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Aude Simar
Professor
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Recent publications

Aude Simar has as main research topic the mechanical behavior of light metallic alloys (mainly aluminum, but also magnesium and titanium). Her focus is on material processing in particular by additive manufacturing (Selective laser melting) and friction stir welding and processing. She studies the link between the material structure, the process conditions, the resulting microstructural features and the mechanical properties including damage, fatigue, impact and toughness. She recently received an ERC starting grant (ALUFIX project) to develop new self-healing aluminum based materials and mitigate damage in existing aluminum alloys.

IMMC main research direction(s):
Processing and characterisation of materials
Solid mechanics

Keywords:
additive manufacturing
fracture mechanics
metallurgy
micromechanics
nanocomposites
plasticity
welding and joining

Research group(s): IMAP

    

PhD and Post-doc researchers under my supervision:



Florent Hannard

graduated as a materials science engineer at Université catholique de Louvain (Belgium) in 2013. He is currently doing a PhD thesis (funded by a FRIA grant), started in September 2013 and under the joint supervision of Prof. Thomas Pardoen and Prof. Aude Simar from UCL. His research focuses on the contribution from microstructure heterogeneities on the micromechanisms of ductile damage and cracking in metallic alloys. In order to address these effects on damage accumulation, a combined experimental and a modeling strategy is developed. The experimental strategy relies on in situ tensile testing coupled to 3D microtomography, in situ laminography during sheet loading and a variety of more classical mechanical tests. A cellular automaton type modeling is used to capture particle size distribution and cluster effects on the void nucleation and coalescence processes. His project also involves the use of friction stir processing (FSP) in order to increase the ductility of industrial aluminium alloys of the 6xxx series. From an applicability viewpoint, this method has the potential to locally improve ductility of sheets at locations where forming involves large strains or of structural components at stress concentration points.


Design, Friction Stir Processing and characterization of a new healable aluminum alloy.
Mariia Arseenko

Aluminum alloys are widely used in the aerospace industry because of a good combination of mechanical properties and lightness. Large iron-rich intermetallic particles contained in the aluminum alloys are their source of damage. My PhD project proposes to aim for a new paradigm very little exploited for metallic systems: damage healing. Thus, I will design, process and characterize a new healable aluminum alloys.
Friction Stir Processing (FSP) will be used to fabricate aluminum based Metal Matrix Composites (MMCs) with healing ability. Indeed, FSP leads to microstructure refinement, homogenization and porosity reduction that can significantly postpone damage. Moreover, FSP provides uniform distribution of reinforcing particles in the produced MMCs. FSP may also be used to process out-of-equilibrium microstructures.
In order to heal damage, low-melting point intermetallic compounds will be embedded in an aluminum matrix by FSP and be the source of damage rather than the iron-rich intermetallic particles. Healing will be triggered by a heat treatment causing local melting of the healing particles.



Sophie Ryelandt

graduated as a physical engineer at Université catholique de Louvain in 1991. After having worked for six years at the R&D center of the Spadel company, she came back at UCL as a senior scientist. She is involved in various applied research projects in collaboration with the industry. Her research domains are dealing with material science, metallic composites, multilayered materials and coatings, additive manufacturing of metals, nanomechanical and mechanical testing and the link between microstructure and mechanical properties.


Aerostream and IAWATHA (additive manufacturing), LOCOTED (thermoelectrics)
Camille van der Rest

Camille van der Rest completed her PhD thesis on the optimisation of Heusler Fe2VAl-based thermoelectric compounds through innovative metallurgical processing in 2015. It was under the joint supervision of Prof. Pascal Jacques and Prof. Aude Simar. Her research topics now concern thermoelectric materials, additive manufacturing and friction stir processing technologies. Concerning thermoelectrics, the main objective is the development of low-cost, non-toxic, and powerful materials that could be used in large-scale industrial applications of heat recovery. In addition, she studies some fundamental aspects in order to improve the performances of such materials, i.e. ordering phenomena in off-stoichiometric Fe2VAl-based Heusler compounds. It is essential to make the link between (innovative) manufacturing processes, microstructures and the functional properties of these TE materials. Concerning additive manufacturing, the main contributions are on the characterisation and optimisation of the microstructures and the mechanical behaviour of Al parts obtained by Selective Laser Melting and the developpment of new materials for additive manufacturing. Again, the link between the process parameters and the final microstructure/properties is a key issue. Finally, Camille developed, together with Prof. Aude Simar and Prof. Pascal Jacques, a novel Friction Melt Bonding (FMB) process in order to weld aluminium alloys and steels. This process is still under development thanks to the collaboration with other researchers of IMAP.


RESTEAR
Thaneshan Sapanathan

completed a mechanical engineering degree and a PhD at Monash University (Australia) in 2010 and 2014, respectively. His thesis was entitled “Fabrication of axi-symmetric hybrid materials using combination of shear and pressure”. During his PhD, he worked on architectured hybrid materials fabrication using severe plastic deformation (SPD) processes. Two novel axi-symmetric SPD techniques were investigated to fabricate hybrid materials with concurrent grain refinements. After that, he started a research project at University of Technology of Compiègne (France) in which he investigated the weldability window for similar and dissimilar material combinations using numerical simulations for magnetic pulse welding. He also studied the interfacial phenomena, behavior of material under high strain rate deformation, modeling and simulation of the magnetic pulse welding/forming. Then, I was working as a postdoctoral research fellow at UCL on the topic of characterizations of aluminium to steel welds made by friction stir welds and friction melt bonding. At present, I am working as a FNRS reserch officer (Chargé de recherche) and investigating intermetallic induced residual stresses and mitigation of hot tear in innovative dissimilar joints.


Friction stir processing based local damage mitigation and healing in aluminium alloys
Matthieu Baudouin Lezaack

Al 7XXX alloys will be characterized before and after friction stir process (FSP) in order to identify the damage mechanisms. The performances of FSPed alloys will be studied by macromechanical testing. Up to now, a 150% increase in ductility was reached by FSP + heat treatments compared to the base 7475 Al material. Then a numerical model will catch the 7XXX aluminium behavior in a close future.


Development of a new healable aluminum alloy processed by selective laser melting
Julie Gheysen


Friction Stir Processing (FSP) and mitigation of crack propagation through second-phase particles​
Nelson Gomes Affonseca Netto


Vieillissement thermomécanique des brasures d'assemblage de composants électroniques pour applications spatiales
Vincent Voet

Les développements d’électroniques pour applications spatiales nécessitent de garantir une durée de vie de 15 ans avec une probabilité d’échec très faible. L’objet de la recherche sera d’établir des outils de conception permettant l’analyse préalable du comportement en fatigue de ces équipements électroniques. La fatigue des circuits électroniques est dominée par la rupture des brasures des composants montés sur circuits imprimés. Une fois solidaires du circuit imprimé, les brasures subissent tout au long de leur vie des contraintes thermomécaniques liées entre autres à l’inhomogénéité des différents coefficients de dilatation thermique des matériaux qui constituent le montage. Chaque composant combiné à chaque type de report doit donc être caractérisé en vieillissement. Cette caractérisation consiste à réaliser des centaines de cycles thermiques en étuve. Ces essais de vieillissement accélérés prennent plusieurs mois et sont coûteux d’où le besoin de pouvoir estimer les probabilités d’échec ou de succès de façon anticipée.
Cette évaluation permettra de donner un intervalle de confiance sur le succès ou l’échec de la qualification d’un nouveau report de composant ou de l’extrapolation d’un report qualifié dans un environnement étendu. La construction de ces outils sera basée sur de la caractérisation par plans d’expériences physiques ou virtuels et de l’analyse de données relatives aux essais déjà réalisés dans le passé par Thalès Alenia Space.
L’analyse des mécanismes et conditions de fissuration impliquera notamment: Métallurgie des brasures SnPb en lien avec les paramètres de fabrication; Identification de lois de comportement thermoviscoplastiques des brasures SnPb à l’aide de la nanoindentation instrumentée; Calcul, par méthodes numériques, des champs de contraintes dans les composants et les brasures, provoqués par l’inhomogénéité des coefficients de dilatation thermique des constituants sur base du modèle constitutif choisi, de la géométrie locale de la soudure et des paramètres identifiés ;Identification des mécanismes de propagation de fissures et identification des liens avec la géométrie et la métallurgie ; en particulier, un élément clé est de pouvoir déterminer la part prise par la phase d’initiation versus propagation des fissures, dans le but éventuel de justifier qu’une des deux puisse être négligée. Dans ce cadre, il est prévu de générer des soudures avec des défauts artificiels contrôlés afin de voir leur impact sur le processus d’initiation de la fissuration, et de le quantifier. L’utilisation de la microtomographie exploitant aussi la corrélation d’image volumique sera un élément important à ce niveau; Vieillissement des brasures sur base des lois de vieillissement établies ; Quantification des incertitudes par approche statistique et probabilité à partir des données expérimentales et également par variation des paramètres clés dans leur plage d’incertitude (défauts géométriques, variations des paramètres constitutifs, présence des pré-défauts, variations de T° extrêmes, etc); Estimation d’un intervalle de confiance préalable de succès ou d’échec des essais envisagés.


On the joining of metallic materiels through means of friction
Nicolas Dimov


Improving the fatigue life of high strength aluminum parts (7xxx) produced by laser powder bed fusion
Nicolas Nothomb

Laser Powder Bed Fusion (L-PBF) is a fast-growing metal Additive Manufacturing (AM) technique (commonly known as 3D printing) that allows for complex part manufacturing and small production series. One of the main drawbacks is the limited material palette currently available and the often poor fatigue performance of the resulting parts. Currently, L-PBF does not allow the production of high performances aluminium alloys parts adapted for the aerospace industry. Indeed, these alloys exhibit severe cracking due to the high thermal gradients during L-PBF process.


The overarching objective of my PhD thesis project is to overcome the challenges of the L-PBF processing of the 7xxx series Al alloys in order to improve their fatigue life. This objective involves the elimination of the three classical issues associated with this process ; (i) the elimination of the deleterious hot cracking, (ii) closing of the porosity and (iii) overcoming the poor surface quality classically observed for AM components. The proposed approach has two major advantages. First, the application of friction stir processing (FSP) to selected regions of structural components ensures defect-free microstructures at locations of stress concentration. This is essential to enhance the quality and reliability needed for generalizing the adoption of metal AM for structural components. Indeed, even very small fractions of porosity will affect fatigue properties. Second, the surface roughness is improved in situ, i.e. AM components can be used in as-printed condition, as opposed to classical surface post-treatments currently preventing the design of AM components with complex internal geometries (where surface finishing by conventional post-treatments is impossible).


Mechanisms leading to failure under static or cyclic loading will be analysed using in-situ techniques (microtomography and crack propagation with image correlation).




In situ and ex situ TEM investigations on novel metallic-based materials
Ankush Kashiwar

The project is focused on the advanced transmission electron microscopy (TEM) characterizations which will be performed on the novel aluminium-based alloys processed by friction stir and 3D printing and involving multi-material (steel, Mg, oxides, Ni-Ti,...) interfaces. The materials are developed or processed in The Institute of Materials and Process Engineering (IMMC) of the Université catholique de Louvain (UCLouvain). The TEM characterization techniques include automated crystallographic orientation mapping in TEM (ACOM-TEM), in-situ TEM experiments including heating, cooling and straining as well as high resolution (scanning-) transmission electron microscopy. The TEM-based characterization will be performed under the supervision of Prof. Nick Schryvers in association with the Electron Microscopy for Materials Science (EMAT) group at the University of Antwerp.



Sutao Han

Use material defects and performance differences to achieve excellent macro-scale mechanical properties


FSAMGSA
Jishuai Li

This project aims to design a gradient structured aluminium by friction stir additive maufacturing.



Recent publications

See complete list of publications

Journal Articles


1. Li, Jishuai; Sapanathan, Thaneshan; Raoelison, Rija Nirina; Hou, Yuliang; Simar, Aude; Rachik, Mohamed. On the complete interface development of Al/Cu magnetic pulse welding via experimental characterizations and multiphysics numerical simulations. In: Journal of Materials Processing Technology, Vol. 296, no. 117185 (2021) (2021). doi:10.1016/j.jmatprotec.2021.117185. http://hdl.handle.net/2078.1/245509

2. Jiménez Mena, Norberto; Sapanathan, Thaneshan; Jacques, Pascal; Simar, Aude. Combined numerical and experimental estimation of the fracture toughness and failure analysis of single lap shear test for dissimilar welds. In: Engineering Fracture Mechanics, Vol. 249, no. 107756 (2021). doi:10.1016/j.engfracmech.2021.107756. http://hdl.handle.net/2078.1/245654

3. Zhao, Lv; Santos Macias, Juan Guillermo; Douillard, Thierry; Li, Zhenhuan; Simar, Aude. Unveiling damage sites and fracture path in laser powder bed fusion AlSi10Mg: Comparison between horizontal and vertical loading directions. In: Materials Science and Engineering: A, Vol. 807, p. 140845 (2021). doi:10.1016/j.msea.2021.140845. http://hdl.handle.net/2078.1/242891

4. Huang, Chunjie; Arseenko, Mariia; Zhao, Lv; Xie, Yingchun; Elsenberg, Andreas; Li, Wenya; Gärtner, Frank; Simar, Aude; Klassen, Thomas. Property prediction and crack growth behavior in cold sprayed Cu deposits. In: Materials & Design, Vol. 206, p. 109826 (2021). doi:10.1016/j.matdes.2021.109826. http://hdl.handle.net/2078.1/246285

5. Sapanathan, Thaneshan; Sabirov, Ilchat; Xia, Peikang; Monclus, Miguel; Molina-Aldareguia, Jon M; Jacques, Pascal; Simar, Aude. High temperature in situ SEM assessment followed by ex situ AFM and EBSD investigation of the nucleation and early growth stages of Fe-Al intermetallics. In: Scripta Materialia, Vol. 200, no. 113910 (2021). doi:10.1016/j.scriptamat.2021.113910. http://hdl.handle.net/2078.1/244929

6. Gheysen, Julie; Marteleur, Matthieu; van der Rest, Camille; Simar, Aude. Efficient optimization methodology for laser powder bed fusion parameters to manufacture dense and mechanically sound parts validated on AlSi12 alloy. In: Materials & Design, Vol. 199, p. 109433 (2021). doi:10.1016/j.matdes.2020.109433. http://hdl.handle.net/2078.1/240767

7. Lezaack, Matthieu Baudouin; Simar, Aude. Avoiding abnormal grain growth in thick 7XXX aluminium alloy friction stir welds during T6 post heat treatments. In: Materials Science and Engineering: A, Vol. 807, p. 140901 (2021). doi:10.1016/j.msea.2021.140901. http://hdl.handle.net/2078.1/243408

8. Avettand-Fènoël, Marie-Noëlle; Sapanathan, Thaneshan; Pirling, Thilo; Racineux, Guillaume; Simar, Aude; Drezet, Jean-Marie. Investigation of residual stresses in planar dissimilar magnetic pulse welds by neutron diffraction. In: Journal of Manufacturing Processes, Vol. 68, p. 1758-1766 (2021). doi:10.1016/j.jmapro.2021.06.071. http://hdl.handle.net/2078.1/249441

9. Heidarzadeh, A.; Mironov, S.; Kaibyshev, R.; Çam, G.; Simar, Aude; Gerlich, A.; Khodabakhshi, F.; Mostafaei, A.; Field, D.P.; Robson, J.D.; Deschamps, A.; Withers, P.J. Friction stir welding/processing of metals and alloys: A comprehensive review on microstructural evolution. In: Progress in Materials Science, Vol. 117, p. 100752 (2021). doi:10.1016/j.pmatsci.2020.100752. http://hdl.handle.net/2078.1/236229

10. Santos Macias, Juan Guillermo; Elangeswaran, Chola; Zhao, Lv; Buffière, Jean-Yves; Van Hooreweder, Brecht; Simar, Aude. Fatigue crack nucleation and growth in laser powder bed fusion AlSi10Mg under as built and post-treated conditions. In: Materials & Design, Vol. 210, p. 110084 (2021). doi:10.1016/j.matdes.2021.110084. http://hdl.handle.net/2078.1/250445


Patents


1. Jacques, Pascal; van der Rest, Camille; Simar, Aude. Method for Welding at least two layers. http://hdl.handle.net/2078.1/135184 http://hdl.handle.net/2078.1/135184

2. Jacques, Pascal; Simar, Aude; van der Rest, Camille; Matagne, Ernest; Roy, Geoffrey; Shmitz, Alain. Thermoelectric conversion module and method for making it. http://hdl.handle.net/2078.1/135212 http://hdl.handle.net/2078.1/135212


Conference Papers


1. Sapanathan, Thaneshan; Ryelandt, Sophie; Miotti Bettanini, Alvise; Jacques, Pascal; Simar, Aude. Segregation of alloying elements on the hot tear formation in friction melt bonding of Al/steel joints. 2021 xxx. http://hdl.handle.net/2078.1/244593

2. Dimov, Nicolas; Charkaluk, Eric; Sapanathan, Thaneshan; Simar, Aude; Vasquez, Elodie; Benoist, Julien. Soudage dissimilaire AA6061 /AA7075 : identification de la fenêtre de paramètres procédé, microstructures et essais statiques. 2021 xxx. http://hdl.handle.net/2078.1/244854

3. Lezaack, Matthieu Baudouin; Hannard, Florent; Simar, Aude. Towards high strength and high ductility 6XXX and 7XXX aluminium alloys. 2021 xxx. http://hdl.handle.net/2078.1/244592

4. Santos Macias, Juan Guillermo; Douillard, Thierry; Zhao, Lv; Maire, Eric; Pyka, Grzegorz; Simar, Aude. Build platform temperature during laser powder bed fusion of AlSi10Mg; influence on 3D microstructure, strength and ductility. 2021 xxx. http://hdl.handle.net/2078.1/244689

5. van der Rest, Camille; Santos Macias, Juan Guillermo; Zhao, Lv; Marteleur, Matthieu; Jacques, Pascal; Simar, Aude. Enhancement of the mechanical behavior of SLM AlSi10Mg by optimized thermomechanical postprocessing routes. In: THERMEC‘2021 – Book of Abstracts, 2021, p. 701 (#1390) xxx. http://hdl.handle.net/2078.1/244611

6. Gomes Affonseca Netto, Nelson; Zhao, Lv; Ding, Lipeng; Idrissi, Hosni; Soete, Jeroen; Pyka, Grzegorz; Charkaluk, Eric; Simar, Aude. Enhancing resistance to fracture in light metals: From Al1050 fracture toughness to Al7075 fatigue crack growth rate. In: Thermec 2021 - Book of Abstracts, 2021 xxx. http://hdl.handle.net/2078.1/244713

7. Dimov, Nicolas; Sapanathan, Thaneshan; Simar, Aude; Charkaluk, Eric; Benoist, Julien. Local damage behaviour of friction stir-welded AA6061 /AA7075 under fatigue and static loading. 2021 xxx. http://hdl.handle.net/2078.1/244752

8. Arseenko, Mariia; Ding, Lipeng; Idrissi, Hosni; Simar, Aude. Production of a healable Al-based Metal Matrix Composites by Friction Stir Processing. In: THERMEC‘2021 – Book of Abstracts, 2021, p. 58-59 (#115) xxx. http://hdl.handle.net/2078.1/244607

9. Gomes Affonseca Netto, Nelson; Zhao, Lv; Charkaluk, Eric; Hosdez, Jérôme; Simar, Aude. On the fatigue crack growth resistance of aluminum matrix composites reinforced by shape memory alloys. 2021 xxx. http://hdl.handle.net/2078.1/244708

10. Gheysen, Julie; Marteleur, Matthieu; Camille van de Rest; Simar, Aude. Efficient optimization methodology for laser powder bed fusion parameters to manufacture dense parts validated on AlSi12 alloy. 2021 xxx. http://hdl.handle.net/2078.1/250733


Book Chapters


1. Simar, Aude; Avettand-Fenoël, Marie-Noëlle. Friction Stir Processing for Architectured Materials. In: Architectured Materials in Nature and Engineering (Springer Series in Materials Science; xxx), Springer, Cham, 2019, p. 195-229. 978-3-030-11941-6. xxx xxx. doi:10.1007/978-3-030-11942-3_7. http://hdl.handle.net/2078.1/214932


Dissertations


1. Simar, Aude. A multiscale multiphysics investigation of aluminum friction stir welds : from thermal modelling to mechanical properties through precipitation evolution and hardening/, prom. : Pardoen, Thomas ; de Meester, Bruno, 2006-07-17. http://hdl.handle.net/2078.1/5203