Ongoing research projects

IMMC

Ongoing research projects in iMMC (October 2021)


This a short description of research projects which are presently under progress in iMMC.
Hereunder, you may select one research direction or choose to apply another filter:

Biomedical engineering

Computational science

Civil and environmental engineering

Dynamical and electromechanical systems

Energy

Fluid mechanics

Processing and characterisation of materials

Chemical engineering

Solid mechanics


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List of projects related to: Processing and characterisation of materials




Development of high-toughness cryogenic alloys
Researcher: Alvise Miotti Bettanini
Supervisor(s): Pascal Jacques

Materials that can perform at extremely low temperatures are in great demand. Applications span from tanks and pressure vessels for LNG (Liquefied Natural Gas) carriers to structural materials in extreme conditions, like the upcoming exploration of Mars. In this context, it is critical to ensure very high toughness, which measures the resistance to crack propagation, at cryogenic temperatures. In this project, the experimental development of Fe-based superalloys is guided by a CALPHAD-based methodology, which allows the calculation of phase stability and phase transformation with computational models in order to reduce the experimental effort and hasten the development cycle of new materials.



CeraMAX / Aerostream
Researcher: Matthieu Marteleur
Supervisor(s): Pascal Jacques

I am currently working on the processing and characterisation of a particular type of ceramics called MAX phases. They present an intermediate behavior between a ceramic and a metal at high temperature, providing a unique combination of functional properties.
My research projects also include Additive Manufacturing on metallic materials, particularly Al and Ti alloys. I am studying the relationship between the process parameters and the resulting microstructure and properties.



DeltaT
Researcher: Valentin Marchal-Marchant
Supervisor(s): Pascal Jacques

obtained his degree in engineering in materials science from the Université catholique de Louvain in 2011. Then, he accomplished his PhD under the supervision of prof. Pascal Jacques, on the study of Physical Vapor Deposition of thick copper films on steel.

His research is now focused on the development of thermoelectric materials and thermoelectric generators for energy harvesting and passive electromechanical systems. It aims at using common and non-toxic materials to generate electrical power from thermal gradients. Nowadays, attention is put on large scale applications owing to more than 7 years of research about thermoelectric materials leaded in IMAP.

The big challenge of this topic is the development of new tools and equipments for material production and assembly, and specific characterization methods. Such a wide range of different tasks can only be achieved thanks to the versatility of technical and scientific expertises of the IMAP team members as well as Lacami support.



Coupled mechanical-electrical effects in highly strained Ge thin films
Researcher: Marie-Stéphane Colla
Supervisor(s): Thomas Pardoen

Graduated in chemical and materials science engineering at the Université catholique de Louvain in 2009 (Belgium). Then, under the supervision of Prof. Thomas Pardoen (iMMC) and Prof. Jean-Pierre Raskin (ICTEAM), she accomplished a PhD on the study of the mechanical properties of thin films, more specifically on the plasticity and creep of freestanding nanocrystalline Pd films. The lab-on-chip technique developed previously at the UCL was adapted to deform Pd thin films. After the PhD, she worked for more than two years at the CRM Group in Liège on the development of industrially viable thin film solar cells on steel. From June 2016 to September 2018, she is back at the UCL as a research engineer involved in projects dealing with the understanding of fracture behaviour of high strength steels under a wide range of strain rates.​ In 2018, she received a 'Chargée de recherches - FNRS grant' and is now working on coupled mechanical-electrical effects in highly strained germanium thin films. Germanium is a promising material for optoelectronic device owing to its compatibility with the standard complementary metal-oxyde-semiconductor (CMOS) technology and to the possibility to convert it into a direct bandgap semiconductor by straining it.



Locoted
Researcher: Geoffrey Roy
Supervisor(s): Pascal Jacques

Geoffrey holds a Master in Mechatronic Engineering (2010) and a PhD in Engineering (2015) from the Université catholique de Louvain where he works as a senior researcher at the Institute of Mechanics, Materials and Civil Engineering (iMMC).
Within the Division of Materials and Process Engineering (IMAP), his research is focused on the development of new thermoelectric materials and systems for a range of applications going from industrial waste heat recovery to autonomous powering of smart sensors. In his research, he pays particular attention to the development of new solutions that present improved both technical and economical profiles in order to facilitate the emergence of these solutions out of the lab.
This research is followed by several companies such as: Drever International, AGC Glass Europe, Carmeuse or Engie.



Aerostream and IAWATHA (additive manufacturing), LOCOTED (thermoelectrics)
Researcher: Camille van der Rest
Supervisor(s): Pascal Jacques, Aude Simar

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.



TECCOMA
Researcher: Pierre Bollen
Supervisor(s): Thomas Pardoen

graduated as engineer in chemistry and materials science at Université catholique de Louvain (Belgium) in 2010. In 2015, he obtained at UCL his PhD thesis entitled hierarchical hybrid materials combining wideband electromagnetic absorption and mechanical performance, funded by a FRIA grant. After working one year as a support engineer in the field of extended finite element modeling, he came back at the UCL as a senior researcher involved in applied research projects in collaboration with industry. He is currently dealing with erosion coating on CFRP as well as thermal and electromagnetic management in electrical power converter.



MACOBIO (MAtériaux COmposites BIOsourcés)
Researcher: Vincent Destoop
Supervisor(s): Thomas Pardoen

made his PhD on the adhesion of tooth-filling materials to the dentine. He’s now working on composite materials to replace metals in aircraft applications. He takes part to projects studying the mechanical behavior of composite materials (mainly polymer matrix reinforced with long fibers) which are new candidate materials for modern planes. Recently, his research was oriented on biosourced composites. His investigations focus on the bulk, cracking, impact and adhesion properties.




Researcher: Catherine Doneux
Supervisor(s): Thomas Pardoen

graduated as Civil Engineer at University of Liege in 1992. She began her career with a first experience on the assessment of an existing prestressed railway bridge. Thanks to several FNRS grants, she obtained a PhD degree in the domain of steel-concrete composite structures under seismic action in 2002 and was involved in several researches on paraseismic design at ULg until 2005. After some career break, she joined UCL in December 2008 to take part to the development of new composite activities related to various applied research projects in collaboration with the industry (aeronautics) Her main fields of expertise are the mechanical characterization of composite materials by mechanical testing, the quality control of the standardised tests and the development of new tests. She has also some experience in fatigue testing, damage characterization and fracture mechanics. She is currently working on the preforming of composite thermoset prepreg fabrics.



BIODEC, STOCC
Researcher: Audrey Favache
Supervisor(s): Thomas Pardoen

obtained a PhD degree in the domain of process control in 2009 at Université catholique de Louvain (Belgium), after having graduated there as chemical engineer in 2005. Since then, she is working as a "senior" researcher on several applied research projects in collaboration with the industry in the domain of mechanics of materials. More particularly, she is interested in the link between the mechanical properties of the individual components of a complex system and the global mechanical response of this system. She applied this approach to the framework of tribology and contact mechanics for understanding the scratch resistance of coatings and multilayered systems. Her work covers both experimental aspects and finite element simulations.



RESTEAR
Researcher: Thaneshan Sapanathan
Supervisor(s): Aude Simar

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.



Renforcement des capacités de RDI des organismes de recherche dans les domaines utiles aux PME
Researcher: Michaël Coulombier
Supervisor(s): Thomas Pardoen

graduated as a material science engineer from UCL in 2006. He finished his PhD in 2012 under the supervision of Prof. Thomas Pardoen (iMMC) and Prof. Jean-Pierre Raskin (ICTEAM) developing a lab on-chip technique for nano-mechanical characterisation of thin films. Since then he has been a research assistant in iMMC involved in various projects dealing with material science, nanomechanical testing and tribology.



Friction stir processing based local damage mitigation and healing in aluminium alloys
Researcher: Matthieu Baudouin Lezaack
Supervisor(s): Aude Simar

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.



Influence of defects on the life of biomedical implants
Researcher: Maïté Croonenborghs
Supervisor(s): Pascal Jacques, Thomas Pardoen

Implants are devices aiming to support, help, or even correct biological structures. However, with time, some of these implants show aging problems. The roots of these problems can have numerous explanations. In some cases, the body reacts to the presence of a foreign body, and this can lead to health risks. Sometimes, the material can show, with time, signs of weakness. Later on, these defects can lead to the failure of the implant.

In the case of permanent stent implants, the presence of a foreign body in the blood vessels can lead to restenosis or late thrombosis. This is why bioresorbable stents are nowadays developed. These stents should support the vessels during their healing period and dissolve in an inoffensive way afterward. Iron-based alloys are investigated for their appropriate mechanical properties but their degradation rate is too low. One investigated solution is to increase surface roughness to dissolve faster the implant. The effect of this roughness on the expansion process has not been analyzed for now.

The case of growth rods shows that the material itself can lead to implant failure. These rods are placed, during surgery, along the spine of scoliotic children. They aim to support the spine and help it to straighten back. However, fracture events occur in 36% of the patients. During the surgery, the rods are bent to fit the natural shape of the spine. The tools employed for this process can introduce some indentation marks on the surface of the rods and decrease their fatigue lifetime.

From these case studies, it is observed that the completion of an implant (i.e. stent implantation process) or its lifetime (i.e. growth rod failure) can be affected by its surface state. This research will therefore focus on the imperfection sensitiveness of such devices. Various kinds of defects are introduced at the sample surface. To understand the influence of these defects on the mechanical properties, these samples are tested and compared.



Fracture toughness of high entropy alloys
Researcher: Antoine Hilhorst
Supervisor(s): Pascal Jacques, Thomas Pardoen

High entropy alloys (HEAs) are a new family of metallic alloys. In contrast to conventional alloys, HEAs have multiple principal elements e.g. the equiatomic "Cantor" alloy CrMnFeCoNi. Alloys in this range of chemical composition have gathered attention only recently. From what was observed in conventional alloys, it was expected that HEAs microstructure be composed of several intermetallic phases but some systems are surprisingly single phase solid solution. Moreover, such single-phase alloys have excellent mechanical properties. For instance, CrMnFeCoNi possess a large fracture toughness, which increases with decreasing temperature, putting this alloy on par with the current best alloys used for cryogenic applications. As such, the objective of the thesis is to understand the underlying mechanisms responsible for the observed macroscopic behavior of such alloys.


The thesis aims to answer several questions such as: What are the mechanisms responsible for the increase in ductility, strength, and fracture toughness with decreasing temperature? What high-throughput methodology would be able to screen the vast range of possible chemical composition of HEAs for high performance alloys?


To understand the deformation mechanisms, several HEAs will be fully characterized from casting to mechanical testing. For the fracture toughness measurements, the essential work of fracture method will be employed as it is best suited for ductile thin sheets than compact tests. Diffusion multiples will be explored as a possible high-throughput method, as the presence of composition gradients allows the simultaneous characterization of a range of composition by techniques such as EDX, EBSD and nano-indentation.



On a chip fracture mechanics test method
Researcher: Sahar Jaddi
Supervisor(s): Thomas Pardoen

The aim of this research is to develop a new testing method based on an-on-chip concept to measure the fracture toughness of freestanding submicron films. This device consists of two major components, a notched specimen and two actuators. When the test structure is released by etching the sacrificial layer, the two actuators contract, this in turn loads the specimen in traction. In order to define the stress intensity factor expression, which is given by this new model, analytical analysis and finite element simulations must be performed in addition to the experimental part, which is based on the microfabrication techniques. Silicon nitride, silicon oxide and metallic glass thin films will be studied during this work. The major goal of this model is to extract fracture toughness of 2D materials like graphene.



Electromechanical properties of thin films
Researcher: Farzaneh Bahrami
Supervisor(s): Thomas Pardoen

The production of Graphene/h-BN heterostructures and the investiong of their microelectromechanical properties, the production of origami and kirigami stacks of Graphene and h-BN, the raman spectroscopy, SEM, TEM AFM and nanoindentation will be used



A microCT-based approach for high-resolution characterization of biodegradable metallic intravascular stent materials
Researcher: Lisa Leyssens
Supervisor(s): Greet Kerckhofs, Pascal Jacques

The goal of my research project is to assess different potential biodegradable metallic intravascular stent materials using high-resolution 3D microfocus X-ray computed tomography (microCT). In a first step, the optimization of microCT and contrast-enhanced microCT (CECT) for the characterization of the 3D microstructure of different blood vessels is performed (aorta, femoral artery, vena cava). Then, this technique is applied to study the degradation behaviour of potential materials for biodegradable metallic intravascular stents. Structural properties are investigated. They are critical because they will influence the mechanical and in vivo behaviour of the stents. The materials (in the shape of wires) are screened to analyze the corrosion and surface changes, before and after immersion tests (in vitro part) and before and after implantation in rat arteries to additionally study interactions between the tissue (artery) and the metal (in vivo part).



Improving the properties of glass fiber reinforced acrylic thermoplastic resin based composites
Researcher: Sarah Gayot
Supervisor(s): Thomas Pardoen

For the manufacturing of continuous fiber reinforced thermoplastic composites (CFRTP), certain monomers can be infused through glass fabric and then polymerized in situ, in order to make a thermoplastic composite part. However, defects - e.g. porosity - can occur in the material, due to the thickness of the laminates and the shrinkage of the resin matrix during polymerization. Such phenomena must be understood, as well as their effects on the mechanical properties of the final composite part.

The originality of this work lies in the very nature of the polymeric matrix used for manufacturing the composite parts, which is thermoplastic instead of thermoset. Little is known about the behaviour of such thermoplastic composites, especially at a microscopic scale. During this PhD, we will try to understand how defects occurring in the material can influence the structural properties of the CFRTP, and we will try to mitigate (or at least control) the incidence of such defects. This will imply a better knowledge of how usual characterisation techniques can be applied from thin to thick composite parts. In particular, digital simulation will be used so as to predict the properties of thick composite parts from those of thinner samples.



Development of thermo-tensile nano devices operating ex situ or in situ in transmission electron microscopes (TEM)
Researcher: Alex Pip
Supervisor(s): Hosni Idrissi

The main goal of my research project is to develop modern miniaturized devices dedicated to quantitative small-scale thermo-tensile testing in-situ inside a transmission electron microscope. These unique devices will be used to investigate the effect of T on the plasticity/failure mechanisms in selected materials, nanocrystalline palladium films and olivine. My project builds up on already existing MEMS devices, namely the commercial Push-to- Pull from Bruker.Inc and UCLouvain’s ‘lab-on-chip’ nano tensile testing devices. Currently, those devices are limited to room temperature experiments. My work will be dedicated to the integration of heating systems inside these two devices, in order to heat samples up to hundreds of °C. This will allow performing in-situ TEM thermo-tensile tests on Pd films and olivine samples where the coupling between tensile loading and heating could lead to unprecedented results regarding the effect of T on the mechanical response and the plasticity/failure mechanisms.

This project has a direct application in the field of geology, as one of the selected material is olivine, the material that makes up most of the upper part of the Earth’s mantle. Thermo-tensile testing of olivine at the micro/nano scale will bring crucial data about its rheology under conditions similar to the Earth’s mantle. This part of the project involving olivine will be performed in close contact with prof. Patrick Cordier and his team at UMET (Université de Lille). The other selected material is Pd, a material that is well known by the UCLouvain’s IMMC researchers used here as a benchmark. I will mostly work within the WINFAB platform, where I will develop and build the new thermo-tensile devices using the nanofabrication equipment. As theses devices are expected to be used in-situ inside a TEM, I will also partly work at the EMAT research center (UAntwerpen).




Impact of membrane characteristics on enzyme reactivity and co-crystallization
Researcher: Sara Chergaoui
Supervisor(s): Patricia Luis Alconero

The project focuses on the enantioselective biocatalytic synthesis of high-value chiral amines. A combined reaction-purification process based on membrane technology and using enzymes will be developed. As opposed to classical batch and multi-step processes, such an integrated approach would allow (i) maintaining the enzyme in the reactor, (ii) intensifying the production of high added-value chemicals, and (iii) recover a highly pure co-product. Novel membranes will be developed and the effect of their composition and structure on the final performance will be studied.



Analysis and understanding of the damage and fracture mechanisms in advanced high strength steels for automotive applications
Researcher: Thibaut Heremans
Supervisor(s): Pascal Jacques, Thomas Pardoen

The environmental challenge the world is facing today is driving car manufacturers to limit their vehicule weight in order to reduce their fuel consumption. As a consequence, steels with higher specific strength performances are being constantly developed, while insuring that proper ductility and toughness levels are retained to allow for forming operations and passengers safety. Lately, the so-called "third generation" of advanced high strength steels (AHSS) has emerged, among which one finds the Quenching & Partioning (Q&P) steels. These Q&P steels demonstrate an excellent combination of ultimate tensile strength (UTS = 1500 MPa) and adequate ductility (TE = 18%). Nevertheless, their fracture properties and the underlying mechanisms are still not fully understood and start raising concerns as the strength levels of these steels increase. Indeed, recent studies have highlighted a shift in failure mechanism, from ductile to brittle, depending on the loading conditions. Although often left behind strength and elongation, toughness issues constitute essential stakes not only for ever more demanding applications but also for forming processes during which edge cracking is a key concern. The objective of my research project is to investigate the failure properties of these Q&P steels in order to understand how microstructural and micromechanical parameters influence the competition between three possible mechanisms : ductile flat, ductile slant and brittle intergranular.



Advanced Characterization of the 3D Morphology of the Bone-Tendon Interface and the Relationship to the Functional Properties
Researcher: Arne Maes
Supervisor(s): Greet Kerckhofs

Within my research project I aim to develop insights in the morphology and the structure-function relationships of the bone-tendon interface. To this end, contrast-enhanced microCT (CE-CT) will be applied for advanced structural characterization. A better understanding of this complex biological tissue is believed to greatly improve the probability of success of regenerative strategies aiming to treat injuries of the bone-tendon interface.



Development and charactrisation of a Fe2VAl-based transverse thermoelectric module built by additive manufacturing
Researcher: Mathieu Delcroix
Supervisor(s): Pascal Jacques

The aim of my thesis is to study and optimise an innovative alternative to classical thermoelectric generators according to different aspects : geometry, materials and manufacturing processes. More specifically, it consists in implementing and optimising a Fe2VAl-based transverse thermoelectric generator with an optimize internal topology built by multimaterial additive manufacturing. The main scientific issues that will dictate the experimental approaches and the modelling steps consist in : (i) understanding the transverse thermoelectric effect and its experimental study coupled with a topological optimisation (since existing studies are mainly theoretical only); (ii) the analyse of the microstructural characteristics resulting from the additive manufacturing on the electrical and thermal properties of the Fe2VAl compound (what has not been done so far), but also of the other compounds that are needed in case of multimaterial additive manufacturing; (iii) optimising the characteristics of a functional transverse thermoelectrical generator in function of the operating conditions.



Micromechanics of crystallization of thermoplastic matrices in the interfiber regions of high-toughness composites
Researcher: Sophie Vanpée
Supervisor(s): Thomas Pardoen

A major effort is being made all over the world by industrial and research actors to lead the technological mutation of the field of advanced continuous fibers polymer composites from the current use of thermosetting matrices to thermoplastic ones which gather economic (increased production rates), environmental (recyclable) and performance advantages (tougher matrices). However, until recently, this transformation was strongly hindered by processing difficulties. Today, a precise prediction of the behavior of these materials based on the processing conditions becomes essential for many actors, such as the company Solvay, the industrial partner of the present thesis.











It is in this context that the thesis will be carried out. The objective of the STOUGH project is to unravel the influence of the composite microstructure on the kinetics and morphology of crystallization within the matrix, particularly in the neighborhood of fibers, in order to evaluate their influence on mechanical properties of the matrix and, hence, of the composite. The project is thus intrinsically multi-scale, which necessitates a combination of analyses at the different levels of the composite system, from its constituents themselves to the unidirectional (UD) ply level and eventually to the macroscopic composite.











The main questions are around the positive or negative impact of the conditions and the type of crystallization on the fracture toughness via local damage or decohesion of the fibers, as well as on the transfer of these effects to the macroscopic scale and the properties of use. To do so, it is necessary to understand what makes the behavior of the semi-crystalline polymer confined between fibers and the non-reinforced version of the same polymer different, and how factors related to transcrystallization condition the local mechanical behavior. Does the crystal morphology induce a local softening of the strength or the opposite? Are macroscopic constitutive models adaptable to this scale? Do the local internal stresses affect the first order strength of the interfaces? These are some of the major scientific questions that motivate the fundamental side of this project and justify the framework of a PhD thesis in collaboration with Solvay.











The thesis will be based on an innovative methodology relying on the use of the appropriate experimental methods for each level of investigation. For instance, it will combine atomic probing and nanoindentation for the nano- and microscopic characterization of the matrix, fiber-matrix interface properties measurements, image correlation analyses at the scale of the representative volume of the UD ply as well as macroscopic tests at the coupon level. Additionally, the project will also include the specimens processing and manufacturing steps, as well as numerical aspects to incorporate the acquired knowledge in existing models.