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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


In-process parameter program for ultrasonic metal welding

Masterthesis

Ultrasonic welding is an established process in many areas of industry. Due to the outstanding electrical properties of ultrasonically welded mixed metal composites, demand has been increasing rapidly for some time, particularly in the field of electromobilisation. The control technology of commercial ultrasonic welding systems is often limited to essential functions. A variable process control was developed at the WKK, with which parameter programmes are to be developed during the welding process as part of this work in order to further improve the composite properties.

Contact: Moritz Liesegang


Design of a clamping device for sheet metal for processing using an ultrasound-assisted process

Research project for Master Students

The integration of ultrasonic vibrations into a manufacturing process often has a positive influence on the manufacturing result. For example, plastic deformability is greatly enhanced by the superimposition of force and vibration. This effect is to be used in a new process based on power ultrasound for joining similar and dissimilar parts, which requires the design of a clamping device for the specimens that also contains a number of sensors.

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


Literature research: Interfaces in composite materials and material composites

Research project for master students

Many properties of composite materials and material composites are determined by the interfaces between the individual materials. The aim of this literature review is to research and summarize the state of the art with a particular focus on fiber-reinforced plastics and ultrasonically welded composites. 

Contact: Moritz Liesegang