Multi-objective optimization of some correlated process parameters in EDM of Inconel 800 using a hybrid approach

Electrical discharge machining (EDM) is an extensively used non-traditional machining process used for conductive materials to get intricate or complex shapes. For any manufacturing industry, optimum parameters of control variables are of sheer importance to improve multiple performance characteristics like surface integrity and productivity. This paper presents multi-objective optimization on the basis of ratio analysis (MOORA) method coupled with principal component analysis (PCA) in order to achieve the optimal combination of EDM parameters. In this research work, response surface methodology was used for designing the experiments considering three input parameters, namely pulse-on time, pulse-off time and pulsed current. All the experiments were conducted at different parametric combinations and the performance, namely material removal rate (MRR) and surface roughness (Ra). Proposed MOORA-PCA hybrid results and conventional MOORA results were compared, and it is found that proposed methods are accurate for predicting the responses. Finally, the control variables, namely pulse-on time (TON), pulse-off time (TOFF) and pulsed current (Ip), were set to 300 µs, 85 µs and 18 A, respectively, to get maximum MRR and minimum surface roughness.