Publications de Helena Van Swygenhoven

Publications associées (61)

Operando X-ray diffraction during laser 3D printing

Steven Van Petegem, Helena Van Swygenhoven, Nicola Casati, Samy Hocine

Laser based additive manufacturing allows to build a designed shape layer-by-layer, offering versatility and flexibility to many metallurgical sectors. The fast cooling rates and repeated heat cycles depending on the laser and scanning parameters are not e ...

2020

Direct observation of crack formation mechanisms with operando Laser Powder Bed Fusion X-ray imaging

Roland Logé, Helena Van Swygenhoven, Jamasp Jhabvala, Eric Boillat, Navid Sohrabi, Hossein Ghasemi Tabasi, Charlotte Léopoldine de Formanoir de la Cazerie, Samy Hocine

Laser powder bed fusion (L-PBF) is a versatile additive manufacturing process that can print geometrically complex metal parts for a variety of applications. However, poor control of defect formation during processing hampers its widespread industrial adop ...

ELSEVIER2022

Impact of in situ nanomechanics on physical metallurgy

Johann Michler, Helena Van Swygenhoven

The mechanical response of modern alloys results from a complex interplay between existing microstructure and its evolution with time under stress. To unravel these processes, in situ approaches intrinsically have a critical advantage to explore the basic ...

2019

In situ characterization of work hardening and springback in grade 2 alpha-titanium under tensile load

Helena Van Swygenhoven

Plastic effects during sheet metal forming can lead to undesirable distortions in formed components. Here, the three-stage work hardening and plastic strain recovery ("springback") in a cold-rolled, alpha-phase commercially pure titanium is examined. Inter ...

2019

Influence of thermo-mechanical history on the ordering kinetics in 18 carat Au alloys

Nadine Baluc, Steven Van Petegem, Helena Van Swygenhoven, Marina Garcia Gonzalez

Precious alloys are subjected to a series of mechanical and thermal operations during manufacturing. For 18 carat gold alloys the processing operations can induce L1(0) ordered nanodomains, known to lead to the buildup of residual stresses, which are the p ...

PERGAMON-ELSEVIER SCIENCE LTD2020

A crystallographic extension to the Olson-Cohen model for predicting strain path dependence of martensitic transformation

Helena Van Swygenhoven

A modification to the empirical Olson-Cohen strain-induced austenite to martensite transformation kinetic model is proposed. The proposed kinetic model accounts for the stress state at the grain level and the crystallography of the transformation mechanism ...

PERGAMON-ELSEVIER SCIENCE LTD2019

Operando X-ray diffraction study of thermal and phase evolution during laser powder bed fusion of Al-Sc-Zr elemental powder blends

Helena Van Swygenhoven, Samy Hocine

Elemental powder blends are an emerging alternative to prealloyed powders for high-throughput alloy design via additive manufacturing techniques. Elemental Al+Sc(+Zr) powder blends were processed by laser powder bed fusion into Al-Sc and Al-Sc-Zr alloys, w ...

2022

Enhanced precipitate growth at reduced temperatures during chemical ordering in deformed red gold alloys

Nadine Baluc, Steven Van Petegem, Helena Van Swygenhoven, Samy Hocine, Marina Garcia Gonzalez

Manufacturing of red gold components relies widely on controlling the formation of ordered precipitates during thermo-mechanical processing. The ordered phase hardens the material, makes it less workable and introduces residual stresses. We show that an in ...

PERGAMON-ELSEVIER SCIENCE LTD2019

Microstructure evolution of stainless steel subjected to biaxial load path changes: In-situ neutron diffraction and multi-scale modeling

Helena Van Swygenhoven

The lattice strain and intensity evolution obtained from in-situ neutron diffraction experiments of 316L cruciform samples subjected to 45 degrees and 90 degrees load path changes are presented and predicted using the multi-scale modeling approach proposed ...

2019

Slip in directionally solidified Mo-alloy micropillars - Part I: Nominally dislocation-free pillars

Cécile Hébert, Emad Oveisi, Steven Van Petegem, Helena Van Swygenhoven, Barbora Bártová, Cécile Renée Maria Marichal

In situ Laue analysis during microcompression reveals plasticity in [0 0 1]-oriented, directionally solidified Mo alloy pillars to start with slip on the {1 1 2} < 1 1 1 > system having the highest Schmid factor followed by slip on the (1 1 0) plane contai ...

Elsevier2012

Measurement and prediction of the transformation strain that controls ductility and toughness in advanced steels

William Curtin, Helena Van Swygenhoven, Francesco Maresca

New-generation multi-phase martensitic steels derive their high strength from the body-centered cubic (BCC) phase and high toughness from transformation of the metastable face-centered cubic (FCC) austenite that transforms into martensite upon loading. In ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Stresses and Strains in Cruciform Samples Deformed in Tension

Helena Van Swygenhoven, Steven Van Petegem

The stress and strain relationship in the gauge region of six cruciform geometries is studied: the ISO standard geometry with slits in arms, two geometries with thinned gauge areas, two geometries with thinned gauge areas and slits in arms, and one modifie ...

Springer2017

Frequency-Induced Bulk Magnetic Domain-Wall Freezing Visualized by Neutron Dark-Field Imaging

Helena Van Swygenhoven

We use neutron dark-field imaging to visualize and interpret the response of bulk magnetic domain walls to static and dynamic magnetic excitations in (110)-Goss textured iron silicon high-permeability steel alloy. We investigate the domain-wall motion unde ...

American Physical Society (APS)2016

Verification of selective laser melting heat source models with operando X-ray diffraction data

Steven Van Petegem, Helena Van Swygenhoven, Samy Hocine

The output obtained from operando X-ray diffraction experiments on Ti-6Al-4V is used to verify the accuracy of four FEM models in predicting the temperature evolution of the solidified domain, the cooling rates of the alpha and beta phases, and the influen ...

ELSEVIER2021

Study of lattice strain evolution during biaxial deformation of stainless steel using a finite element and fast Fourier transform based multi-scale approach

Helena Van Swygenhoven, Steven Van Petegem

A multi-scale elastic-plastic finite element and fast Fourier transform based approach is proposed to study lattice strain evolution during uniaxial and biaxial loading of stainless steel cruciform shaped samples. At the macroscale, finite element simulati ...

Pergamon-Elsevier Science Ltd2016

Helium-vacancy cluster in a single bcc iron crystal lattice

Helena Van Swygenhoven

The properties of the cluster HenV, an iron vacancy with an increasing number of He atoms, is studied with molecular statics and molecular dynamics simulations. A study of the binding energy of the self-interstitial atom (SIA) and the He, shows that from n ...

2011

Characterization of the deformation and phase transformation behavior of VC-free and VC-containing FeMnSi-based shape memory alloys by in situ neutron diffraction

Helena Van Swygenhoven, Steven Van Petegem, Christian Leinenbach

The stress-induced fcc-austenite to hcp-martensite transformation in the iron based shape memory alloy (SMA) Fe-17Mn-5Si-10Cr-4Ni with and without VC precipitates is investigated by in-situ neutron diffraction measurements upon uniaxial loading and unloadi ...

Elsevier Science Sa2017

Following dislocation patterning during fatigue

Helena Van Swygenhoven, Steven Van Petegem, Nicolò Grilli, Ainara Irastorza Landa

Precursors of failure are dislocation mechanisms at the nanoscale and dislocation organization at the mesoscale responsible for long-range internal stresses and lattice rotation. Detailed information on the link between both scales is missing, computationa ...

Elsevier2016

A High Resolution Digital Image Correlation Study under Multiaxial Loading

Helena Van Swygenhoven, Wei-Neng Hsu

In this study, a miniaturized cruciform-shaped sample geometry which allows reaching high plastic strain under equibiaxial loading with reduced thickness at the test section is presented. The thinning method results in excellent surface quality that can be ...

SPRINGER2019

Large scale 3-dimensional atomistic simulations of screw dislocations interacting with coherent twin boundaries in Al, Cu and Ni under uniaxial and multiaxial loading conditions

Satish I Rao, Helena Van Swygenhoven

Large scale 3D atomistic simulations are performed to study the interaction between a curved dislocation with a dominant screw character and a Coherent Twin Boundary (CTB). Three FCC metals (Al, Cu and Ni) are addressed using 6 embedded-atom method (EAM) p ...

2019