Modelling the WEDM Process Parameters for Cryogenic Treated D-2 Tool Steel by Integrated RSM and GA

Abstract

Wire electric discharge machine (WEDM) is a thermo-electric spark erosion machining process to cut very hard conductive material with the help of a wire electrode. Cryogenic treated high carbon high chromium tool steel (D-2 tool steel) is used for the current investigation. Cryogenic treatment is a surface process in which the material is placed in nitrogen environment (below -190 C) to remove stress and enhance wear resistance. The purpose of this study is to investigate the effect of parameters on surface roughness for WEDM. D-2 tool steel is used in die and punch industries, where wear takes place due to frequent operation of die-punch. To increase the wear resistance the cryogenic treated work-piece is used for the research. The Mathematical modelling of the process is carried with the help of Response surface methodology (RSM). The central composite rotatable design (CCRD) has been used to planning the experiments. The input process parameters are pulse on time, pulse off time, servo voltage and peak current. Out of which Pulse on-time has maximum effect on surface roughness as compared to other process parameters. Genetic algorithm is used to predict the best individual parameters along with the predicted fitness values.