Comparison of Optimum Cutting Parameters in Machining Die Steel (EN 31) by using Gray Relational Analysis and TOPSIS

Manufacturing industries are undergoing various changes due to the unending need of the customers for qualitative, reliable and sophisticated parts and products in the modern era and technological world. Accompanying the development of mechanical industry, the demands for alloy materials having high hardness and impact resistance are increasing. To meet such requirements manufacturers are make use of EDM machines. EDM are used to cut conductive metals of high hardness or the materials that are difficult to cut or impossible to cut with the traditional methods. The machines are also specialized in cutting complex contours or fragile geometries that would be difficult to be produced using conventional cutting methods. However, environmental impact due to release of toxic emissions aerosols during the process, poor operational safety due to fire hazard, electromagnetic radiation and non-bio degradable waste are the major problems concerned with conventional dielectric fluids (i.e. kerosene, hydro carbon, etc.,). To reduce the problems with conventional die electric fluids waste palm oil blended with kerosene is used. The present work was to examine the effects of process parameters on the machining quality and to obtain optimal process parameters in order to maximize Material Removal Rate and Minimize the Surface Roughness and Dimensional deviation error. The process parameters that are consider for the present work is current (I), voltage (V), pulse on (Pon), and pulse off (Poff) and responses are metal removal rate (MRR), surface roughness (Ra) and dimensional deviation (DD). Comparison of optimum values by using multi objective optimization techniques like Gray Relational analysis (GRA) and TOPSIS.