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Nanoscale frictional phenomena at solid–solid surfaces with lubricants are studied numerically using a lattice model which consists of two rigid substrates and a monolayer of lubricant molecules. The maximum static frictional force, which works on the driven upper solid, is always finite and obeys a certain scaling relation. The lubricant layer, however, shows a kind of phase transition from a pinned state to free sliding state when the strength of the interaction potential with the substrates decreases. We discuss the peculiar pinning mechanism of the upper substrate in the presence of a lubricant monolayer.

Wear and friction hold an important place in engineering. Currently, scientific societies are struggling to control wear by means of studies on lubricants. Boric acid constitutes an important alternative with its good tribological properties similar to MO₂S and graphite alongside with low environmental impacts. Boric acid can be used as a solid lubricant itself whereas it can be added or blended into mineral oils in order to yield better mechanical and tribological properties such as low shear stress due to the lamellar structure and low friction, wear and surface roughness rates. In this study, distinguishing from the literature, boric acid addition effect considering the temperature was investigated for the conventional ranges of internal combustion engines. Surface roughness, wear and friction coefficient values were used in order to determine tribological properties of boric acid as an environmentally friendly additive and mineral oil mixture in the present study. Wear experiments were conducted with a ball on disc experimental setup immersed in an oil reservoir at room temperature, 50${}^{\circ }$C and 80${}^{\circ }$C. The evolution of both the friction coefficient and wear behavior was determined under 10N load, at 2m/s sliding velocity and a total sliding distance of 9000m. Surface roughness was determined using atomic-force microscopy (AFM). Wear rate was calculated utilizing scanning electron microscope (SEM) visuals and data. The test results showed that wear resistance increased as the temperature increased, and friction coefficient decreased due to the presence of boric acid additive.

In this paper, it is described that the motion of water droplets on the hydrophobic surface of ZnO nanorod array impregnated lubricant, is called slippery liquid-infused porous surface (SLIPS). The energy gradient required to induce the motion of the droplets is created on the boundary of superhydrophobic ZnO nanorod array and SLIPS. Because of the lower viscous force of SLIPS, the water droplet can rapidly move for longer distance on the surface. In view of changing the release distance of water droplet, the mechanism for the rapid movement is discussed. The results indicate that the movement distance of water droplet markedly increases with the increasing of the release distance. Because the potential energy of the height is converted into kinetic energy, the water droplet intensively collides the interface between ZnO nanorod array and SLIPS. This impact makes the water droplet distort, which enhances the driving force. These new findings will not only deepen our understanding of the relationship between surface structure and dynamic wetting properties, but also afford the new notion and beneficial reference for designing liquid droplet transportation devices in micro-fluidic systems.

This paper presents molecular dynamic modeling and simulation of lubricant between sliding solids. Linear $n$-alkanes with united atoms were used to model lubricant while iron sliding solids were modeled with body-centered cubic crystal lattices. We employed various potential functions, including the embedded atom method, the multibody force field and the Lennard–Jones potential, to approximate the interatomic interactions in the molecular model. Hydrodynamic lubrication was considered in this paper. We found that the temperature and the chain length of alkanes had effects on the friction between lubricated sliding solids. In addition, one debris, modeled as a nanoparticle, was added in the lubricant to study its effect on the friction. It was observed that nanoparticles would increase the friction in hydrodynamic lubrication.

Presses for hot sheet metal forming are critical assets and significant investments for manufacturers engaged in press hardening operations. With metal sheets reaching temperatures of about 900 °C, a fire on the press where mineral oil based lubricants are involved can cause extreme hazards for operators, damages to or loss of the press itself, production losses due to suspended operations for extended periods of time, and damages to customer relationships resulting from a loss in trust in supply reliability. Ultimately, such losses could cost manufacturers millions. Protecting such assets by replacing mineral oil based lubricants with a reliable risk prevention product can reduce the risk of such losses and advance the safety efforts of the manufacturer. This paper describes a case where reliability of the production has increased considerably by choosing a fire resistant lubricant alternative for the hydraulic, greases, gear oils and slide way oil.