Tribological properties of CeF3 nanoparticles as additives in lubricating oils

This paper reports the synthesis of cerium trifluoride (CeF3) nanoparticles in the microemulsion of polybutanediimide (T154)/cyclohexane/water and their tribological properties as additives in lubricating oils. The results show that CeF3 nanoparticles are spherical and cylindrical in shape (size: 25 nm) and possess excellent extreme pressure and friction-reducing properties. The maximum nonseisure load (PB) is increased by 85.3%, and the decreasing percentage of friction coefficient is above 25% as compared with background oil (500SN base oil + 4.6% T154 + 3% calcium alkylsulfonate (T101) + 3% methyl-tricaprylamine chloride (aliquat336)). These may be caused by the formation of a transfer film in the contact surfaces. However, CeF3 nanoparticles cannot improve the anti-wear performance of lubricating oil effectively, and the reason may be that F- ion generated by decomposing CeF3 corrodes the rubbing surfaces. (C) 1999 Elsevier Science S.A. All rights reserved.