Fundamental Research on Plasma Flow and Plasma-Solid Interactions for Laser-Induced Plasma Deburring.

去除材料以制造零件或特征通常会导致不需要的小碎片（超出工件上的期望特征的剩余小片材料），其通常需要通过附加工艺去除。由于小特征尺寸、大毛刺与特征尺寸比和严格的几何特征公差等常见挑战，微型去毛刺可能特别耗时且昂贵。 通过该奖项，将研究激光诱导等离子体去毛刺工艺，以确定等离子体流（电离气流）和等离子体-固体相互作用是否可以有效地去除微毛刺，而不会对工件造成重大损害。如果这一点得到验证，那么激光诱导等离子体去毛刺可以在广泛的特征形状和材料的微去毛刺中找到应用。这种新的能力可以使许多先进的制造业受益，这些制造业依赖于无毛刺、微尺度结构和特征，用于医疗支架、燃料喷射器孔等应用。虽然这项研究的重点是获得对等离子体流与微尺度结构（MEMS）及其粘附表面相互作用的基本理解，但这些基本知识可能使制造业中的许多其他领域或技术受益，航空航天和航空领域，例如，基于激光等离子体的表面颗粒清洁、超音速流减阻和微/纳卫星推进。除了研究部分，研究生和本科生参与研究活动的计划将加强先进制造业未来的劳动力。下一代制造工程师将通过丰富的制造本科课程和当地社区外展活动来培养。 本项目的总体目标是对激光诱导等离子体去毛刺过程中的激光诱导等离子体流、等离子体-固体相互作用以及工件上毛刺周围的影响有一个很好的基本了解。 具体的研究目标是：（1）从根本上认识激光诱导等离子体流动（2）了解等离子体对工件表面完整性、微观结构和机械性能的影响;以及（3）确定等离子体流和等离子体-固体相互作用是否能够产生足够强的冲击以有效地去除微裂纹，而不造成显著的工件损坏。具体的研究工作包括：（1）对激光诱导等离子体去毛刺过程进行时间分辨的测量和观察;（2）建立一个模型，以深入了解毛刺周围的等离子体流动和等离子体-固体相互作用过程;并且，在本发明中，（3）在激光之前和之后表征工件和工件-感应等离子体去毛刺，以帮助了解毛刺去除机制，并确定该过程对剩余表面的影响。该奖项反映了NSF的法定使命，并被认为值得支持，使用基金会的知识价值和更广泛的影响审查标准进行评估。

Removing material to fabricate parts or features can often result in unwanted small burrs (remaining small pieces of material beyond the desired features on workpieces) that typically need to be removed by additional processes. Micro scale deburring can be especially time consuming and expensive due to common challenges such as small features sizes, large burr-to-feature size ratios, and tight geometric feature tolerances. Through this award, a laser-induced plasma deburring process will be studied to determine if plasma flow (ionized gas flow) and plasma-solid interactions can effectively remove micro burrs without imparting significant damage to the workpiece. If this is verified, then laser-induced plasma deburring could find application in micro-deburring a wide range of feature shapes and materials. This new ability could benefit many advanced manufacturing industries relying on burr free, micro-scale structures and features for applications such as medical stents, fuel injector holes, etc. Although this research is focused on gaining a fundamental understanding of plasma flow interactions with micro scale structures (burrs) and the surfaces to which they adhere, the basic knowledge may benefit many other areas or technologies in manufacturing, aerospace and aeronautical fields, e.g., laser plasma-based surface particle cleaning, supersonic flow drag reduction, and micro/nanosatellite propulsion. In addition to the research component, planned engagement of graduate and undergraduate students in the research activities will strengthen the future workforce in advanced manufacturing industries. The next generation of manufacturing engineers will be cultivated through both an enriched undergraduate course on manufacturing, and local community outreach activities. The overall goal of this project is to gain a good fundamental understanding of laser-induced plasma flow, plasma-solid interactions and effects around a burr on a workpiece in the laser-induced plasma deburring process. The specific research objectives are to: (1) fundamentally understand laser-induced plasma flow (including the associated shock wave) and plasma-solid interactions around a burr on a workpiece; (2) understand the plasma effects on burrs and on workpiece surface integrity, microstructures and mechanical properties; and (3) determine if the plasma flow and plasma-solid interactions can generate sufficiently strong impacts to effectively remove micro burrs, without imparting significant workpiece damage. The specific research tasks include: (1) perform time-resolved measurements and observations of the laser-induced plasma deburring process; (2) develop a model to gain insights into the process of the plasma flow and plasma-solid interactions around a burr; and, (3) characterize burrs and workpieces before and after laser-induced plasma deburring to help understand the burr removal mechanism and determine the impact of the process on the remaining surface.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.