Optimization of Micro EDM Drilling Process Parameters for Titanium Alloy by Rotating Electrode

Present era demands better quality of micro holes and good dimensional accuracy with regards to drilled workpiece. Micro EDM drilling utilizes thermal effect rather than mechanical force to remove material, so it is suitable for machining hard materials and is free from burr formation. Main problem encountered in micro EDM drilling is removal of debris particles, hence to overcome this problem electrode rotation method is used. This paper presents the experimental study for optimization of micro EDM drilling of Titanium alloy (Ti6Al4V) by using copper tungsten (CuW) electrode. Planning of experiment was done using response surface methodology (RSM) based central composite design (CCD) for analyzing effect of process parameters like pulse on time, discharge voltage, capacitance and electrode rotation speed on responses such as material removal rate (MRR), side gap width and taper ratio. ANOVA was performed to find the influencing process parameters. For MRR discharge voltage, capacitance and electrode rotation speed are influencing parameters. While side gap width is influenced by pulse on time, capacitance and electrode rotation speed whereas taper ratio is influenced by pulse on time and capacitance. The optimised values of process parameters viz pulse on time, discharge voltage, capacitance and electrode rotation speed for MRR, side gap width and taper ratio with single objective and multi-objective optimization are reported for Hyper 15W machine.