Publications associées à Investigation of microstructure and mechanical properties of W-Y and W-Y2O3 materials fabricated by powder metallurgy method

Design for demise applied to spacecraft structural panels and experiments for ClearSpace One platform

With growing awareness of the vulnerability of the near-Earth space region and the anticipated surge in satellite objects, efforts are underway to assess and implement various mitigation strategies. These aim to minimize the impact of space activities and ...

EPFL2024

Liquid metal infiltration of silicon based alloys into porous carbonaceous materials Part-III: Experimental verification of conversion products and infiltration depth by infiltration of Si-Zr alloy into mixed SiC/ graphite preforms

Ludger Weber, Alberto Ortona, Manoj Kondibhau Naikade, Caroline Hain, Annapaola Parrilli

Porous carbonaceous preforms, made from graphite and silicon carbide (SiC) powders, with varying graphite powder mass fractions and particle sizes, were infiltrated at 1500 degrees C and 1700 degrees C by Si-8 at. pct Zr alloy to produce dense Si-Zr-SiC co ...

ELSEVIER SCI LTD2023

Micromechanics of oxide inclusions in ferrous alloys

Alejandra Inés Slagter

Oxide inclusions are inevitably present in steel as a direct consequence of the steelmaking process; as a result, a cubic centimetre of modern steel will generally contain about a million of these hard and brittle micrometre-sized ceramic particles. Inclus ...

EPFL2023

Neural Network Potentials for Age Hardening Aluminum Alloys

Daniel John Gilles Marchand

High-strength metal alloys achieve their performance via careful control of precipitates and solutes. The nucleation, growth, and kinetics of precipitation, and the resulting mechanical properties, are inherently atomic scale phenomena, particularly during ...

EPFL2022

Liquid metal infiltration of silicon based alloys into porous carbonaceous materials. Part II: Experimental verification of modelling approaches by infiltration of Si-Zr alloy into idealized microchannels

Ludger Weber, Giovanni Bianchi, Alberto Ortona, Manoj Kondibhau Naikade, Caroline Hain

In this work, the mechanisms leading to the pore closure in reactive melt infiltration (RMI) of carbon by pure silicon and a near eutectic Si-8 at-pct Zr alloy at 1500 and 1700 degrees C under vacuum were studied. Various geometrical configurations of micr ...

ELSEVIER SCI LTD2022

Effect of chromium content on microstructural evolution of CoNiAlW superalloy

Cyril Cayron

Effects of chromium (Cr) content on types and morphologies of various phases of a newly developed Co-Ni-Al-W superalloy (Co-30Ni-6W-9Al-3Ti-1Ta) have been investigated in this study. Microstructural examinations were carried out by field-emission scanning ...

SPRINGER HEIDELBERG2022

Micro-addition of Fe in highly alloyed Cu-Ti alloys to improve both formability and strength

Cyril Cayron, Roland Logé, Baptiste Thomas Jean Rouxel

Cu-Be alloys provide excellent electrical and mechanical properties, but present serious health hazards during manufacturing. Among alternative alloys, the Cu-Ti system has the highest yield strength; however, Ti cannot be easily solutionized at concentrat ...

ELSEVIER SCI LTD2022

Modeling of precipitate strengthening with near-chemical accuracy: case study of Al-6xxx alloys

William Curtin, Yi Hu

Many metal alloys are strengthened by controlling precipitation to achieve an optimal peak-aged condi-tion where the strength-limiting processes of precipitate shearing and Orowan looping are thought to be comparable. Qualitative models have long captured ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Surface energy contributions to the work of infiltration in metal matrix composite processing

Andreas Mortensen, Gionata Schneider

The work needed to mechanically drive molten metal into a porous solid preform when producing a composite material by infiltration can significantly exceed the energy change required for thermodynamically reversible infiltration. We measure, by quantitativ ...

2021

Coupled segregation mechanisms of Sc, Zr and Mn at theta ' interfaces enhances the strength and thermal stability of Al-Cu alloys

Baptiste Thomas Jean Rouxel, Lu Jiang

The refinement and thermal stability of intermediate theta-prime (theta') precipitates are critical in the development of new high strength 2xxx series aluminium-copper (Al-Cu) alloys for high temperature applications. In this work, we use trace additions ...

PERGAMON-ELSEVIER SCIENCE LTD2021

A ductility criterion for bcc high entropy alloys

William Curtin, Binglun Yin, Eleanor Yi Kei Mak

A current goal driving alloy development is the identification of alloy compositions for high temperature applications but with the additional requirement of sufficient ductility at ambient temperatures. Multicomponent, single-phase, polycrystalline High E ...

PERGAMON-ELSEVIER SCIENCE LTD2021

Characterization of untransformed ferrite in 10Cr and 12Cr ODS steels

Roland Logé

Two new ferrito-martensitic oxide dispersion strengthened (ODS) steels reinforced with (Y, Ti, O) nanoparticles were elaborated using a high-energy attritor. The milled powder was consolidated by hot extrusion at 1050 degrees C. The two types of ODS steels ...

ELSEVIER SCI LTD2021

Microstructural Evolution Study of Fe-Mn-Al-C Steels Through Variable Thermomechanical Treatments

Roland Logé, Oscar Zambrano Zambrano

The microstructural evolution of the two austenitic alloys Fe-20Mn-3Al-0.7C wt pct and Fe-20Mn-6Al-0.7C wt pct when different thermal and thermomechanical treatments are performed has been studied. To this end, a generic industrial die of 100 ton capacity ...

SPRINGER2021

Giant hardening response in AlMgZn(Cu) alloys

William Curtin, Daniel John Gilles Marchand

This study presents a thermomechanical processing concept which is capable of exploiting the full industrial application potential of recently introduced AlMgZn(Cu) alloys. The beneficial linkage of alloy design and processing allows not only to satisfy th ...

PERGAMON-ELSEVIER SCIENCE LTD2021

High energy barriers for edge dislocation motion in body-centered cubic high entropy alloys

William Curtin, Francesco Maresca, Alireza Ghafarollahi, Recep Ekin Kubilay

Recent theory proposes that edge dislocations in random body-centered cubic (BCC) high entropy alloys have high barriers for motion, conveying high strengths up to high temperatures. Here, the energy barriers for edge motion are computed for two model allo ...

NATURE RESEARCH2021

Phase Studies of Additively Manufactured Near Beta Titanium Alloy-Ti55511

Helena Van Swygenhoven, Nicola Casati

The effect of electron-beam melting (EBM) and selective laser melting (SLM) processes on the chemical composition, phase composition, density, microstructure, and microhardness of as-built Ti55511 blocks were evaluated and compared. The work also aimed to ...

2020

Effect of dislocations, Al-3(Sc,Zr) distribution and ageing temperature on theta ' precipitation in Al-Cu-(Sc)-(Zr) alloys

Baptiste Thomas Jean Rouxel

The 2xxx series aluminium alloys, which contain Cu as the main addition element, are widely used in the aerospace industry for their high specific strength. The main strengthening contribution in these alloys comes from the formation of theta' precipitates ...

ELSEVIER SCI LTD2020

Machine learning for metallurgy I. A neural-network potential for Al-Cu

Albert Johann Glensk, William Curtin, Daniel John Gilles Marchand, Abhinav Jain

High-strength metal alloys achieve their performance via careful control of precipitates and solutes. The nucleation, growth, and kinetics of precipitation, and the resulting mechanical properties, are inherently atomic scale phenomena, particularly during ...

2020

Operando X-ray diffraction during laser 3D printing: from machine design to experiments and computer simulations

Samy Hocine

The importance of additive manufacturing, also known as 3D printing, has grown exponentially in the recent years thanks to its high flexibility to manufacture intricate parts. This process can be divided into many different sub-categories, depending on the ...

EPFL2020

Effect of Ag Addition on the Hot Deformation, Constitutive Equations and Processing Maps of a Hot Extruded Mg-Gd-Y Alloy

Roland Logé

Hot deformation behavior of the extruded Mg-6Gd-3Y (GW63) and Mg-6Gd-3Y-1Ag (GW63-1Ag) alloys was assessed by shear punch testing (SPT) method in the temperature range of 623 K to 723 K and shear strain rate of 1.6 x 10(-2)to 1.3 x 10(-1) s(-1). Microstruc ...

SPRINGER2020