To the New Concept of Green Tribology

Abstract

The aim of the present work is to confirm the fundamental possibility of creating new generation of the nanostructured composite coatings-orientants are studied under conditions of boundary lubrication in inactive oil, as green tribology aspect and to experimentally prove the efficacy of the nanostructured composite coatings-orientants for engineering applications. Tribological properties of nanostructured composite coatings-orientants are studied under conditions of boundary lubrication in inactive oil, as green tribology aspect. The friction tests were carried out by using two test configurations: "ball-ondisc" and "ring-to-ring". As lubricants some model and commercial oils were used. It is found that the friction coefficient and its temperature dependence differ significantly for nanostructured composite coatings under study. The obtained results were attributed to different orientating effect of these coatings on structural ordering in boundary layers, which structure is considered as a mesophase of liquid crystals. The findings suggest that the nanostructured composite coatings-orientants with orientating effect on boundary layers are advantageous for improving antifriction characteristics and for governing processes of boundary lubrication. The nanostructured composite coatingsorientants can improve lubricating properties of oils (with and without additives) and may be advantageous for engineering practice as they improve antifriction characteristics of rubbing pairs and allow controlling the processes of boundary lubrication. Thus, received nanostructured composite coatingsorientants can be today the best materials of green tribology in engineering.

Interfacial Structure and Tribological Property of Adsorbed Layer Formed by Dibasic Acid Ester Derivative

“…It is generally known that unsaturated fatty acids with double bonds in the alkyl chain, such as oleic acid, are less effective in reducing friction and wear in high-temperature environments. This is because, although molecular motion is more intense in high-temperature environments, the bending structure at the cis-type double bond prevents the formation of a densely packed layer due to steric hindrance, and the adsorbed layer cannot be maintained sufficiently stable against friction [8,29]. On the other hand, when the density of an adsorbed layer is high, the interaction between the alkyl chains increases the film strength and improves the friction and wear properties [30,31].…”

Tribological Investigations of Silicon Nitride Lubricated by Ionic Liquid Aqueous Solutions

“…Investigations on water lubricity and on the wear mechanisms of silicon nitride (Si 3 N 4 ) describe that tribochemical wear causes the formation of an amorphous protective layer which leads to a reduction of friction and wear [18]. The formation of silica Si(OH) 4 is activated by friction as a function of contact pressure, sliding speed, humidity [19] and temperature [20]. This results in an ultra-smooth surface and a very thin hydrodynamic lubricating film is formed even at very low sliding speeds [18].…”