Affiliation:
1. Don State Technical University, Rostov-on-Don
Abstract
Introduction.The possibility of using monocarboxylic acids as a lubricant composition additive, and the effect of their concentration in lubricant on the evolution of the friction factor of a brass-steel couple, as well as the morphology of the film surface under friction is considered. The work objective is to study the effect of the concentration of carboxylic acids in the lubricant composition on the evolution of the friction factor of copper – steel alloy.Materials and Methods.Tribological studies of a brass-steel friction couple in aqueous solutions of monocarboxylic acids with the concentrations of 0.025; 0.05; 0.1; 0.2; 0.5 mol/l are carried out. Using scanning electron microscopy, we have studied the morphology of the servovite film surface that is formed on a steel disk after frictional interaction of a brasssteel couple in aqueous solutions of acids with the concentration of 0.1 mol/l.Research Results.Tribological characteristics of the brasssteel tribocoupling in aqueous solutions of carboxylic acids of various concentrations are studied. The optimum acid concentration in the lubricant composition is specified. Herewith, a selective transfer and a wearless friction regime are implemented under friction of the brass 59–steel 40X couple. A decrease in the friction ratio to 0.009 and 0.007 is found out under friction in aqueous solutions of valeric and caproic acids, respectively. The formation of an anti-friction film on the steel surface is identified through the scanning electron microscopy. It is established that the film formed in an aqueous solution of caproic acid has a denser structure in comparison with the film formed under friction in aqueous solutions of butyric and caproic acids.Discussion and Conclusions.Thus, the tribological studies of a brass-steel friction couple in aqueous acid solutions show that the optimum molar acid concentration in the lubricant composition is 0.1 mol/l. At this acid concentration, the values of the friction factor characteristic of the wearless mode are attained.
Publisher
FSFEI HE Don State Technical University
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