Understanding the Influence of the Magnetic Field, Particle Size, and Concentration on the Tribological Performance of Superparananolubricants
Ana Emília Diniz Silva Guedes, Valdicleide Silva e Mello, F. Bohn, Salete Martins Alves
Abstract
We investigated superparamagnetic nanolubricants and verified the influence of the magnetic field, particle size, and concentration on the tribological performance. The superparamagnetic nanoparticles were synthesized with two different sizes (7 and 15 nm) and dispersed in mineral oil with concentrations of 0.2 and 0.4 wt% The tribological tests were performed using a high-frequency reciprocating rig (HFRR), with and without a constant magnetic field acting in the nanolubricant. The positive effect of the magnetic field on the friction behavior was verified only in the nanolubricant with particles with diameter of 15 nm, at some concentration. In terms of the worn area, the magnetic field promoted a wear reduction for all combinations of size and concentrations. Regarding the wear mechanism, there were fewer grooves on the worn surface and with a smaller depth when the magnetic field was applied to the nanolubricant. For all experimental conditions abrasion was the main wear mechanism.