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毛刺(超出工件上所需特征的剩余小块材料)，通常需要通过额外的工艺去除。由于特征尺寸小、毛刺与特征尺寸之比大、几何特征公差小等常见挑战，微尺度去毛刺可能特别耗时且昂贵。通过该奖项，将研究激光诱导的等离子体去毛刺过程，以确定等离子体流(电离气体流)和等离子体-固体相互作用是否能够有效去除微小毛刺，而不会对工件造成重大损害。如果这一点得到证实，那么激光诱导等离子体去毛刺可以应用于广泛的特征形状和材料的微去毛刺。这种新的能力可以使许多先进的制造业受益，这些应用依赖于无毛刺的微尺度结构和特征，如医疗支架、燃料喷射器孔等。虽然这项研究的重点是对等离子体与微尺度结构(BURR)及其附着表面的相互作用有一个基本的了解，但基本知识可能有助于制造业、航空航天和航空领域的许多其他领域或技术，如基于激光等离子体的表面粒子清洗、超音速流动减阻和微/纳米卫星推进。除了研究部分，计划中的研究生和本科生参与研究活动将加强未来先进制造业的劳动力。下一代制造业工程师将通过丰富的制造业本科课程和当地社区外展活动来培养。该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动、等离子体-固体相互作用以及毛刺周围的影响有一个很好的基础了解。具体的研究目标是：(1)从根本上了解激光诱导的等离子体流(包括相关冲击波)和毛刺周围的等离子体-固体相互作用；(2)了解等离子体对毛刺以及对工件表面完整性、显微组织和机械性能的影响；(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影响，有效地去除微小毛刺，而不会给工件造成重大损害。具体的研究任务包括：(1)对激光诱导等离子去毛刺过程进行时间分辨的测量和观察；(2)开发一个模型，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；以及(3)表征激光诱导等离子去毛刺前后的毛刺和工件，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，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

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.