Tribofilm formation and characterization of lubricating oils with biofuel soot and inorganic fluorides

Abstract A series of tribological experiments have been conducted to characterise and study the formation of tribofilms derived from TiF 3 and FeF 3 catalysts impregnated in soot-contaminated lubricants. Results showed that inorganic fluorides reduced friction and wear in the specimen contaminated lubricants. With the best results observed when TiF 3 was used. There were also indications that the frictional process, when coupled with the fluorides induced a structural change in the soot particles within the contact zones, contributing to the improved tribological performance. The key contributors to the formation of robust tribofilms were adsorption and tribo-chemical reactions. The better tribological response leads to a method for the design of engine lubricants to mitigate against the effects of soot contamination.