Investigating Performance of Wire Electric Discharge Machining of Nimonic 90 and RSM Modeling

Nimonic nickel-based superalloys are widely used in many industries like aerospace engine components and hot chambers of gas turbines, jet engines, and heat exchangers owing to their high resistance to creep, oxidation, and corrosion. These properties even do not lose at elevated temperatures. Conventional machining methods have various encounters like surface roughness, tool wear rate, tool failures, and surface characteristics. To overcome these challenges, shifting from these traditional processes to non-traditional machining processes is required. Hence, in this study, a Wire Electric Discharging Machine (WEDM) a nonconventional method has been chosen to machine high-hardness material like Nimonic 90 with great precision. WEDM experiments were carried out using CCD with three factors of input. Servo-voltage, Pulse-on time, and tension in the wire are taken as inputs having three different levels consisting of 20 runs based on RSM to analyse the responses such as MRR and SR. A scanning electron microscope (SEM) is used to understand the surface topography of a workpiece whose roughness is more and less and of those with high MRR and Low MRR. On Surface globules, micro-cracks, pits, and debris are observed. Pulse-on and wire tension have more impact on Material removal over servo voltage, whereas for better surface finish Wire tension has more influence than Pulse-on and servo voltage.