Investigation of white layer thickness, material removal rate, and tool wear rate of Inconel 718 by nano-Al2O3-mixed electrical discharge machining

Nano powder mixed electrical discharge machining (NPMEDM) is an advanced thermo-physical process. It is used to create complex, precise shapes in hard-to-machine materials, such as nickel-based alloys like Inconel 718, due to their mechanical properties. This study introduces magnetic field assistance to improve the discharge state. Nano aluminum oxide was added to biodegradable soybean oil, serving as the insulating fluid to machine Inconel 718 alloy. The study examined the impact of machining parameters, including current, pulse on time, powder concentration, and magnetic field assistance, on outcomes like white layer thickness, material removal rate, and tool wear rate. Minitab software facilitated a general full factorial multi-level design to analyze the results. Findings showed that adding nano Al 2 O 3 with a magnetic field is crucial in enhancing process performance. The lowest white layer thickness achieved was 20.59 µm, showing a 54.32% improvement. The highest material removal rate was 13.259 mm 3 /min, with an increase of 42.193%. The tool wear rate also improved; the minimum value was 0.0228 mm 3 /min, reduced by about 80.44% compared to using no powder in the dielectric fluid. Optimal settings to enhance performance were found to be a current of 8 A, pulse on time of 100 µs, powder concentration of 4 g/l, and a magnetic field intensity of 0.2 T.