A fundamental study on the influence of the pulse duration and the interval between pulses on the productivity and the electrode wear in sinking EDM of INCONEL 718

Abstract

EDM is a machining process that promotes the removal of material by applying electrical discharges. The knowledge of the parameters that allows greater productivity is important for reducing manufacturing time of a piece. At the same time, it is necessary to reduce the cost of the process by reducing the consumption of raw materials. For this, it is essential to understand how the process parameters affect the productivity and the electrode wear. In this context, this paper aims to analyze the behavior of the process with the variation in four levels of the duration of the voltage pulse (ti) and the duration of the interval between pulses (to) during step EDM roughing of the alloy INCONEL 718 with respect the wear on the electrode and the removal rate of the workpiece material. For all tests, the duration of the EDM process was the same. To obtain the productivity of the process was considered the rate of removal of material from the part by measuring the mass difference before and after of the machining. Of the same way, the electrode wear was measured. The test results were processed and analyzed statistically. As result, it can be seen that there is a value for ti which provides a higher rate of removal and a tendency towards a zero for electrode wear with the use of long to. Also it showed a reduction in removal rate with decreasing to. Some observations on the possible causes that led to the results were performed.