Synergistic effect of silica and pure palm oil on the machining performances of Inconel 690: A study for promoting minimum quantity nano doped-green lubricants

Abstract

Nanofluid based lubricants have immense acceptability in sustainable and eco-friendly machining of superalloys – this is due to their superior heat transfer ability. Extreme demands for sustainable manufacturing compelled the manufacturers to avail synergistic benefits with higher machinability and lower carbon footprint on the environment. For that purpose, the performance of an indigenously developed minimum quantity nano-green lubricant is investigated in milling of Inconel 690. Accordingly, nano-silica (vol% varying from 0.5 to 1.5%) was reinforced into palm oil and sprayed into the tool-chip interface through minimum quantity lubrication set up. The milling operations were executed under five different lubricating mediums: dry, minimum quantity palm oil, 0.5% silica deposited palm oil, 1% silica deposited palm oil, and 1.5% silica deposited palm oil. Comparative tool life, surface roughness, resultant cutting force, and cutting temperature were assessed. Subsequently, SEM and EDX images were analyzed to confirm the governing tool wear mechanisms. Experimental data shows that 1% silica deposited palm oil medium performs better concerning all machining responses. Furthermore, a multi-objective response surface methodology (MORSM) confirmed that speed of 88.18 m/min, feed of 0.11 mm/tooth, depth of cut of 0.50 mm, and 1%-MQNGL based lubricating condition are the optimal design parameters to achieve sustainable working environment.