Publications associées à Composition and structure of Fe(III)-precipitates formed by Fe(II) oxidation in water at near-neutral pH: Interdependent effects of phosphate, silicate and Ca

Composition and Element Distribution Mapping of γ′ and γ" Phases of Inconel 718 by High-Resolution Scanning Transmission Electron Microscopy and X-ray Energy-Dispersive Spectrometry

The main strengthening mechanism for Inconel 718 (IN718), a Ni-based superalloy, is precipitation hardening by gamma ' and gamma '' particles. It is thus essential, for good alloy performance, that precipitates with the desired chemical composition have ad ...

MDPI2024

Machine learning for metallurgy IV: A neural network potential for Al-Cu-Mg and Al-Cu-Mg-Zn

William Curtin, Daniel John Gilles Marchand

Most metallurgical properties, e.g., dislocation propagation, precipitate formation, can only be fully understood atomistically but most phenomena and quantities of interest cannot be measured experimentally. Accurate simulation methods are essential but f ...

2022

Effect of alkali, aluminium and equilibration time on calcium-silicate-hydrates

Yu Yan

Calcium silicate hydrate (C-S-H) is the main hydration product in Portland and blended cements, and greatly affects durability and mechanical properties of the hydrated cement. In the presence of Al-rich supplementary cementitious materials (SCMs), C-(A-)S ...

EPFL2022

Early Precipitation Stages of Sigma Phase in Alloy 28 Studied with Scanning Electron Microscopy and Atom Probe Tomography

This study deals with early stages of sigma phase growth in a high end austenitic stainless steel - Alloy 28 (EN 1.4563/UNS N08028). Its precipitation kinetics was followed by a series of heat treatments at 800 degrees C for holding times up to 30 000 s. T ...

2021

Ruthenium on phosphorous-modified alumina as an effective and stable catalyst for catalytic transfer hydrogenation of furfural

Gaël Peng, Thibault Xavier Florian Fovanna, Oliver Kröcher, Davide Ferri

Supported ruthenium was used in the liquid phase catalytic transfer hydrogenation of furfural. To improve the stability of Ru against leaching, phosphorous was introduced on a Ru/Al2O3 based catalyst upon impregnation with ammonium hypophosphite followed b ...

2020

Cellulose phosphorylation comparison and analysis of phosphorate position on cellulose fibers

David Lyndon Emsley, Jayasubba Reddy Yarava, Michel Bardet, Julien Bras

Chemical modifications of cellulose fibers as pretreatment for cellulose nanofibrils (CNF) production have been investigated to improve the production process and the quality of obtained cellulosic nanomaterial. In this study, phosphorylation of cellulose ...

ELSEVIER SCI LTD2020

The effect of sodium hydroxide on Al uptake by calcium silicate hydrates (C S H)

Christian Ludwig, Barbara Lothenbach, Sonya Barzgar, Alessio Di Giacomo, Mohamed Tarik

To reduce the CO2 emissions from cement production, Portland cement (PC) is partially replaced by supplementary cementitious materials (SCM). Reactions of SCM with PC during hydration leads to the formation of CSH with more silicon and aluminum than in PC, ...

2020

Early Stages of Precipitation In Aluminum Alloys by First-Principles and Machine-Learning Atomistic Simulations

Daniele Giofré

Age hardening induced by the formation of (semi)-coherent precipitate phases is crucial for the processing and final properties of the widely used Al-6000 alloys despite the early stages of precipitation are still far from being fully understood. This cruc ...

EPFL2018

Strain-induced dissolution of Y-Ti-O nano-oxides in a consolidated ferritic oxide dispersion strengthened (ODS) steel

Mathijs Pieter van der Meer, Roland Logé

The present study shows the influence of severe plastic deformation on highly stable Y-Ti-O nano-oxides present in ferritic ODS alloys used for nuclear applications. An innovative strain path implying alternated compressions was used to deform the material ...

2018

Structure of precipitates and orientation relationships in Al, Ge, Mo-doped higher manganese silicide crystals

Philippe Buffat, Marco Cantoni, Elena Suvorova Buffat

The structure of Al, Ge, Mo-doped Higher Manganese Silicide (HMS) crystals with the general formulas Mn(Si0.99Ge0.01)(1.75), Mn(Si0.995Ge0.005)(1.75) and (Mn0.98Mo0.02)(Si0.98Ge0.02)(1.75)Al-0.01 was investigated by scanning and transmission electr ...

Taylor & Francis Ltd2017

Structural, tribo-mechanical, and thermal properties of NbAlN coatings with various Al contents deposited by DC reactive magnetron sputtering

Silviu Cosmin Sandu

DC reactive magnetron sputtered Nb2AlyNx coatings with various Al contents (y/(y + z)) ranging from 0 to 0.75 were deposited using different ratios of the currents applied to the Al and Nb targets in order to systematically control their chemical compositi ...

Elsevier Science Sa2017

Microalloying for the controllable delay of precipitate formation in metal alloys

William Curtin, Michael Frederick Francis

A model is presented to predict the effectiveness of dilute solutes in delaying precipitate formation, with application to natural and artificial aging in metal alloys. Control of aging is achieved via the binding, at natural aging temperatures, and releas ...

Elsevier2016

Imaging and characterization of gamma ' and gamma '' nanoparticles in Inconel 718 by EDX elemental mapping and FIB-SEM tomography

Philippe Buffat

Microstructural characterization of Inconel 718 superalloy after three different heat treatment variants was performed by electron microscopy and electron tomography techniques, taking advantage of recent development in quantitative electron microscopy. Di ...

Elsevier Science Inc2015

Effect of treatment on the microstructural characteristics of bio-improved sand

Lyesse Laloui, Dimitrios Terzis

Bio-chemical processes have recently become the core of several studies in the geoengineering field, where the emphasis is placed on new and emerging applications. Microbially Induced Calcite Precipitation has been introduced as an alternative cementation ...

IOS Press, 20152015

Aluminium and alkali uptake in calcium silicate hydrates (C-S-H)

Émilie Michèle L'Hôpital

Calcium silicate hydrate (C-S-H) is the main hydrate phase in Portland cements. Its composition varies depending on the Ca/Si ratio and on the presence of other ions such as aluminium (called CA- S-H) or alkalis. This thesis aimed to study the compositi ...

EPFL2014

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

Modelling Hydration Kinetics of Cementitous Systems

Aditya Kumar

The modeling platform µic has been extended to study the hydration of cement based systems. It is shown that the hydration kinetics of alite can be described through the implementation of two mechanisms: a solution controlled dissolution (SCD) mechanism fo ...

EPFL2012

Structure and thermal stability of arc evaporated (Ti0.33Al0.67)(1-x)SixN thin films

(Ti0.33Al0.67)(1-x)SixN (0

2008

Analysis of nano-sized irradiation-induced defects in Fe-base materials by means of small angle neutron scattering and molecular dynamics simulations

Gang Yu

Thermonuclear fusion of light atoms is considered since decades as an unlimited, safe and reliable source of energy that could eventually replace classical sources based on fossile fuel or nuclear fuel. Fusion reactor technology and materials studies are i ...

EPFL2008

On the relationship between the microstructure and the mechanical properties of an ODS ferritic/martensitic steel

Amuthan Ramar

In the quest of materials for the first wall of the future fusion reactor, it has been shown that oxide dispersion strengthened (ODS) ferritic / martensitic (F/M) steels appear to be promising candidates. The inherent good mechanical properties supported b ...

EPFL2008