The influences of spark energy density on the electrical discharge machining (EDM)
H. R. Rezaei Ashtiani, F. Hojati
Abstract
Electrical discharge machining (EDM) is one of the most famous and powerful non-traditional machining processes, capable of machining difficult-to-machine conductive material. Spark energy density is one of the most important aspects of the EDM process in which the material removal rate (MRR) is indicated utilising effective spark erosion. In this study, the influences of spark energy density on the EDM characteristics such as MRR and surface roughness (SR) of hot tool steel (H13) were experimentally investigated. The EDM was conducted under the different processing parameters, such as pulse on-time, pulse current, and machining area, and also the effects of electrical discharge energy on the machining characteristics were investigated. Experimental results indicated that the amount of transferred energy into the workpiece increased with increases in pulse on time and spark energy density has an optimum value for each machining area that produces effective sparks which in turn increases MRR and improves surface quality. After the optimum value of pulse on-time, MRR decreases because of decreasing plasma channel efficiency. On the other hand, with increasing pulse current, spark energy density and as a result, MRR and SR increased.