Avaliação experimental de nanolubrificante híbrido composto de Al2O3 e grafite

Abstract

Hybrid nanolubricants are obtained by the addition of two or more dissimilar types of nanoparticles to the base lubricant and have numerous applications in several engineering segments. In this research was evaluated a new composition of hybrid nanolubricant from the addition of the nanoparticles of Al2O3 and graphite varying the concentration from 0.1 g / L to 2.0 g / L in the mass ratio of 50/50 for a lubricant POE oil for application in refrigeration system. Alumina nanoparticles were commercially acquired, while the graphite nanoparticles were developed in a high energy planetary mill, both of which were characterized by MEV, MEV-FEG, DRX, FRX, EDX and Particle Sizing. The hybrid nanolubricant samples were prepared through the two-step method with duration of 24 hours in the stage of sonication and 24 hours in the stage of rotary agitation. Subsequently the hybrid nanolubricant samples were evaluated for stability through visual inspection, particle sizing, Zeta potential and hydrogenation potential. They were also submitted to the experimental analyzes for the measurement of the thermo-rheological properties, through the essays of density, thermal conductivity, dynamic viscosity, shear stress and strain rate. As well as the tribological performance analysis for the characterization of the efficiency of the hybrid nanolubricant in comparison to the lubricant POE oil reference. From the evaluations developed in this research, it was concluded that the changes observed in the thermo-rheological properties and tribological performance of the proposed hybrid nanolubricants, were not positive in relation to the lubricant POE oil reference.