Effect of the physical properties of different vegetable oil-based nanofluids on MQLC grinding temperature of Ni-based alloy

Palm oil was used as the base oil of minimum-quantity lubricant cooling (MQLC) grinding of Ni-based alloy. Eight nanofluids with different volume fractions of 0.5, 1, 1.5, 2, 2.5, 3, 3.5, and 4 % were prepared by using carbon nanotube (CNT) nanoparticles for the experiment on MQLC grinding of Ni-based alloy. Grinding force, grinding temperature, and proportionality coefficient of energies transferred into the workpiece were analyzed and discussed based on the thermal conductivity, viscosity, and contact angle of the nanofluid. Heat exchange performances of the eight prepared nanofluids were studied in sequence. The volume fraction of 2 % nanofluid achieved 21.93 N grinding force, the lowest grinding temperature of 109.8 °C, and the lowest proportionality coefficient of 42.7 %. The high thermal conductivity of nanofluids is conducive to quick heat transfer. High viscosity promotes the lubrication effect and can reduce energy input and the production of grinding heat. The contact angle and surface tension of eight kinds of nanofluids showed a trend of 2 % < 2.5 % < 4 % < 3.5 % < 3 % < 1.5 % < 1 % < 0.5 %. Thus, the volume fraction of 2 % nanofluid-based MQLC grinding Ni-based alloy achieved the optimal lubrication and heat transfer performance.