Performance evaluation of aluminium oxide nano particles in cutting uid 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 in the context of improvements in main cutting force, tool ank wear, crater wear, surface roughness, microhardness, machined surface morphology, chip morphology, chip reduction coecient and apparent coecient of friction under three dierent cutting uid applications, i.e. compressed air, water soluble coolant based Minimum Quantity Lubrication (MQL), and a nano uid (using eco-friendly radiator coolant as the base uid and Al2O3 as the nanoparticle) based MQL technique using cermet cutting inserts. A comparative assessment was performed to select which uid performed better in terms of machining attributes between three cutting uids. A MQL technique was used in which a smaller volume of coolant was sprinkled at high pressure. This method is found to be the most eective alternative to minimize health risks and machining costs, which are quite high in other setups. The test specimen was machined at three dierent cutting speeds i.e. 100, 120, and 140 m/min along with two machining parameters i.e. feed and depth of cut, which were kept constant, respectively, at 0.2 mm/rev and 0.4 mm. Outcomes made a conclusion that Al2O3 enriched ecofriendly nano-coolant outperformed both compressed air and water soluble coolant in terms of every machinability aspect.