Experimental study on the feasibility of graphite nanoparticles with fruit tree-based vegetable oils for nanofluid MQL in milling AISI 304 stainless steel

Using nanofluid in minimum-quantity lubrication (MQL) can improve lubrication performance as a green lubricant technology. However, the impact of nanoparticle concentration in various vegetable-based oils on machining performance is still uncertain. Therefore, this study aims to investigate the effect of graphite nanoparticles with different concentrations (0, 0.3 wt%, 0.6 wt%, and 0.9 wt%) on various vegetable-based oils (virgin coconut oil, olive oil, and palm oil) for MQL during milling AISI 304 stainless steel. The machining test was used with constant parameters: a cutting speed of 160 m/min, a feed rate of 0.05 mm/rev, and a depth of cut of 0.2 mm. The experimental results indicate that palm oil-based nanofluids added with a range of 0.3 wt% and 0.6 wt% graphite nanoparticles produce the best lubricant performance. Even 0.3 wt% graphite concentration provides the maximum reduction of cutting force and surface roughness at 29.6% and 57.2%, respectively, compared to the dry condition. The best performance of this concentration was consistent across all types of vegetable oils used.