INVESTIGATION OF GRAPHITE AND COPPER ELECTRODES ON EDM MACHINING OF P20 STEEL

Abstract

This study investigates the material removal and surface roughness of P20
steel by electric discharge machining (EDM) between two common electrodes:
copper and graphite. The Box-Behnken experimental method and the quadratic
regression equations are used to represent the mathematical-statistical
relationship between the EDM machining parameters and machining
performances (material removal rate and surface roughness). Experimental
results and data processing show that the higher the machining current, the
higher the material removal rate, but the higher the surface roughness of the
workpiece. The copper electrode has 16.4% higher material removal rate and
11.2% lower machined surface roughness than the graphite electrode. This study
serves as a database for selecting electrode materials in EDM machining.