Project 10: Small scale deformation and failure of Mo silicides

M.Sc. Georg Winkens

Supervisors: Prof. Ruth Schwaiger, Prof. Martin Heilmaier

The aim of this thesis is to gain an understanding of deformation and failure mechanisms in Mo silicides, in the individual phases as well as the alloys themselves. For the Mo-Si-Ti alloys, the influence of the protective coating layer is investigated as well.

Nanoindentation is a well-established technique to analyse mechanical properties on the micron and submicron scale and allows for ambient as well as elevated temperature measurements with a straightforward sample preparation and testing procedure. Therefore, nanoindentation will be the main method to analyse the Mo silicides, with and without coating layer.

Using the micro-milling capabilities of focused ion beams (FIB) in combination with the load-displacement resolution of a nanoindenter, micro-compression testing of pillars will be used to determine stress-strain curves of the materials. Additional in-situ imaging using SEM will support the investigation of micromechanical properties, as well as a large breadth of structural characterisation methods including SEM, AFM, TEM and ToF-SIMS. The characterisation will be done in close cooperation together with Project 3.

This way, a thorough understanding of the micromechanical properties and microstructure and the influence of temperature and mechanical load will be gained.