Influence of Al₂O₃ and palm oil–mixed nano-fluid on machining performances of Inconel-690: IF-THEN rules–based FIS model in eco-benign milling

With the increased prerequisites for ecological protection, the vegetable oil and nano-fluid-based minimum quantity lubrication (MQL) technology have become a modern research trend. For instance, the palm oil exhibits superior lubricity owing to fatty acid and film-developing characteristics of the carboxyl group. Conversely, due to unique physiochemical properties of Al₂O₃ nano-particles, they exhibit superior lubricity during machining operations. Thus, here, it was attempted to discover the benefits of Al₂O₃ and palm oil–mixed nano-fluid in MQL-assisted milling of Inconel 690 for eco-benign and cleaner manufacturing. During the experiment, different concentrations (0.5–5%) of Al₂O₃ nano-particles were mixed with palm oil. Afterward, the performances were evaluated with respect to the surface roughness, specific cutting energy, tool wear, and cutting temperature. From an economic perspective, the determination of ideal concentration (%) of the Al₂O₃ nano-particle is a crucial concern. Thus, a fuzzy interference system (FIS)–based model has been developed to obtain the optimum concentration (%) of Al₂O₃ nano-particle. The multi-performance characteristics index (MPCI) values confirmed that 2.5% was the optimum concentration for Al₂O₃ in MQL milling environment. Afterward, the machining performances obtained from 2.5% Al₂O₃ particle concentration have been compared with dry, flood, and pure palm oil condition. It is clearly found from the comparison that MQL milling with 2.5% Al₂O₃ nano-particle concentration demonstrated much better machining behavior than another lubricating medium.