Precision machining of insulated materials by electro-chemical discharge machining in electrolyte containing enriched micro bubbles

绝缘材料的精密或微加工方法落后于金属或半导体。本研究旨在改善电化学放电加工的性能。(1)在电火花加工（EDM）和电化学加工（ECM）等电加工中，高峰值和低平均放电能量密度有助于提高形状精度。在小于1ms的脉冲持续时间下观察气泡产生的过程。当施加电压时，开始通过电解在电极周围产生气泡。在电极被完全覆盖之后，发生放电。气泡在脉冲间隔期间消失。因此，在低占空比和短脉冲持续时间下观察到较少的去除。(2)多电极电火花加工装置研制了一种重力进给式电火花加工装置，其中六个电极在上保持器处径向排列，在下电极导轨处成一直线。每个电极都与其他电极绝缘。(3)加工机理分析比较了单电极、等电位电源和分电位电源在70。V作为施加电压，10 Hz作为频率，80%作为占空比。在单电极等电位加工中，由于电极周围存在大量的气泡，导致加工孔边缘变钝。此外，气泡的流动影响孔的椭圆度。分光光度法测得的孔入口形状精度优于其他方法。

Precision or micro machining methods for insulated materials lag behind ones for metals or semiconductors. This study aims to improve the performance electro-chemical discharge machining (ECDM).(1) Measurement of conditions in gapHigh peak and low average discharge energy density leads to improve the form accuracy in electrical machining such as electrical discharge machining (EDM) and electro-chemical machining (ECM). The process of bubble generation was observed under a pulse duration less than 1 ms. When the voltage was applied, the bubble generation around an electrode by the electrolysis began. After the electrode was completely covered, discharge occurred. The bubbles disappeared during the pulse intervals. Therefore, less removal was observed at a low duty and short pulse duration.(2) Machining unit with multiple electrodesA gravity-feed type unit for ECDM was made in which six electrodes were aligned radially at the upper holder and in line at the lower electrode guide. Each electrode was insulated from the others.(3) Analysis of machining mechanismThe machining performance was compared among the single electrode, equi-potential power and divided power under the conditions of 70. V as the applied voltage, 10 Hz as the frequency and 80% as the duty. In the single electrode and equi-potential power, the edge of machined hole became dull because the abundant bubbles always remained around the electrodes. In addition, the flow of the bubbles affected the ellipticity of the holes. The form accuracy of the hole entrance by the divided power was better than the others.