Study of surface morphology on micro machined surfaces of AISI 316 by Die Sinker EDM

Abstract

Materialsurface roughness improvement using electrical discharge machining has become a key research area in the last two decades. Material may migrate to the machined surface of workpiece either from the tool electrode or from powder mixed in dielectric which resulting change in composition. The present study is to investigate the optimum values of the major intervening parameters in micro machining of Stainless Steel (SS) 316 by Die Sinker EDM process.by using a 900 μm circular copper electrode. The discharge current, pulse-on time and pulse-off time, gap were selected as the process parameters. The effect of materials transfer on the machined surface characteristics is also presented. Micro structure evaluation is by Scanning electronic microscopy showed the topography of the machined surface, there are micro cracks, recast layers, discrete craters along with spherical droplets left on the EDM surface, which indicate that the material removal mechanism is melting and evaporation and formation of surfaces. The Taguchi method is initially applied to determine the optimum process parameters and the number of experiments required to model the responses