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M. Rath, A. Krumphals, M. Stockinger, E. Kozeschnik:
"Microstructural Modelling of Thermo-mechanically Processed Ni-base Superalloys";
Talk: 6th International Conference on Recrystallization and Grain Growth, Pittsburgh; 2016-07-17 - 2016-07-21.

Controlling the grain size during thermo-mechanical processing of Nickel-base superalloys is essential in assuring the demanded mechanical properties. In order to determine appropriate process parameters in advance, mainly semi-empirical models for the description of the deformation behavior and the microstructure evolution are used. However, these models are generally not able to describe multi-modal grain size distributions evolving during thermo-mechanical processing. In the present work, a new approach for microstructural modeling of the evolving grain size distribution is developed, which is focused on a state-parameter-based modeling of the microstructure evolution taking into account several microstructural mechanisms, such as recrystallization and grain growth as well as precipitation, simultaneously. To capture the grain structure evolution, a new size-class based approach is developed on basis of a physically-based model for recrystallized grain nucleation and growth in combination with a dislocation density and subgrain evolution model in the framework of an extended Kock-Mecking type approach.

Ni-base superalloys, microstructure modelling