The growing need to increase productivity and pressures for more sustainable manufacturing processes lead to a shift to less harmful lubrication systems that are less harmful to nature and the
people involved. The minimal quantity lubrication system (MQL) stands out in this respect, especially
in interrupted cutting processes such as milling, due to the cutting interface’s highly dynamic and
chaotic nature. Using graphene sheets in cutting fluids also increases the efficiency of machining
processes. This work investigates the influence on thermophysical and tribological properties of
concentrations of 0.05 wt% and 0.1 wt% of graphene sheets in two vegetable-based and one mineralbased cutting fluids. The fluids are first characterized (viscosity, thermal conductivity, diffusivity, and
wettability) and tested in reciprocating and ramp milling tests; all experiments are based on norms.
The results show that the experiments with cutting fluids (with and without graphene) showed better
tribological behavior than those in dry conditions. The graphene sheets alter the thermo-physical
and tribological properties of the cutting fluids. The MQL15 vegetable-based fluid showed better
lubricating properties in the milling tests, with better conditions for tribosystem chip–tool–workpiece
interfaces, which makes the friction coefficient, and wear rate stable. Vegetable-based cutting fluids,
even in minimum quantities and with graphene nanoparticles, have a high potential for increasing
the efficiency and sustainability of the milling process.
