MECHANISM OF BOUNDARY LUBRICATION WITH ZINC DITHIOPHOSPHATE

Experiments were carried out with pure zinc dithiophosphate in paraffin as a lubricant. Different friction tests using smooth and rough surfaces were studied by surface analysis (Auger electron spectroscopy and secondary ion mass spectroscopy) and lubricant analysis (thin layer chromatography). Four types of surface transformation were detected: soft track, cutting track, delamination and adherent film. The wear rate was minimal when an adherent film was formed on steel and cast iron surfaces. The role of the additive in the formation of the film is outlined. Surface products play an important part in the production of a paste in the contact zone. This paste, which is compressed in the interface, is the dominant factor affecting wear behaviour. © 1979.