| 摘要: | 當採用陣列電極進行電化學加工微孔陣列時，因具有無法同時旋轉多個電極及無法於電極內設計流道，導致電解液供給不良，造成加工精度不良或無法加工之情形。為了克服前述各項困難點，本論文採用超音波與磁場複合輔助進行遮罩式電化學加工微孔陣列之研究，利用磁場與超音波振動輔助一體式刀具電極對SUS 304不銹鋼試片進行遮罩式電化學加工微孔陣列，並探討超音波功率等級、工作電壓、脈衝休止時間及刀具電極進給速率等不同加工參數對平均對角線長、對角線長全距及微孔入出口之錐角等各種加工特性之影響。
實驗結果顯示，使用超音波輔助振動刀具電極會造成電解液產生快速的壓力變化，形成泵吸作用與空蝕作用，而添加磁場會與電場相互作用產生勞倫茲力，上述這些輔助方式會促使加工間隙中的電解液更新，快速排除加工區域中的反應熱及不導電之深褐色金屬氧化物，進而提升加工能力及材料移除率並降低微孔陣列之平均對角線長。當使用超音波與磁場複合輔助時，相較於單純超音波輔助或磁場輔助，可以得到較佳的平均對角線及表面品質。當採用實驗參數組合為超音波功率等級Level 8(Amplitude：1.30 μm )、工作電壓16 V、脈衝休止時間70 μs及刀具電極進給速率7 μm/s時，可得到最佳平均對角線長546 μm，以及較小的對角線長全距25 μm，並能改善微孔入出口之錐角。
;During the electrochemical machining(ECM) of the micro-hole array by using array electrodes, the poor processing accuracy or inability of the process resulted from the problems of the poor supply of electrolyte which are resulted from the inability to rotate multiple electrodes at the same time and the inability to design a flow channel in the electrodes. To overcome these difficulties, ultrasonic vibration and magnetic field were adapted to assist through-mask electrochemical machining of the micro-hole array in this study. The one-piece array electrode assisted by ultrasonic vibration and a magnetic field was used to produce a micro-hole array on SUS 304 in the ECM process. Discussions follow on the influences of the various processing characteristics, such as average diagonal length, diagonal length range, inlet taper angle, and outlet taper angle, which resulted from the various processing parameters, including ultrasonic power level, working voltage, pulse off time, and electrode feed rate.
The experimental results have shown that the ultrasonic vibration-assisted electrodes quickly changed the pressure of the electrolyte, producing a pumping effect and a cavitation effect, and the interaction between the magnetic field and the electric field generated a Lorentz force. These auxiliary methods promoted the renewal of the electrolyte into the machining gap, which quickly excludes the reaction heat and the non-conductive dark brown metal oxide in the processing area, thereby improving the processing ability and material removal rate and reducing the average diagonal length of the micro-hole array. When ultrasonic and magnetic field assistances were applied simultaneously, better average diagonal and surface qualities were obtained compared with the ultrasonic assistance or magnetic field assistance independently. The experimental parameter combination, including ultrasonic power level 8 (amplitude: 1.30 μm), working voltage 16 V, pulse off time 70 μs, and tool electrode feed rate 7 μm/s, resulted in a minimum average diagonal length of 546 μm and the smallest diagonal length range of 25 μm while improving the inlet and outlet taper angles of the micro-holes. |
