Formation of Anti-Wear Tribofilms via α-ZrP Nanoplatelet as Lubricant Additives

Effective tribofilms are desirable to protect mechanical systems. In this research, an alternative nanolubricant is developed to replace commercial ZDDP-containing lubricants. Tribological studies were carried out using a pin-on-disk configuration in a reciprocating motion. We investigated the characteristics of the tribofilm formed through the addition of α-ZrP nanoparticles in a reference oil. Experiments were conducted on a base oil where 0.2 wt% of the additive was used. Experimental results showed superior tribological performance of the sheet-like nanoparticles a 50% reduction in friction and a 30% reduction in wear when compared to the base oil containing 0.8 wt% ZDDP. XPS spectroscopic analysis indicates that an anti-wear tribofilm composed of Fe2O3, ZrO2, and Zr(PO4)2 is formed. This zirconium based tribofilm is characterized by a lower surface roughness and an improved load bearing capability than the ZDDP tribofilm. The low-phosphorus-content-lubricant additives have strong potential as substitutes for ZDDP. Future studies will focus on the optimization of tribological.