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The present research investigated the lubrication performances of AlO/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 AlO 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 AlO NPs obtained lower R = 0.3, lower specific grinding energy ( U = 75.93 J/mm), and lower surface roughness ( Ra = 0.386 μm), indicating better lubrication performance. The mixed NP consisting of AlO 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 AlO/SiC (2:1) mixed NPs obtained the smallest R = 0.28 and specific grinding energy ( U = 60.68 J/mm), thus indicating the best lubrication performance. Therefore, 2:1 is the optimal ratio for mixed NPs. [ABSTRACT FROM AUTHOR]

Given the increasing attention to environmental and health problems caused by machining, the development of an environment-friendly grinding fluid has become an urgent task. As an environment-friendly grinding fluid, vegetable oil has gained considerable attention. In this study, seven typical vegetable oils (i.e., soybean, peanut, maize, rapeseed, palm, castor, and sunflower oil) were used as the minimum quantity lubrication (MQL) base oil to conduct an experimental evaluation of the friction properties of the grinding wheel/workpiece interface. With nickel-based alloy GH4169 as workpiece material, the flood grinding working condition and MQL grinding working condition (i.e., using the seven vegetable oils and paraffin oil) were selected. The evaluation of the lubrication property mainly referred to grinding force, friction coefficient, specific grinding energy, and grinding ratio (G-ratio), as well as surface morphology and surface roughness. Experimental results indicated that MQL grinding using vegetable oil achieved a lower friction coefficient, specific grinding energy, and grinding wheel wear than flood grinding. Among the grinding fluids, castor oil achieved the best lubrication property and the best surface quality of workpiece. Castor oil had a friction coefficient and specific grinding energy of 0.30 and 73.47 J/mm 3 , which decreased by 50.1% and 49.4%, respectively, compared with flood grinding. Moreover, various grinding fluids changed cutting forces through changes in their lubrication property and further changed G-ratio. However, lubrication property was one of factors that influenced the G-ratio. Maize oil had the highest G-ratio of 29.15. Peanut, sunflower, and soybean oil with more saturated fatty acids, castor oil with more castor acids, and palm oil with numerous palmitic acids were suitable as lubricating fluids. [ABSTRACT FROM AUTHOR]