Investigation on the Performance of Macro Electrochemical Milling

Due to the use of standard electrodes electrochemical milling avoids the complex electrode design which is often a burden in sinking ECM. In this process material is removed by a tubular tool following a predefined path in a layer-by-layer fashion. In this initial study the influence of different process parameters, electrode geometry and electrode rotation on the process performance is investigated. Experiments showed that the best performance in terms of removal rate, surface quality and accuracy can be obtained when using a pulsed voltage input. Moreover, inaccuracies due to the tubular electrode shape can be avoided by using alternative electrodes which distribute the flushing holes over the entire cross section of the electrode or by decreasing the inner diameter of the tubular electrodes. Finally specific milling aspects like performing multiple passes and step-over were investigated. It was shown that further improvements are necessary to obtain a good part accuracy.