Publications related to Relations between roughness, temperature and dry sliding friction at the atomic scale

Effect of wear particles and roughness on nanoscale friction

Jean-François Molinari, Enrico Milanese, Tobias Brink

Frictional contacts lead to the formation of a surface layer called the third body, consisting of wear particles and structures resulting from their agglomerates. Its behavior and properties at the nanoscale control the macroscopic tribological performance ...

2022

Modeling the origins of adhesive wear across scales

Son-Jonathan Pham-Ba

Friction and wear occur at every interface between solid materials. In the design of mechanical devices, it is desirable to be able to quantify and control the amount of friction and wear, as well as predict their evolution with time. ``Tribology'' is the ...

EPFL2022

Understanding the mechanisms of adhesive wear for heterogeneous materials through atomistic simulations

Jean-François Molinari, Sacha Zenon Wattel, Antonio Joaquin Garcia Suarez

When two rough surfaces slide against each other, two main behaviors can be observed at the asperity level: A ductile behavior where the asperities tend to smooth out or a brittle behavior where the asperities detach and form debris. Recently, a critical l ...

2022

A parameter-free mechanistic model of the adhesive wear process of rough surfaces in sliding contact

Jean-François Molinari, Lucas Henri Galilée Frérot, Tobias Brink

In order to develop predictive wear laws, relevant material parameters and their influence on the wear rate need to be identified. Despite decades of research, there is no agreement on the mathematical form of wear equations and even the simplest models, s ...

2021

Bridging scales in wear modeling with volume integral methods for elastic-plastic contact

Lucas Henri Galilée Frérot

All mechanical systems, naturally occurring or human-produced, are subjected to friction and wear at the interface of solid constituents. Large portions of energy dissipation and loss of material, in every-day life and industrial applications alike, are du ...

EPFL2020

Surface roughness evolution in adhesive wear processes

Enrico Milanese

Geological faults movements generating earthquakes, a vehicles' tyres rolling on the pavement, and a chalk writing on a blackboard are all different examples of frictional systems. In these systems, which are everywhere around us, two separate bodies are i ...

EPFL2020

Transition from Exponentially Damped to Finite-Time Arrest Liquid Oscillations Induced by Contact Line Hysteresis

François Gallaire, Elise Flore Céline Lorenceau, Benjamin Jérémy Dollet

To clarify the role of wetting properties on the damping of liquid oscillations, we studied the decay of oscillations of liquid columns in a U-shaped tube with controlled surface conditions. In the presence of sliding triple lines, oscillations are strongl ...

AMER PHYSICAL SOC2020

The Role of Reynolds Number Effect and Tip Leakage in Compressor Geometry Scaling at Low Turbulent Reynolds Numbers

Jürg Alexander Schiffmann, Markus Diehl, Christoph Schreiber

In compressor design, a convenient way to save time is to scale an existing geometry to required specifications, rather than developing a new design. The approach works well when scaling compressors of similar size at high Reynolds numbers but becomes more ...

2020

Surface textures suppress viscoelastic braking on soft substrates

John Martin Kolinski, Martin Louis Francis Coux

A gravity-driven droplet will rapidly flow down an inclined substrate, resisted only by stresses inside the liquid. If the substrate is compliant, with an elastic modulus G < 100 kPa, the droplet will markedly slow as a consequence of viscoelastic braking. ...

National Academy of Sciences2020

A mechanistic understanding of the wear coefficient: From single to multiple asperities contact

Jean-François Molinari, Lucas Henri Galilée Frérot, Ramin Aghababaei

Sliding contact between solids leads to material detaching from their surfaces in the form of debris particles, a process known as wear. According to the well-known Archard wear model, the wear volume (i.e. the volume of detached particles) is proportional ...

2018

Adhesive wear mechanisms uncovered by atomistic simulations

Jean-François Molinari, Lucas Henri Galilée Frérot, Ramin Aghababaei, Enrico Milanese, Tobias Brink

In this review, we discuss our recent advances in modeling adhesive wear mechanisms using coarse-grained atomistic simulations. In particular, we present how a model pair potential reveals the transition from ductile shearing of an asperity to the formatio ...

SPRINGEROPEN2018

On the debris-level origins of adhesive wear

Jean-François Molinari, Ramin Aghababaei, Derek Warner

Every contacting surface inevitably experiences wear. Predicting the exact amount of material loss due to wear relies on empirical data and cannot be obtained from any physical model. Here, we analyze and quantify wear at the most fundamental level, i.e., ...

Natl Acad Sciences2017

Self-Replenishing, Wear-Resistant and Anti-Sticking Surfaces Based on Liquid Impregnation of Microstructured Mesoporous α-AI₂O₃ [Alpha Alumina] Matrices

Sriharitha Rowthu

Fabrication of wear-resistant omniphobic surfaces is a persistent scientific challenge and essential for various applications such as in paint industries, fluid transport, antifouling, reduction of friction drag on ship hulls, and stain resistant textiles. ...

EPFL2016

Characterization of Grey Cast Iron-Steel Tribo-system under Starved Lubrication Conditions : Failure, Failure Detection and Laser Surface Texturing

Fatemeh Saeidi

Reducing friction and wear is essential for building efficient systems with low energy consumption and a long lifetime. Surface texturing is one of the methods to reduce friction and wear, especially in oil-lubricated systems. However, there is still a lac ...

EPFL2016

A Facile in Situ and UV Printing Process for Bioinspired Self-Cleaning Surfaces

Yves Leterrier, Sara Dalle Vacche, Marina Aymara González Lazo, Ioannis Katrantzis, Feyza Karasu Kiliç

A facile in situ and UV printing process was demonstrated to create self-cleaning synthetic replica of natural petals and leaves. The process relied on the spontaneous migration of a fluorinated acrylate surfactant (PFUA) within a low-shrinkage acrylated h ...

MDPI2016

Tribocorrosion under fluid lubrication : modeling wear of CoCrMo artificial hip joints

Shoufan Cao

Wear is still the key problem causing the failure and limiting the lifetime of artificial hip joints, especially for the polymer acetabular cup in the metal-on-polymer and ceramic-on-polymer articulations. To reduce the wear, metal-on-metal articulation ha ...

EPFL2016

The effect of loading on surface roughness at the atomistic level

Jean-François Molinari, Guillaume Anciaux, Peter Spijker

One of the key points to better understand the origins of friction is to know how two surfaces in contact adhere to one another. In this paper we present molecular dynamics (MD) simulations of two aluminium bodies in contact, exposed to a range of normal l ...

Springer-Verlag2012

Dry sliding contact between rough surfaces at the atomistic scale

Jean-François Molinari, Guillaume Anciaux, Peter Spijker

Although, a lot is known about the factors contributing to friction, a complete physical understanding of the origins of friction is still lacking. At the macroscale several laws have long since described the relation between load (Amontons, Coulomb), appa ...

Springer US2011

Influence of emulsion composition on lubrication capacity and texture perception

Stefano Mischler

P>The role of fat content and type of surfactant for oral friction processes and texture perception of oil-in-water emulsions was assessed. Emulsions at 22% and 33% fat content containing either sodium caseinate or a sucrose ester as emulsifier were compar ...

2009

Stability and physical properties of alkylsilane and alkylphosphonate self-assembled monolayer (SAM) films on metal oxide substrates characterized at the micro- and nanoscale

Enamul Hoque

Self-assembled monolayer (SAM) films have attracted immense attention for both fundamental and applied research. A SAM is composed of a large number of molecules with a head group that chemisorbs onto a substrate, a tail group that interacts with the outer ...

EPFL2007