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The purpose of this paper is to investigate the influence of fluor‐oligomeric coat on the mechanical properties of steel surface, as well as the chemical interaction of fluor‐oligomeric films with surface and theoretical‐phenomenological interpretation of structural processes in friction surface.

Four groups of specimens were studied: two groups of specimens without any wear tests – initial steel specimen as control version and a specimen which was ten times coated by fluor‐oligomer, and two groups of specimens, which were tribologically tested for one million cycles – without any coating and coated specimens. Closed kinematical profile scheme roller‐roller of steel 45 was chosen for tribological tests. Wear of friction surface after those tests was investigated. The interaction between fluor‐oligomer and iron was studied by means of Mössbauer spectroscopy. The micro‐hardness of matrix was also measured.

Affecting the surface of steel by the fluor‐oligomer and friction produces the complicated processes of carbide decay and formation occur. The mechanisms are found which are related to the weakening of chemical bond in steel during the absorption, to the generation of microscopic ruptures, to the decrease (30‐50 per cent) of the amount of carbides and its increase during the friction (up to 50 per cent). The mechanical effect which causes the regeneration of carbides during friction is revealed. Tribological efficiency of fluor‐oligomeric coats (five times lower wear of coated specimens) is explained by the balance of three processes – the softening of matrix during adsorption, the detention of dislocations, and formation of hard particles in the matrix.

The complex mechanism of the increase of wear resistance is explained by filling of ductile matrix with carbide particles.

The purpose of this paper is to investigate the tribological behaviour of commercially available SAE 10 mineral and rapeseed oils containing Fe particles synthesized directly in the oil phase.

Sub-micron Fe particles (50-340 nm) were synthesized by wet chemical reduction reaction of FeSO₄ by sodium borohydride in the rapeseed and mineral oils in the presence of surfactant: block copolymer (ENB 90R4) or oxyethylated alcohol (OS-20). A four-ball wear tribometer was used to investigate the tribological properties of mineral and rapeseed oil: coefficient of friction (COF), wear scar diameter and wear loss. Viscosity measurements of oil solutions and determination of synthesized Fe particles size were performed as well.

The presence of Fe particles (0.1 weight per cent) in the rapeseed and mineral oils caused the little change in the COF but resulted in marked improvement of anti-wear property. The oils containing Fe particles with slightly higher viscosity are giving more friction due to viscous drag. The anti-wear enhancement is attributed to the formation of tribofilm and superior load-bearing capability of the modified oil. Both rapeseed and mineral oils irrespective of used surfactant in the presence of 0.1 weight per cent Fe particles (50-140 nm) show sufficiently improved anti-wear properties.

The data collection about tribological behaviour of oils containing Fe particles and various additives in lubricants has a practical interest. The findings could be helpful to increase the knowledge of the behaviour of real tribological systems, where the metallic debris are generated during friction and contaminate the lubricating oil.