Comprehensive machining analysis to establish cryogenic LN2 and LCO2 as sustainable cooling and lubrication techniques

This novel work analyzes different cooling and lubrication techniques namely without coolant (i.e. dry), with coolant (i.e. flood), and cryogenic with LCO2 and LN2 when drilling titanium alloy. The number of holes drilled for dry, with coolant (flood) and cryogenic with LCO2 and LN2 are 20, 140, 202 and 293 respectively before reaching tool wear criteria. Also, the better results of surface finish, power consumption, hole quality indicators, microhardness and chip analysis were observed for cryogenic machining with either LCO2 or LN2 in contrast with dry and flood machining. These results establish cryogenic LN2 and LCO2 as sustainable cooling and lubrication techniques to reduce tool wear and power consumption, thus improving machining productivity and quality as compared to flood cooling.