Experimental Investigation of Uncoated Electrode and PVD AlCrNi Coating on Surface Roughness in Electrical Discharge Machining of Ti-6Al-4V

The surface texture on the EDM is an important quality indicator since it directly affects the cost of the further finishing work. The coating over the tool electrode in EDM can improve productivity, electrode wear resistance and surface quality. In the present study, the surface roughness of the EDM machined surface with coated and uncoated electrodes was evaluated. Al and AlCrNi coated Al electrode has been used for the study on machining Titanium alloy (Ti-6Al-4V). Current (I), voltage (Vg) and pulse on time (Ton) have been used as technology parameters under Taguchi method with regression model and optimal technology parameters. It was found as I and Vg are the parameters could strongly affect surface quality. The coated tool electrode can produce better surface quality than uncoated tool electrode. The optimal technological parameters with coated and uncoated electrodes were found as I = 10 A, Ton = 500 µs and Vg = 40 V.