Performance evaluation of aluminium 6063 drilling under the influence of nanofluid minimum quantity lubrication

For environmental and economic reasons, recent research in industry and academia has sought ways to reduce the use of machining fluids. New cutting techniques are to be investigated to achieve this objective. Minimal quantity of lubrication (MQL) is a recent technique introduced in machining to obtain safe, environmental and economic benefits, reducing the use of coolant lubricant fluids in metal cutting. The objective of this work is to compare the performance of different lubrication conditions (dry, flooded, pure MQL and nanofluid MQL) with respect to the cutting forces (thrust force and torque), tool wear and surface roughness in the drilling of aluminium 6063 alloy by using HSS drill tools. In both MQL methods (pure MQL and MQL with nano-particles) oil supply rate is fixed at 200 ml/h and air pressure is fixed at 70 Psi. The nano-particles (Al2O3) of 20 nm in size are considered for the nanofluid with volumetric concentration of 1.5% in base oil (soya bean oil). The experimental results show that the nanofluid MQL (NFMQL) significantly increases the number of drilled holes and reduces the drilling torques and thrust forces as compare to other coolant-lubrication conditions. Superior results of NFMQL may be attributed to the reason that NFMQL produces low friction force at the tool/chip and tool/workpiece interfaces due to its rolling effect of nano-particles and superior cooling performance. In addition, the nanofluid MQL effectively eliminates chips and burrs to enhance the surface quality of holes and also increases the tool life by obtained lowest tool wear.