Master Thesis

Master thesis topics 2023-2024

• Development of nanostructured glasses with improved properties for industrial applications

Traditional window glasses have a homogeneous and fully amorphous structure, which limits the range of their possible properties. In the fields of metal alloys and organic polymers, the combination of different phases into the same bulk material enables high functionalization and high-performance materials. The global framework of the present topic is the control of the nanostructured structures of phase separated glasses.

By reviewing the phenomenon of phase separation in glasses from a new perspective at the nanometer scale, it is anticipated that superior and/or unique performances compared to traditional glasses can be achieved. Specifically, this master thesis will investigate how different types of nanostructures influence the physical properties of the bulk glass, mainly optical and mechanical. The students will learn to choose experimental parameters, synthesize their own nanostructured glasses and characterize them by combining various state-of-the-art techniques. A particular attention will be paid to the nanoscale characterization using Transmission Electron Microscopy and the local structure of the amorphous material.

This final year project will be carried out in close cooperation with the boundary-pushing Technovation Centre of AGC Glass Europe. It is possible to combine this thesis project with an industrial internship at AGC’s Technovation Centre.

Contact:         
Promotor: Stéphane Godet (stephane.godet@ulb.be)
Supervisor: Kevin Przepiora (kevin.przepiora@agc.com) & Claire Fourmentin (claire.fourmentin@ulb.be)
Researcher : Léa Duboz

Industrial partner:
AGC Glass Europe

• New Titanium alloys with damage tolerance for 3D printing: a necessary development for the energy transition in aerospace

Damage tolerance for aircraft material is critical in the aerospace sector and it is becoming even more crucial in the framework of the energy transition where weight reduction is a key factor in reducing fuel consumption for the energy transition. Titanium alloys are known to have a high strength-to-density ratio, therefore they fit the weight saving requirement. However, their low work-hardening capabilities does not allow them to exhibit a high tolerance to defect.

Recently, the development of a new non-conventional plasticity mechanism called “RIP”* in alpha + beta Titanium alloys enables to reach a high level of work-hardening. Hence, this discovery might be a game changer for aircraft industry, especially regarding 3D printed parts where defects are inherent to the process.

In this context, the student will work on new titanium material grade of great industrial interest (Ti575) in which RIP phenomenon occurs. The project aims at investigating the deformation mechanisms that occurs at different scales as well as exploring and optimizing the mechanical properties in this novel alloy and their evolution during tailored heat-treatments.

Industrial collaboration: This study is part of a collaboration with 4 divisions of the Safran Group.

Academic Collaboration: Professor Frédéric Prima, Chimie-Paris.

*RIP stands for Reorientation Induced-Plasticity

Contact:         
Promotor: Stéphane Godet (stephane.godet@ulb.be
Supervisor: Harena Rakotozafy (harena.rakotozafy@ulb.be)
Researcher : Léa Dumas

Industrial Partner:
Safran

• Natural & recyclable composites for next-generation automotive: study of damage behaviour via quantitative microscopy

Emerging markets, such as electric vehicles, unmanned air vehicles, or urban air mobility, come with an enormous challenge of light weighing, in order to minimize the power consumption of vehicles. However, light weighing cannot be carried out at the expense of safety or performance. Moreover, the solution has to be sustainable, from resource management, recycling, emission perspectives, while remaining cost-effective and profitable for all actors of the supply-chain. In this context, composite materials and high performance polymers are considered as a solution, part of an optimal multi-material design. More particularly, Solvay’s Thermoplastic Composite Platform manufactures a recyclable composite, based on polypropylene resin and natural flax fibres (PP+flax). Solvay, ULB and VUB are collaborating on the investigation of PP+flax composite damage and fracture behaviours, with the final goal of manufacturing a demonstrator electrical drive unit for an electric vehicle.

This Master’s Thesis aims at providing a better understanding of the damage mechanisms in the considered PP+flax composite. Preliminary tests performed during last year Master’s Thesis have provided a first identification of the main damage mechanisms. Now, the goal is to perform a quantitative microscopy study, which consists in the development of an image processing methodology to quantify key factors of the damage state in the material, based on microscope images. This master thesis will take a mixed path of both experimental and data processing/modelling works. The lab work will consist in conducting mechanical tests (tensile, fatigue, etc.) and fractography using Optical Microscope and Scanning Electron Microscope (SEM). The latter will be of prime interest to gather fractured-surfaces images as input data for designing the image processing steps.

Contact:         
Promotor: Stéphane Godet (stephane.Godet@ulb.be)
Supervisor: Alexia Chabot (alexia.chabot@ulb.be)
Researchers : Samuel Collot & Maya Daussin

Industrial partner:
Solvay
 

• Additive manufacturing of soft-magnetic alloys for electrical cars

The development of electrical cars calls for the development of environmentally and yet efficient magnetic materials to work in an alternative field. Fe—Si alloys are great candidates. Nevertheless, the geometry of the devices as to be optimized together with its crystals orientation in order to maximize its magnetic properties. In this framework, additive manufacturing is essential to develop optimized macroscopic geometries while ensuring during or via post-treatment an optimized microstructure. In close collaboration with the Sirris research center, we will study the properties of an Fe-6%Si alloy printed by laser powder bed fusion. This Master’s thesis can be coupled to an industrial internship at Sirris.

Contact:         
Promotor: Stéphane Godet (stephane.godet@ulb.be)
Supervisor: Loïc Malet (loic.malet@ulb.be)

Industrial Partner:
Sirris

• Up-Cycling Aluminium for 3D printing applications: application to high-strength alloys for the aerospace industry

High-strength aluminum alloys are widely used in the aerospace industry. Decarbonation and energy transition are the current (and historically) biggest challenge and it calls for new completely new designs and concepts. 3D-printing will for sure play a major role in this transition. However, currently used aluminum grade cannot be printed and suffer from severe cracking during building. The 4MAT department collaborates with the SIRRIS research center on the use of powders that have been surface treated. Preliminary results are very promising. Cracking is greatly reduced if not totally absent. This groundbreaking technology is presently being patented. It offers the possibility to use recycled powder as starting material. This is particularly interesting in view of the huge amount of aluminium scrap that will come with the change in the aerospace fleet that will accompany the energy transition.

In the present study, we will focus on the understanding of the exact nature of the coating and the underlying mechanisms preventing cracking. The microstructures will be characterized a different scales using advanced microscopy techniques. The precipitation heat-treatment usually applied to provide maximum strength to the aerospace part will be scrutinized and optimized for the particular microstructures obtained by 3D printing.

Contact:         
Promotor: Stéphane Godet (stephane.godet@ulb.be)
Supervisor: Loïc Malet (loic.malet@ulb.be)
Researcher : Romain Giaux

Industrial Partner:
Sirris

• Durability of 3D-printed aluminium: a study at the micron scale

It makes no doubt 3D printing is going to play a major role in order to save weight and redesign parts of the next generation of airplanes. Specific compositions have been developed in order to make them compatible with the additive manufacturing process and the high cooling rates associated. Very little is known regarding the corrosion behaviour of these alloys although it is crucial to ensure long-term durability and repair of the parts.

In the present Master’s thesis, we will focus on the characterization of the electro-chemical behaviour at the scale of a few microns, i.e. we will be able to probe the behaviour of single grains and of specific areas of interest such as grain boundaries, precipitates etc. This topic will beneficiate from thecombined expertises of the 4MAT and ChemSin Departments. The 3D printed material is provided by Anyshape, a company certified by Airbus and supplier for of Al parts produced by additive manufacturing.

Contact:          
Promotors: Stéphane Godet (stephane.godet@ulb.be) and Jon Ustarroz (jon.ustarroz@ulb.be)
Supervisors: Loïc Malet (loic.malet@ulb.be) and Leonardo Coehlo (leonardo.bertolucci.coelho@ulb.be)

Industrial Partner:
Anyshape

• Medieval glasses: provenancing and experimental reconstitution of the recipe

The project aims to compare the composition of Stavelot monastery glasses with glasses made from local raw materials to contribute to the reconstruction of the chaîne opératoire for glass making in the medieval period (9th to 12th century).

Context:
For most of history (if the modern, industrial period is not taken into account) glass was produced using a silica source, a flux (plant ash, a mineral Sosa source - usually natron or wood ash) and modifiers to colour, decolour or opacify the glass. In the 9th century glass production in Western and Central Europe drastically changes. It no longer relies on the import and recycling of glass from Egyptian and Levantine origin, local recipes emerges using ashes from wood and bracken as flux. Compared to earlier periods the trace and minor elemental composition of medieval glasses is much more varied, especially at the onset of this technology. This is linked to variation in ash composition (origin, period of harvesting, and pre-treatment). Very studies have so far focused on the composition of ashes and the influence of their pre-treatment on the final glass composition.

Objectives:
- Part of the glasses excavated in Stavelot were characterised previously. One of the objectives of this project is to contribute to the elemental characterisation of the rest of the glass corpus. Sr and Nd isotopic analysis of the glass of sector 2 and elemental (LA-ICP-MS) and Sr and Nd isotopic analysis of the 12th century glass will be performed to determine the provenance of these glasses and compare them to previous results [1,2].
- To prepare modern glasses mimicking the medieval ones, raw materials (oak, beech and bracken) will be collected around Stavelot at different seasons and will be pre-treated according to recipes found in medieval literature. Quartz from Stavelot-Venn massif will be collected in vein and at the bottom of the rivers. All these materials will be characterised in depth by classical methods (XRD, XRF, TGA, DTA, ICP-OES) as well as by LA-ICP-MS) to try to determine the provenance of the materials constituting the medieval glasses.
- In a third step, a limited number of glasses will be made using the raw materials collected in the field. Glass will be produced based on recipes from medieval literature : 12th century recipes from Theophilius and from Epistola Abreviatoria in renaissance Spain [3]. Ashes of oak, beech, bracken or a mixture of those ashes will be used. These experiments will be carried out at 1100°C with firings ranging from 8 to 24 hours in oxidising and reducing atmospheres. The same experiments will also be performed in a Differential Scanning Calorimetry in order to follow the reactions to determine the glass transition temperature and melting point of the final glass, providing the workability window of the finished glass24. The effect of the treatments and recipes on glass composition, colour, texture and workability will be assessed. Elemental analysis will be performed by (LA)-ICP-MS and the characterisation will be finished by isotopic analysis (Sr & Nd).

Contact:         
Promotor: marie-paule.delplancke@ulb.be
Supervisor: alicia.van.hammeert@ulb.be
Researcher : Nathan Kail

References

1. Van Wersch, L., Biron, I., Neuray, B., Mathis, F., Chêne, G., Strivay, D., et al., 2014. Early medieval stained-glass window from Stavelot (Belgium). ArcheoSciences, 38, 219-234.
2. Van Ham-Meert, A.; Bolea-Fernández, E.; Joke, B.; Bevan, D.; Jochum, K.P.; Neuray, B.; Stoll, B.; Vanhaecke, F.; Van Wersch, L. (2021) Comparison of Minimally Invasive Inductively Coupled Plasma–Mass Spectrometry Approaches for Strontium Isotopic Analysis of Medieval Stained Glass with Elevated Rubidium and Rare-Earth Element Concentrations. ACS omega 6, 18110-18122
3. Govantes-Edwards,D.J.,López Rider, J., Duckworth, C. (2020) Glassmaking in medieval technical literature in the Iberian Peninsula, Journal of Medieval Iberian Studies, 12:2, 267-291, DOI: 10.1080/17546559.2020.1772990

• Reactivity of geopolymer cements based on mining and urban wastes

The project aims study the reactivity of geopolymer cement prepared by direct mecanosynthesis of mining and urban wastes to optimise their composition and mechanical properties.

Context:
Mining wastes coming from the copper and cobalt metallurgy in the Democratic Republic of Congo are a major danger for the population and the environment (i.e. water and air pollution by heavy metals). In addition, used glass bottles and ashes coming from burning wood in urban environment are simply dumped and are also an environmental issue. To contribute to a sustainable development of DRC, we are developing a project to valorise these wastes in the preparation of cements. A preliminary study demonstrated that it is possible to prepare geopolymer cements by combining the three wastes and local clay. It also showed that the fraction of crystalline minerals in the mining wastes is too high to get a good reactivity and thus the required mechanical properties of the hydrated cements. A mechanical crushing is necessary to increase the amorphous fraction in the mixture.

Objective:
The goal of this project is to study the mechanisms leading to the geopolymerization and to optimise the proportions of the ingredients to reach the best mechanical properties of the hardened cement paste. The nature of the best activator for the geopolymerization will be also studied. The project involves structural (XRD, SEM), thermal (DTA, DSC, conduction calorimetry) and elemental characterisation at the different steps of the geopolymer cement synthesis.

Contact:         
Promotor: marie-paule.delplancke@ulb.be
 

• Recycling lithium batteries - Creating sustainable electrochemical pathways

Context:
The imperative to decarbonize has propelled a massive push in the manufacturing of electric vehicles. Recycling end of life batteries and incorporating recycled content into battery production are essential components in forging a sustainable and circular battery value chain. Various recycling processes based on the principles of pyro and hydrometallurgy have been developed hitherto to process end-of-life Li ion batteries. Hydrometallurgical processes are preferred over pyrometallurgical processes as they are less energy intensive. One of the key challenges in hydrometallurgical recovery of battery waste is to avoid excessive consumption of non-recyclable chemicals such as inorganic acid, reducing agents and precipitating agents.

Project:
The objective of this work is to create an alternative electrochemical process in which the reagent used for dissolution of metals from the battery waste would be regenerated in an electrochemical reactor. Simultaneously, the researcher will also work towards designing a reactor in which the dissolved metals can be precipitated as metal hydroxides using membrane electrolysis.

Using electrons as green reagents, the researcher will work towards developing a sustainable closed-loop process for battery recycling. However, the chemistry developed in this flowsheet can be widely applicable for metal extraction towards various waste streams. Thus, a significant portion of the research will also be dedicated towards understanding the reaction mechanisms.

Contact :           
Promotor : prakash.venkatesan@ulb.be

References 1. Recycling lithium-ion batteries from electric vehicles, Nature 575(7781) (2019) 75-86. 2. Hydrometallurgical Processes for Recycling Spent Lithium-Ion Batteries: A Critical Review. ACS Sustainable Chemistry & Engineering 2018, 6 (11), 13611-13627
 

• Novel solvometallurgical recovery of copper and cobalt from a cobalt-copper ore

Context:
The high increase in demand for cobalt and copper across the world market, caused on the one hand by technological innovations and on the other hand by the energy transition, is leading to the development of sustainable processes for the extraction of these metals. Many disadvantages, which are not negligible, have been reported for the so-called conventional processes, namely: high energy consumption (3.83 MWh/T), generation of large quantities of dust (10% of the feed), environmental pollution due to the gases from the reactors for pyrometallurgy; a large quantity of water in the hydrometallurgical process leading to a lot of liquid effluents loaded with heavy metals to be managed (183 m3/h). To solve this problem, innovative processes are emerging such as solvometallurgy, which is a new branch of extractive metallurgy that is being intesnsely researched and includes solvoleaching, solvent extraction between two non-aqueous phases and electrowinning in a non-aqueous medium. Unfortunately, few studies have been carried out in this field, limited only to the possibility of solubilizing copper and cobalt by solvoleaching without considering the kinetic aspect of this step. This project aims to study and model the kinetics of the different chemical reactions that take place during solvoleaching in order to provide the first important foundations of this new and promising process.

Project:
The research in the laboratory will mainly consist of carrying out solvoleaching tests under optimal conditions and following the evolution of the extraction yield of copper and cobalt as a function of time and temperature. These data will allow the phenomenon and the kinetic mechanism of the solvoleaching to be modelled by an empirical approach with the various models existing in the literature of classical leaching.

Contact :           
Promotor : prakash.venkatesan@ulb.be
Daily Supervisor: heritier.tshipeshi.makina@ulb.be
 

• Sustainable iron metal production by direct electroreduction of iron ore

Steel production accounts for more than 8% of global emissions and sustainable steel production is key to achieve a decarbonized economy. The direct electroreduction of iron oxide to produce metallic iron (ULCOS project) is truly a fascinating field of research and offers a breakthrough alternative to the existing status quo of blast furnace based iron production. The reaction happens in alkaline media and the mechanism of electroreduction -ie, solid state direct reduction is yet to explored in detail. Furthermore, a lot of other sources such as bauxite residue can be directly used to produce metallic iron via this method. The student will work on firstly understanding the fundamental reaction mechanism of direct electroreduction of iron from iron oxide in alkaline media.

Promotor : prakash.venkatesan@ulb.be

 

• Rare earth combined with electricity production in a fuel cell

Rare earth elements (REEs) are considered to be critical metals by the EU due to risks associated with supply chain and increasing demand from clean-tech applications. More than 20% of REEs produced are consumed for producing NdFeB permanent magnets. Thus, end of life products containing rare-earth permanent magnets such as NdFeBs are important secondary resources from which REEs can be recycled. Several processes – pyrometallurgical, hydrometallurgical and electrochemical, have been successfully demonstrated to recover critical metals from the magnets. This project aims to recover REEs from NdFeB magnets inside a configuration of a fuel cell. Such a process a) can be carried out at room temperature b) Does not consume acid and can thus be a closed loop process consistent with green chemistry principles c) Can also produce energy. The researcher will undertake the exciting and challenging task of constructing the REE-FC which will not only involve reactor construction but also working on finding thermodynamically the appropriate cathodic and anodic reactions to ensure the result of a spontaneous reaction with a reasonable cell voltage. The influence of several parameters – pH, concentration of ions, the chosen cathodic reaction, solution ionic strength on key outcomes such as power density, current efficiency and percentage of metal extraction will be systematically investigated.

Promotor : prakash.venkatesan@ulb.be

References 1. Prototype of a scaled‐up microbial fuel cell for copper recovery, Journal of Chemical and Biotechnology, Volume92, Issue11 November 2017, 2817-2824 2. Selective electrochemical extraction of REEs from NdFeB magnet waste at room temperature, Green Chem., 2018,20, 1065-1073

• Recycling critical metals from samarium cobalt magnet waste - Electrowinning of cobalt

Samarium cobalt magnets (SmCo) are resistive to corrosion, have excellent thermal stability and are increasingly used in consumer electronics, aerospace and medical technology. Recycling SmCo magnets can result not only in recovery of valuable critical metals but also lower the environmental footprint of primary mining. In this project, students will focus on designing an environmentally friendly hydrometallurgical recycling process that can selectively recover critical metals from the SmCo waste in a closed-loop manner.

The research performed earlier in the lab has already made substantial progress with leaching, samarium recovery and iron removal. Herein the focus will be completely on selective electrowinning of cobalt from the waste. The researchers will perform electrodeposition experiments using rotating disk electrode to find optimum conditions (Temperature, pH, concentration, use of additives) to minimize the parasitic reaction of hydrogen evolution and deposit cobalt at high efficiency. The findings will be in an electrowinning cell wherein the optimum conditions will be tested to extract cobalt more or less completely from the leachates.

Promotor : prakash.venkatesan@ulb.be

 

• Redox targeting based redox flow batteries

Redox flow batteries are considered as one of the important solutions to large scale energy storage because the energy density and power density of these systems are decoupled. Due to this, these batteries are scalable and offers flexibility. The ability to use high energy density electrode materials is often limited in RFBs due to various reasons and one of the eminent solutions to avoid this is to use redox-targeting based RFBs (RT-RFB). It is based on the concept of redox-targeting reactions between a redox mediator and battery material, with which power is generated via the electrochemical reactions of the redox mediators as RFBs, while energy is stored in solid materials via the redox-mediated chemical reactions. Thus far, LiFePO4 has been successfully demonstrated as an electrode with dibromoferrocene as a redox mediator. Materials with higher voltages such as lithium cobalt oxide, NMC etc offer higher energy density however they are yet to be demonstrated in an RT-RFB cell as no suitable redox mediator has been proposed yet. This project aims to achieve a RT-RFB with high energy density electrodes such as NMC, LCO. The researchers will be exploring various cell chemistries using different electrodes and redox mediators. Many different pairing reactions with corresponding redox mediators will be investigated to obtain optimum energy and power densities.

Promotor : prakash.venkatesan@ulb.be

 

• Electrochemical recovery of lithium from low concentrated leachates

Context:
This thesis will be performed as a part of the Horizon 2020 project RELiEF - https://www.lithium-relief.eu/ . In this project, we have performed already the task of extracting lithium from solid mine tailings where the concentration of lithium is very low with marked efficiency (>95% extracted).

To recover Li from the resulting leached solution or brines, several techniques have been explored, such as precipitation, membrane separation, a combination of membrane separation and ion exchange, and solvent extraction. Nonetheless, these conventional methods face challenges such as excessive chemical usage, waste generation, and limited selectivity, which hinder their widespread adoption. To circumvent these challenges, electrochemical separation and purification methods have emerged as promising alternatives.

This project involves the use of a three-chamber electrochemical separation technique to recover lithium. The process works by passing a solution containing lithium ions through the middle chamber, where the positively charged cations are pulled through a CEM membrane to the cathode side, while the negatively charged anions move through an AEM membrane to the anode side. The resulting cathodic water reduction reaction transforms the lithium ions into LiOH.

The main goal of this project is to be creative and optimize the process by identifying the most effective oxidation reaction (and cell configuration) to make the entire process energy-efficient or even self-sustaining. The team will explore the effects of different anolyte and catholyte concentrations, as well as the concentration of the lithium salt solution to determine the impact on lithium recovery rates and percentages.

​​​​​​​Promotor : prakash.venkatesan@ulb.be

Master thesis 2022-2023

• Thomas Gruzelle – Recycling critical metals from samarium cobalt magnet waste
• Alexis Schiby – Rare earth recovery combined with electricity production in a fuel cell
• Murat Tanriverdi – An acid free closed-loop recycling of Lithium batteries
• Guillaume Mac Donough – 
• Pablo Segarra Duran – 
• Mickael Leicht – 
• Thibaut Henri Motteu –