Grain growth in nanocrystalline materials

• Applicant: Privatdozentin Dr. Dana Zöllner
• Subject Area: Materials Science
• Term: from 2009 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 130519204

Within the framework of this project grain growth in nanocrystalline materials will be investigated. Unlike conventional materials metals and alloys of nanocrystalline size have quite different mechanical properties, which is not only of scientific but also of intense technological interest considering that an increase of grain size during grain growth from nm to μm can result in a loss of important materials properties making them unusable in application. The standard Monte Carlo Potts model will be modified regarding the mobility, energy and width of grain boundaries and their junctions allowing the simulation of nanocrystalline grain growth. In large simulation studies different metrical and geometrical properties will be observed, where for initially very small grains after an exponential growth kinetics a linear growth kinetics is expected changing in later stages to parabolic behaviour.A statistical mean-field theory will be developed based on a generalised Lifshitz-Slyozov- Wagner theory. It should describe the different growth regimes and yield for each regime a separate growth law and an associated analytical grain size distribution function. Furthermore, experimental investigations of grain growth in nanocrystalline materials are planned, e.g., in-situ x-ray experiments of coarsening in nanocrystalline iron. The results of simulation and theory will be considered in conjunction with the experimental findings.

• DFG Programme: Research Grants