Effects of surfactant and MoO 3 nanofluid on tribological and machining characteristics in minimum quantity lubrication (MQL)-turning of AISI 304 steel

Friction, cooling performance, and human and environmental toxicity are always been of great concern for cutting fluids in conventional machining processes. Thus to tackle the above problems, nano-cutting fluids are predominately utilized in machining industries because of their better lubricity and heat transferability. Besides the above-listed advantages, the nanofluids came up with their stability issue with time. In such a scenario, the surfactants are mixed with nano-cutting fluids in optimum ratio to cop-up the stability issue. The surfactants also possess good lubricant properties, so the surfactants not only stabilize the nano-cutting fluids but also contribute to machining performance. The current experimental study also inspects the effect of surfactants on tribological and machining characteristics in the minimum quantity lubrication-turning of AISI 304 steel. Herein, MoO₃/water nanofluid is mixed with six different surfactants. Zeta potential and thermal conductivity tests are performed initially to obtain an optimum value of mixture ratio and volumetric concentration. The observed outcomes exhibited a significant reduction in cutting forces, friction coefficient, surface roughness, tool wear, and contact angle. In the present study, SPAN20 surfactant at a mixture ratio of 3:2 and 0.45 vol% provide the best machining performance, which significantly reduced the average cutting force and tool wear by 32.05% and 53%, respectively, with a minimum surface roughness of 1.21 µm.