Optimizing EDM performances of stir cast eutectic AL-6.1% Ni alloy through Taguchi-grey relational approach

Abstract The objective of this research is to enhance the performance of the Electrical Discharge Machining (EDM) for the eutectic Al–6.1% Ni alloy to improve Material Removal Rate (MRR), Tool Wear Rate (TWR), and Surface Roughness (SR) by considering the variation in process parameters. With the help of Grey Relational Analysis (GRA) and the Taguchi method, the research establishes that the best settings are a pulse width of 10 μs, an interpulse time of 8 μs, a flushing pressure of 2 kg cm −2 , and a current of 5 A that provide the best compromise between these performance criteria. The microstructure of the stir cast eutectic Al–6.1% Ni is greatly enhanced compared to those of pure aluminium, where the hardness, tensile strength, and yield strength are revealed by nickel aluminide (Al 3 Ni). Nevertheless, there is a low value of elongation of only 3.6% for this alloy, which indicates that there is a decline in the ductility; thus, it is not suitable for applications that require high ductile parts. These results in the ANOVA show that pulse width has the highest percentage of 37% influence on MRR, TWR, and SR, which supports its importance in improving EDM performance. The flushing pressure was not found to be very important. It was found that the performance has been enhanced by 12.9% with the best possible combination of parameters. This approach improves surface quality through minimizing the incidences of over melting and erosion, even though the pulse width is larger and the interpulse time is short. The work also underlines the need for thorough parameter setting and validation; it is possible to achieve notable enhancements in the alloy machining productivity and the surface quality by fine-tuning the EDM parameters.