Analysis of vegetable oil-based nano-lubricant technique for improving machinability of Inconel 690

Conventional cutting fluids are applied to dissipate the heat generated in the cutting zone during machining. However, the use of metal cutting fluids causes adverse impacts on workers' health and the environment. Minimum quantity lubrication (MQL) has drawn attention to eliminating the use of mineral-based cutting fluids. The effectiveness of MQL can be further enhanced by employing vegetable oil and nanoparticles. Nanofluidbased lubricants result in superior heat transfer capacity and improved lubricity. In this context, the performance of vegetable oil mixed with and without molybdenum disulfide nanoparticles (nMoS2) applied with MQL is investigated during the machining of Inconel 690. The nanoparticles with different concentrations (0.5%, 1%, and 1.5%) are added in canola oil, and friction coefficient, thermal conductivity, viscosity, and wettability of nanofluids are analyzed. The machining experiments are performed under dry, flood cooling, MQL, and nMQL. The machining performance is evaluated by measuring tool wear, surface roughness, chip morphology, cutting temperature, and energy consumption. The findings revealed the superiority of nMQL with 54%, 29%, and 13% reduction in surface roughness and 56%, 39%, and 12% reduction in energy consumption compared to dry, flood cooling, and MQL environments. Also, nMQL has led to longer tool life. The effectiveness of nMQL has resulted in better tribological conditions in the cutting zone with enhanced cooling/lubricating action of vegetable oil and lamellar structure of nMoS2. The results show a significant role of nano-cutting fluid-based lubricant applications in the machining industry to meet energy-saving and sustainability goals without compromising product quality.