The goal for this master thesis is to improve and map the main factors behind friction and wear for a commercial product used by Kongsberg automotive. Components in a gear shifter are investigated and the target is to achieve high tribological quality of the force transmission. Finding a solution for low friction and wear which is independent of lubrication is the main issue for all involved co...

We investigate the velocity dependence of the friction between two rigid blocks limited by a self-affine surface such as the one generated by a crack. The upper solid is subjected either to gravity or to an extemal elastic stiffness, and is driven horizontally at constant velocity, V, while the lower solid is fixed. For low velocities, the apparent friction coefficient is constant. For high vel...

Unlike the well known Amontons-Coulomb laws of dry friction, the recent precise experimental studies of low velocity friction dynamics provide sensitive tests for a theoretical description. We introduce a model, in which the friction force originates from multistability induced by interactions of individual pairs of asperities whose properties undergo a slow time evolution due to plastic creep ...

Being a complex nonlinear phenomenon, friction is a difficult part to characterize and identify in a mechanical system. Friction is the result of interaction between one body over or along another and is dependent on many parameters, such as contact geometry, topography, surface materials, presence and type of lubrication and relative motion. The classical Coulomb friction has been widely used ...

Internal friction, which reflects the "roughness" of the energy landscape, plays an important role for proteins by modulating the dynamics of their folding and other conformational changes. However, the experimental quantification of internal friction and its contribution to folding dynamics has remained challenging. Here we use the combination of single-molecule Förster resonance energy transf...

Electronic friction and the ensuing nonadiabatic energy loss play an important role in chemical reaction dynamics at metal surfaces. Using molecular dynamics with electronic friction evaluated on the fly from density functional theory, we find strong mode dependence and a dominance of nonadiabatic energy loss along the bond stretch coordinate for scattering and dissociative chemisorption of H_{...

This paper comparatively studies the tribological behaviour of different types of diamond-like carbon (DLC) coatings in a reciprocating sliding wear test. The results are interpreted in terms of structure and surface morphological characteristics. At the beginning of each reciprocating sliding wear test, the higher coefficient of friction of the DLC coatings reflects the original surface condit...