Collaborative Research: Physical Mechanism of Melt Pool Oscillation and Spatter Formation in Laser Powder Bed Fusion Additive Manufacturing

合作研究：激光粉末床熔融增材制造中熔池振荡和飞溅形成的物理机制

• 批准号: 1933368
• 负责人: Wenda Tan
• 金额: $ 26万
• 依托单位: University of Utah
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-10-01 至 2022-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1933368&HistoricalAwards=false
• 关键词: Collaborative; Research; Physical; Mechanism; Melt

Laser powder bed fusion (LPBF) is a widely used additive manufacturing process that can 3D print complex metallic components that can not be produced by conventional manufacturing technologies. Spattering, the uncontrolled eruption of metal droplets, is a critical problem in LPBF systems and is a major cause of poor quality in components printed using the process. In spite of this, the fundamental reasons for spatter formation are not well understood and effective approaches for reducing spatter in LPBF are not available. This award supports fundamental research to understand spatter formation. The research team will perform experiments and computer simulations to observe the dynamic process of spatter formation and model the behavior of the molten metal pool to reveal the spatter formation mechanisms. The outcomes of the research will provide important guidance for optimizing the LPBF process to produce defect-free 3D printed metal parts. This will significantly expedite the applications of 3D printing in aerospace, biomedical, automotive, and other industries and will strengthen the manufacturing capability and competitiveness of U.S. industry. Spatter formation in LPBF is a highly transient process with complex coupling of multi-physics. Due to a limited ability to observe and measure the controlling parameters with adequate spatial and temporal resolution, there is a lack of understanding of the fundamental physics of spatter formation in LPBF. The objectives of this research are to: (i) test the hypothesis that the spatter formation is caused by melt pool oscillation, (ii) test the hypothesis that melt pool oscillation is caused by three physics mechanisms (i.e., non-uniform laser absorption, random powder blocking, and random powder merging), and (iii) evaluate the significance of the three hypothetical mechanisms to melt pool oscillation and spatter formation. A synergistic experimental and numerical investigation will be performed to achieve the research objectives. On the experimental side, a novel two-view high-speed imaging system, including synchrotron-based, side-view, X-ray imaging and a visible-light camera at 45 degrees to the horizontal direction will be used to provide 3-dimensional information on the dynamic behavior of the powder particles, melt pool, depression zone, and spatters. On the numerical side, a multi-physics model will be established to simulate the laser-matter interaction, multi-phase thermofluidic flow, dynamic surface motion, and fluid-solid interaction.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

激光粉末床熔融（LPBF）是一种广泛使用的增材制造工艺，可以3D打印传统制造技术无法生产的复杂金属部件。金属液滴的不受控制的喷发飞溅是LPBF系统中的一个关键问题，也是使用该工艺打印的组件质量差的主要原因。尽管如此，飞溅形成的根本原因还没有得到很好的理解，也没有有效的方法来减少LPBF中的飞溅。该奖项支持基础研究，以了解飞溅的形成。研究小组将进行实验和计算机模拟，以观察飞溅形成的动态过程，并模拟熔融金属池的行为，以揭示飞溅形成机制。研究结果将为优化LPBF工艺以生产无缺陷的3D打印金属零件提供重要指导。这将大大加快3D打印在航空航天、生物医学、汽车等行业的应用，并将增强美国工业的制造能力和竞争力。LPBF中溅射的形成是一个多物理场耦合的高度瞬态过程。由于有限的能力，观察和测量的控制参数与足够的空间和时间分辨率，有一个缺乏了解的基本物理的飞溅形成LPBF。本研究的目的是：（i）检验飞溅形成是由熔池振荡引起的假设，（ii）检验熔池振荡是由三种物理机制（即，非均匀激光吸收、随机粉末阻塞和随机粉末合并），以及（iii）评估三种假设机制对熔池振荡和飞溅形成的重要性。一个协同的实验和数值研究将进行，以实现研究目标。在实验方面，一个新的双视图高速成像系统，包括同步加速器为基础的，侧视图，X射线成像和可见光相机在45度的水平方向将被用来提供三维信息的粉末颗粒，熔池，凹陷区，和飞溅的动态行为。在数值方面，将建立一个多物理模型，模拟激光与物质的相互作用、多相热流体流动、动态表面运动和流固相互作用。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Revealing transient powder-gas interaction in laser powder bed fusion process through multi-physics modeling and high-speed synchrotron x-ray imaging

• DOI: 10.1016/j.addma.2020.101362
• 发表时间: 2020-10-01
• 期刊: ADDITIVE MANUFACTURING
• 影响因子: 11
• 作者: Li, Xuxiao;Zhao, Cang;Tan, Wenda
• 通讯作者: Tan, Wenda

Quantitative investigation of gas flow, powder-gas interaction, and powder behavior under different ambient pressure levels in laser powder bed fusion

• DOI: 10.1016/j.ijmachtools.2021.103797
• 发表时间: 2021-09-13
• 期刊: INTERNATIONAL JOURNAL OF MACHINE TOOLS & MANUFACTURE
• 影响因子: 14
• 作者: Li, Xuxiao;Guo, Qilin;Tan, Wenda
• 通讯作者: Tan, Wenda