24. May. 2012, 16:15 Uhr, Gebäude NW1, Raum H3
Nanostructures in 1 Billion Tons: Using ab-initio based multiscale models and atomic scale experiments for understanding the mechanical behavior of metallic and biological structural materials
Prof. Dierk Raabe, MPI Düsseldorf
Despite the existence of several thousand types of metallic alloys for structural applications more specific and well-tailored novel materials with superior properties are required for future applications in the fields of energy conversion and storage, mobility, health, infrastructure, and safety.
While properties of novel complex metallic multiphase materials can typically be to some extent successfully be developed and optimized with respect to desired properties by well-educated try-and-error methods through combinations of beneficial constitution and lattice defects, ab initio modeling techniques as well as an atomistic understanding of alloying may enormously accelerate and guide this development process and render it into a more science-based approach. Within the realm of ab initio electronic-structure theory, quantum-mechanical methods allow the generation of spin-dependent structural models of crystalline phases, the calculation of enthalpies, and the calculation of other measures, such as the stacking-fault energy and other lattice defects, as a function of temperature. These theoretical methods – together with atomic scale characterization (atom probe tomograhy, electron microscopy) and advanced metallurgical synthesis - provide a solid ground for a novel methodological approach to metallic alloy design, paralleled by classical continuum approaches of modeling and experiments.
The talk presents this strategy of multiscale simulation and joint experimental structure analysis for two exemplary types of structural materials, namely, ultra high strength Fe-Mn steels for engineering design applications and mineralized chitin composites such as encountered in arthropods.