P. Mitchell
Dec 1, 1984
Citations
0
Influential Citations
149
Citations
Quality indicators
Journal
Wear
Abstract
Abstract The use of soluble Mo-S compounds as lubricant additives for reducing friction and wear, increasing load-carrying capacity, promoting fuel economy and as antioxidants is related to their structures and chemical properties. The compounds discussed include tetrathiomolybdates and complexes of molybdenum with xanthates, dithiocarbamates, dithiophosphates, diketones, dithiols and dimercaptothiadiazole. Structures of the compounds are described. Features of their UVvisible, IR and nuclear magnetic resonance spectra which are useful for characterization are listed. The preparative chemistry of the molybdenum dithiophosphates is discussed in relation to the composition of additive packages. Antiwear and extreme pressure mechanisms of the compounds are discussed with reference to their decomposition in bulk oil and at surfaces, sorption processes, formation of surface films and layers and decomposition to molybdenum disulphide. The importance of the Mo-S combination is emphasized. The tribological performance of Mo-S complexes, organosulphur compounds, molybdenum disulphide and zinc compounds is compared.