Theoretical and computational studies on nanofriction: A review

Abstract

The subject of nanofriction having its origins in the late 19th century has slowly but surely started picking up lately. With rapid advancements in science and technology throughout the last century, understanding nanofriction has been gaining prominence. In this context, and in the current 21st century of nanotechnology, it is expected that nanofriction will play a predominant role, as we try moving forward to solve the most pressing medical and biological problems with the usage of nanobots. It is important to understand the challenges we have to encounter in order to solve these problems for the benefit of the human race. The availability of high speed computers and smart algorithms has made it possible to investigate the problems (as outlined above and many more) without compromising on the complexities involved. The focus of the present review is to bring together major theoretical/mathematical models and computational approaches to study friction at nanoscale. The role of adhesion in the estimation of force of friction at nanoscale has also been clearly outlined. A critical discussion on the significance of single and multiple asperity models towards estimating friction at nanoscale has also been provided. At the end, a short description on scanning probe microscopy in estimating nanofriction has been provided for the completeness of the review.

SiC-Coated SiC Die for Galling-Free Forging of Pure Titanium

“…This classical understanding on the chemical galling behavior is further advanced by the computational chemistry on the nano-friction. 11) After the first principle calculation, two matters with nearly the same density of state (DOS) in the local electron structure, are easy to adhere to each other; while two with significant difference in DOS have less bound interface. Dense ¢-SiC coating punch and die have covalent bonding state in the cubic structure while titanium is a typical transition metal in metallic bonding to have free electron pair.…”

Atomistic Modelling of Energy Dissipation in Nanoscale Gears

“…Concerning item (2), it is well-established that the friction laws known from macroscopic systems cannot, in general, be extrapolated to nanoscale systems [17,18,19,20,21,22], and this has lead to a large number of experimental [23,24,25,26,27] and model-based [28,29,30,31] investigations. In general terms, two qualitatively different friction regimes have been identified, which depend on the center-of-mass velocity: (a) a low-speed, stochastic regime (v 1000 cm/s) [32], where the system is close to thermal equilibrium and friction is governed by Brownian motion, (b) a high-speed, viscous regime [32,31], where the system is out of equilibrium and friction is proportional to the number of collisions with surface corrugations per unit time [31].…”

An efficient computational model for adhesive contact mechanics based on a lumped parameter formulation

“…19 In addition to being significantly more affordable than experimental methods, computational approaches allow for fine control of the procedure and simulate the desired condition. 20 Finite element (FE) methodarguably the most commonly-used computational techniquehas been extended to the studies in adhesive contact mechanics for determining various parameters like deformations, forces, and stress fields. 21 However, almost all such studies require special-purpose or in-house developed software, whereas FE analysis is commonly carried out using commercial software like Abaqus CAE.…”