Publications associées à Hot working

Laser powder bed fusion of Fe-based shape memory alloys for novel structural metamaterials and "smart" structures

Laser powder bed fusion (LPBF) is a powder-based additive manufacturing (AM) technique, which shows great potential in the production of complex-shaped parts with unprecedented design freedom. In addition, it allows for an active manipulation of the micros ...

EPFL2023

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

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

Influence of Joule Effect Heating on Recrystallization Phenomena in Inconel 718

Roland Logé, Mathijs Pieter van der Meer

In this article, the Joule effect heating influence on recrystallization phenomena in the Inconel 718 nickel-based superalloy is investigated in details. On the one hand, static recrystallization kinetic studies at 1020 degrees C after cold deformation up ...

SPRINGER2021

Enhanced strength and toughness of bulk ultrafine grained Cu by nacre-inspired lamellar structure

Roland Logé, Jun Wang, Chenguang Li

An ultrafine grained (UFG) bulk Cu with a novel nacre-inspired lamellar structure containing nano-bridges and aligned nanopores at inter-lamellar interfaces was fabricated by consolidation of a nanocrystal-attached ultrathin Cu flake powder by spark plasma ...

2020

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

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

On the chevron morphology of surface martensite

Roland Logé, Cyril Cayron, Annick Pauline Baur

It is established that the annealing twin boundaries of austenite act as nucleation sites for the martensitic transformation. In the present study, we observe that in surface martensite the transformation only takes place for twin boundaries that are appro ...

2019

Microstructure and flow stress evolution during hot deformation of 304L austenitic stainless steel in variable thermomechanical conditions

Roland Logé, Ke Huang

Most of industrial hot deformation processes are performed in variable conditions where the strain rate and/or deformation temperature are not constant. In this work, hot compression tests in both constant and varying strain rate conditions were performed ...

Elsevier2018

Competition between intragranular and intergranular deformation mechanisms in ODS ferritic steels during hot deformation at high strain rate

Roland Logé

Oxide Dispersed Strengthened (ODS) ferritic stainless steels present well-known fine grains microstructures where dislocation movement is hindered by a dense precipitation of nano-oxides particles. Previous research, on the thermomechanical behavior at hig ...

Springer Verlag2017

Controlling grain structure and texture in Al-Mn from the competition between precipitation and recrystallization

Roland Logé, Ke Huang

The recrystallization behaviour of Al-Mn alloys (AA3xxx series alloys) is affected by randomly distributed dispersoids present before annealing, by dispersoids precipitated at grain/subgrain boundaries before the onset of recrystallization, and by disperso ...

Elsevier2017

In Situ Characterization of Inconel 718 Post-Dynamic Recrystallization within a Scanning Electron Microscope

Roland Logé

Microstructure evolution within the post-dynamic regime following hot deformation was investigated in Inconel 718 samples with different dynamically recrystallized volume fractions and under conditions such that no delta-phase particles were present. In si ...

2017

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

The surprising influence of continuous alternating electric current on recrystallization behaviour of a cold-rolled Aluminium alloy

Cyril Cayron, Roland Logé, Ke Huang

Pronounced acceleration of recrystallization in cold worked metals is generally observed during annealing with additional high density electric current pulses. In this work, continuous alternating current of low density was applied to heat cold-rolled samp ...

Elsevier2017

Recrystallization behavior of multi-directionally forged over-aged and solution treated Al-Cu-Mg alloy during non-isothermal annealing

Roland Logé, Saeed Khani Moghanaki

The recrystallization behavior of an Al-Cu-Mg alloy is investigated in multi-directionally forged over-aged and solution treated alloys, during non-isothermal annealing. Deformation and non-isothermal annealing are performed with a Gleeble 3800 thermo-mech ...

Elsevier Sci Ltd2017

Mean field modelling of dynamic and post-dynamic recrystallization during hot deformation of Inconel 718 in the absence of δ phase particles

Roland Logé

Dynamic and post-dynamic recrystallization kinetics were investigated during hot-working of Inconel 718 as a function of temperature,strain and strain rate in the single phase domain.The post-dynamic evolution was found to be extremely fast and impacting s ...

Elsevier2016

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

Évolution microstructurale et propriétés mécaniques d'un alliage Co-Ni-Cr

Raffaele Cosimati

This study concerns the evolution of the thermomechanical properties of new high-performance materials. In particular, we focus on the relationship between the microstructure and the mechanical properties of a superalloy based on Co-Ni-Cr. Superalloys are ...

EPFL2016

Microstructural characterizations of 14Cr ODS ferritic steels subjected to hot torsion

Roland Logé

Oxide dispersion strengthened (ODS) steels are very promising materials for nuclear applications. In thispaper, the hot working behavior of ODS ferritic steels, consolidated by hot extrusion, is studied through torsion tests. Three ODS steels are produced ...

Elsevier2015

Magnesium interatomic potential for simulating plasticity and fracture phenomena

William Curtin, Michael Frederick Francis

Magnesium has multiple dislocation and twinning systems with starkly different properties, which make its plastic deformation strongly anisotropic and highly complex. Existing empirical interatomic potentials fail to capture the full scope of these propert ...

Institute of Physics2015