微電化學放電加工法應用於硼矽玻璃的精微加工及精度改善之研究

Improving Machining Precision of Pyrex Glass by Using Micro Electrochemical Discharge Machining

楊景棠(Ching-Tang Yang)

指導教授 ： 顏炳華

國立中央大學/工學院/機械工程學系/博士(2007年)

摘要

電化學放電加工是加工非導電硬脆材料的新興技術，加工材料不受限於材料的硬度、導電度，但是由於其加工過程中涵蓋了電解反應、熱熔融與蝕刻反應，加工機制複雜使其未能有效控制加工品質，離產業的實用化仍有段差距；因此探討電化學放電加工的基本加工機制、開發及改善電化學放電加工在微孔與線切割上的品質是本論文所要探討的主題。
本研究藉由攝影機觀察加工過程及加工電壓電流的波形，釐清加工中化學蝕刻與放電在材料移除機制上所扮演的角色，包括將硼矽玻璃置放於電解液中，並以CO2雷射加工玻璃表面，以模擬硼矽玻璃在如同電化學放電加工高溫高壓下的蝕刻狀況；另外使用傳統的放電加工，加工ITO導電玻璃(Indium Tin Oxide)，以暸解玻璃材料在純放電加工下的表面狀況，分別比較純化學蝕刻、純放電加工與電化學放電加工三種加工方法的加工表面狀況，進一步探討加工的材料移除機制；並開發直徑小於0.3mm的電化學放電微鑽孔技術，針對微孔的錐度，提出了使用Al2O3電泳沉積研磨的方法來改善微孔品質，由實驗結果顯示，微孔經階級式電極研磨500秒後，可將平均粗糙度降至5nm，錐度可以改善至0.2o；在線切割加工的應用上，如何減少切割痕(saw mark)與切槽寬度(kerf)是必須克服的議題，本研究在電解液中添加SiC磨粒，由於磨粒的研磨效果，在擴槽量、粗糙度及加工速度上相對於純電化學放電線切割加工都有較佳的表現，達到擴槽量為0.024mm，粗糙度為0.84μm Ra。

關鍵字

線切割 ； 電泳沉積研磨 ； 微孔加工 ； 玻璃加工 ； 電化學放電加工

並列摘要

Electrochemical discharge machining (ECDM) is new and developing technology to non-conductive hard brittle materials. The advantage of the technology is no limitation on brittleness and electrical conductivity. Since the complexity of ECDM involves the interdependency of thermal, electrochemical and mechanical effects, the machining quality can’t reach the application in industry. In view of such drawbacks, this study aims to investigate the machining mechanism in ECDM and enhance the precision quality of micro-holes and micro-slits machined by ECDM.
Real time photographs and the current response were taken to observe the transition process in ECDM. The effects of chemical etching were studied by comparing three surface morphologies, high temperature chemical etching, electrical discharge machining (EDM) and ECDM. The machining mechanism can be further analyzed. Micro-holes of glass with diameter less then 0.3mm and thickness 1.5mm were developed. This study proposed using Al2O3 electrophoretic deposition grinding (EPDG) to further improve taper and surface roughness of the microholes. The surface roughness and taper angle can be improved to 5nm Ra and 0.2o after 500 sec grinding time, respectively. In the wire cut application, it is important to decrease the saw mark and kerf loss. This study proposed adding SiC abrasives in the electrolyte to improve the micro-slits quality. The expansion of micro-slit and surface roughness achieved were 0.024mm and 0.84μm Ra, respectively.

並列關鍵字

wire cut ； electrophoretic deposition grinding ； micro-hole ； glass drilling ； ECDM

參考文獻

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