Experimental investigation of nanofluids as a coolant for minimum quantity lubrication MQL in turning operation

Abstract

newlineThe nanofluids for MQL during machining application were prepared through a two-step method by adding different concentrations ranging from 0.5 to 3 wt.% in a step of 0.5 wt.% of CNTs, SiO2 and biochar nanoparticles. The nanofluids were first agitated with the assistance of a motorized stirrer for 30 min at 500 rpm, followed by 15 min of ultra-sonication in a probe-type ultrasonicator to ensure even dispersal of the nanoparticles. The effectiveness of these nanofluids under MQL machining was evaluated by comparing the material removal rate (MRR), surface roughness (Ra), temperature (ºC) at the tooltip, and tool wear. MRR was computed by comparing the mass of the part before and after machining, considering machining time. The average of Ra values was calculated by checking the surface roughness on the workpiece at three different places using a surface roughness tester (Surf test SJ-210). The heat generated at the tool-work interface was quantified using a non-contact type infrared thermometer (Evive model). The tool wear was scanned in the tool nose and at the blunt end of the tooltip using the scanning electron microscope (SEM)