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

Evaluation of Interface and Residual Strain of NiTi Layer Deposited on NiTiX Substrate by Laser Powder Bed Fusion

Elyas Ghafoori, Christian Leinenbach, Irene Ferretto, Mahbod Golrang, Mahshid Memarian

This study investigates the microstructure and properties of functionally graded NiTi alloy bilayers. The NiTi layer is printed by laser powder bed fusion on a NiTiX (where X is Hf or Cu) substrate prepared by vacuum arc remelting. Specimens produced with ...

Wiley-V C H Verlag Gmbh2024

Control of intermetallics in the interface in directed energy deposition of titanium on stainless steel 316L

Di Cui

Application of a single metal or alloy is often restricted by its properties from optimal combination of performance and cost. Therefore, there is a vast need of joining dissimilar metals for various applications in biomedical, aerospace, automobile and ma ...

EPFL2023

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

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

Tailored deformation behavior of 304L stainless steel through control of the crystallographic texture with laser-powder bed fusion

Christian Leinenbach, Roland Logé, Efthymios Polatidis, Markus Strobl

Laser-powder bed fusion (L-PBF) has gained significant research interest, not only for its profound advantage of producing near-net shape complex geometries of metallic parts, but also for the possibility of producing tailored microstructures. Here we expl ...

ELSEVIER SCI LTD2022

HIERARCHICAL MARKOV CHAIN MONTE CARLO METHODS FOR BAYESIAN INVERSE PROBLEMS

Juan Pablo Madrigal Cianci

This thesis is devoted to the construction, analysis, and implementation of two types of hierarchical Markov Chain Monte Carlo (MCMC) methods for the solution of large-scale Bayesian Inverse Problems (BIP). The first hierarchical method we present is base ...

EPFL2022

Reduced-order Models for Simulating Coupled Geometric Instabilities in Steel Beam-columns Under Inelastic Cyclic Straining

Alexander Riley Hartloper

Numerical models that can simulate coupled geometric instabilities in steel beam-columns are required for the seismic assessment of certain steel moment-resisting frames. Reliably simulating coupled instabilities requires that the steel material is precise ...

EPFL2021

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

Roland Logé, Oscar Zambrano Zambrano

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

APT/TEM characterization of the element segregation in ferritic/martensitic steels after irradiation in SINQ

Lijuan Cui

Ferritic /martensitic (FM) steels are among the most important materials in various nuclear applications. As radiation-induced segregation (RIS) is one of the major factors for embrittlement of nuclear materials, thereofre it is essential to study the RIS ...

EPFL2021

Complexity analysis of stochastic gradient methods for PDE-constrained optimal control problems with uncertain parameters

Fabio Nobile, Matthieu Claude Martin, Sebastian Krumscheid

We consider the numerical approximation of an optimal control problem for an elliptic Partial Differential Equation (PDE) with random coefficients. Specifically, the control function is a deterministic, distributed forcing term that minimizes the expected ...

2021

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

Atomic scale investigations of fracture in metal alloys

Eleanor Yi Kei Mak

The demand for metal alloys with superior structural performance in industrial applications continues to increase, as does the need for more-energy efficient materials and methods. Many materials that are otherwise attractive for structural applications ar ...

EPFL2021

Understanding Thermomechanical Treatments Induced by Laser Powder Bed Fusion Process

Hossein Ghasemi Tabasi

Additive Manufacturing (AM) is referred to technologies that produce directly 3D parts in a layer-by-layer fashion. Laser Powder Bed Fusion (L-PBF) is one of the most important AM processes, enabling production of very complex metallic objects from a compu ...

EPFL2021

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

Cyril Cayron, Roland Logé, Bo Xiao

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

Advanced analytical electron microscopy applied to Solid Oxide Cell materials and their degradation

Stéphane François Jean Poitel

Electron microscopy offers a wide range of techniques to study materials. Environmental Scanning Electron Microscopy (ESEM), in particular, allows the characterisation of samples at high-temperature using a laser heating stage, and under various gaseous at ...

EPFL2020

Quantum Monte Carlo approach to the non-equilibrium steady state of open quantum systems

Alexandra Nagy

Many-body open quantum systems are exposed to an essentially uncontrollable environment that acts as a source of decoherence and dissipation. As the exact treatment of such models is generally unfeasible, it is favourable to formulate an approximate descri ...

EPFL2020

Additive Manufacturing of L12 Precipitate Strengthened Nickel and Aluminum Alloys

Seth James Griffiths

Metal Additive Manufacturing (AM) technologies have enabled the manufacturing of parts with complex geometries that were previously not feasible with conventional manufacturing. Unfortunately, many commercial engineering alloys (with the exception of alloy ...

EPFL2020

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

Helena Van Swygenhoven, Wei-Neng Hsu, Efthymios Polatidis

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

In situ characterization of a high work hardening Ti-6Al-4V prepared by electron beam melting

Helena Van Swygenhoven, Karl Alan Sofinowski, Nicola Casati

A multi-phase Ti-6Al-4V prepared by electron beam melting and thermal post treatments has been shown to exhibit increased strength and ductility over standard wrought or hot isostatic pressed Ti-6-Al-4V. The mechanical improvements are due to a prolonged, ...

2019

Deformation-induced martensitic transformation under multiaxial loading

Wei-Neng Hsu

The deformation-induced martensitic transformation observed in specific materials can enhance their mechanical properties or result in functional properties. For example, the transformation induced plasticity (TRIP) effect results in a good combination of ...

EPFL2019