Publications de Helena Van Swygenhoven

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

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

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, 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

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

Helena Van Swygenhoven

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 ...

Nature Research2021

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

Helena Van Swygenhoven, Nicola Casati, Efthymios Polatidis

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 ...

2021

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

Helena Van Swygenhoven, Steven Van Petegem, 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

Additive micro-manufacturing of crack-free PDCs by two-photon polymerization of a single, low-shrinkage preceramic resin

Jürgen Brugger, Demetri Psaltis, Christophe Moser, Helena Van Swygenhoven, Eirini Kakkava, Lorenz Hagelüken, Georgia Konstantinou, Nikolaos Nianias, Jieping Wang

Additive manufacturing (AM) methods are being integrated in ceramics fabrication either as the main manufacturing tool or for auxiliary purposes. By using polymers, powders and preceramic formulated materials, AM techniques are pushing towards higher resol ...

2020

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

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

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 ...

ELSEVIER2020

Neutron Diffraction and Diffraction Contrast Imaging for Mapping the TRIP Effect under Load Path Change

Helena Van Swygenhoven, Markus Strobl, Efthymios Polatidis

The transformation induced plasticity (TRIP) effect is investigated during a load path change using a cruciform sample. The transformation properties are followed by in-situ neutron diffraction derived from the central area of the cruciform sample. Additio ...

MDPI2020

Deformation mechanisms in a superelastic NiTi alloy: An in-situ high resolution digital image correlation study

Helena Van Swygenhoven, Efthymios Polatidis

An in-situ high resolution digital image correlation investigation during uniaxial tensile deformation reveals the recoverable and the non-recoverable strain mechanisms in a Ni51Ti49 alloy with a mean grain size of 35 mu m. Recoverable strain is due to the ...

2020

Phase Studies of Additively Manufactured Near Beta Titanium Alloy-Ti55511

Helena Van Swygenhoven, Nicola Casati

The effect of electron-beam melting (EBM) and selective laser melting (SLM) processes on the chemical composition, phase composition, density, microstructure, and microhardness of as-built Ti55511 blocks were evaluated and compared. The work also aimed to ...

2020