Surface characteristics of EN19 steel materials by EDM using Graphite mixed Dielectric medium

Abstract

Surface reformation by quantifiable transfer of the added powder particles during electric discharge machining (EDM) has materialized in the last decade. Material may be delivered on to the machined surface of the work piece by the erosion of the electrode or by the addition of the powder in dielectric. In addition of this, the breakdown of the hydro carbon in the dielectric contributes carbon to the spark which may also cause surface modification. In the present research, experimental investigation has been carried out on EN19 alloy steel surface modification during graphite mixed EDM process. Central composite design of experiments was used to conduct the experiments by considering peak current, gap voltage and pulse on time as input process parameters and micro hardness as response parameter. From the experimental results, It was observed the great variation in the Surface roughness and micro structure of the machined surface. The optimal set of input parameters for producing better surface finish and good harness are determined by the Invasive weed optimization algorithm.