Experimental investigation on micro-electro discharge machining process using tungsten carbide and titanium nitride-coated micro-tool electrode for machining of Ti-6Al-4V

Titanium alloy Ti-6Al-4 V is used in numerous applications because of its low weight associated with high strength, excellent resistance to fatigue and creep, good resistivity in corrosive environments, and biocompatibility. The Micro-Electro Discharge Machining (MEDM) is one of the finest non-conventional machining processes used for machining Ti-6Al-4 V. In this research article an attempt has been made to study effect of thin film coating of titanium nitride (TiN) on tungsten carbide (WC) micro-electrode on tool wear rate (TWR), over cut (OC) and depth of machining (Z coordinator) during micro-drilling of Ti-6Al-4 V. A detailed experimental investigation has been carried out with the help of Taguchi's L9 orthogonal array for understanding the mechanism of the process. The process parameters such as voltage, spindle rotation and capacitance are considered to perceive their effect on TWR, OC and Z coordinator. Uncoated WC and TiN-coated WC micro-tool electrodes has been used during machining Ti-6Al-4 V in order to compare listed responses. The experimental results of TiN-coated micro-electrode showed that TWR decreased by 16.32 %, depth of machining increased by 20.83% and OC reduced by 12% as compared to uncoated WC micro-tool electrode.