Experimental investigation of the effects of tool initial surface roughness on the electrical discharge machining (EDM) performance

Abstract

Electrical discharge machining (EDM) has become an essential process in the modernized manufacturing, as it has been applied in diverse applications such as die cavities manufacturing for automotive components, connecting rods, and different intricate shapes. The proper choice of EDM machining conditions is one of the most critical aspects to consider in the die-sinking electrical discharge machining, as they have great influence on machining performance. Among the parameters and conditions that may affect the machining characteristics, the electrode’s initial surface roughness has not been considered in previous researches. In this study for the first time, the effects of the tool initial surface roughness on the EDM performance are investigated. Experiments are conducted on a die-sinking EDM machine with several different tool initial surface roughness values and EDM parameters to find out the effects on the EDMed workpiece surface roughness, tool wear rate (TWR), material removal rate (MRR), and the tool surface roughness after machining. The results show that TWR increases and MRR decreases by increase in tool surface roughness during finish, semi-rough, and rough EDM processes. In addition, workpiece surface roughness after EDM machining slightly depends on initial tool surface roughness, while the tool surface roughness after machining depends greatly on EDM machining parameters.