Publications associées à Influence of Cr on the nucleation of primary Al and formation of twinned dendrites in Al-Zn-Cr alloys: Can icosahedral solid clusters play a role?

Unique corrosion behavior of an archaeological Roman iron ring: Microchemical characterization and thermodynamic considerations

The corrosion mechanisms of a Roman iron bezel ring were investigated by in-depth characterization of its uncommon corrosion pattern and thermodynamic modelling. A silver foil and altered glass remnants were identified, covered with thick strata of magneti ...

2024

First-principles thermodynamics of precipitation in aluminum-containing refractory alloys

Anirudh Raju Natarajan

Materials for high -temperature environments are actively being investigated for deployment in aerospace and nuclear applications. This study uses computational approaches to unravel the crystallography and thermodynamics of a promising class of refractory ...

Pergamon-Elsevier Science Ltd2024

Composition and Element Distribution Mapping of γ′ and γ" Phases of Inconel 718 by High-Resolution Scanning Transmission Electron Microscopy and X-ray Energy-Dispersive Spectrometry

Philippe Buffat

The main strengthening mechanism for Inconel 718 (IN718), a Ni-based superalloy, is precipitation hardening by gamma ' and gamma '' particles. It is thus essential, for good alloy performance, that precipitates with the desired chemical composition have ad ...

MDPI2024

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

Alexandre Achille Looten

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

Solute-strengthening in metal alloys with short-range order

William Curtin, Shankha Nag

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

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

Vacancy segregation and intrinsic coordination defects at (111) twist grain boundaries in diamond

Christian Brandl, Carolina Baruffi

High radiation damage resistance has become increasingly important for applications of functional materials in harsh environments. The high radiation damage resistance diamond cubic carbon is a unique material which is considered for radiation environments ...

Pergamon-Elsevier Science Ltd2023

Processability, microstructure and precipitation of a Zr-modified 2618 aluminium alloy fabricated by laser powder bed fusion

Christian Leinenbach, Xavier Maeder

Additive manufacturing offers the opportunity to produce complex geometries from novel alloys with improved properties. Adapting conventional alloys to the process-specific properties can facilitate rapid implementation of these materials in industrial pra ...

2022

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

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

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

Effect of Y2O3 dispersoids on microstructure and creep properties of Hastelloy X processed by laser powder-bed fusion

Christian Leinenbach

Laser powder bed fusion (LPBF) was used to consolidate powders of a Ni-Cr-Fe-Mo alloy (Hastelloy X) blended with 1 wt% Y2O3 nanometric powders. The nearly-dense, crack-free specimens, with and without oxide dispersion strengthening (ODS), exhibit high-aspe ...

ELSEVIER2022

Development of High-Strength Aluminum Alloys for Additive Manufacturing

Marvin Lennard Schuster

Metal additive manufacturing (AM) offers the possibility to rapidly produce complex geometries that are not achievable with conventional manufacturing methods. The two most common technologies, Laser Powder Bed Fusion (LPBF) and Direct Metal Deposition (DM ...

EPFL2022

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

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

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

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

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