Optimization of Machining Parameters and Analysis of the Surface Characteristics in Micro-electrical Discharge Machining of 310 and 316 Stainless Steel

An experimental investigation was performed using a tungsten carbide tool to study the micro-electrical discharge machining behavior of two different grades of stainless steel (310 and 316 SS). The machining parameters considered to investigate the machining behavior of the chosen materials were (a) V: voltage (V), (b) C: capacitance (pf), (c) T_on: pulse-on time (µs), and (d) T_off: pulse-off time (µs). The machining behavior of stainless steel was evaluated in terms of material removal rate and tool wear rate. Taguchi L₁₆ orthogonal array and gray relational analysis techniques were employed to design and optimize the machining conditions for both responses. Scanning electron microscopy, energy-dispersive spectroscopy, and optical microscopic analyses were also performed to identify the characteristics of the machined surface, characteristics of the micro-tool, and the elemental composition of the machined surface. The optimum machining condition for 310 steel was found as 150 V, 100 pf, 30 µs (T_on), and 20 µs (T_off). On the other hand, the optimum parametric condition for 316 steel was 200 V, 1000 pf, 20 µs (T_on), and 25 µs (T_off).