Optimization of wire electrical discharge machining (WEDM) process parameters using genetic algorithm

Wire electrical discharge machining (WEDM) is a special form of traditional electrical discharge machining in which the electrode is a continuously moving conducting wire. The mechanism of metal removal in wire electrical discharge machining involves the complex erosion effect from electric sparks generated by a pulsating direct current power supply. The sparks generated between two closely spaced electrodes are immersed in dielectric liquid. However, dimensional accuracy and surface finish largely depend on process parameters such as discharge current, pulse duration, pulse frequency, wire speed, wire tension and dielectric flow rate. An experimental study has been carried out on a Robofil 100 WEDM machine to identify various significant control factors and their interactions that affect the machining performance such as metal removal rate (MRR) and surface finish (SF) based on Taguchi method. The relationship between control factors and responses like MRR and SF are established by means of non-linear regression analysis resulting in a valid mathematical model. Finally, genetic algorithm, a popular evolutionary approach, is used to optimize the wire electrical discharge machining process with multiple objectives. The study demonstrates that the WEDM process parameters can be adjusted to achieve better metal removal rate and surface finish simultaneously.