Performances of Al2O3/SiC hybrid nanofluids in minimum-quantity lubrication grinding

The present research investigated the lubrication performances of Al2O3/SiC nanofluid minimum-quantity lubrication (MQL) grinding in accordance with recent technologies used in conducting minimum-quantity lubrication grinding with nanofluids. The mean grain size of the Al2O3 and SiC nanoparticles (NPs) was set to 50 nm, and the difficult grinding Ni-based alloy was used as the workpiece material in the experiment. Grinding force was measure by using a three-component dynamometer and then used to calculate grinding force ratio (R). Workpiece surface roughness was measured by a roughness tester. Five groups of NPs were mixed with synthetic lipids at a mass fraction of 6 %. The lipids were then used as the grinding fluid for the nanofluid MQL grinding. Results showed that, compared with pure SiC NPs, pure Al2O3 NPs obtained lower R = 0.3, lower specific grinding energy (U = 75.93 J/mm3), and lower surface roughness (Ra = 0.386 μm), indicating better lubrication performance. The mixed NP consisting of Al2O3 and SiC NPs achieved even lower R and surface roughness than pure NPs because of the “physical synergistic effect.” The optimal ratio of the effect of mixed NPs was explored based on this finding. The Al2O3/SiC (2:1) mixed NPs obtained the smallest R = 0.28 and specific grinding energy (U = 60.68 J/mm3), thus indicating the best lubrication performance. Therefore, 2:1 is the optimal ratio for mixed NPs.