Research Group Nestler - Inst. for Appl. Mater. - Microstructure Modelling and Simulation (IAM-MMS)

The institute "Microstructure Modelling and Simulation" IAM-MMS has a long-time experience in the development of material models and massively parallel simulation software to describe the development of microstructures in multi-component and multi-phase material systems. The main focus of the research work lies in the development of phase-field modelling in order to simulate structural transformations by considering multiphysical and multiscale influences. The combined modelling methods describe phase transitions, mass and heat diffusion, transport processes in cellular, porous and particular systems, flow processes, and elastoplastic developments of stresses. The simulation software can successfully be applied for microstructure simulations in numerous materials, such as metallic alloys, ceramic materials, geological, biomimetic systems, and high-temperature superconductors. In parameter studies, correlations between characteristic microstructure quantities and processing conditions are analysed. Microstucture simulations act as the link between atomistic and macroscopic calculation methods and herewith pursue the objectives of the future technology "Integrated Computational Materials Engineering". To integrate thermodynamic functions into phase-field modelling, efficient formalisms are implemented, and methods of data analysis in 3D are developed to evaluate simulated and experimental data of complex microstructures in an automated fashion. Outstanding progress is achieved in developing microstructures for materials in energy systems. For high-temperature steels with nanoscale particle distributions, the effect of the polycrystalline grain structure on the material properties is elaborated, which is significant for the application in fossil and solar thermal power plants. For geothermal systems, the efficiency of hydrothermal processes is calculated in rock and sand structures. In extensive 3D simulations, based on metal foams, optimized cellular structures are designed for the application in heat exchangers and heat storage systems, in combination with phase change materials.