Dear students,
Some calls for proposals may still be in preparation. Initiative enquiries can be directed to the academic staff if you cannot find a suitable thesis here.

Interfaces in composite materials and material composites

Masterthesis

Many properties of composite materials and material composites are determined by the interfaces between the individual materials. The aim of this thesis is to analyse the interfaces of ultrasonically welded composite materials in detail and correlate them with process parameters. 

Contact: Moritz Liesegang 


Investigation of the fatigue behaviour of duplex steel as a function of the manufacturing process

Masterthesis

The fatigue behaviour of a duplex steel (1.4462) in the high-cycle fatigue range is to be investigated as part of this work. Duplex steel consists of equal proportions of austenitic and ferritic phases, with a good combination of mechanical properties and corrosion resistance. The samples are available in a conventionally cast state and in two additively manufactured states. The aim is to investigate the fatigue behaviour in load increase and single-stage tests and to carry out comprehensive characterisation depending on the manufacturing process using microstructural analyses.

Contact: Constanze Backes


Frequency dependence of plastic deformability during ultrasonic welding of metals

Masterthesis

Ultrasonic welding is an innovative and promising joining technique for hybrid material systems. The joining of dissimilar material types is interesting for high-performance structures, e.g. in electronics or aviation. The plastic deformability of metallic joining partners during the process is a basic prerequisite for a successful process and the production of robust welded joints. This work therefore aims to investigate the plastic deformation of metal-safe materials during the ultrasonic welding process as a function of the working frequency.

Contact: Moritz Liesegang


Design of ultrasonic welding sonotrodes

Bachelor thesis or research project for Master students

Sonotrodes are tools that transmit the vibration into the components during ultrasonic-assisted processes such as ultrasonic welding. To do this, the sonotrode must be acoustically designed so that the natural frequencies match those of the rest of the system. The design is comparatively complex, depending on the geometry of the sonotrode and the material used, and is typically carried out using finite element simulation.

In this work, ultrasonic welding sonotrodes are to be designed using CAD and FEM, which differ in terms of geometry and the materials used.

Contact: Moritz Liesegang