The Rheology of Nanolubricants Based on Fe2O3, Al2O3, and ZnO Oxide Nanoparticles: A Comparative Study

In the present article, a comparative study of the rheological characteristics of nano-lubricants based on Fe2O3, Al2O3 and ZnO nanoparticles is carried out. The base fluid used is 20W40 engine oil. The nanofluid samples were prepared in the solid volume fractions (0.25%; 0.50%; 0.75% and 1%). The measurements have been performed at different temperatures, ranging between 20 °C and 60 °C and at shear rates ranging from 100 s-1 to 300 s-1. The results obtained have shown that nanofluids based on Fe2O3 and ZnO nanoparticles exhibit a non Newtonian shear thinning behaviour while the nanofluid based on Al2O3 nanoparticle exhibit a Newtonian behaviour. The Al2O3/oil nanofluid has a lower dynamic viscosity than Fe2O3/oil and ZnO/oil nanofluids. The increase in temperature leads to a reduction of more than 80% in viscosity for all nanofluids. On the other hand, the increase of the nanoparticles volume concentration clearly improves the dynamic viscosity.