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: 1946743
• 负责人: Wenda Tan
• 金额: $ 21.36万
• 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: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2022-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1946743&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.

活页夹喷射是一种3D打印方法，由于其多功能材料选项（几乎任何粉末状材料），高生产率和适度的设备成本，它越来越重要。可以说，这是唯一适用于金属和陶瓷的主流3D打印技术。它发现在能源，航空航天，化学和其他行业中的应用不断增加。在粘合剂喷射过程中，3D零件按一层打印。在每一层上，粉末床都会散开，并将微观液滴沉积在粉末床上的选定位置。 这些液滴渗透到床上并将颗粒结合在一起。由于液滴的撞击速度相当高，因此它可能会严重干扰粉末床并在3D打印零件中引起毛孔。这些孔可以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的粘合剂粉相互作用，并确定技术解决方案，以消除粘合剂喷射产品中大毛孔的形成。这将显着提高用粘合剂喷射过程制造的零件的性能，并扩大其在各个行业中的应用。这将通过允许为许多不同行业生产低成本的定制组件，从而增强美国行业的制造能力和竞争力。这项研究将调查粘合剂喷射过程中的粘合剂 - 粉状交互。研究目标是检验以下假设：部分饱和（预润湿）粉末将通过（i）加速粘合剂吸收和（ii）增加粉末床的凝聚力来抑制粉末溅射并减少孔形成。将进行协同实验和数值研究以实现研究目标。在实验侧，将建立一个定制的粘合剂喷射系统，以启用粉末床的控制预润湿以及粘合剂喷射参数的柔性调节（例如，液滴尺寸，撞击速度等）。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Spater/孔形成的影响。原位高速X射线成像和前坐骨表征将用于观察动态粘合剂 - 粉状相互作用。在建模方面，集成计算流体动力学和离散元素方法的多物理模型将用于模拟粘合剂喷射过程中的粘合剂 - 加油和粉末 - 粉状相互作用。实验结果和数值结果的结合将用于检验研究假设。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响评估标准，被认为值得通过评估来获得支持。