單晶鑽石銑刀設計及其於微銑削鏡面加工之應用

Abstract

微細銑削受限於刀具尺寸微小，切削速度遠低於ㄧ般傳統的切削加工，因此不易獲得良好的加工表面。本研究利用設計刀具和添加奈米切削液輔助加工兩個方式，嘗試改善此一問題。在刀具設計方面，於文中利用單晶鑽石材料，設計出雙刃偏心微銑刀，並對此一幾何外型之單刃和雙刃刀具，與不對稱偏心刀具對加工面之影響做一試驗與分析討論。而本研究所設計的雙刃偏心微細刀具幾何外型簡單，易於製作且微小化容易，微細銑削加工過程中，添加含有奈米顆粒的表面改質劑，由於奈米顆粒有助於降低金屬接觸面之摩擦係數，使得切屑排出阻力變小，排屑較為順暢，相對的減少了切屑殘留在加工表面，成功改善了加工面之表面粗糙度與表面光度，達到鏡面的效果。在刀具比較方面，將本研究設計的刀具和ㄧ般市售刀具，在相同加工狀況下做比較，證實本研究所設計的刀具較一般市售刀具更容易加工出較佳表面品質，達到鏡面的程度。因此本研究所設計的微細銑刀，在合適的加工參數及條件下，確能符合預期目標。

Limited by the size restriction, the cutting speed of micro milling tool is slower than traditional machining one and ideal maching surface condition is not easy to obtain. In this study, the problems above were successfully improved by designing tool shape and applying nano cutting fluid. In tool designing, single crystal diamond was used to design asymmetric two-flute micro tools. The influence on maching surface caused by the single-flute, two-flute, and asymmetric shape of tools were discussed and analyzed in this study, respectively. And the asymmetric two-flute micro tools have a simple shape that is easy to minimize and fabricate. Less friction coefficient for chip flow was obtained and less chip remained on maching surface when cutting fluid with nano particles was applied. The experimental results showed that the roughness of maching surface was successfully improved and a mirror surface was obtained in this study. It is found that the special tools developed in this study were easier to get high surface quality than the ordinary ones under the same cutting conditions and could nearly achieve the expected purpose in this study.