Related Papers
Tribology Letters
Surface and tribological characteristics of tribofilms formed in the boundary lubrication regime with application to internal combustion engines
2003 •
Martin Priest
Lubricants
Reducing Friction and Wear of Tribological Systems through Hybrid Tribofilm Consisting of Coating and Lubricants
2014 •
Braham Prakash
Surface and Coatings Technology
Tribological coatings for lubrication over multiple thermal cycles
2009 •
Christopher Muratore
Journal of Tribology
Effect of dispersant concentration with friction modifiers and anti-wear additives on the tribofilm composition and boundary friction
2021 •
Ramin Rahmani
To extend drain intervals and improve efficiency, new engine oils with increased dispersant concentration and reduced viscosity are required. Low viscosity engine oils can increase the prevalence of boundary friction at low temperature and increase its severity at higher temperatures. As a result, combinations of organic and inorganic friction modifiers (FM) will be used to reduce boundary friction across a range of temperatures, also preventing damage to vehicle catalysts. This paper presents an experimental case study of such new generation of fully-formulated engine lubricants with varying concentrations of polyisobutylene succinimide dispersant, organic and inorganic FM. Representative conditions pertaining to those encountered at the top dead centre reversal of the piston compression ring-cylinder liner contact are created, and the generated friction measured through use of a sliding-strip tribometry. Subsequently, X-Ray Photoelectron Spectroscopy (XPS) is used to determine the composition of the formed surface tribofilms in order to explain the observed frictional characteristics. The key interactions and frictional behaviour of the dispersant and friction modifiers are highlighted across a range of operating temperatures.
The Tribological Effects of Lubricating Oil Containing Nanometer-Scale Diamond Particles
2015 •
Matthew Marko
Wear
Friction and wear of solid lubricant films deposited by different types of burnishing
2007 •
Alexey Moshkovich
International Journal of Precision Engineering and Manufacturing
Synergistic effect of a coating and nano-oil lubricant on the tribological properties of friction surfaces
2012 •
JungHo Park
Tribological behavior of vegetable oil-based lubricants with nanoparticles of oxides in boundary lubrication conditions
Braulio Barros
This work studied the development of vegetable based lubricants and the addition of oxides nanoparticles (ZnO and CuO) as additive for extreme pressure (EP), exploring the EP and oil base influence in tribological behavior. The results showed that with the addition of nanoparticles to conventional lubricant, the tribological properties can be significantly improved. A smoother and more compact tribofilm has formed on the worn surface, which is responsible for the further reduced friction and wear. Also, lubricants developed from modified vegetable oil can replace mineral oil, improving the tribological and environmental characteristics. However, the addition of nanoparticles in vegetable base lubricants is not beneficial to wear reduction.
8th International Colloquium, Esslingen "Tribology 2000"
A MOLECULAR MODEL FOR BOUNDARY LUBRICATION: ON THE BASICS OF MOLECULAR TRIBOLOGY
1992 •
Hector J Franco
A boundary lubrication regime model in which almost all the friction and wear are due to physical interaction processes in the interface between tribological surfaces is introduced. In this model the operation conditions for the tribological system are related with its solid elements properties and the physical-chemical characteristics of the lubricant. This generic lubricant has been considered as formed by a modified base stock and an anti-wear/extreme pressure a.w./e.p. additive. In this picture, molecular sizes and adsorption energies play an important role in the interface where the macroscopic contact geometry is taken into account based in the Hertz's theory for the calculation of the surface-surface direct real contact area under applied load. The block on ring FALEX-TIMKEN tester was used for measurements of friction force at different temperatures as function of the sliding velocity and applied mechanical load. These tests were carried out using three different formulated lubricant oils. Also, measurements of wear as function of the applied load were done. Once the generic additive adsorption energy and the effective base stock molecular size were estimated, they were introduced in the calculation for simulation. The model reproduces the experimental wear trends at low temperatures and explanations of data features can be drawn. Chemical wear may be involved as shown by the estimated values for the energies of adsorption. However, the model under estimates the measure of wear at high temperatures owing to the explicit neglection of chemical wear processes.
Chemistry and Technology of Fuels and Oils
Effect of the soap cation on tribological characteristics of lubricating material
1989 •
Hoolo Nyane
