Tribology involves not only two-body contacts of two solid materials—a substrate and a counter-surface; it often involves three-body contacts whether the third body is intentionally introduced or inevitably added during the sliding or rubbing. The intentionally added third body could be lubricant oil or engineered nano- material used to mitigate the friction and wear of the sliding contact. The inevitably added third body could be wear debris created from the substrate or the counter surface ...

A complete understanding of the mechanism of boundary lubrication is a goal that scientists have been striving to achieve over the past century. Although this complicated process has been far from fully revealed, a general picture and its influencing factors have been elucidated, not only at the macroscopic scale but also at the nanoscale, which is sufficiently clear to provide effective instructions for a lubrication design in engineering and even to efficiently control the boundary lubricat...

Computer simulations of friction between polymer brushes are usually simplified compared to real systems in terms of solvents and geometry. In most simulations, the solvent is only implicit with infinite compressibility and zero inertia. In addition, the model geometries are parallel walls rather than curved or rough as in reality. In this work, we study the effects of these approximations and more generally the relevance of solvation on dissipation in polymer-brush systems by comparing simul...

We report on the frictional properties of epitaxial graphene on SiC in ultra high vacuum. Measurements have been performed using a microtribometer in the load regime of 0.5 to 1 mN. We observed that a ruby sphere sliding against graphene results in very low friction coefficients ranging from 0.02 to 0.05. The friction and also the stability of the graphene layer is higher than that under similar conditions in ambient conditions. The friction shows a load dependence. Finally it was found that ...

The energy transition and dissipation of atomic-scale friction are investigated using the one-dimensional Prandtl–Tomlinson model. A systematic study of the factors influencing the energy dissipation is conducted, indicating that the energy that accumulated during the stick stage does not always dissipate completely during stick-slip motion. We adopt the energy-dissipation ratio (EDR) to describe the relationship between the energy dissipated permanently in the system and the conservative rev...

The paper is devoted to the contributions of Coulomb and Amontons to the physics of friction from the viewpoint of current discussions and attempts to formulate generalized laws of friction.