Effect of h-BN nanoparticles on the tribological and rheological properties of API-Group I Oils

The paper investigates the effect of hexagonal boron nitride (h-BN) nanoparticles on the tribological and rheological properties of the API-Group I lubricants i.e. Solvent neutral (SN)-500, Bright Stock (BS)-270, and thirdly a mixture of SN-500 and BS-270. The tribological properties of the base oils and the nanolubricants are studied using a four-ball tester and the experiments are carried out as per ASTM D4172 standard. It is observed that the addition of 0.25 wt.% h-BN nanoparticles improves the tribological properties of base oils. The wear scar diameter reduces by 2.51%, 19.78% and 3.17% for SN-500, BS-270, and BS+SN at 0.25 wt% h-BN nanoparticles concentration respectively. The rheological properties of the lubricants are measured on Anton Paar’s MCR 102. BS-270 depicts the maximum viscosity among the Group I oils equal to 289.14 mPa.s at 40 °C. Further, all the oils depict an increase in the dynamic viscosity with an increase in the concentration of nanoparticles.