Indigenously synthesized sustainable CuO,TiO 2 nanofluids for machining AISI1040 steel

Abstract

Nanoparticles are increasingly utilized in various applications due to their high surface-to-volume ratio,which leads to enhanced properties. Researchers are striving to develop sustainable methods for synthesizing nanoparticles, as physical methods require significant energy and chemical methods involve harsh chemicals. This study aims to synthesize CuO nanoparticles using a green method with lemon peel extract and prepare TiO₂ nanoparticles using an energy-efficient and sustainable technique. A green cutting fluid is formulated using sunflower oil as the base, incorporating 0.3wt% CuO nanoparticles, 0.3wt% TiO₂ nanoparticles, and 0.3wt% CuO/TiO₂ hybrid nanoparticles. The synthesized nanofluids are evaluated for their thermo-lubricity properties. The performance of these green cutting fluids is tested in machining applications by turning AISI 1040 steel at various cutting velocities, feeds, and depths of cut. The minimum cutting temperature is achieved with the minimum quantity lubrication (MQL) application of CuO nanofluid, showing reductions of 28%, 11.76%, and 18.18% compared to sunflower oil at a cutting velocity of 80 m/min, feed of 0.77 mm/rev, and depth of cut of 0.9 mm respectively. The lowest cutting force is observed with the MQL application of TiO₂ nanofluid, with reductions of 59.13%, 29.13%, and 14.70% under the same conditions. The best surface roughness is also achieved with the MQL application of TiO₂ nanofluid, showing decrease of 44.02%, 17.58%, and 14.70% compared to sunflower oil. Given the importance of surface finish in industrial applications, green synthesized TiO₂ nanofluid is identified as the most effective for machining.