Effects of processing parameters on electrode loss of micro-EDM milling with spiral electrode

In order to uplift the machining efficiency and accuracy of micro electrical discharge machining (micro-EDM) milling, this paper studied the prediction and compensation method of electrode loss and established a fixed length compensation model for micro-EDM milling with spiral electrodes. It was verified through experiments that the model can successfully predict the electrode loss of micro-EDM milling with spiral electrodes. On the basis of a single factor experiment, the influence of processing parameters (pulse width, pulse interval, peak current, rotating speed) on the actual relative volume loss ratio (theta(r)) of micro-EDM milling with spiral electrodes was studied. Then, based on the orthogonal experiment, the optimization of the theta(r) of micro-EDM milling with spiral electrodes based on fixed length compensation was studied. Through signal-noise ratio (SNR) analysis, the optimal processing parameter combination of theta(r) was obtained as the pulse width of 4.2 mu s, the pulse interval of 13 mu s, the peak current of 4A, and the rotating speed of 1400r/min. Under this parameter combination, the theta(r) of micro-EDM milling with spiral electrodes based on fixed length compensation could be reduced to 22.23%. Variance analyses were carried out on the outcomes, and a process model of theta(r) based on fixed length compensation was established. Because the predicted results were consistent with the results of the validation test, the reliability of the process model was proved.