Publications associées à A one-step mechanism for new twinning modes in magnesium and titanium alloys modelled by the obliquity correction of a (58 degrees, a+2b) prototype stretch twin

Publications associées (18)

EBSD study of variant reorientation, texture, and twin formation in a martensitic NiTi alloy deformed in compression

Junfeng Xiao, Roland Logé, Cyril Cayron, Mathijs Pieter van der Meer

Martensitic crystallography plays a vital role in the texture evolution and mechanical properties in Nickel-Titanium (NiTi) shape memory alloys when subjected to deformation. However, their microstructural changes during deformation are not well known and ...

Pergamon-Elsevier Science Ltd2023

The effect of stress triaxiality on the phase transformation in transformation induced plasticity steels: Experimental investigation and modelling the transformation kinetics

Helena Van Swygenhoven, Nicola Casati

In situ multiaxial loading during neutron diffraction tests were undertaken on a low-alloyed Quenched and Partitioning (Q&P) Transformation Induced Plasticity (TRIP) Bainitic Ferrite (TBF) steel with dispersed austenite particles. The effect of stress tria ...

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

Computational Modeling of the Oxygen Evolution Reaction at Semiconductor-Water Interfaces: A Path Towards Breaking Linear Scaling Relationships

Patrick Gono

Photoelectrochemical water splitting is a promising source of clean, renewable fuel in the form of hydrogen. Despite extensive research endeavors, the widespread adoption of this technology is impeded due to suboptimal catalysts for the oxygen evolution re ...

EPFL2020

Atomistic modeling of fracture

William Curtin, Predrag Andric

Atomistic modeling of fracture is intended to illuminate the complex response of atoms in the very high stressed region just ahead of a sharp crack. Accurate modeling of the atomic scale fracture is crucial for describing the intrinsic nature of a material ...

2019

Description of the capacity degradation mechanism in LaNi5-based alloy electrodes

Andreas Züttel, Philippe Mauron, Mariana Spodaryk, Marco Roman Holzer

The mechanism of the capacity degradation of LaNi5-based alloy electrodes was investigated with a special focus on the influence of the alloy and surface composition, as well as the unique structure obtained by gas atomisation. The electrochemical properti ...

Elsevier Science Sa2015

First-principles core structures of < c+a > edge and screw dislocations in Mg

William Curtin

The core structures of < c + a > edge and screw dislocations in Mg are computed using density functional theory (DFT). Both types dissociate into two 1/2 < c + a > partials on the second-order pyramidal planes. These DFT results are then allowed to relax w ...

Elsevier2014

A New Mechanism for Twin Growth in Mg Alloys

William Curtin, Aitor Luque Gomez

Twinning is an important deformation mode in lightweight Mg alloys, but the mechanisms of nucleation and growth of twins and their interactions with solutes remain largely unresolved. Here, a new model for thermally-activated, stress-driven growth of twin ...

Elsevier2014

Morphology and Growth Kinetic Advantage of Quenched Twinned Dendrites in Al-Zn Alloys

Michel Rappaz

Twinned dendrites appearing in an Al-26 wt pct Zn alloy have been quenched during growth using a specifically designed setup that is positioned on top of a directional solidification experiment. X-ray tomography performed at the Swiss Light Source (SLS-bea ...

Springer Verlag2013

Deformation modes in magnesium (0001) and (0 1 -1 1) single crystals: simulations versus experiments

William Curtin, Aitor Luque Gomez

Magnesium is an excellent candidate as lightweight structural material, but has strong plastic anisotropy, and the activation of, operation of, and competition between different slip and twinning systems remain active areas of research. Here, the nucleatio ...

Institute of Physics2013

Microstructure and precipitates in annealed Co38Ni33Al29 ferromagnetic shape memory alloy

Barbora Bártová

Transmission electron microscopy was performed to investigate the microstructure and precipitates in the annealed Co38Ni33Al29 ferromagnetic shape memory alloy. Apart from the dendritic secondary phase in the austenite matrix, micron-sized (up to 100 μm) f ...

Elsevier Science Sa2013

Two-step transition in a magnetoelectric ferrimagnet Cu2OSeO3

Helmuth Berger, Ivica Zivkovic

We report a detailed single-crystal investigation of a magnetoelectric ferrimagnet Cu2OSeO3 using dc magnetization and ac susceptibility along the three principal directions [100], [110], and [111]. We have observed that in small magnetic fields two magnet ...

2012

Processing and Mechanical Properties of Alumina Reinforced Copper-Aluminum Composites

Carmen Krüger

Copper-based composites reinforced with alumina particles are produced by two different pro- cesses, namely gas pressure driven infiltration of a porous alumina preform and a two-step in-situ process developed in the course of this work. The resulting comp ...

EPFL2012

Optimization of the chemical composition and manufacturing route for ODS RAF steels for fusion reactor application

Nadine Baluc

As the upper temperature for use of reduced activation ferritic/martensitic steels is presently limited by a drop in mechanical strength at about 550 degrees C, Europe, Japan and the US are actively researching steels with high strength at higher operating ...

IOP Publishing Ltd2009

Characterization and modeling of twinned dendrite growth

The formation of feathery grains during semi-continuous casting of Al-alloys [1, 2] is an interesting problem from both practical and theoretical points of view. These structures are formed by a lamellar sequence of twinned and untwinned regions separated ...

EPFL2009

Unraveling the Catalytic Pathway of Metalloenzyme Farnesyltransferase through QM/MM Computation

Matteo Dal Peraro

The protein farnesyltransferase (FTase) is a Zn2+-metalloenzyme that catalyzes the farnesylation reaction, i.e., the transfer of the 15-carbon atom farnesyl group from farnesyl diphosphate (FPP) to a specific cysteine of protein substrates. Oncogenic Ras p ...

2009

HREM studies of twins in Cd1−xZnxTe (x ≈ 0.04) thin films grown by molecular beam epitaxy

Nava Setter, Igor Stolichnov, Marco Cantoni

The microstructure of ferroelectric Cd1−xZnxTe (CZT) thin films with x ≈ 0.04 grown by molecular beam epitaxy has been studied by means of cross sectional high-resolution transmission electron microscopy (HREM). High- density {1 1 1} lamellar twins are fou ...

2009

Study of twinned dendrite growth stability

Michel Rappaz, Jonas Valloton

Under certain thermal conditions (G approximate to 1 x 10(4) K/m, v(s) approximate to 1 x 10(-3) m/s), < 1 1 0 > twinned dendrites appear in aluminum alloys and can overgrow regular columnar dendrites, provided that some convection is also present in the m ...

Elsevier2009