Synthesis, characterization, and application of Al2O3/coconut oil-based nanofluids in sustainable machining of AISI 1040 steel

Abstract

The nanoparticles are suspended in a base fluid to create a colloidal suspension. They have great thermophysical and rheological qualities, making them a promising candidate for use in heat transfer applications. Nonetheless, vegetable oil has poor thermal and oxidative stability at higher temperatures, thus nano-additives are utilized to improve its cooling and lubricating properties. In this context, the thermophysical characteristics of nano-Al2O3 enriched coconut oil and their significant influence on the machinability of AISI-1040 steel have been investigated. The different %wt. concentrations (0.25% to 1.50%) of nano-Al2O3 are dispersed in coconut oil to analyse the wettability, dynamic viscosity, and thermal conductivity. Then, the turning experiments are carried out under dry, flood, MQL with pure coconut oil (MQL-CO), and nanofluid-MQL (NFMQL). The findings reveal that the incorporation of nanoparticles in coconut oil results in a reduction of up to 70% in the contact angle, indicating improved wettability. In addition, nanoparticle addition greatly improves the dynamic viscosity and thermal conductivity of the base fluid. NFMQL also greatly decreases tool wear and surface roughness in comparison to other cooling methods.