Surface science and the atomic-scale origins of friction: what once was old is new again

Krim, J.

doi:10.1016/s0039-6028(01)01529-1

Cited by 119 publications

(70 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[1][2][3][4] Friction is an extremely complex physical process, and its origin can vary from system to system. This is in part because the contact topology, molecular interactions and mechanisms of energy dissipation can vary with material and physical conditions, such as whether the contact is dry or lubricated by an intervening liquid or solid.…”

Section: Introductionmentioning

confidence: 99%

Non-equilibrium phase behavior and friction of confined molecular films under shear: A non-equilibrium molecular dynamics study

Maćkowiak

Heyes

Dini

et al. 2016

The Journal of Chemical Physics

View full text Add to dashboard Cite

The phase behavior of a confined liquid at high pressure and shear rate, such as is found in elastohydrodynamic lubrication, can influence the traction characteristics in machine operation.Generic aspects of this behavior are investigated here using Non-equilibrium Molecular Dynamics (NEMD) simulations of confined Lennard-Jones (LJ) films under load with a recently proposed wall-driven shearing method without wall atom tethering [Gattinoni, Maćkowiak, Heyes, Brańka and Dini, Phys. Rev. E 90, 043302 (2014)]. The focus is on thick films in which the nonequilibrium phases formed in the confined region impact on the traction properties. The nonequilibrium phase and tribological diagrams are mapped out in detail as a function of load, wall sliding speed and atomic scale surface roughness, which is shown can have a significant effect. The transition between these phases is typically not sharp as the external conditions are varied. The magnitude of the friction coefficient depends strongly on the nonequilibrium phase adopted by the confined region of molecules, and in general does not follow the classical friction relations between macroscopic bodies, e.g., the frictional force can decrease with increasing load in the Plug-Slip (PS) region of the phase diagram owing to structural changes induced in the confined film. The friction coefficient can be extremely low (∼ 0.01) in the PS region as a result of incommensurate alignment between a (100) face-centered cubic wall plane and reconstructed (111) layers of the confined region near the wall. It is possible to exploit hysteresis to retain low friction PS states well into the Central Localization high wall speed region of the phase diagram.Stick-Slip behavior due to periodic in-plane melting of layers in the confined region and subsequent annealing is observed at low wall speeds and moderate external loads. At intermediate wall speeds and pressure values (at least) the friction coefficient decreases with increasing well depth of the LJ potential between the wall atoms, but increases when the attractive part of the potential between wall atoms and confined molecules is made larger.2

show abstract

Section: Introductionmentioning

confidence: 99%

Non-equilibrium phase behavior and friction of confined molecular films under shear: A non-equilibrium molecular dynamics study

Maćkowiak

Heyes

Dini

et al. 2016

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…However, nanoscale measurements have shown that friction is observed even in the absence of wear, and the fundamental origin of friction is still controversial. [1][2][3][4] Numerous models of the origin of sliding friction have been developed and recently reviewed. [5][6][7][8] These include the classical adhesion theory, 9 the related adhesion hysteresis theory 10 and treatments where the separation is due to cracking.…”

Section: Introductionmentioning

confidence: 99%

A thermodynamic model of sliding friction

Makkonen

2012

AIP Advances

View full text Add to dashboard Cite

show abstract

“…1 The significance of this progress is particularly clear if we compare it with what had been done in the centuries after the friction laws were stated by Amonton and Coulomb, and elaborated upon by Leonardo da Vinci. 2 Microscopic experiments on friction, 3 and subsequent theory and simulation were started only in the last 15 years.…”

Section: Introductionmentioning

confidence: 85%

Nonlinear friction of a damped dimer sliding on a periodic substrate

2004

View full text Add to dashboard Cite

The nonlinear sliding friction of a dimer over a substrate is studied within a one-dimensional model, consisting of a vibrating dimer (two masses connected by a spring), internally damped, sliding over a sinusoidal potential. Molecular dynamics simulations show that the friction force has an approximate v −3 dependence if the velocity is sufficiently large, and that there is a striking periodic variation of the proportionality coefficient with the ratio of the length of the dimer to the substrate wavelength. The nonlinear velocity dependence was predicted earlier for a Langevin model of an adsorbed layer in the presence of strong external force. We study it here in detail in the transient regime and without external force. We obtain the dependence on key parameters (internal dissipation, dimer mass, substrate corrugation, and length ratio), and examine the validity of the friction law. A semianalytical expression is suggested which confirms the numerical observations in the high-velocity regime.

show abstract

Surface science and the atomic-scale origins of friction: what once was old is new again

Cited by 119 publications

References 62 publications

Non-equilibrium phase behavior and friction of confined molecular films under shear: A non-equilibrium molecular dynamics study

Non-equilibrium phase behavior and friction of confined molecular films under shear: A non-equilibrium molecular dynamics study

A thermodynamic model of sliding friction

Nonlinear friction of a damped dimer sliding on a periodic substrate

Contact Info

Product

Resources

About