Optimization of Process Parameters of Electric Discharge Machining Based on Neural Networks and Taguchi Method

Abstract

EDM is one of the most extensively used non-conventional material newlineremoval processes for difficult-to-cut materials. EDM is a thermo-electric newlineprocess in which material is removed from work piece by erosion effect of series newlineof electric discharges (sparks) between tool and work piece immersed in a newlinedielectric liquid. Physical and metallurgical properties do not create any newlinelimitation for the materials to be machined on EDM as there is no physical newlinecontact between tool and work piece. This is why EDM is very popular in newlinemachining difficult-to-cut materials. The full potential of EDM process has not newlineyet been exploited due to its complicated discharge mechanism. Though a lot of newlineresearch has been done to improve the process performance, optimal selection of newlineprocess parameters for the best performance measures still remains a challenge. newlineThe present work comprises two parts. newlineFirst part investigates the influence of input parameters (process newlineparameters) on performance measures. Experiments have been carried out on newlinedie-sinking EDM by taking Inconel 718 as work material and copper as newlineelectrode. Inconel 718 has been selected as work material as less amount of work newline(with specific regard to electric discharge machining of this material) is reported newlinein the literature. Inconel 718, a nickel based super alloy, is a precipitationhardenable newlinenickel-chromium alloy containing significant amounts of iron, newlineniobium, and molybdenum along with lesser amounts of aluminum and titanium. newlineOwing to its excellent mechanical and metallurgical properties this alloy finds newlineextensive use in gas turbines, rocket motors, spacecraft, nuclear reactors, pumps newlineand tooling. Formation of complex shapes by this material along with reasonable newlinespeed and surface finish is not possible in traditional machining. newlineEDM is one of newlinethe most suitable processes to shape this alloy. For experimentation, Shape factor newline(SF), Pulse-on-time (Ton), Discharge current (Id), Duty cycle (and#950;), Flushing newlinepressure (P) and Tool electrode lift time (TL) have been taken as input newlineparameters.