ToF‐SIMS analysis of friction surfaces tested with mixtures of a phosphite and a friction modifier

Abstract

AbstractThe adsorption behaviour of a mixture of lubricant additives onto ferrous materials has been investigated by time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS). Six mixtures were made by mixing one of two types of phosphites and one of three types of friction modifiers for subjecting to lubrication tests. By ToF‐SIMS analysis of the friction surfaces tested with these mixtures, the following conclusions were obtained. Adsorption of palmitic acid and glycerol monooleate was inhibited in the presence of phosphites, but the adsorption of oleyl amine was not inhibited by the phosphites. On the other hand, the reaction of tri‐n‐butylphosphite was inhibited in the presence of oleyl amine, but for other mixed systems no inhibition of the reaction of phosphites by a friction modifier was observed. Except for oleyl amine mixed systems, the amount of reaction product of the phosphites was found to be correlated to the lubrication properties for all of the other mixture systems. Copyright © 2001 John Wiley & Sons, Ltd.