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Publications associées (21)

Roughness Evolution Induced by Third-Body Wear

Jean-François Molinari, Tobias Brink, Antonio Joaquin Garcia Suarez

Surface roughness is a key factor when it comes to friction and wear, as well as to other physical properties. These phenomena are controlled by mechanisms acting at small scales, in which the topography of apparently flat surfaces is revealed. Roughness i ...

2024

Thermal Modelling and Experimental Validation in the Perspective of Tool Steel Laser Polishing

Alexandre Masserey, Eric Boillat, Bastian Meylan

Laser polishing (LP) is a process that allows a significant reduction of the surface roughness of a metal workpiece via re-melting a shallow layer of material. However, the practical use of LP is limited due to the difficulty of satisfying the high surface ...

MDPI2022

Adhesive wear regimes on rough surfaces and interaction of micro-contacts

Jean-François Molinari, Son-Jonathan Pham-Ba

We develop an analytical model of adhesive wear between two unlubricated rough surfaces, forming micro-contacts under normal load. The model is based on an energy balance and a crack initiation criteria. We apply the model to the problem of self-affine rou ...

2021

A numerical study of the statistics of roughness parameters for fluctuating interfaces

Elisabeth Agoritsas

Self-affine rough interfaces are ubiquitous in experimental systems, and display characteristic scaling properties as a signature of the nature of disorder in their supporting medium, i.e. of the statistical features of its heterogeneities. Different metho ...

2021

Jamming with Tunable Roughness

Matthieu Wyart, Carolina Brito Carvalho dos Santos

We introduce a new model to study the effect of surface roughness on the jamming transition. By performing numerical simulations, we show that for a smooth surface, the jamming transition density and the contact number at the transition point both increase ...

AMER PHYSICAL SOC2020

The transfer of forces through rough surface contact in concrete

Max Tirassa

Aggregate interlocking is a phenomenon occurring when the opposite sides of a concrete crack slide relative to each other. Due to surface roughness, protruding material from one crack-side can engage with the opposite one and thus exchange forces. This aff ...

EPFL2020

Hydraulic Transport Through Calcite Bearing Faults With Customized Roughness: Effects of Normal and Shear Loading

Marie Estelle Solange Violay, Mateo Alejandro Acosta

Understanding fluid flow in rough fractures is of high importance to large scale geologic processes and to most anthropogenic geo‐energy activities. Here we conducted fluid transport experiments on Carrara marble fractures with a novel customized surface t ...

2020

Appearance of polished 18 karat gold surfaces: linking aesthetics to surface features

Leili Batooli

Impeccable appearance of surfaces is a key constraint in high-end jewelry and watch manufacturing. Based on long tradition in the industry, appearance of products is assessed by trained individuals through visual inspection in designated intervals on the p ...

EPFL2019

Nanostructured surface topographies have an effect on bactericidal activity

Jürgen Brugger, Songmei Wu

Background Due to the increased emergence of antimicrobial resistance, alternatives to minimize the usage of antibiotics become attractive solutions. Biophysical manipulation of material surface topography to prevent bacterial adhesion is one promising app ...

2018

A Method to Form Smooth Films of Liquid Metal Supported by Elastomeric Substrate

Stéphanie Lacour, Arthur Edouard Hirsch

Several methods are proposed to manipulate and pattern liquid metal films into elastic conductors but all lack precise control over the film thickness and roughness, thereby limiting its uniformity, stability, and reproducibility. Here, an approach relying ...

2018

Optimisation of Current and Pulse Duration in Electric Discharge Drilling of D2 Steel Using Graphite Electrode

Electric discharge machining (EDM) is one of the viable techniques for machining of D2 steel, in which the material removal occurs by spark erosion. The poor selection of EDM parameters affect the machining quality and productivity. Considering this, the p ...

2018

Fabrication method of functional micro/nano structures over large-area, flexible and high curvature surfaces, by drawing a fiber from a preform

Dang Tùng Nguyen, Fabien Sorin, Alexis Gérald Page, Wei Yan, Yunpeng Qu

The method for drawing a fiber with a textured surface comprises the following steps: - forming of a preform from which the fiber is to be drawn with a textured surface; - addition of an outer layer to the textured preform to preserve the shape of the text ...

2017

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

Development of a system for part quality prediction and process parameters adjustment in wire electrical discharge machining

Olcay Akten

In the past decades, wire electric discharge machining (W-EDM) has undergone a number of techno-logical developments aimed at improving its process performance. Still the current practice of W-EDM is not defect-free and results in a number of surface relat ...

EPFL2015

Light Transport Matrix recovery for nearly planar objects

Martin Vetterli, Paolo Prandoni, Loïc Arnaud Baboulaz, Niranjan Thanikachalam

The light transport matrix has become a powerful tool for scene relighting, owing to the versatility of its representational power of various light transport phenomenon. We argue that scenes with an almost planar surface geometry, even with significant amo ...

SPIE2014

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

Jean-François Molinari, Guillaume Anciaux, Peter Spijker

We investigate the friction of deformable bodies, with nano-scale self-affine fractal rough surfaces, at the atomic scale using molecular dynamics. Different temperatures (0-400 K) are studied, while roughness and applied load are changed. During sliding, ...

Elsevier Sci Ltd2013

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

Fluorine based plasma treatment of biocompatible silicone elastomer. Effect of temperature on etch rate and surface properties

Arnaud Bertsch, Cyrille Hibert

This paper describes F-based dry etching and resulting surface properties of biocompatible silicone elastomer. The etch rate of polysiloxane and surface morphology was found to be highly temperature dependent. An increase in temperature results in a signif ...

2008

On the Parameterization of Surface Roughness at Regional Scales

Marc Parlange, Charles Vivant Ignacio Meneveau

A parameterization for surface roughness and blending height at regional scales, under neutral atmospheric stability, is studied and tested. The analysis is based on a suite of large-eddy simulations (LES) over surfaces with varying roughness height and mu ...

2007

Microbial growth on partially saturated rough surfaces: Simulations in idealized roughness networks

Dani Or

A new model is developed to study the effect of aqueous phase configuration on microbial growth on rough surfaces under different hydration conditions. Surface roughness is idealized using a network of conical pits (sites) on a regular lattice connected by ...

American Geophysical Union2007

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