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: 2223014
• 负责人: Wenda Tan
• 金额: $ 26万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-12-01 至 2024-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2223014&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.

激光粉床融合（LPBF）是一种广泛使用的添加剂制造工艺，可以3D打印复杂的金属组件，无法由常规制造技术产生。飞溅是金属液滴的不受控制的喷发，是LPBF系统中的一个关键问题，是使用该过程打印的组件质量差的主要原因。尽管如此，尚未充分理解飞溅形成的基本原因，并且没有可用的有效方法来减少LPBF的飞溅。该奖项支持基本研究以了解Spaters的形成。研究团队将执行实验和计算机模拟，以观察溅射形成的动态过程，并模拟熔融金属池的行为以揭示飞溅形成机制。该研究的结果将为优化LPBF工艺提供重要的指导，以产生无缺陷的3D印刷金属零件。这将大大加快3D印刷在航空航天，生物医学，汽车和其他行业中的应用，并将增强美国行业的制造能力和竞争力。 LPBF中的飞溅形成是一个高度瞬态的过程，具有复杂的多物理耦合。由于使用足够的空间和时间分辨率观察和测量控制参数的能力有限，因此缺乏对LPBF中溅射形成的基本物理学的了解。这项研究的目的是：（i）检验以下假设：溅起形成是由熔体池振荡引起的，（ii）检验熔体池振荡是由三种物理学机制引起的假设（即，不均匀的激光吸收，，，吸收了不均匀随机粉末阻塞和随机粉末合并），（iii）评估了三种假设机制熔融池振荡和溅射形成的重要性。将进行协同实验和数值研究以实现研究目标。在实验方面，一种新型的两视频高速成像系统，包括基于同步加速器的侧视图，X射线成像和45度的可见光相机，可用于提供3维有关粉末颗粒，熔体池，抑郁区和飞溅的动态行为的信息。在数值方面，将建立多物理模型，以模拟激光 - 物质的相互作用，多相热流动流，动态表面运动和流体 - 固定相互作用。此奖项反映了NSF的法定任务，并被视为值得的支持值得通过使用基金会的智力优点和更广泛影响的评论标准进行评估。