Nanotribology of Aqueous Solutions of Monobasic Carboxylic Acids in a Copper Alloy‒Steel Tribological Assembly

Abstract

The tribological properties of the “copper alloy–carboxylic acid‒steel” system are studied. It is found that the wear-free mode accompanied by an increase in the pH of lubricant solutions, a decrease in the electrical conductivity, and a variation in the friction-surface charge is implemented in the “copper alloy–valeric acid–steel” and “copper alloy–caproic acid–steel” tribosystems. With the help of quantum-chemical calculations via the UB3LYP/Lanl2DZ method, it is demonstrated that the total charge of a metal cluster, the local distribution of electron and spin densities at copper atoms, and the structure of hydrocarbon radicals of carboxylic acids affect the physicochemical properties of the system during the formation of servovite films.