Publications associées à Pseudoelasticity

On the slip burst amplitude cutoff in dislocation-rich microcrystals

The plastic deformation of small-scale face-centered cubic metals exhibits intermittent slip burst events that appear on stress-strain curves as sudden strain jumps and/or load drops. These events are generally attributed to the avalanche-like cooperative ...

Pergamon-Elsevier Science Ltd2023

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

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

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

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

Structural Phase Transition and Bandgap Control through Mechanical Deformation in Layered Semiconductors 1T-ZrX2 (X = S, Se)

Oleg Yazyev, Helmuth Berger, Ana Akrap, Michele Pizzochero, Edoardo Martino, Kristians Cernevics, Konstantin Semeniuk

Applying elastic deformation can tune a material's physical properties locally and reversibly. Spatially modulated lattice deformation can create a bandgap gradient, favoring photogenerated charge separation and collection in optoelectronic devices. These ...

AMER CHEMICAL SOC2020

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

Helena Van Swygenhoven, Efthymios Polatidis

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

Deformation-induced martensitic transformation under multiaxial loading

Wei-Neng Hsu

The deformation-induced martensitic transformation observed in specific materials can enhance their mechanical properties or result in functional properties. For example, the transformation induced plasticity (TRIP) effect results in a good combination of ...

EPFL2019

A High Resolution Digital Image Correlation Study under Multiaxial Loading

Helena Van Swygenhoven, Efthymios Polatidis, Wei-Neng Hsu

In this study, a miniaturized cruciform-shaped sample geometry which allows reaching high plastic strain under equibiaxial loading with reduced thickness at the test section is presented. The thinning method results in excellent surface quality that can be ...

SPRINGER2019

Soft microfabricated neural implants: a path towards translational implementation

Nicolas Vachicouras

Neuroprosthetics are a class of medical devices that aim to restore lost or impaired functions of the nervous system by electrical stimulation or recording of neural tissue. State of the art neural implants suffer today from a mechanical mismatch compared ...

EPFL2019

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

Helena Van Swygenhoven, Efthymios Polatidis, 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

A crystallographic extension to the Olson-Cohen model for predicting strain path dependence of martensitic transformation

Helena Van Swygenhoven, Efthymios Polatidis

A modification to the empirical Olson-Cohen strain-induced austenite to martensite transformation kinetic model is proposed. The proposed kinetic model accounts for the stress state at the grain level and the crystallography of the transformation mechanism ...

PERGAMON-ELSEVIER SCIENCE LTD2019

Hybrid laser 3D microprocessing in glass/polymer micromechanical sensor: towards chemical sensing applications

Yves Bellouard

We demonstrate the fabrication of a 3D polymer/glass micromechanical sensor by combining two femtosecond laser direct writing processes: subtractive laser-assisted chemical etching combined with additive two-photon polymerization techniques. In the first s ...

SPIE-INT SOC OPTICAL ENGINEERING2018

Elastic strain engineering for ultralow mechanical dissipation

Tobias Kippenberg, Dalziel Joseph Wilson, Nils Johan Engelsen, Sergey Fedorov, Ryan Daniel Schilling, Amir Hossein Ghadimi

Extreme stresses can be produced in nanoscale structures, a feature which has been used to realize enhanced materials properties, such as the high mobility of silicon in modern transistors. Here we show how nanoscale stress can be used to realize exception ...

IEEE2018

Elastic strain engineering for ultralow mechanical dissipation

Tobias Kippenberg, Dalziel Joseph Wilson, Nils Johan Engelsen, Sergey Fedorov, Ryan Daniel Schilling, Amir Hossein Ghadimi

Extreme stresses can be produced in nanoscale structures, a feature which has been used to realize enhanced materials properties, such as the high mobility of silicon in modern transistors. Here we show how nanoscale stress can be used to realize exception ...

American Association for the Advancement of Science2018

Variant Selection in Fe-20Ni-1.8C under Bending

Roland Logé, Cyril Cayron, Annick Pauline Baur

Variant selection is commonly observed in martensitic steels when a stress is applied to the material during transformation. Classically, the selection phenomenon is modelled considering the work of the shape strain in the applied stress field. This shape ...

2018

Engineering reversible elasticity in ductile and brittle thin films supported by a plastic foil

Stéphanie Lacour, Nicolas Vachicouras, Christina Myra Tringides

Reversible deformation is a unique property of elastic materials. Here, we design and fabricate highly stretchable multilayered films by patterning Y-shaped motifs through films of non- elastic materials, e.g. plastics, metals, ceramics. By adjusting the g ...

Elsevier Science Bv2017

Characterization of the deformation and phase transformation behavior of VC-free and VC-containing FeMnSi-based shape memory alloys by in situ neutron diffraction

Helena Van Swygenhoven, Steven Van Petegem, Christian Leinenbach

The stress-induced fcc-austenite to hcp-martensite transformation in the iron based shape memory alloy (SMA) Fe-17Mn-5Si-10Cr-4Ni with and without VC precipitates is investigated by in-situ neutron diffraction measurements upon uniaxial loading and unloadi ...

Elsevier Science Sa2017

Effect of recrystallization on hot deformation mechanism of TA15 titanium alloy under uniaxial tension and biaxial gas bulging conditions

Ke Huang, Gang Liu

To investigate the effect of recrystallization on hot deformation mechanism of TA15 titanium alloy, rolled sheet and laser-welded tubes before and after recrystallization annealing were tested by uniaxial tensile tests and biaxial gas bulging respectively. ...

Elsevier2017

Study of lattice strain evolution during biaxial deformation of stainless steel using a finite element and fast Fourier transform based multi-scale approach

Helena Van Swygenhoven, Steven Van Petegem

A multi-scale elastic-plastic finite element and fast Fourier transform based approach is proposed to study lattice strain evolution during uniaxial and biaxial loading of stainless steel cruciform shaped samples. At the macroscale, finite element simulati ...

Pergamon-Elsevier Science Ltd2016

Molecular dynamics at constant Cauchy stress

Fabio Pavia, Ronald Earle Miller

The Parrinello-Rahman algorithm for imposing a general state of stress in periodic molecular dynamics simulations is widely used in the literature and has been implemented in many readily available molecular dynamics codes. However, what is often overlooke ...

American Institute of Physics2016

Investigation of the relationships between mechanical properties and microstructure in a Fe-9%Cr ODS steel

Roland Logé

Ferritic-martensitic Oxide Dispersion Strengthened (ODS) steels are potential materials for fuel pin cladding in Sodium Fast Reactor (SFR) and their optimisation is essential for future industrial applications. In this paper, a feasibility study concerning ...

Edp Sciences S A2016