HISTORY OF OILADDITVES FROM MACRO TO NANO SURFACE TRIBOLOGY IN TRIBOTEST RIGS AND INTERNAL COMBUSTION ENGINES

Abstract

This study explains the tribological history of the lubricant (engine oil additives) which formed protective layer between rubbing surfaces (from macro-micro to nano microscopy) from 1999 up to nowadays. First tests were carried out in Pin-on-Disc test rig. Colourful layers of protective additives for motor oils formed on the rubbed surfaces under boundary lubrication conditions during experiments. The second test rig was a reciprocating pin-on-plate machine where the formal test conditions were determined and applied for tribotest using real engine material such as piston rings and cylinder liner. Real engine tests were also carried out. Wear tracks, layers of additives were examined using optical, electron microscopy with X-ray diffraction analysis and AFM (Atomic Force Microscopy) measurements. The most successful examination was that additives layers were detected in nanoscale dimension by AFM on the rubbed surfaces.