Tribology Characteristic of Ball Bearing SKF RB-12.7/G20W using SAE 5W-30 Lubricant with Carbon-Based Nanomaterial Addition

The thermophysical, rheological, and tribological properties in lubricant are essential for preserving the engines, power steering systems, and engine components from damage caused by friction and wear. The incorporation of nano-sized particles into lubricating oils has been reported to enhance these properties. Therefore, this study explores the impacts resulting from the incorporation of graphene, multiwalled carbon nanotubes (MWCNT), double-walled carbon nanotubes (DWCNT), and single-walled carbon nanotubes (SWCNT) at a quantity of 0.04 grams into the SAE 5W-30 base oil. These nanoparticles were synthesized using a two-step method, resulting in nanolubricants. The addition of carbon-based nanomaterials increases the density and decreases the viscosity of the base lubricant. The flow of nanolubricants exhibits non-Newtonian shear thinning behavior during the test at elevated temperatures. The results of the four-ball tribo-tester test reveal the increase of Coefficient of Friction (CoF) values and the extent of wear scar area. Further, the Scanning Electron Microscopy (SEM) analysis was employed to observe the wear morphology of the nanolubricants on the SKF RB-12.7/G20W ball bearing. Its results indicate a prevalence of groove-type wear as compared to conventional lubricants.