Performance evaluation of aluminium oxide nano particles in cutting fluid with minimum quantity lubrication technique in turning of hardened AISI 4340 alloy steel

The current research comprises various machinability aspects of 4340 hardened alloy steel which are scrutinized with in context of improvements in main cutting force, tool flank wear, crater wear, surface roughness, microhardness, machined surface morphology, chip morphology, chip reduction coefficient and apparent coefficient of friction under three different cutting fluid applications i.e. compressed air, water soluble coolant based MQL, and nanofluid (using eco-friendly radiator coolant as the base fluid and Al2O3 as the nanoparticle) based MQL technique using cermet cutting inserts and a comparative assessment was performed to select which fluid performed better in terms of various machining attributes among three cutting fluids. The minimum quantity lubrication technique was used in which a smaller volume of coolant sprinkled at high pressure. This method is found as the most effective alternative to minimize health risks and machining costs, which is quite high in other setups. The test specimen was machined at three different cutting speeds i.e. 100,120 and 140m/min along with two machining parameters i.e. feed and depth of cut were kept constant respectively at 0.2mm/rev and 0.4mm. Outcomes made a conclusion that Al2O3 enriched ecofriendly nano-coolant outperformed both compressed air and water soluble coolant in terms of every machinability aspects.