Recherche

Afficher tous les résultats pour

Accueil

Personne

Roland Logé

Cette personne a quitté l’EPFL

À propos
Confidentialité
Mentions légales

Graph Chatbot

Publications associées (129)

Page 3 sur 7

Numerical Modeling of Tube Forming by HPTR Cold Pilgering Process

Roland Logé

For new fast-neutron sodium-cooled Generation IV nuclear reactors, the candidate cladding materials for the very strong burn-up are ferritic and martensitic oxide dispersion strengthened grades. Classically, the cladding tube is cold formed by a sequence o ...

Springer Verlag2016

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

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

Quantitative prediction of crystallization in laser powder bed fusion of a Zr-based bulk metallic glass with high oxygen content

Roland Logé, Jamasp Jhabvala, Navid Sohrabi, Hossein Ghasemi Tabasi, Toni Ivas

One of the main challenges in the fabrication of bulk metallic glasses (BMGs) via laser-based additive manufacturing (AM) is undesirable crystal phase formation, which usually deteriorates the mechanical properties of the BMG fabricated parts. Understandin ...

Elsevier Sci Ltd2024

Hot deformation of a Fe-Mn-Al-C steel susceptible of κ-carbide precipitation

Roland Logé

The mechanical properties of Fe-Mn-Al-C steel are significantly enhanced after κ-carbide precipitation via aging; however, most aging treatments are energy demanding because they require relatively high temperatures and extended holding times. This researc ...

Elsevier Science Sa2017

Nondestructive characterization of laser powder bed fusion parts with neutron Bragg edge imaging

Roland Logé, Christian Leinenbach, Nikola Kalentics

Laser powder bed fusion is an efficient technique for additive manufacturing of metallic materials. The quality of the material produced depends on the optimization of a large range of build parameters and the complex thermo-mechanical build process is pro ...

ELSEVIER2021

Probabilistic and deterministic full field approaches to simulate recrystallization in ODS steels

Roland Logé

Mechanical and functional properties of Oxide Dispersion Strengthened (ODS) ferritic/martensitic steels are strongly related to their microstructures. Thus, numerical modeling of microstructure evolution during ODS forming is of prime importance. In this w ...

ELSEVIER2020

Monitoring of laser-induced fast recrystallization in SS-316L through synchrotron X-ray diffraction

Roland Logé, Cyril Cayron, Milad Hamidi Nasab, Reza Esmaeilzadeh, Claire Navarre, Charlotte Léopoldine de Formanoir de la Cazerie, Lucas Maximilian Schlenger

Laser based heat treatments have multiple applications for local tuning of microstructures. They are particularly relevant in the context of laser-based additive manufacturing (LAM), in order to relieve residual stresses or introduce equiaxed structures th ...

Elsevier Sci Ltd2024

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

Roland Logé, Cyril Cayron, 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

Solute-dislocation interactions and creep-enhanced Cu precipitation in a novel ferritic-martensitic steel

Roland Logé, Cyril Cayron

G115 steel has gained a growing interesting recently for its use in next-generation ultra-supercritical power plant applications. Due to the high densities of dislocations and lath martensite boundaries in G115 steel, interactions between solutes and dislo ...

PERGAMON-ELSEVIER SCIENCE LTD2020

In-situ fabrication of Ti-TiCx metal matrix composite by laser powder bed fusion with enhanced elastic modulus and superior ductility

Roland Logé

The production of high stiffness Ti-based Metal Matrix Composites (Ti-MMCs) displaying significant ductility is extremely challenging due to the high reinforcement content required. This study outlines the production process of stiffness-driven Ti-TiC MMCs ...

2024

The relationship between low-temperature toughness and secondary crack in low-carbon bainitic weld metals

Roland Logé, Cyril Cayron

This paper aims to reveal the relationship among low-temperature toughness, microstructure and secondary crack from both microstructural and crystallographic perspectives. Instrumented Charpy tests were carried out in the upper platform, transition tempera ...

2018

Harmonizing sound and light: X-ray imaging unveils acoustic signatures of stochastic inter-regime instabilities during laser melting

Roland Logé, Milad Hamidi Nasab, Reza Esmaeilzadeh, Charlotte Léopoldine de Formanoir de la Cazerie, Lucas Maximilian Schlenger, Florian Aymanns

Laser powder bed fusion (LPBF) is a metal additive manufacturing technique involving complex interplays between vapor, liquid, and solid phases. Despite LPBF's advantageous capabilities compared to conventional manufacturing methods, the underlying physica ...

Nature Portfolio2023

{10(1)over-bar2} twinning mechanism during in situ micro-tensile loading of pure Mg: Role of basal slip and twin-twin interactions

Roland Logé, Johann Michler, Xavier Maeder, Daniele Casari, Nicolò Maria Della Ventura

An SEM in situ uniaxial tensile testing setup allowing HR-EBSD acquisition during deformation was used to study the extension twinning mechanism in magnesium(Mg) at the micron scale. Structures were fabricated with two different crystal orientations, respe ...

2021

Simple shear extrusion versus equal channel angular pressing: A comparative study on the microstructure and mechanical properties of an Mg alloy

Roland Logé, Cyril Cayron, Aryan Rezaei Rad

Two severe plastic deformation (SPD) techniques of simple shear extrusion (SSE) and equal channel angular pressing (ECAP) were employed to process an extruded Mg -6Gd -3Y -1.5Ag (wt%) alloy at 553 K for 1, 2, 4 and 6 passes. The microstructural evolutions ...

KEAI PUBLISHING LTD2023

A critical assessment of experimental investigation of dynamic recrystallization of metallic materials

Roland Logé, Ke Huang

Dynamic recrystallization (DRX) often takes place during hot deformation of metallic materials, which then exerts significant influence on the final microstructures and mechanical properties of the formed components. A considerable number of published pape ...

2020

Critical crystallization properties of an industrial-grade Zr-based metallic glass used in additive manufacturing

Roland Logé, Jamasp Jhabvala, Navid Sohrabi

The major challenge to overcome when processing metallic glasses (MGs) is to avoid crystallization. Therefore, time-temperature-transformation (TTT) diagrams are used, but they are often derived from experiments in which heating or cooling rates are limite ...

2021

Laser shock peening: A promising tool for tailoring metallic microstructures in selective laser melting

Roland Logé, Ke Huang, Nikola Kalentics, Manuel Ortega Varela De Seijas

Metallic parts made by Selective Laser Melting (SLM) are known for their heterogeneous microstructures in the as-built (AB) state. In this paper, Laser Shock Peening (ISP) was performed on a 316 L stainless steel part fabricated by SLM. The LSP treatment i ...

2019

The flow stress evolution and grain refinement mechanisms during hot deformation of Al-Mg alloy

Roland Logé, Ke Huang

In this study, the hot deformation behavior of an Al-1% Mg alloy with very coarse initial grain size was investigated in terms of flow stress evolution and grain refinement mechanism. The large grain size was employed to study the traditional continuous dy ...

2017

On the sluggish recrystallization of a cold-rolled Al–Mn–Fe–Si alloy

Roland Logé, Ke Huang

Annealing of supersaturated AA3xxx alloys at low temperatures usually results in sluggish recrystallization kinetics. This is due to the joint effect of the following factors: low nucleation rate, reduced grain boundary mobility, and large amount of fine p ...

Springer Verlag2016

An investigation on reorientation and textural evolution in a martensitic NiTi rolled sheet using EBSD

Roland Logé, Cyril Cayron, Junfeng Xiao

Variant reorientation is a ubiquitous phenomenon in shape memory alloys and has a great influence on their texture and mechanical response. In the present study, a martensitic NiTi rolled sheet is investigated by the electron backscattering diffraction (EB ...

PERGAMON-ELSEVIER SCIENCE LTD2022