Publications related to Hydrogen embrittlement

Using video detection of snow surface movements to estimate weak layer crack propagation speeds

Johan Alexandre Philippe Gaume, Bertil Trottet, Alec van Herwijnen

Dry-snow slab avalanches release due to crack propagation in a weak snow layer under a cohesive snow slab. Crack propagation speeds can provide insights into the potential size of avalanches and inform fracture and avalanche release models. Despite their i ...

CAMBRIDGE UNIV PRESS2023

Natural aging and vacancy trapping in Al-6xxx

William Curtin, Michele Ceriotti

Undesirable natural aging (NA) in Al-6xxx delays subsequent artificial aging (AA) but the size, composition, and evolution of clustering are challenging to measure. Here, atomistic details of early-stage clustering in Al-1% Mg-0.6%Si during NA are studied ...

Springer Heidelberg2023

Delayed Hydride Cracking in Irradiated and Unirradiated Zircaloy-2 Cladding

Aaron William Colldeweih

Zirconium alloys used in the nuclear industry are exposed to extreme conditions undergoing high levels of irradiation damage and corrosion. Zircaloy-2 is used as nuclear fuel cladding in boiling water reactors and for the encapsulation of the spallation ta ...

EPFL2022

Experimental investigation of dowel action using advanced measurement techniques

Aurelio Muttoni, Marko Pejatovic

Existing shear-cracked structures need to be reliably verified in order to avoid redundant interventions. Code provisions often raise shear safety and/or fatigue life concerns of the reinforcement subjected to stress concentrations due to cyclic dowel acti ...

2022

Crack propagation speeds in weak snowpack layers

Johan Alexandre Philippe Gaume, Jürg Schweizer, Bertil Trottet, Grégoire Bobillier, Alec van Herwijnen

For the release of a slab avalanche, crack propagation within a weak snowpack layer below a cohesive snow slab is required. As crack speed measurements can give insight into underlying processes, we analysed three crack propagation events that occurred in ...

CAMBRIDGE UNIV PRESS2021

Laser powder-bed fusion of metallic alloys with enhanced microstructures and properties

Navid Sohrabi

Laser powder-bed fusion (LPBF) is an additive manufacturing (AM) process that uses a laser to selectively melt a powder bed. This process can build dense samples with complicated geometries from a wide variety of metallic alloys. In this thesis, LPBF of al ...

EPFL2021

Micro-mechanical insights into the dynamics of crack propagation in snow fracture experiments

Johan Alexandre Philippe Gaume, Jürg Schweizer, Grégoire Bobillier, Alec van Herwijnen

Dry-snow slab avalanches result from crack propagation in a highly porous weak layer buried within a stratified and metastable snowpack. While our understanding of slab avalanche mechanisms improved with recent experimental and numerical advances, fundamen ...

NATURE RESEARCH2021

APT/TEM characterization of the element segregation in ferritic/martensitic steels after irradiation in SINQ

Lijuan Cui

Ferritic /martensitic (FM) steels are among the most important materials in various nuclear applications. As radiation-induced segregation (RIS) is one of the major factors for embrittlement of nuclear materials, thereofre it is essential to study the RIS ...

EPFL2021

A decohesion pathway for hydrogen embrittlement in nickel: Mechanism and quantitative prediction

William Curtin, Xiaoqing Zhou, Ali Tehranchi

Hydrogen embrittlement (HE) is a ubiquitous and catastrophic mode of fracture in metals. Here, embrittlement is considered as an intrinsic ductile-brittle transition at the crack tip, where H at the crack tip can reduce the stress intensity K-Ic for cleava ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Combining alloy and process modification for micro-crack mitigation in an additively manufactured Ni-base superalloy

Roland Logé, Christian Leinenbach, Jamasp Jhabvala, Xavier Maeder, Hossein Ghasemi Tabasi, Toni Ivas, Rafal Wróbel

The additive manufacturing (AM) of the gamma' precipitation strengthened Ni-base superalloys still remains a challenge due to their susceptibility to micro-cracking. Post-processing, such as HIPing, has been shown to heal the micro-cracks but it remains de ...

ELSEVIER2020

How Fast Cracks in Brittle Solids Choose Their Path

John Martin Kolinski

While we fundamentally understand the dynamics of simple cracks propagating in brittle solids within perfect (homogeneous) materials, we do not understand how paths of moving cracks are determined. We experimentally study strongly perturbed cracks that pro ...

2020

Fiber-Tip Polymer Microcantilever for Fast and Highly Sensitive Hydrogen Measurement

Giovanni Dietler, Sandor Kasas, Jiangtao Zhou, Leonardo Venturelli, Yiping Wang, Chaohui Li, Meng Zhu, Cong Xiong

Hydrogen as an antioxidant gas has been widely used in the medical and biological fields for preventing cancer or treating inflammation. However, controlling the hydrogen concentration is crucial for practical use due to its explosive property when its vol ...

AMER CHEMICAL SOC2020

Analysis of hydrogen distribution and migration in fired passivating contacts (FPC)

Christophe Ballif, Franz-Josef Haug, Aïcha Hessler-Wyser, Quentin Thomas Jeangros, Andrea Ingenito, Matthieu Despeisse, Philippe Wyss, Mario Joe Lehmann

High temperature passivating contacts for c-Si based solar cells are intensively studied because of their potential in boosting solar cell efficiency while being compatible with industrial processes at high temperatures. In this work, the hydrogenation mec ...

2019

Local Study on Hydrogen and Hydrogen Gas Bubble Formation on a Platinum Electrode

Hubert Girault, Andreas Stephan Lesch, Alberto Battistel, Christopher Raymond Dennison

This work investigates the effect of current density on the hydrogen gas bubble formation during electrolysis on a platinum electrode. Local detection of bubble evolution was performed electrochemically by using a hydrogen-collecting microelectrode placed ...

AMER CHEMICAL SOC2019

The role of atomistic simulations in probing hydrogen effects on plasticity and embrittlement in metals

William Curtin, Ali Tehranchi

Atomistic simulations are a powerful complement to experimental probes for understanding the nanoscale processes associated with the effects of hydrogen (H) on plasticity and fracture that are the underlying causes of hydrogen embrittlement (HE). Current e ...

PERGAMON-ELSEVIER SCIENCE LTD2019

High-Temperature Water Effects on the Fracture Behaviour of Low-Alloy Reactor Pressure Vessel Steels

Zaiqing Que

The structural integrity of the reactor pressure vessel (RPV) of light water reactors (LWR) is of utmost importance regarding operation safety and lifetime. High-temperature water (HTW) and hydrogen absorbed from environment, in synergy with irradiation em ...

EPFL2019

An Unconventional Iron Nickel Catalyst for the Oxygen Evolution Reaction

Xile Hu, Michaël Bensimon, Anne-Clémence Corminboeuf, Fang Song, Michael Markus Busch, Elitsa Petkucheva

The oxygen evolution reaction (OER) is a key process that enables the storage of renewable energies in the form of chemical fuels. Here, we describe a catalyst that exhibits turnover frequencies higher than state-of-the-art catalysts that operate in alkali ...

2019

A Sustainable Approach to Produce Stiff, Super-Tough, and Heat-Resistant Poly(lactic acid)-Based Green Materials

Nicolas Candau, Oguzhan Oguz, Mehmet Kerem Citak, Fatma Nalan Cetin

Circumventing inherent embrittlement, poor heat resistance, and melt elasticity of poly(lactic acid) (PLA) without compromising its remarkable stiffness and strength has become a particular challenge in polymer science due to increasing demand for green ma ...

AMER CHEMICAL SOC2019

Influence of ply-angle on fracture in antisymmetric interfaces of CFRP laminates

John Botsis, Georgios Pappas, Charlie Joseph Simon Blondeau

Laminated composites are prone to fracture at layer interfaces. Such damage impairs their structural response and engenders important constraints in design. In this work, the influence of ply orientation on crack growth resistance was studied for three dif ...

ELSEVIER SCI LTD2019

Ductility reduction factor formulations for seismic design of RC wall and frame structures

Katrin Beyer, Matteo Zerbin

Seismic design of standard structures is typically founded on a force-based design approach. Over the years this approach has proven robust and easily applicable by design engineers and - in combination with capacity design principles - it provides a good ...

2019