Process Enhancement of WEDM Operational Parameters of Inconel 718 Superalloy Using RSM Based MOPSO Algorithm

Wire electrical discharge machining is extensively employed in high-precision manufacturing industries for exceptional accuracy in producing intricate shapes. To machine complex cuts with high precision, careful selection of input parameters should be ensured. When the response parameters to be optimized are more than one, the complexity of obtaining optimal solutions increases. In the present paper, the Response surface methodology integrated with the multi-objective particle swarm optimization (MOPSO) technique was implemented to address the issue by obtaining the optimal Pareto front of the two responses of a multi-objective problem. Box-Behnken design (BBD) consisting of 27 experiments was conducted on Inconel 718 material to optimize pulse-on time (Ton), pulse-off time (Toff), servo voltage (SV), and wire feed (WF). Surface roughness (Ra) and the kerf width (KW) were considered as response parameters in this study. The optimal conditions were found to be Ton at 106 µs, Toff at 49 µs, SV at 46 V and WF at 6 m/min. The optimal solutions provided by the MOPSO algorithm gave the best trade-off relation between the selected response parameters. There is an improvement of surface roughness by 30% and kerf width by 2.17%. Also, the microstructure analysis and the 3D morphology study confirm that the surface integrity of the machined sample using optimal conditions is better than the initial experiments of the BBD design, thereby validating the proposed MOPSO algorithm in the context of WEDM.