Tribological studies of 1-alkyl-2,5-dithiohydrazodicarbonamides and their Mo-S complexes as EP and multifunctional additives

This communication reports a comparative study of the anti-wear, extreme pr essure and friction reducing properties of 0.5% (w/v) admixtures of paraffi n oil with 1-alkyl-2,5- dithiohydrazodicarbonamide ligands and their Mo-S c omplexes, i.e. mu-hydroxo-mu-(1-alkyl-2,5-dithiohydrazodicarbonamido)-bis-[ dioxohydroxo molybdenum VI] using 12.7 mm diameter steel bearing balls in a four-ball test. In particular, the additive mu-hydroxo-mu-(1-n-butyl-2,5-d ithiohydrazodicarbonamido)-bis-[dioxohydroxo molybdenum VI] exhibits an inc rease in the load carrying capacity of the lubricant and a decrease in the values of wear and coefficient of friction. The surface analysis of the wea r-scar matrix of the used ball specimen has been investigated by SEM and AE S techniques. (C) 2000 Elsevier Science Ltd. All rights reserved.