Microstructure and Properties
The interplay of microstructure and properties is at the core of materials science and engineering and is key to design optimized – often multifunctional - materials. Fracture toughness, strength, ductility, thermal conductivity, thermal stability, corrosion resistance, electrical conductivity, magnetic coercivity, and magnetic hysteresis are prominent examples of material properties, which we tailor by the extrinsic and intrinsic “architecture” of materials. In contrast to ideal single crystals, advanced materials typically contain a complex microstructure. Examples of microstructure elements are stable or metastable phases (their alignment can be manipulated by synthesis and subsequent thermo-mechanical treatments), texture, stacking faults, interfaces (with and without enrichment of alloying additions), dislocations, and point defects; in addition, these “imperfections” contain themselves defects of lower dimensionality and can undergo phase transformations.
Our research deals with resolving the interplay of microstructure components and material properties and to establish quantitative relationships based on length-scale bridging experiments and simulations:
- Tuning stacking fault energy and/or electronic structure of materials to enhance strength and also toughness (steels, HEA/CCA alloys, metallic glasses)
- Phase transformations of grain boundaries and dislocations and their impact on transport properties (pure metals, alloys, intermetallic materials, phase diagrams and defect phase diagrams)
- Microstructure design for functional materials (thermoelectrics, photovoltaics, magnetic materials, …)
- Traps for hydrogen to prevent embrittlement and enable materials for hydrogen economy (steels, alloys, barrier coatings, hydrides)
- Experimental and computational tools to resolve microstructure details and properties with high spatial resolution