Elevated ZnO Concentrations as a Trade-Off Strategy to Decrease Spindle Speeds in Face Milling

Higher productivity, lower cost, environmental requirement and occupational health have become serious challenges for manufacturing industries nowadays. In this study, a mixture comprising canola oil, emulsifier and ZnO nanoparticles was applied as the cutting oil for face milling of stainless steel SS316L. Previous studies have demonstrated decreasing surface roughness with increasing spindle speed. Numerous previous studies have also revealed decreasing surface roughness with increasing ZnO concentrations. However, a relationship between elevated ZnO concentrations and reduced spindle speeds has barely been addressed. Building on this circumstance, a novel machining strategy was proposed in this study by employing elevated ZnO concentrations as a trade-off strategy to reduce the spindle speeds. The spindle speeds in this study were 1500, 1800 and 2100 rpm. The experiment demonstrated that elevating ZnO concentrations from 1.0 to 4.0 wt% could be used to decrease the spindle speeds from 2100 to 1800 rpm while maintaining acceptable surface roughness. Although future studies are warranted, reducing spindle speed is beneficial for manufacturing industries as it may contribute to lower electrical energy consumption. Furthermore, the proposed trade-off strategy can also be implemented for manufacturing industries located in regions with limited electrical grid capacity, for example, due to restricted capacity of electrical transformers.