Tribological Characteristics of Chemically Inactive Surfaces in Lubricants Doped with Cholesterol and Fatty Acid Compounds

Abstract

It is found that in inactivated vaseline oil, with the addition of oleic acid, the glass samples characterized by the destruction of the contacting surfaces and a significant increase in the coefficient of friction are set almost at the same load of 0.9 to 1.2 MPa. The addition of liquid-crystal cholesterol compounds to an inactivated lubricant during the friction of chemically inactive surfaces (glass) leads not only to a decrease in the coefficient of friction but also to an increase in the load capacity. For example, an additive of 3.0 wt % of the oleic acid cholesterol ester in vaseline oil increases the loading capacity by six to seven times when the glass is rubbed against the glass compared to the medium containing oleic acid. At the same time, using scanning electron microscopy and profilometry at loads of more than 4 MPa, the formation of microgrooves on the rubbing surfaces, which do not affect the characteristics and stability of friction, is established. The results obtained can be effectively used in the friction and processing of chemically inactive surfaces, such as glass, ruby, and diamond in the glass, watch, and diamond industries.