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Concept

Cleavage (geology)

Publications associées (31)

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

Reactivation of variably sealed joints and permeability enhancement in geothermal reservoir rocks

Michael Heap, Alexandra Roma Larisa Kushnir

Hydraulic stimulation of enhanced deep geothermal reservoirs commonly targets pre-existing joint networks with the goal of increasing reservoir permeability. Here, we study the permeability and strength of joint-free and jointed Buntsandstein sandstones fr ...

2023

Nanotwinning-assisted recrystallization

Roland Logé

Dynamic recrystallization helps to refine grain structures in metals and tune their properties. Confining recrystallization within prior nanoscale twinning provides a path for reaching exceptional grain refinement. ...

NATURE PORTFOLIO2022

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

Roland Logé

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

Brittle faulting of ductile rock induced by pore fluid pressure build‐up

Marie Estelle Solange Violay, François Xavier Thibault Passelègue, Corentin Jean-Marie Rémi Noël

Under upper crustal conditions, deformations are primarily brittle (i.e., localized) and accommodated by frictional mechanisms. At greater depth, deformations are ductile (i.e., distributed) and accommodated by crystal plasticity, diffusion mass transfer o ...

2021

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

Crystallographically Oriented Hybrid Perovskites via Thermal Vacuum Codeposition

Mohammad Khaja Nazeeruddin, Mounir Driss Mensi, Hiroyuki Kanda, Cristina Roldán Carmona, Maria Cristina Momblona Rincón, Yen-Cheng Liu, Nadja Isabelle Desiree Klipfel

Hybrid lead halide perovskites typically form polycrystalline films that have multiple grain sizes and surface defects. A key engineering challenge toward commercialization is therefore the production of homogeneous, defect-free largearea devices achieving ...

2021

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

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

Mechanical and hydraulic transport properties of transverse-isotropic Gneiss deformed under deep reservoir stress and pressure conditions

Marie Estelle Solange Violay, Mateo Alejandro Acosta

In central Europe, many geo-energy reservoirs have revealed to be hosted in transverse isotropic crystalline rock, where the rock's mechanical and hydraulic transport properties are poorly constrained. Here, we performed triaxial experiments on Cresciano G ...

2020

Microfluidic-Based Study on the Activation and Evolution of Calcite Bio-Mineralization for Geotechnical Applications

Lyesse Laloui, Dimitrios Terzis, Filippo Miele, Ariadni Elmaloglou

The field of geotechnics is moving fast towards benefiting from new methods and tools to improve the understanding of couplings among complex transport, chemical and biological phenomena. Calcite bio-mineralization, result of bio-grouting, stands out as su ...

ASCE2020

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

Dynamic recrystallization study of a Fe-Mn-Si based shape memory alloy in constant and variable thermomechanical conditions

Roland Logé

The dynamic recrystallization of a Fe-Mn-Si based shape memory is studied for the first time, under constant and variable thermo-mechanical conditions. The effect of strain rate and deformation temperature on the microstructural evolution is investigated, ...

ELSEVIER SCIENCE INC2019

The interplay between deformation mechanisms in austenitic 304 steel during uniaxial and equibiaxial loading

Helena Van Swygenhoven, Wei-Neng Hsu

The preferred deformation mechanisms with respect to the load path are studied in a medium stacking fault energy 304 austenitic stainless steel that exhibits both transformation induced plasticity and twinning induced plasticity. In situ neutron diffractio ...

2019

Atomistic study of hydrogen embrittlement of grain boundaries in nickel: I. Fracture

William Curtin, Ali Tehranchi

Hydrogen ingress into a metal is a persistent source of embrittlement. Fracture surfaces are often intergranular, suggesting favorable cleave crack growth along grain boundaries (GBs) as one driver for embrittlement. Here, atomistic simulations are used to ...

Elsevier2017

Study on the mixed dynamic recrystallization mechanism during the globularization process of laser-welded TA15 Ti-alloy joint under hot tensile deformation

Ke Huang

In this article, the hot deformation mechanism of a laser-welded near a TA15 Ti-alloy joint was studied by hot tensile tests conducted at temperatures ranging from 800 degrees C to 900 degrees C with strain rates ranging from 1.0 x 10(-1) s(-1) to 1.0 x 10 ...

Elsevier2017

Heat kernel methods for Lifshitz theories

Diego Blas Temino, Mario Herrero Valea

We study the one-loop covariant effective action of Lifshitz theories using the heat kernel technique. The characteristic feature of Lifshitz theories is an anisotropic scaling between space and time. This is enforced by the existence of a preferred foliat ...

Springer Nature2017

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

Upscaling the evolution of snow microstructure : from 4D image analysis to rigorous models

Quirien Eibhilín Krol

Snow microstructure and its evolution play an important role for various applications of snow physics in cryospheric sciences. The main modes of microstructure evolution in snow are referred to as isothermal and temperature gradient metamorphism. The forme ...

EPFL2017

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