Publications associées à In situ transmission electron microscopy of the interaction between a moving dislocation and obstacles of dislocation character in pure iron

Solute-strengthening in metal alloys with short-range order

Recent surging interest in strengthening of High Entropy Alloys (HEAs) with possible chemical ordering motivates the development of new theory. Here, an existing theory for random alloys that accounts for solute-dislocation and solute–solute interactions i ...

2024

Photo-Fenton inactivation of MS2 bacteriophage at alkaline pH by Fe salts or nm to μm-sized oxides, and the Janus-faced effects of natural organic matter in surface waters

César Pulgarin, Stefanos Giannakis, Ogadimma Cassandra Oji-Okoro, Giulio Farinelli

In this study, MS2 bacteriophage was inactivated by homogeneous and heterogeneous photo-Fenton processes in an alkaline matrix (pH 8) using low concentrations of H2O2 and iron forms (1 mg/L), including Fe(II), Fe(III), and Fe (hydr)oxides. As a reference, ...

Elsevier2024

Phase Transformation-Induced Interfacial Debonding of Silica Inclusions in Iron

Andreas Mortensen, Alejandra Inés Slagter, David Hernandez Escobar, Julie Nathalie S Gheysen

We document that in unstressed, undeformed, samples of pure iron containing silica inclusions precipitated by melt deoxidation, the iron matrix and a small fraction of the silica inclusions are locally separated at room temperature by a void. Thermal cycli ...

Springer2023

The influence of lattice misfit on screw and edge dislocation-controlled solid solution strengthening in Mo-Ti alloys

William Curtin, Carolina Baruffi, You Rao

Mo-Ti alloys form solid solutions over a wide range of compositions, with lattice misfit parameters increasing significantly with titanium content. This indicates a strong increase in the critical stress for edge dislocation motion. Here, we probe the tran ...

SPRINGERNATURE2023

Origin of the enhanced pseudo-elasticity of additively manufactured Fe-17Mn-5Si-4Ni-10Cr-(V, C) shape memory alloy fabricated by laser powder bed fusion

Christian Leinenbach, Irene Ferretto

This study investigated the origin of the enhanced pseudo-elasticity of additively manufactured vanadium carbide-containing Fe-based shape memory alloys. The aged samples with two different starting microstructures, as-built and solution-treated, showed co ...

Elsevier Science Sa2023

Murunskite - a new class of functional material

Davor Tolj

The subject of the present work is discovery and in-depth characterization of a new class of functional materials. Tuning of the bond polarity and orbital occupation with a goal of establishing balance between localization and delocalization of electrons - ...

EPFL2023

Microstructure et usinabilité d'alliages de titane béta-métastable

Loïc Favre

Titanium has become in recent years an interesting material in many applications that require a combination of high mechanical properties and low density. It has the peculiarity of undergoing an allotropic transformation at 882°C. Below this temperature, ...

EPFL2023

Enhanced Leaching of Zinc Ferrite by the Formation of a Solid Solution With Magnetite in Hydrochloric Acid Solution

The high zinc and iron contents of electric arc furnace (EAF) dust in the forms of zinc ferrite (ZnFe2O4) and magnetite (Fe3O4) make it a valuable secondary source of these metals. ZnFe2O4 and Fe3O4 are known to form a solid solution at all compositions, a ...

SPRINGER2023

Room-temperature strength of the interfacial bond between silica inclusions and iron

Andreas Mortensen, Alejandra Inés Slagter, David Hernandez Escobar, Sergio Perosanz Amarillo

The strength of the interface between iron (Fe) and individual spherical silica (SiO2) inclusions of 5 +/- 1 mu m diameter is measured by means of in-situ micro-cantilever bending tests conducted under displacement control within a scanning electron micros ...

Pergamon-Elsevier Science Ltd2023

Strengthening mechanisms in dilute and random solid solution high-entropy BCC alloys

Alireza Ghafarollahi

Tuning the mechanical properties of metals, including strength, through adjusting the type and/or concentration of added solute elements, has been recognized as an effective way to design and produce materials with desired or optimized mechanical propertie ...

EPFL2022

Screw vs. edge dislocation strengthening in body-centered-cubic high entrophy alloys and implications for guided alloy design

William Curtin, Francesco Maresca, Carolina Baruffi

Body-centered-cubic (BCC) high entropy alloys (HEAs) can show exceptionally high strength up to high temperatures. Mechanistic theories are needed to guide alloy discovery within the immense multicomponent HEA compositional space. Here, two new theories fo ...

SPRINGER HEIDELBERG2022

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

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 post-heat treatment conditions on shape memory property in 4D printed Fe-17Mn-5Si-10Cr-4Ni shape memory alloy

Christian Leinenbach, Irene Ferretto

The influence of post-heat treatment on the microstructure and properties of 4D printed Fe-17Mn-5Si-10Cr-4Ni (wt. %) shape memory alloy (SMA) produced via a laser powder bed fusion process is investigated in this study. It is shown that heat-treatment temp ...

2022

Strong silicon oxide inclusions in iron

Andreas Mortensen, Léa Deillon, Alejandra Inés Slagter, Joris Pierre Everaerts

Oxide inclusions are ubiquitous in steel and are known to affect, generally in a negative sense, the mechanical performance of steel products. Micromechanical properties of those phases are therefore important, yet they have remained largely unexplored. We ...

2022

Evolution of deformation twinning mechanisms in magnesium from low to high strain rates

Johann Michler, Cyril Cayron, Amit Sharma, Roland Logé, Manish Jain, Xavier Maeder, Nicolò Maria Della Ventura

We present a systematic investigation of {10 (1) over bar2} extension twinning mechanism in single crystal magnesium micropillars deformed over seven orders of magnitude of strain rate, from 10(-4) to 500 s(-1), revealing how the accommodation of newly for ...

ELSEVIER SCI LTD2022

Effect of different ions on dissolution rates of silica and feldspars at high pH

Karen Scrivener, Barbara Lothenbach, Mahsa Bagheri, Mahdieh Shakoorioskooie

The dissolution kinetics of silica-containing minerals in aggregates influences strongly the process of ASR in concrete. In this paper, the effect of different ions on the dissolution rates of SiO2 (amorphous and quartz) and feldspars at high pH values was ...

Pergamon-Elsevier Science Ltd2022

Precipitation Strengthening in Al-Mg-Si Alloys

Yi Hu

Precipitation strengthening is one of the key strengthening strategies in many industrial alloys like aluminum alloys, nickel-based superalloys, etc. The yield strength of alloy is improved by forming precipitates in materials and employing them as obstacl ...

EPFL2021

Modeling peak-aged precipitate strengthening in Al–Mg–Si alloys

William Curtin, Yi Hu

Strengthening by needle-shaped precipitates is critical in Al–Mg–Si alloys. Here, the strengthening is studied computationally at the peak-aged condition where precipitate shearing and Orowan looping are usually considered to have equal strengths. Pseudo-r ...

2021

Theory of kink migration in dilute BCC alloys

William Curtin, Alireza Ghafarollahi

Plastic deformation in elemental BCC metals and dilute alloys is controlled by the slower of the kink pair nucleation and kink migration processes along screw dislocations. In alloys nucleation is facilitated and migration inhibited, leading to a concentra ...

2021