Collaborative Research: Modulating Powder Bed Cohesion to Reduce Defects in Binder Jetting

合作研究：调节粉床内聚力以减少粘合剂喷射缺陷

• 批准号: 2223002
• 负责人: Wenda Tan
• 金额: $ 21.36万
• 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 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2223002&HistoricalAwards=false
• 关键词: Collaborative; Research; Modulating; Powder; Bed

Binder jetting is a 3D printing method that is increasingly important due to its versatile material options (virtually any powdered material), high production rates, and modest equipment cost. It is arguably the only mainstream 3D printing technique that works for both metals and ceramics. It has found growing applications in energy, aerospace, chemical, and other industries. In the binder jetting process, the 3D parts are printed layer by layer. On each layer, the powder bed is spread and microscopic droplets are deposited on selected locations on the powder bed. These droplets penetrate into the bed and bind the particles together. Since the impacting speed of the droplet is rather high, it can significantly disturb the powder bed and cause pores in the 3D-printed parts. These pores can drastically reduce the strength and other mechanical properties of the products. This award supports fundamental research to understand the binder-powder interaction in binder jetting and identify technical solutions to eliminate the formation of large pores in the binder jetting products. This will significantly improve performance of parts fabricated with the binder jetting process and expand its applications in various industries. This will strengthen the manufacturing capability and competitiveness of U.S. industry by allowing for rapid fabrication of low-cost custom components for many different industries.This research will investigate the binder-powder interaction in the binder jetting process. The research objective is to test the hypothesis that partially saturating (pre-wetting) the powder will suppress powder spattering and reduce pore formation by (i) accelerating binder absorption and (ii) increasing the cohesion of the powder bed. A synergistic experimental and numerical investigation will be performed to achieve the research objectives. On the experimental side, a customized binder jetting system will be established to enable controlled pre-wetting of the powder bed as well as the flexible adjustment of binder jetting parameters (e.g., droplet size, impact velocity, etc.). Parametric studies will be performed to identify the effects of binder jetting parameters and binder/powder material properties on the spatter/pore formation. In-situ high-speed X-ray imaging and ex-situ characterization will be used to observe the dynamic binder-powder interaction. On the modeling side, a multi-physics model that integrates the computational fluid dynamics and discrete element method will be used to simulate the binder-powder and powder-powder interactions during the binder jetting process. The combination of experimental and numerical results will be used to test the research hypothesis.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.

粘合剂喷射是一种越来越重要的 3D 打印方法，因为它具有多种材料选择（几乎任何粉末材料）、高生产率和适中的设备成本。它可以说是唯一同时适用于金属和陶瓷的主流 3D 打印技术。它在能源、航空航天、化工和其他行业的应用越来越广泛。在粘合剂喷射过程中，3D 部件被逐层打印。在每一层上，粉末床被展开，并且微小的液滴沉积在粉末床上的选定位置上。 这些液滴渗透到床中并将颗粒粘合在一起。由于液滴的冲击速度相当高，它会显着扰乱粉末床并导​​致 3D 打印部件出现孔隙。这些孔隙会大大降低产品的强度和其他机械性能。该奖项支持基础研究，以了解粘合剂喷射中粘合剂-粉末的相互作用，并确定消除粘合剂喷射产品中大孔形成的技术解决方案。这将显着提高采用粘合剂喷射工艺制造的零件的性能，并扩大其在各个行业的应用。这将允许为许多不同行业快速制造低成本定制组件，从而增强美国工业的制造能力和竞争力。这项研究将研究粘合剂喷射过程中粘合剂-粉末的相互作用。研究目的是测试以下假设：部分饱和（预润湿）粉末将通过（i）加速粘合剂吸收和（ii）增加粉末床的内聚力来抑制粉末飞溅并减少孔隙形成。将进行协同实验和数值研究以实现研究目标。在实验方面，将建立定制的粘合剂喷射系统，以实现粉末床的受控预润湿以及粘合剂喷射参数（例如液滴尺寸、冲击速度等）的灵活调整。将进行参数研究，以确定粘合剂喷射参数和粘合剂/粉末材料特性对飞溅/孔隙形成的影响。原位高速 X 射线成像和异位表征将用于观察动态粘合剂-粉末相互作用。在建模方面，将使用集成计算流体动力学和离散元方法的多物理模型来模拟粘合剂喷射过程中粘合剂-粉末和粉末-粉末的相互作用。实验和数值结果的结合将用于检验研究假设。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。