| 摘要: | 本研究旨在開發創新電解混氣技術，並探討其在電化學加工（Electrochemical Machining, ECM）中的應用，以提升加工精度與效率。ECM 具備無應力加工、高表面品質及適用於高硬度材料等優勢，然而，在微細加工與窄縫加工製程中，由於電解液供應受限與氫氣氣泡累積，往往影響加工穩定性與效率。因此，本研究提出以電解混氣裝置改善電解液流動性，進而改善加工特性。本裝置透過精準控制氣泡尺寸與混氣比例，使電解液密度降低，提高其於加工間隙內的更新速率，最終提升加工品質與材料移除率。
本研究首先建立電解混氣裝置，並透過影像量測技術分析氣泡尺寸分佈及混氣比例的影響。實驗結果顯示，本技術可透過調整混氣電流來精確控制混氣比例，提升電解液更新效率。此外，將混氣裝置應用於三種主要電化學加工模式（電化學鑽孔、電化學線加工與電化學雕模加工）進行驗證，結果顯示混氣技術能有效提升加工速度，減少流痕並改善表面粗糙度，其中表面粗糙度可降低超過 60%。
進一步，本研究結合混氣電解液與序列脈衝電源技術，分析不同脈衝頻率對加工特性的影響。實驗結果顯示，當序列脈衝頻率提高至 250 Hz 時，加工間隙最大增幅可達 25%，顯示高頻脈衝能有效提升材料移除率與加工效率。此外，透過流場模擬與高速攝影觀察，證實混氣技術可提升電解液流速（最大提升 13.86%），並抑制空穴效應，提高加工穩定性與精度。
為進一步驗證 混氣對電化學加工間隙極化現象之改善效果，採用固定式加工設定（間隙 0.05 mm）觀察不同混氣電流下電源啟動瞬間之電流波形。實驗結果顯示，混氣電流提升可有效降低極間阻抗，其中在混氣電流 3 A 時加工電流達最大值，對應之極間阻抗由 0.9 Ω 降至 0.63 Ω，顯示極化現象改善程度達 29.9%。此結果驗證混氣電解液確實可藉由提升流速改善極化效應，且其正向影響程度高於混氣造成電導度下降的負面影響，進一步強化混氣技術於提升加工穩定性與效能上的貢獻。
最後，本研究探討脈衝式氣泡流對 ECM 加工的影響，發現脈衝頻率為 15 Hz 時能獲得最深加工深度與最大特徵寬度，且適當混氣可有效降低表面粗糙度（最大改善率 40%）。然而，當脈衝頻率過高時，氣泡分佈過於分散，可能影響電導度與流場更新效率。
綜合研究結果，電解混氣技術結合序列脈衝電源與脈衝式氣泡流，不僅可提升 ECM 加工效率，亦能改善加工品質與穩定性。本技術可應用於高精密微細加工領域，如航空航太、精密模具製造與電子產業，為提升電化學加工技術的應用範圍與產業競爭力提供重要參考。
;This study aims to develop an innovative gas-mixed electrolysis technology and explore its application in electrochemical machining (ECM) to enhance machining precision and efficiency. ECM offers advantages such as stress-free machining, high surface quality, and suitability for high-hardness materials. However, in micro-machining and narrow-gap machining processes, limitations in electrolyte supply and the accumulation of hydrogen bubbles often affect machining stability and efficiency. Therefore, this study proposes an electrolytic gas-mixing device to improve electrolyte flowability and enhance machining characteristics. By precisely controlling bubble size and gas-mixing ratio, the device reduces electrolyte density, increases renewal rates within the machining gap, and ultimately enhances machining quality and material removal rates.
The study first establishes the electrolytic gas-mixing device and employs image measurement techniques to analyze bubble size distribution and the effects of gas-mixing ratios. Experimental results indicate that the gas-mixing ratio can be precisely controlled by adjusting the mixing current, thereby improving electrolyte renewal efficiency. Additionally, the gas-mixing device is applied to three primary ECM modes—electrochemical drilling, electrochemical wire machining, and electrochemical die-sinking—to verify its effectiveness. Results show that the gas-mixing technology significantly enhances machining speed, reduces flow marks, and improves surface roughness, with a reduction of over 60% in surface roughness.
Furthermore, this study integrates gas-mixed electrolytes with a sequential pulse power supply to analyze the effects of different pulse frequencies on machining characteristics. Experimental results show that increasing the sequential pulse frequency to 250 Hz results in a maximum machining gap increase of 25%, demonstrating that high-frequency pulses effectively enhance material removal rates and machining efficiency. Additionally, flow field simulations and high-speed imaging observations confirm that the gas-mixing technique increases electrolyte flow velocity (with a maximum improvement of 13.86%) and suppresses cavitation effects, improving machining stability and precision.
Finally, the study investigates the influence of pulsed bubble flow on ECM machining. It is found that at a pulse frequency of 15 Hz, the greatest machining depth and feature width are achieved, while appropriate gas mixing effectively reduces surface roughness (with a maximum improvement of 40%). However, when the pulse frequency is too high, bubble distribution becomes overly dispersed, potentially affecting conductivity and flow field renewal efficiency.
In conclusion, the combination of electrolytic gas-mixing technology with sequential pulse power and pulsed bubble flow not only enhances ECM efficiency but also improves machining quality and stability. This technology can be applied to high-precision micro-machining fields, such as aerospace, precision mold manufacturing, and the electronics industry, providing valuable insights for expanding ECM applications and enhancing industrial competitiveness.
Keywords: Electrochemical machining, Micro-bubbles, Gas-mixed ECM, Electrolysis gas mixing. |
