Material Removal Mechanisms in Vortex Machining

该奖项的研究目标是了解一种新的纳米级表面去除工艺，该工艺利用抛光液的局部诱导涡流。这些涡流是由浸没在流体中靠近待加工表面的微米级振荡纤维产生的，涡流相对于探针是静止的。不同直径（7 µm至400 µm）的探头，以高频（100 Hz至10 Hz）振荡。s的kHz）将产生不同尺寸和幅度的局部涡流，导致横向尺寸小于一毫米的材料去除覆盖区。工艺足迹的大小将由驱动振荡的振幅和频率以及探头相对于工件的取向来控制。将使用分析模型来隔离产生不同涡流模式和速度分布所需的纤维尺寸和驱动频率。内部实验装置将使预测的涡流动力学和实际的工艺材料去除足迹之间的相关性。实际机制（工艺参数和浆料成分）有助于材料去除率和表面质量。如果成功，该项目将实现具有以下特征和能力的相对低成本技术：1）尺寸可控的亚毫米尺寸的工具，3）从高度局部化的区域去除材料而不对工件造成损坏的能力，4）能够完成传统上具有挑战性的几何形状，例如微流体通道和凹入特征，以及5）能够去除由使用较大工具的当前子孔径工艺所赋予的中间空间频率误差。 这将伴随着分析模型的实验验证，这将有利于最佳工艺参数的方便隔离。参与的本科生和研究生将获得与美国制造业相关的核心技术的能力，如微型制造，精密设计，计量学和化学示范模块将通过夏令营计划开发，以促进科学和工程学科，并在研究生水平的机械工程，光学和纳米科学课程中突出精密工程的跨学科性质。

The research objective of this award is to obtain an understanding of a new, nanometer level, surface removal process that utilizes locally induced vortices of polishing slurry. These vortices are produced by a micrometer scale oscillating fiber immersed in the fluid near to the surface to be machined, the vortices being stationary relative to the probe. Probes of varied diameters (7 µm to 400 µm), oscillating at high frequencies (over 100 Hz to 10?s of kHz) will produce localized vortices of varying size and magnitude resulting in material removal footprints with lateral dimensions of less than a millimeter. The size of the process footprint will be controlled by the amplitude and frequency of the driving oscillations and the orientation of the probe with respect to the workpiece. An analytical model will be used to isolate the fiber sizes and drive frequencies required to produce differing vortex patterns and velocity profiles. An in-house experimental set-up will enable correlations between the predicted vortex dynamics and the actual process material removal footprints. Actual mechanisms (process parameters and slurry composition) contributing to material removal rates and surface quality will also be investigated.If successful this project will realize a relatively low cost technology with the following features and capabilities; 1) sub millimeter sized tooling of controllable size, 3) the ability to remove material from highly localized regions without imparting damage into the workpiece, 4) the ability to finish traditionally challenging geometries such as micro fluidic channels and re-entrant features, and 5) the ability to remove mid spatial frequency errors imparted by current subaperture processes that use larger tooling. This will be accompanied by experimental verification of analytical models which will facilitate expedient isolation of optimal process parameters. The undergraduate and graduate students involved will gain competency in core technologies relevant to US manufacturing such as micro-manufacturing, precision design, metrology, and chemistry Demonstration modules will be developed to promote science and engineering subjects through summer camp programs and to highlight the interdisciplinary nature of precision engineering in graduate level Mechanical Engineering, Optics and Nanoscale Science programs.