Development of Cavitation Aided Ultra-precision Surface Finishing Technique of 3-dimentional Curved hole

在这项研究中，空化辅助加工提出了一个精确的微图案化方法的基础上的一个新的概念，积极利用空化在抽吸流的加工现象。空化现象自发现以来，一直是流体机械的主要问题，它会引起流体机械的磨损、振动和噪声。空化辅助加工是利用设置在工件表面加工点上方的节流器对空化和加工液的流动进行部分限制，使分散在加工液（水）中的微小磨粒在工件表面发生干涉，从而实现对工件表面的清洗或喷丸等加工。通过使限流器沿着平行于工件表面的流动方向滑动，加工现象沿沿着工件表面连续发生。在微图形化过程中，除了所需加工区域之外的抛光玻璃表面被聚酯膜掩蔽，并且其通过空化辅助加工而被加工。通过释放掩膜，在玻璃表面获得所需的微轮廓，研究了微图形化方法在玻璃表面形成微轮廓的机理和特性。随着掩模膜的厚度或掩模所确定的加工宽度的减小，所生成的微图案的形状精度变得更高。在玻璃表面获得了依赖于掩模图形的微台阶槽、微台阶凹坑等微细图形，为空泡辅助加工应用于硬脆材料的微细加工提供了可能。

In this study, the cavitation aided machining is proposed as a precision micro patterning method based on the new concept of a positive use of cavitation in a suction flow for machining phenomenon. There have been problems on cavitation that causes erosion, vibration and noise of fluid machinery since its discovery. However, its advantages on cleaning or peening and so on were recently reported.The cavitation aided machining makes loose micro abrasive grains, which are mixed in machining fluid of water, to interfere in the workpiece surface with impact of cavitation and flow of machining fluid restricted partially by the restrictor setting above a machining point on workpiece surface. The machining phenomenon continuously occurs along the workpiece surface by sliding a restrictor along the flowing direction parallel to the workpiece surface. In the micro patterning process, the polished glass surface except for the required machining region is masked by polyester film, and it is machined by the cavitation aided machining. The required micro profile on glass surface is obtained after releasing masking film.The micro profile generation mechanism and characteristics of glass by the proposed micro patterning method has been investigated in this study. The form accuracy of generated micro patterns become higher with decreasing the thickness of masking film or the machining width determined by the mask. Several micro patterns on glass surface, for example the micro terraced groove, the micro terraced dimple and so on, depend on mask patterns have been obtained, and there is a possibility of cavitation aided machining applying to the micro fabrication of hard and brittle materials.