電化學放電加工（Electrochemical Discharge Machining , ECDM）是以高溫熔融並藉此高溫可加快蝕刻速度的加工機制，因此非常適合應用於石英材料之精微加工。而由於電化學放電加工主要是藉由電化學反應在電極表面形成之氣膜而產生放電現象之材料移除模式，所以氣膜的結構及穩定性為影響加工效率及精度之關鍵因素。因此本研究將首先探討不同氣膜結構對於加工性能之影響，而後為了提升加工石英材料之加工性能，擬以球狀之電極外形改善現有電化學放電加工在深孔加工效率不佳的問題。 從實驗結果得知，由圓柱電極的氣膜包覆狀態中發現，由於圓柱電極的外形導致在加工初期，短暫的氣膜成形時間將降低加工效率；而氣膜的緻密性及其穩定程度也對加工性能造成顯著的影響。除此之外，由電流波形及加工後微孔之表面形貌可判斷不同氣膜結構於放電頻率及加工精度的差異；而電解液濃度也將影響氣膜的組成結構。在充份了解氣膜對於加工性能的影響後，由於圓柱電極的外形限制，不但使得加工時氣泡容易堆積於入口處，並且阻礙電解液的流動以致於對加工效率造成嚴重的影響，而在微孔之剖面及出口處也因圓柱電極外形的影響大幅降低加工後微孔之精度。而本研究採用的球狀電極，其加工性能與圓柱電極相比較，不但可大幅度的將加工時間縮短了83%、擴孔量減少65%，同時於貫穿孔加工後，出口處不會瞬間破裂而影響其微孔品質，也可得到孔壁剖面筆直度較高之微孔輪廓，以獲得高精度之石英微孔。 Electrochemical discharge machining（ECDM）is used high-temperature melting assisted by accelerated chemical etching, hence it is well suitable for quartz material precisely machining. During ECDM, gas film will be formed on the tool electrode surface due to electrochemical reaction and then result in discharge phenomenon. Therefore both the structure and stability of gas film have significant effect factors on the efficiency and precision of machining. For this reason, first we will discuss the influence of different gas film structure on machining characteristics in this study. And then in order to improve the machining characteristics which is processed the quartz material. Try using the spherical electrode to improve present electrochemical discharge machining which has the problem about efficiency on the deep hole. Experimental results show the coalesce status of gas film in the cylinder electrode decreased the machining efficiency because of the short time of gas film. Compact and stability of gas film lead to influence of machining characteristics. Moreover, current waveform and appearance of micro-hole can analyze the difference of different coalesce status of gas film structure on discharge frequency and machining precision. The electrolyte concentration will also influence the gas film structure. Therefore this study is using spherical electrode to overcome such problem mention above. Compare with the cylinder electrode, the machining time is decreased 83%, the micro-hole diameter is reduced 65%. Meanwhile after passes through the perforation hole processing, the exit of micro-hole can not break to effect its quality. It can get higher straight of hole wall cross-section, and obtain the high-accuracy micro-hole in quartz.
