電化學放電加工於石英玻璃加工精度改善之研究

The Research of Improving the Machining Quality and Accuracy in Electrochemical Discharge Machining

林正宜(Cheng-yi Lin)

指導教授 ： 洪勵吾

國立中央大學/工學院/機械工程學系/碩士(2012年)

摘要

微機電系統近年來在科技工業上扮演舉足輕重的角色，其中光學
玻璃和石英等硬脆材料的應用與日俱增。電化學放電加工(ECDM)是
加工非導電材料的新興加工技術，具有殘留熱應力低、加工精度高、
加工速率快以及電極磨耗低等優點。
　　本文使用直徑100um之碳化鎢刀具作為工具電極，電解液採用
氫氧化鉀(KOH)溶液搭配不同濃度之乙醇(Ethanol)，利用電化學放電
加工對石英玻璃進行鑽孔，分別使用不同電解液濃度、電壓、頻率、
電解液高度等參數，對於氣膜穩定性、厚度以及加工精度造成的影響
作研究與分析。
　　實驗結果顯示，相較於未添加乙醇的電解液，在使用添加乙醇
6.5wt%的電解液作加工時，有較佳的表面過切量以及表面精度，並且
在加工時受到氣泡球的影響較少，電解液的對流效果也較好。添加
6.5wt%乙醇之電解液在過切量的表現上，比起未添加乙醇時，最多可
減少57%，而表面的熱影響區也大幅減少。

關鍵字

電化學放電加工 ； 石英玻璃

並列摘要

MEMS is one of the most important technology in the future. Pyrex glass and quartz are widely used in MEMS. Electrochemical discharge machining(ECDM) is one of the novel technologies applied on machining non-conductive materials. ECDM has serveral advantages, such as low residual stress on the surface, high quality, high machining rate and low tool electrode wear.
　　A tungsten carbide cylindrical electrode with diameter of 100um is selected as the tool electrode. KOH solution contained with different concentration of ethanol is selected as the electrolyte. In this study, the method of ECDM is performed on drilling mirco holes on qurtz. By using the parameters, such as electrolyte concentration, applied voltage, frequency and electrolyte level, the stability and thickness of gas film along with the machining quality are analyzed.
　　From experimental results, it shows that the overcut, quality on the hole entrance and electrolyte circulation are better when the electrolyte contains 6.5wt% of ethanol. The influences of gas bubble and the heat affected zone are also less. Compared with KOH electrolyte, the overcut of the electrolyte contains 6.5wt% of ethanol can be reduced up to 57%.

並列關鍵字

Quartz ； Electrochemical discharge machining

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