Effect of slotted electrodes on improvement in machining performance of large-scale electrical discharge machining

Abstract

Under special conditions, electrical discharge machining is prone to experiencing poor machining removal rate. This creates debris deposits that lead to decreased machining efficiency and poorer machining quality in the machining workpieces during machining operations. Thus, the present study investigated the use of slotted electrodes to improve machining debris removal and compared the machining capability of such electrodes with that of cylindrical, nonslotted electrodes. Concurrently, oscilloscopes were used to measure the machining voltage and current signals during the machining process, in which waveforms were analyzed to gain insight into the electrical discharge condition of the electrical discharge machining. Compared with general cylindrical, nonslotted electrodes, the deep slotted electrodes improved the material removal rate on large-scale and hemisphere electrical discharge machining result by 91% and 116.7%, respectively. The experiment results also show that slotted electrodes are inapplicable to finishing operations. Therefore, during roughing operations, slotted electrodes should be used to lower machining time; during finishing operations, cylindrical, nonslotted electrodes should be used to adjust machining precision.