Helena Van Swygenhoven

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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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

The role of pre-existing mobile and immobile dislocation densities on the evolution of geometrical necessary dislocation densities (GNDs) during cyclic fatigue in shear is studied using a continuum dislocation-based model incorporated in a crystal plastici ...

We report on the development of a miniaturized device for operando X-ray diffraction during laser 3D printing. The printing chamber has a size of only 130 x 135 x 34 mm(3) and is optimized to be installed at synchrotron beamlines. We describe the design co ...

The introduction of a well-controlled population of coherent twin boundaries (CTBs) is an attractive route to improve the strength ductility product in face centered cubic (FCC) metals. However, the elementary mechanisms controlling the interaction between ...

Deformation in nanocrystalline (NC) materials is strongly influenced by the presence of a large fraction of grain boundaries. We present a comparative study on the role of intragranular root-mean-square strain and crystal-lographic texture on recovery proc ...

In situ multiaxial loading during neutron diffraction tests were undertaken on a low-alloyed Quenched and Partitioning (Q&P) Transformation Induced Plasticity (TRIP) Bainitic Ferrite (TBF) steel with dispersed austenite particles. The effect of stress tria ...

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, ...

Helena Van Swygenhoven

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Operando X-ray diffraction during laser 3D printing

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

Impact of in situ nanomechanics on physical metallurgy

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

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

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

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

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

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

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

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

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

A High Resolution Digital Image Correlation Study under Multiaxial Loading

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

Effect of pre-existing immobile dislocations on the evolution of geometrically necessary dislocations during fatigue

A miniaturized selective laser melting device for operando X-ray diffraction studies

Deciphering the interactions between single arm dislocation sources and coherent twin boundary in nickel bi-crystal

An in-situ synchrotron study on microplastic flow of electrodeposited nanocrystalline nickel

The effect of stress triaxiality on the phase transformation in transformation induced plasticity steels: Experimental investigation and modelling the transformation kinetics

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