Evaluation of frictional properties of tribomaterials under sparse lubrication

Frictional properties of typical tribomaterials are evaluated under sparse lubrication conditions where lubricating oil is supplied but its amount is far from sufficient even for boundary lubrication. These conditions are provided by employing a mist oiling system which can continuously supply oil at constant, extremely low and quantitatively controlled rates. First, basic data on the properties of the oil mist are given and a quantitative determination of oil supply onto a sliding surface is described. Then frictional properties evaluated under stepwise increasing loads are presented for iron/steel, surface modification, ceramics and self-lubricating materials, and their characteristic behaviour is discussed.