Publications associées à Hard-sphere displacive model of deformation twinning in hexagonal close-packed metals. Revisiting the case of the (56, a) contraction twins in magnesium

Publications associées (29)

Deformation twinning mechanism in magnesium at the microscale: strain rate, temperature and orientation effects

The project aims to validate some recent theoretical developments on the deformation twinning nucleation mechanism in HCP metals through small-scale mechanic experiments. To this end, a systematic investigation of the mechanical response of pure magnesium ...

EPFL2022

Evolution of deformation twinning mechanisms in magnesium from low to high strain rates

Roland Logé, Cyril Cayron, Johann Michler, Xavier Maeder, Nicolò Maria Della Ventura

We present a systematic investigation of {10 (1) over bar2} extension twinning mechanism in single crystal magnesium micropillars deformed over seven orders of magnitude of strain rate, from 10(-4) to 500 s(-1), revealing how the accommodation of newly for ...

ELSEVIER SCI LTD2022

Phase transformation induced distortions in red gold alloys

Margaux Nathalie Dominique Larcher

Red gold alloys owe their warm and attractive colour to the combination of gold and copper atoms. Thanks to their good mechanical properties and resistance to corrosion, red gold alloys are used in luxury industries as well as in dentistry. Around the equi ...

EPFL2021

{10(1)over-bar2} twinning mechanism during in situ micro-tensile loading of pure Mg: Role of basal slip and twin-twin interactions

Roland Logé, Johann Michler, Xavier Maeder, Daniele Casari, Nicolò Maria Della Ventura

An SEM in situ uniaxial tensile testing setup allowing HR-EBSD acquisition during deformation was used to study the extension twinning mechanism in magnesium(Mg) at the micron scale. Structures were fabricated with two different crystal orientations, respe ...

2021

Adapting Virtual Embodiment through Reinforcement Learning

Olaf Blanke, Ronan Boulic, Bruno Herbelin, Thibault Serge Mario Porssut

In Virtual Reality, having a virtual body opens a wide range of possibilities as the participant's avatar can appear to be quite different from oneself for the sake of the targeted application (e.g. for perspective-taking). In addition, the system can part ...

2021

Theory of twin strengthening in fcc high entropy alloys

William Curtin, Recep Ekin Kubilay

Twinning in fcc High Entropy Alloys (HEAs) has been implicated as a possible mechanism for hardening that enables enhanced ductility. Here, a theory for the twinning stress is developed analogous to recent theories for yield stress. Specifically, the stres ...

2021

Complements to Mugge and Friedel's Theory of Twinning

Cyril Cayron

The crystallography of twinning is based on the concepts of simple shear and obliquity introduced by Mugge, Mallard and Friedel at the turn of the last century, with tensor mathematics later developed by Bilby, Bevis and Crocker in the 1960s. We propose a ...

2020

Measurement and prediction of the transformation strain that controls ductility and toughness in advanced steels

William Curtin, Helena Van Swygenhoven, Francesco Maresca

New-generation multi-phase martensitic steels derive their high strength from the body-centered cubic (BCC) phase and high toughness from transformation of the metastable face-centered cubic (FCC) austenite that transforms into martensite upon loading. In ...

PERGAMON-ELSEVIER SCIENCE LTD2020

An Analytical Method to Predict the Structural Behavior of Timber-Concrete Structures With Brittle-to-Ductile Shear Connector Laws

Eugen Brühwiler

Timber-Concrete Composite (TCC) structures allow taking synergistic advantage of the properties of both materials to optimize the overall performances in terms of lightness, slenderness, acoustic insulation, vibrational behaviour and environmental footprin ...

ELSEVIER SCI LTD2020

Atomic Scale Investigations into the Origins of Ductility in Mg Alloys

Rasool Ahmad

The industrial applications of Mg, the lightest structural metal, and abundant in Earth's crust, are hampered by its low intrinsic ductility and low fracture toughness at room temperature which is attributed to the underlying less symmetric and plastically ...

EPFL2020

Deformation mechanisms in a superelastic NiTi alloy: An in-situ high resolution digital image correlation study

Helena Van Swygenhoven

An in-situ high resolution digital image correlation investigation during uniaxial tensile deformation reveals the recoverable and the non-recoverable strain mechanisms in a Ni51Ti49 alloy with a mean grain size of 35 mu m. Recoverable strain is due to the ...

2020

Experimental studies of hydro-mechanical couplings in Enhanced Geothermal Reservoirs

Mateo Alejandro Acosta

Enhanced Geothermal Systems (EGS) allow for worldwide geothermal electricity production. They target deep (3-5 km), fractured rock reservoirs whose permeability is artificially increased through hydraulic stimulations (fluid injections). The injections mod ...

EPFL2020

The thermally activated distortion with amplification effect and related variant selection in red gold alloys

Roland Logé, Cyril Cayron, Margaux Nathalie Dominique Larcher

Variant selection during the A1→L10 transformation in a polycrystalline red gold alloy close to equiatomic Au-Cu composition has been extensively studied by Electron Backscatter Diffraction (EBSD) in our previous work. The use of a mathematical description ...

2020

Variant selection in martensitic steels

Annick Pauline Baur

The martensitic phase transformation in steel is one of the most famous solid state transformation because of its contribution in the development of the modern industry. This transformation from a face-centered cubic (FCC) high temperature phase, called th ...

EPFL2019

The interplay between deformation mechanisms in austenitic 304 steel during uniaxial and equibiaxial loading

Helena Van Swygenhoven, Wei-Neng Hsu

The preferred deformation mechanisms with respect to the load path are studied in a medium stacking fault energy 304 austenitic stainless steel that exhibits both transformation induced plasticity and twinning induced plasticity. In situ neutron diffractio ...

2019

Streaming From a Moving Platform with Real-Time and Playback Distortion Constraints

Laura Toni, Giuseppe Cocco

Video streaming from remotely controlled moving platforms such as drones have stringent constraints in terms of delay. In some applications such videos have to provide real-time visual feedback to the pilot with an acceptable distortion while satisfying hi ...

IEEE2019

Graph-based Transform Coding with Application to Image Compression

Pascal Frossard, Ntorina Thanou, Giulia Fracastoro

In this paper, we propose a new graph-based coding framework and illustrate its application to image compression. Our approach relies on the careful design of a graph that optimizes the overall rate-distortion performance through an effective graph-based t ...

2019

In Situ Deformation Studies of HCP Metal Alloys with Neutron Diffraction, X-Ray Diffraction, and High Resolution Digital Image Correlation

Karl Alan Sofinowski

Mg and Ti alloys are attractive materials for structural applications in the transportation and biomedical industries due to their high strength-to-weight ratios. However, due to their hexagonally close-packed (HCP) lattice structure, they exhibit poor for ...

EPFL2019

Large scale 3-dimensional atomistic simulations of screw dislocations interacting with coherent twin boundaries in Al, Cu and Ni under uniaxial and multiaxial loading conditions

Satish I Rao, Helena Van Swygenhoven

Large scale 3D atomistic simulations are performed to study the interaction between a curved dislocation with a dominant screw character and a Coherent Twin Boundary (CTB). Three FCC metals (Al, Cu and Ni) are addressed using 6 embedded-atom method (EAM) p ...

2019

Dislocation Cross-Slip in Face-Centered Cubic Solid Solution Alloys

Wolfram Georg Nöhring

The mechanical strength of metals depends on their resistance against various microscopic deformation processes. In ductile metals, the most important process is shearing of the crystal lattice by dislocations. One of the fundamental aspects of dislocation ...

EPFL2018