Tribological mechanisms of nano-cutting fluid minimum quantity lubrication: a comparative performance analysis model

The nano-fluid system efficiency is mostly governed by the amount, structure, and characteristics of the nano-additives and the mechanism by which the nano-fluids are distributed and sprayed to the tool-workpiece interface zone. The utilization of nano-additive-based cutting fluid demonstrated significant improvement in the wear behavior of the cutting tool. They also provide excellent cooling capabilities when machining is carried out at high temperatures especially when cutting difficult-to-machine workpiece material. The present study offers an in-depth study aided with solid analysis and interpretation for the tribological phenomenon associated with the nano-cutting fluids. In the current study, a relative wear volume model has been proposed and validated for two nano-cutting fluid cases. The presented model reveals that nanotubes offer less induced abrasive wear in comparison with the nanoparticles (i.e., the ratio between the induced nanoparticles wear to the nanotubes wear ranges from 139 up to 360 when the applied forces ranges from 10 up to 3000 N, respectively). To validate the model findings, machining experiments were carried out on Inconel 718 under nano-cutting fluid minimum quantity lubrication (MQL) with different cutting parameters and nano-additive concentrations. Two nano-additives performance have been worked out with the MQL conditions, namely, alumina nanoparticles (Al2O3) and multi-walled carbon nanotubes (MWCNTs). The wear on the flank face is determined for each cutting run to evaluate the performance of both nano-cutting fluids. The model estimates found to be consistent with the experimental findings as as MWCNTs showed less tool wear compared with Al2O3(i.e., varied from 2 up to 150% at different cutting speeds and feed rates).