Role of TiF3 catalyst in the tribological properties of biofuel soot-contaminated liquid paraffin

A four-ball tribological test was used to investigate the effects of a TiF3 catalyst on the tribological behaviors of biofuel soot (BS)-contaminated liquid paraffin (LP). The effects of load and rotational speed were studied as well. Scanning electron microscopy with energy-dispersive spectroscopy and X-ray photoelectron spectroscopy were conducted to investigate surface element content and chemical valence state, respectively. Results showed that the extreme pressure properties of BS-contaminated LP were all promoted with or without the presence of 0.5 wt% TiF3. The TiF3 catalyst material significantly contributed to the antiwear and the antifriction properties of LP with or without BS contamination. These results were caused by the decomposition of the TiF3 catalyst into TiO2 and fluoride (FeF2) which improved the lubricity.