Performance evaluation of minimum quantity lubrication technique in grinding of AISI 202 stainless steel using nano-MoS₂ with vegetable-based cutting fluid

Due to environmental issue and stringent rules over defilement and contamination of the environment, the demand for renewable and biodegradable cutting fluids is increasing. In this study, an eco-friendly minimum quantity lubrication (MQL) technique using vegetable oil–based cutting fluid (rapeseed oil) by varying MQL flow rate and MQL pressure was investigated in the grinding of AISI 202 stainless steel. In addition to explore the cooling capabilities of rapeseed oil, nano-MoS₂ was added to the rapeseed oil to prepare different concentrations (0.5 wt% and 1.0 wt%) of nanofluids. The main objective of this experiment is to examine the performance of different grinding environments (dry, flood, pure MQL, and nanofluid MQL) with respect to grinding characteristics, namely, grinding forces, surface morphology, surface roughness, and temperature. Experimental results revealed that NFMQL grinding with vegetable oil was performed much superior as compared with the dry, wet, and pure MQL machining. The lowest specific normal force and tangential force are observed to be 9.2 N/mm and 0.76 N/mm respectively under 1.0 wt% concentration of MoS₂ nanoparticles at oil flow rate of 120 ml/h and air pressure 90 psi under MQL grinding condition, which decreased by 43% and 33%, respectively, as compared with dry conditions. Furthermore, the application of nanofluid also leads to the reduction of surface roughness and surface temperature. MQL application with MoS₂ nanofluid helps in effective flushing of chip material from the grinding zone, thereby improving the lubrication and cooling capabilities during the grinding of the AISI 202 stainless steel. In summary, appropriately chosen minimum quantity lubrication parameters can enhance the lubrication and cooling properties of the oil film and improve the grinding characteristics.