Comparison of the Tribofilms Formed on Piston Ring and Cylinder Samples in a Fired Engine and a Reciprocating Tribometer

摘要

To understand the tribological performance of engine components operating in the boundary and mixed lubrication regimes it is essential to understand the tribochemical processes that occur due to interaction between the additives in the oil and the surfaces in contact. This is done by physically and chemically characterising these surfaces. Engine tests are costly and the complex environment makes understanding the fundamentals of the tribochemical mechanisms at work very challenging. Hence laboratory tribometers. e.g. pin-on-disc, block-on-ring, ball-on-plate, are used to test materials and oils in contact conditions "similar" to those in an engine. It is therefore very important to understand the limitations tribometers have in simulating engine conditions, in this case in effectively reproducing the tribochemical interactions that occur between oil additives and the surfaces in contact.