Open positions: MSc and BSc students
Are you looking for projects for your master thesis, semester project or an international research internship? We have a range of projects available and are always here to support motivated students on their career paths.
Type of projects:
Semester project, degree project, research internship, research project for visiting students, ...
Contact if you want to know more about current opportunities in the following areas:
Static and dynamic properties of steel powders for cold gas spray repair
Cold gas spraying is an additive process based on the solid-state deposition of metallic powders, accelerated to high speeds by a pressurised gas. Powder particles impinging onto the substrate adhere on it due to extensive plastic deformations. The main advantages of cold spray, as compared to other additive processes, consist in the low temperature, limiting the modification of substrate materials, and the high productivity (several kg per hour). Cold spray of carbon steels is evaluated as a future on-site repair technology for large-scale infrastructure, such as rails or pipeline elements. The repair methods employed today are mostly based on welding, thermally affecting the base materials and lowering mechanical properties around the welded zone. Cold spray would avoid this issue, preserving the properties of the base materials, and potentially offering high quality repair techniques.
In this project, you will evaluate the static mechanical properties of as gas-atomized and thermally annealed steel microparticles for cold gas spray repair. Using micromechanical techniques (microcompression, nanoindentation) coupled with finite element methods you will extract mechanical properties of partricles and relate them to sprayability of powders. You will also use laser-induced particle impact testing to test dynamic mechanical properties of the powders at impact velocities of several hundred meters per second, as directly relevant to the cold gas spray process.
Methods you will learn: nanoindentation, microcompression, optical microscopy, scanning electron microscopy, finite-element modelling, laser-induced particle impact testing, working with a laser-optical setup and laser safety
Microparticle impacts at supersonic velocities—a detailed view of processes that are important in manufacturing, materials processing and materials degradation
High-velocity impacts (tens to hundreds of meters per second) of microparticles on metals are central to a wide range of industrial applications. Particle-target interactions play a crucial role in failure prevention (wear and erosion), processing (water jet cutting, shot peening) and manufacturing (thermal- and cold-spray coating and additive manufacturing). We want to study these phenomena at the single-particle level using laser-induced particle impact testing (LIPIT). In LIPIT, microparticles (~1–100 μm) are launched at a target material at velocities of ~1–3000 m/s [1,2]. We observe the particle's trajectory and impact on a target with micrometer-scale spatial and nanosecond-level temporal resolution using a high-frame-rate imaging system and enable the measurement of kinetic parameters of projectiles before, during, and after mechanical interactions with the sample.
Your project: You will look at a range of impact scenarios and study materials response to microparticle impact. You will learn to set up and work with laser systems and analyze materials with micromechanical methods and focused electron and ion beam microscopy.
Observing microparticle impacts at hundreds of meters per second. a) In LIPIT, individual microparticles are launched towards a target by laser ablation of a sacrificial metal layer and subsequent, rapid expansion of a polymer film. b) Synchronized, high-speed videography is used for the direct observation of the particles’ trajectory and impact and the measurement of particle velocities. The sequence captures the impact-induced adhesion of a single metal microparticle on a metal target—the fundamental process of kinetic manufacturing processes such as cold-spray coating.
[1] D. Veysset, J.-H. Lee, M. Hassani, S. E. Kooi, E. L. Thomas, and K. A. Nelson, “High-velocity micro-projectile impact testing,” Appl Phys Rev, vol. 8, no. 1, p. 011319, Mar. 2021, doi: 10.1063/5.0040772.
[2] Mostafa Hassani-Gangaraj, David Veysset, Keith A. Nelson, Christopher A. Schuh, "In-situ observations of single micro-particle impact bonding", Scripta Materialia, Volume 145, 2018.
High-resolution additive manufacturing of metals
We have the ambition to establish next-generation metal additive manufacturing (AM) processes with micron-scale resolution and excellent materials performance.
Novel AM capabilities with a minimum feature size of <10 μm could strongly benefit the manufacturing of complex 3D structures for microelectromechanical systems, 3D electronics, or devices for energy storage [2]. Yet, existing technologies often suffer from unsatisfactory materials performance [3]—a serious challenge for their impact.
Your project: You will help to develop new manufacturing processes, set up and program AM equipment, and study microstructure and properties of printed materials with a range of analysis tools.
[2] Hirt, L. et al. Additive Manufacturing of Metal Structures at the Micrometer Scale. Advanced Materials 29, 1604211 (2017).
[3] Reiser, A. et al. Metals by Micro-Scale Additive Manufacturing: Comparison of Microstructure and Mechanical Properties. Adv Funct Mater 30, 1910491 (2020).
