed in future work. With significantly greater computational capabilities in the future, the developed method may potentially be utilized as a means to understand physical phenomena and select key process parameters for PBF fabrications of small features.