Analytical and high resolution electron microscopy characterisation of microstructures in WEA/WEC- and FGA-regions

• Applicants: Professor Dr. Joachim Mayer; Dr. Alexander Schwedt
• Subject Area: Thermodynamics and Kinetics as well as Properties of Phases and Microstructure of Materials
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 523648868

The present project is part of the Research Unit FOR 5701 and aims at a microstructural understanding of the premature failure mechanisms caused by unconventional grain refinement at very early stages of loading under high cycle fatigue conditions. In the research programme, we will use modern, partially unique correlative characterisation techniques to reveal structural and chemical information on the internal structure in the WEA/FGA regions and to provide these to the other groups in the Research Unit. Our findings on the WEA and FGA structural elements on the atomic scale will make it possible to draw conclusions on the unexpectedly high thermodynamic stability of the obtained nanocrystalline regions. The investigations will also allow to gain further insight in the thermally induced phase transitions in nanocrystalline compounds and will reveal the thermodynamic mechanisms. Our results will provide microstructural guidance to the main aim of the Research Unit to develop sustainable strategies to suppress both types of failures mechanisms.

• DFG Programme: Research Units
• Subproject of: FOR 5701: Identification of the formation mechanisms of white etching cracks and fine granular dark areas during fatigue loading – parallels and differences (White and Dark)