Dependences of changes in the structural viscosity of oil films on the friction surface with fullerene compositions
DOI:
https://doi.org/10.31891/2079-1372-2021-100-2-34-40Keywords:
fullerenes, oil film, fullerene compositions, structural viscosity, sol structure, gel structure, electrostatic field of the friction surface, dynamic viscosityAbstract
In this work, the physical phenomenon of the formation of an oil film containing fullerenes was further developed, on the friction surface of tribosystems, which, in contrast to the known ones, takes into account the structural viscosity and structure of the formed film under the action of the electrostatic field of the friction surface. An increase in load significantly increases the structural viscosity of the gel structure, 13 - 20 times. The concentration of fullerenes in the base lubricant does not significantly affect the dynamic viscosity of aggregates in the composition of the liquid and the structure of the gel.
An increase in the tribological properties of the base lubricant medium reduces the value of the structural viscosity of the gel on the friction surface by a factor of 3. At the same time, the concentration of fullerenes in the range of 0.5 - 1.5% does not have a large effect on these indicators. This phenomenon can be explained by the presence or absence of an additive package in the base lubricating medium. For those oils where the additive package is absent or present in a small amount J/m3, the introduction of a fullerene composition promotes the formation of clusters and micelles, which increase the structural viscosity and, consequently, form a film on the friction surface in the form of a gel structure. Conversely, if fullerenes are introduced into a base oil that contains a large and balanced additive package, where tribological properties are high J/m3, interaction at the molecular level does not occur. Fullerenes to a lesser extent will form stable aggregates in the form of micelles.
The effect of reducing the coefficient of friction, equal to 96 %, is typical for low and medium loads of operation of tribosystems and base lubricants with average values of tribological properties. With increasing loads or tribological properties of base oils, the effect of the use of fullerenes decreases
References
2. Matviyenko V.N., Kirsanov Ye.A. Vyazkost' i struktura dispersnykh sistem // Vestnik Moskovskogo universiteta. Seriya 2. Khimiya. – 2011. – T.52. – № 4.– S. 243– 276. [Russian]
3. Bibik Ye.Ye. Reologiya dispersnykh sistem. – L.: Izd-vo Leningradskogo un-ta, 1981. -172s. [Russian]
4. Reyner M. Reologiya / M. Reyner. // perev. s angl. pod red. E.I. Grigolyuka. – M.: Nauka, 1965. – 223s. [Russian]
5. Anurag Singh, Prashant Chauhan, Mamatha T. G. A review on tribological performance of lubricants with nanoparticles additives // Materials today: proceedings Volume 25, Part 4, 2020, Pages 586-591 https://doi.org/10.1016/j.matpr.2019.07.245 [English]
6. Kravtsov A.G. Investigation of the structural viscosity of oil films on the friction surface with fullerene compositions. Problems of Tribology, Vol 26, No 1/99, 2021, pp. 13-19. https://doi.org/10.31891/2079-1372-2021-96-1-13-19 [English]
7. Kravtsov A.H. Rozrobka makroreolohichnoyi modeli relaksatsiyi napruzhenʹ v mastylʹniy plivtsi na poverkhni tertya pry nayavnosti fullereniv/ Problemy trybolohiyi. – 2018. – № 4. – S. 36– 40. [Ukraine]
8. Zakharchenko M.B. Yntehralʹnyy parametr otsenky trybolohycheskykh svoystv smazochnykh materya-lov // Zbirnyk naukovykh pratsʹ Ukrayinsʹkoyi derzhavnoyi akademiyi zaliznychnoho transportu. Tom 2. – Kharkiv: UkrDAZT, 2015. – Vyp. 151. – S. 5– 10. [Russian]
