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Pascal Jacques
Professor
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Recent publications


research focuses on the physical and mechanical metallurgy of several engineering alloys: advanced high strength steels for automotive applications with also concerns about hydrogen embrittlement; new high strength metastable titanium alloys for aerospace applications; new thermoelectric or magnetocaloric Heusler compounds for energy harvesting or magnetic cooling; bioresorbable alloys for cardiovascular implants; high entropy alloys with improved toughness; new alloys with improved properties specifically designed for 3D printing.

Research group(s): IMAP

PhD and Post-doc researchers under my supervision:


Development of high-toughness cryogenic alloys
Alvise Miotti Bettanini

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.


Characterization and physics based modeling of plasticity and fracture of Dual-Phase steels towards ultratough materials by microstructure optimization
Karim Ismail

The research work, in collaboration with company ArcelorMittal, is about the plasticity, the damage and the crack propagation resistance of dual-phase steels, which are commonly used in the automotive industry. A minimum level of fracture toughness is required to prevent the propagation during forming operations of small edge damage or cracked zones induced by cutting. Therefore, unravelling the relationship between fracture toughness, microstructure and damage mechanisms is essential to develop advanced steels with superior forming ability. Furthermore, reaching superior fracture toughness could open to other potential applications.
Experimental works as well as computational modeling are used to study the behavior of such steels. A model for the plastic behavior and for the damage mechanisms related to the microstructure has been developed. A finite element based unit cell approach is used to address the plastic behavior, locally as well as at the macroscopic scale. A particular focus is put on the effect of particle morphology and orientation that have not been much investigated and that considerably affect local mechanical fields, and hence damage and fracture behavior. A two-stage void coalescence process is suggested in elongated microstructures. The data extracted from the elastoplastic analysis are fed into a cellular automaton approach of the damage evolution. This model introduces a statistical description of the material while using relatively simple damage evolution laws. Furthermore, the essential work of fracture method is used to quantify the resistance to the propagation of a crack on thin sheets. Martensite morphology in the form of platelets seems to be a means to reach a high fracture toughness. Finally, damage mechanisms are observed post-mortem and hole expansion ratio tests will be performed.


CeraMAX / Aerostream
Matthieu Marteleur

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
Valentin Marchal-Marchant

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.


Study of the hardening properties, damage resistance and toughness of a new family of beta metastables titanium alloys
Laurine Choisez

The association of different plastic deformation modes (TRIP, TWIP) induces unmatched levels of mechanical properties in a new beta metastables titanium alloys family. A hardening beyond the theoretical limit is especially noticed, together with a uniform deformation 3 to 4 times higher than the one in a classic TA6V alloy and a yield stress superior of 30 percent to the one in a
TWIP alloy. A positive synergy is thought to exist between a high hardening and the damage resistance and toughness of such materials. My thesis will consist in the study of the damage resistance and the toughness of several beta metastables titanium alloys with different prevailing plastic deformation mechanisms in order to highlight the mechanism responsible of the post-necking deformation properties.


Surface mechanical treatment by friction stir processing of additive manufactured aluminium alloy parts to improve mechanical behaviour
Juan Guillermo Santos Macias

This research project aims at improving the mechanical behaviour of additive manufactured parts through a friction stir processing (FSP) surface mechanical treatment. This post-processing method significantly enhances ductility and is expected to also enhance fatigue resistance. Fatigue is a critical phenomenon in many applications, e.g. structural parts in the aerospace industry. More specifically, this research is focused on studying the effect of FSP on the microstructure (porosity and second phase size and spatial distribution) and mechanical behaviour (residual stresses and fatigue) of selective laser melting AlSi10Mg parts. Furthermore, in order to define an adequate FSP patterning strategy, the project will also feature an analysis of the influence of processing parameters through a chained thermal and microstructural model.


Locoted
Geoffrey Roy

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.



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.


Influence of defects on the life of biomedical implants
Maïté Croonenborghs

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 afterwards. 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 a 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 to 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
Antoine Hilhorst

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.


Optimisation of the corrosion rate of iron-based alloys for bioresorbable stent applications
Sarah Reuter

The purpose of this PhD thesis is to optimise the metallic surface of iron-based alloys that are good candidates for bioresorbable stents but which corrosion properties are still insufficient. I will thus be working on these alloys by improving their surface properties, by acidifying the surface. Indeed, the corrosion products and salt compounds get deposited due to a neutral/basic environment in the close vicinity of the metal surface. These compounds act as a barrier for further corrosion. By acidifying the metallic surface, this would inhibit, or at least diminish, the deposition of these compounds. The corrosion properties of these metals will be studied by the use of electrochemical tests as well as immersion tests. The surface will be acidified by the presence of protons. This will be done by adding hydrogen in the metal. Nevertheless, the presence of hydrogen is known to weaken the metal. In order to avoid this weakening, the hydrogen will be trapped inside the steel.
This project englobes different disciplines and is made alive thanks to close collaboration with different entities of the UCL.


A microCT-based approach for biomechanical characterization of biodegradable metallic intravascular stents
Lisa Leyssens

The goal of my research project is to develop a highly detailed, advanced characterization platform to assess different aspects of biodegradable metallic intravascular stents using high-resolution 3D microfocus X-ray computed tomography (microCT). This will improve the understanding of the functional behavior of biodegradable stents in order to improve their design for potential clinical use. Structural properties will be investigated. They are critical because they will influence the mechanical and in vivo behavior of the stents. The mechanical properties will be assessed through 3D local strain mapping using 4D microCT. Finally, the stents will be screened in vivo to analyze the corrosion and surface changes, before and after implantation in rat arteries, and to quantify tissue ingrowth. Contrast-enhanced microCT will be used to visualize the vascular tissue. Different metallic alloys will be compared throughout the project.



Amandine Duchaussoy

Implementation of titanium alloys used for additive manufacturing


Analysis of hydrogen uptake mechanisms in Al-Si coated high strength steels during hot stamping process
Mohamed Krid


Bioresorbable TWIP-CF
Galy Ingrid Nkou Bouala

The goal of my research project is to develop and optimize TWIP steels and new alloys for their use as bioresorbable stents. For this application, these materials have to be mechanically strong, biocompatible and their degradation rate has to be adapted to the healing rate of the stented artery. For that, their structure, microstructure and mechanical properties are characterized. For example, Microstructure and phases are evaluated by means of SEM, EDS or EBSD. Tensile tests and indentation tests are used to investigate their mechanical properties. The link between the composition, the microstructure and the multifunctional profile (mechanical behavior and biocorrosion) of these materials could thus be identified.



Recent publications

See complete list of publications

Journal Articles


1. Scarcello, Eleonora; Lobysheva, Irina; Bouzin, Caroline; Jacques, Pascal; Lison, Dominique; Dessy, Chantal. Endothelial dysfunction induced by hydroxyl radicals – the hidden face of biodegradable Fe-based materials for coronary stents. In: Materials Science and Engineering: C, Vol. 112, p. 110938 (2020). doi:10.1016/j.msec.2020.110938. http://hdl.handle.net/2078.1/229665

2. Xiong, Zhiping; Jacques, Pascal; Perlade, Astrid; Pardoen, Thomas. On the sensitivity of fracture mechanism to stress concentration configuration in a two-step quenching and partitioning steel. In: International Journal of Fracture, Vol. on line (2020). doi:10.1007/s10704-020-00448-0. http://hdl.handle.net/2078.1/230007

3. Choisez, Laurine; Ding, Lipeng; Marteleur, Matthieu; Idrissi, Hosni; Pardoen, Thomas; Jacques, Pascal. High temperature rise dominated cracking mechanisms in ultra-ductile and tough titanium alloy. In: Nature Communications, Vol. 11, no.1, p. 2110 (2020). doi:10.1038/s41467-020-15772-1. http://hdl.handle.net/2078.1/229668

4. Scarcello, Eleonora; Lambremont, Alexia; Vanbever, Rita; Jacques, Pascal; Lison, Dominique. Mind your assays: Misleading cytotoxicity with the WST-1 assay in the presence of manganese. In: PLOS ONE, Vol. 15, no.4, p. e0231634 (2020). doi:10.1371/journal.pone.0231634. http://hdl.handle.net/2078.1/229603

5. Xiong, Zhiping; Jacques, Pascal; Perlade, Astrid; Pardoen, Thomas. Characterization and control of the compromise between tensile properties and fracture toughness in a quenched and partitioned steel. In: Metallurgical and Materials Transactions A - Physical Metallurgy and Materials Science, Vol. 50, p. 3502-3513 (2019). doi:10.1007/s11661-019-05265-2. http://hdl.handle.net/2078.1/217519

6. Marteleur, Matthieu; Idrissi, Hosni; Amin-Ahmadi, Behnam; Prima, Frédéric; Schryvers, Dominique; Jacques, Pascal. On the nucleation mechanism of {112}〈111〉mechanical twins in as-quenched β metastable Ti-12 wt.% Mo alloy. In: Materialia, Vol. 7, p. 100418 (2019). doi:10.1016/j.mtla.2019.100418. http://hdl.handle.net/2078.1/218865

7. Jimenez-Mena, Norberto; Simar, Aude; Jacques, Pascal. On the interplay between intermetallic controlled growth and hot tearing susceptibility in Al-to-steel welding with additional interlayers. In: Materials & Design, Vol. 180, p. 107958 (2019). doi:10.1016/j.matdes.2019.107958. http://hdl.handle.net/2078.1/217398

8. Verhaegen, Carole; Lepropre, Sophie; Octave, Marie; Brusa, Davide; Bertrand, Luc; Beauloye, Christophe; Jacques, Pascal; Kefer, Joëlle; Horman, Sandrine. Bioreactivity of Stent Material: <i>In Vitro</i> Impact of New Twinning-Induced Plasticity Steel on Platelet Activation. In: Journal of Biomaterials and Nanobiotechnology, Vol. 10, no.04, p. 175-189 (2019). doi:10.4236/jbnb.2019.104010. http://hdl.handle.net/2078.1/220203

9. Jimenez mena, Norberto; Sapanathan, Thaneshan; Drezet, Jean-Marie; Pirling, Thilo; Jacques, Pascal; Simar, Aude. Residual stresses of friction melt bonded aluminum/steel joints determined by neutron diffraction. In: Journal of Materials Processing Technology, Vol. 266, p. 651-661 (2019). doi:10.1016/j.jmatprotec.2018.11.030. http://hdl.handle.net/2078.1/207775

10. Miotti Bettanini, Alvise; Ding, Lipeng; Mithieux, Jean-Denis; Parrens, Coralie; Idrissi, Hosni; Schryvers, Dominique; Delannay, Laurent; Pardoen, Thomas; Jacques, Pascal. Influence of M23C6 dissolution on the kinetics of ferrite to austenite transformation in Fe-11Cr-0.06C stainless steel. In: Materials & Design, Vol. 162, p. 362 - 374 (2019). doi:10.1016/j.matdes.2018.12.005; 10.1016/j.matdes.2018.12.005. http://hdl.handle.net/2078.1/208252


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. Hilhorst, Antoine; Pardoen, Thomas; Jacques, Pascal. Sur la caractérisation de la ténacité exceptionnelle des alliages à haute entropie à base de métaux de transition. http://hdl.handle.net/2078.1/226233

2. Ismail, Karim; Pardoen, Thomas; Jacques, Pascal; Perlade, A; Brassart, L. Fracture mechanisms of dual-phase steels exhibiting a platelet-like microstructure.. http://hdl.handle.net/2078.1/226646

3. Ismail, Karim; Brassart, Laurence; Perlade, A; Jacques, Pascal; Pardoen, Thomas. Fracture mechanisms of dual-phase steels exhibiting a platelet-like microstructure. http://hdl.handle.net/2078.1/226644

4. Choisez, Laurine; Marteleur, Matthieu; Jacques, Pascal. On the damage resistance of TRIP-TWIP beta-metastable Ti-12wt.%Mo alloy. http://hdl.handle.net/2078.1/226606

5. Choisez, Laurine; Ding, Lipeng; Idrissi, Hosni; Jacques, Pascal. On the fracture mechanisms of Ti-12 wt.%Mo alloy exhibiting TRIP-TWIP effects. http://hdl.handle.net/2078.1/226604

6. Nguyen, Van-Dung; Harik, P; Hilhorst, Antoine; Pardoen, Thomas; Jacques, Pascal; Noels, Ludovic. A multi-mechanism non-local porosity model for high-ductile materials; application to high entropy alloys. http://hdl.handle.net/2078.1/226263

7. Ismail, Karim; Brassart, Laurence; Perlade, Astrid; Jacques, Pascal; Pardoen, Thomas. Résistance à la fissuration exceptionnelle d’aciers dual-phase à microstructure plaquettaire. http://hdl.handle.net/2078.1/226308

8. Leyssens, Lisa; Verhaegen, Carole; Horman, Sandrine; Jacques, Pascal; Kerckhofs, Greet. Optimization of contrast-enhanced micro-CT for characterization of the in vivo behavior of biodegradable metallic intravascular stents. http://hdl.handle.net/2078.1/219156

9. Sapanathan, Thaneshan; Jimenez-Mena, Norberto; Drezet, Jean-Marie; Cabeza, Sandra; Pirling, Thilo; Jacques, Pascal; Simar, Aude. Residual stresses in Al6061/DP600 welds produced by a process derived from Friction Stir Welding. http://hdl.handle.net/2078.1/219667

10. Croonenborghs, Maïté; Jacques, Pascal. Iron-based biodegradable stents: impact of surface roughness on mechanical properties. http://hdl.handle.net/2078.1/218882


Book Chapters


1. Jacques, Pascal. Phase transformations in transformation induced plasticity (TRIP)-assisted multiphase steels. In: Phase transformations in steels. Volume 2: Diffusionless transformations, high strength steels, modelling and advanced analytical techniques , Woodhead Publishing: Cambridge, UK, 2012, p. 213-246. 978-1-84569-971-0. doi:10.1533/9780857096111.2.213. http://hdl.handle.net/2078.1/122798

2. Jacques, Pascal; Furnemont, Quentin; Godet, Stéphane; Conlon, K.. Micromechanical characterisation and modelling of TRIP-assisted multiphase steels. In: Annual report 2003 NRC-CNRC , xxx, 2003, p. 42-43. http://hdl.handle.net/2078.1/74933

3. Jacques, Pascal. Transformation-induced plasticity in Steels. In: Thermodynamics, Microstructures and Plasticity , xxx, 2003, p. 241-250. http://hdl.handle.net/2078.1/74934


Dissertations


1. Jacques, Pascal. On the control of the interactions between phase transformations and mechanical properties in finely-grained multiphase alloys, a way for sustainable development in materials science, 2007-09-03. http://hdl.handle.net/2078.1/5190

2. Jacques, Pascal. On the physics and mechanics of phase transformations in TRIP-assisted multiphase steels, prom. : Delannay, Francis, 1999-02-02. http://hdl.handle.net/2078.1/20871