Tool wear, hole quality, power consumption and chip morphology analysis for drilling Ti-6Al-4V using LN2 and LCO2

For the first time, thrust force, power consumption, flank tool wear using FE-SEM and line scan EDS analysis; hole quality indicators and hole surface analysis using FE-SEM, microhardness and chip morphology for drilling Ti-6Al-4V using cryogenic coolants (LN<inf>2</inf> and LCO<inf>2</inf>) and flood coolant are comprehensively investigated. 146 blind holes are drilled for all three cooling conditions. 72% and 50% lesser tool wear is observed for LCO<inf>2</inf> and LN<inf>2</inf> respectively, compared to flood machining. Adhesion wear mechanism is found to be the predominant factor leading to higher tool wear during flood machining. The demonstrated superior performance of LCO<inf>2</inf> for all the machinability indicators in this research is a significant finding for machining Ti-6Al-4V for the high-value manufacturing industries.