以電解混氣法輔助微電化學高深徑比鑽孔加工之研究;Research on high aspect ratio micro holes by electrochemical drilling combine with electrolytic gas-mixing method

NCU Institutional Repository > 工學院 > 機械工程學系碩士在職專班 > 博碩士論文 > Item 987654321/96396

請使用永久網址來引用或連結此文件: http://ir.lib.ncu.edu.tw/handle/987654321/96396

題名:	以電解混氣法輔助微電化學高深徑比鑽孔加工之研究;Research on high aspect ratio micro holes by electrochemical drilling combine with electrolytic gas-mixing method
作者:	黃和銘;Huang, He-Ming
貢獻者:	機械工程學系在職專班
關鍵詞:	微細深孔;微電化學加工;高深徑比;氣液兩相流;定電流源;Micro deep hole;Electrochemical micro-machining;High aspect ratio;Gas-liquid two-phase flow;Constant current source
日期:	2025-01-20
上傳時間:	2025-04-09 18:25:18 (UTC+8)
出版者:	國立中央大學
摘要:	電化學鑽孔加工(Electrochemical Drilling, ECD)不受材料硬度、韌性限制，能在極堅硬、韌性極強之零件上加工出高精度微孔，故此技術已廣泛用於大量生產具微孔之相關零件。ECD施作過程中，由於加工間隙狹窄，電解產物難以順利帶離加工區，造成電解液流動阻礙，流體流速降低，最終可能導致表面缺陷。若將氣體與電解液充分混合，並泵入工件陽極和工具陰極之間的間隙，使流場呈氣液兩相，便可調節加工間隙的平衡，達到改變流場特性之目的。故本研究以微電化學鑽孔加工(Micro Electrochemical Drilling, μECD)結合電解產氣技術，於SUS304不鏽鋼進行高深徑比鑽孔加工，加工陰極使用附絕緣層之銅管電極，其外徑約為320 μm，工件厚度選用5 mm及150 mm兩種尺寸進行研究。在電化學鑽孔過程中，一律以直流定電流源模式進行加工，確保可得到較佳之孔壁垂直度。其中，欲探討之研究參數包括電解液電導度、加工電流、進給速度、混氣電流等參數對孔之品質特性之影響。在研究流程方面，首先透過加工工件厚度為5 mm之通孔取得最佳參數，接著，在電解液中混入氣泡，並以混氣裝置控制混氣電流，嘗試取得更佳之擴孔量及入出口差。結果發現，隨著混氣電流增加，微孔之擴孔量皆有縮小趨勢，然而隨著電極進給速度與混氣電流同時增加至一定程度後，會產生反效果，甚至導致無法鑽通5 mm之淺孔。為了得知混氣電解液在高深徑比之深孔有無影響，故調整進給速度，並更換工件尺寸，改為長度150 mm之SUS304不鏽鋼棒材。最終，以進給速度0.36 mm/min，未混氣且以定電流源模式加工之極限深度為91.7 mm，深徑比為189.85;而使用混氣電解液後，以定電流源模式加工之極限深度為124.9 mm，深徑比為248.31，改善比例為30.7%。 ;Electrochemical drilling (ECD) is not constrained by material hardness or toughness, allowing it to machine high-precision micro-holes in extremely hard and tough components. As a result, this technology has been widely adopted for the mass production of parts featuring micro-holes. During the ECD process, the narrow machining gap can hinder the removal of electrolysis by-products from the machining area, obstructing electrolyte flow and reducing fluid velocity. This may ultimately result in surface defects. By fully mixing gas with the electrolyte and pumping the mixture into the gap between the anode workpiece and the cathode tool, the flow field can be adjusted to a gas-liquid two-phase state, thereby balancing the machining gap and altering flow characteristics. In this study, micro-electrochemical drilling (μECD) combined with electrolysis gas generation technology was used to drill high aspect ratio holes in SUS304 stainless steel. The cathode tool was a copper tube electrode with an insulating layer, having an outer diameter of approximately 320 μm. Two workpiece sizes, 5 mm and 150 mm in thickness, were selected for the study. The electrochemical drilling process was performed using a direct current constant-current source mode to ensure better verticality of the hole walls. The research parameters investigated included electrolyte conductivity, machining current, feed rate, and gas-mixing current, and their effects on the quality characteristics of the drilled holes were examined. In terms of the research procedure, optimal parameters were first determined by machining through-holes in workpieces with a thickness of 5 mm. Next, bubbles were introduced into the electrolyte, and the gas-mixing current was controlled using a gas-mixing device to achieve improved overcut and entrance-exit differences. The results showed that as the gas-mixing current increased, the overcut of the micro-holes tended to decrease. However, when both the electrode feed rate and gas-mixing current were increased beyond a certain point, adverse effects occurred, even resulting in failure to penetrate 5 mm shallow holes. To investigate the impact of gas-mixed electrolytes on high aspect ratio deep holes, the feed rate was adjusted, and the workpiece size was changed to a 150 mm long SUS304 stainless steel rod. Ultimately, at a feed rate of 0.36 mm/min, the maximum depth achieved using a non-gas-mixed electrolyte in constant-current source mode was 91.7 mm, with an aspect ratio of 189.85. In contrast, with the use of a gas-mixed electrolyte under constant-current source mode, the maximum depth reached was 124.9 mm, with an aspect ratio of 248.31, representing an improvement ratio of 30.7%.
顯示於類別:	[機械工程學系碩士在職專班 ] 博碩士論文

文件中的檔案:

檔案	描述	大小	格式	瀏覽次數
index.html		0Kb	HTML	9	檢視/開啟

在NCUIR中所有的資料項目都受到原著作權保護.

社群 sharing

資料載入中.....