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E. Kabliman, C. Schlögl, J. Kronsteiner, E. Kozeschnik:
"Integrated Modeling of Materials Microstructure during Thermo-Mechanical Processing: a DYNACalc Material Model";
Talk: EUROMAT 2017, THESSALONIKI; 2017-09-17 - 2017-09-22.

The evolution of materials microstructure during production processes is governed by complex interacting mechanism, which strongly influence the final material properties as a function of processing conditions and the material microchemistry. In present work, we introduce an integrated approach for modeling of microstructure evolution during thermo-mechanical treatment using the finite element method and thermo-kinetic simulations of precipitation kinetics. For this purpose, we use a commercial LS-DYNA® software of LSTC [1] with a physically based model of microstructure evolution implemented into a material subroutine USERMAT. This model has been developed at LKR Leichtmetallkompetenzzentrum Ranshofen GmbH in the last years and describes work hardening, dynamic recovery and static recrystallization based on evolution of the mean dislocation density [2-4]. The MatCalc executables are used for calculation of the precipitate distribution at every integration point and time [5]. These executables require a user-defined MatCalc script, which contains information about material, model and processing parameters, as well as the MatCalc databases. The final subroutine is then named as DYNACalc Material Model. To demonstrate our approach, we choose an Al-Cu-Mg alloy, which is widely used in structural applications due to its high strength and fatigue resistance properties. The material model is applied in a compression test using an axisymmetric 2D model of a 5 mm diameter by 10 mm cylindrical specimen as described in [4]. The results demonstrate the evolution of precipitation distribution depending on thermo-mechanical parameters as well as local microstructure evolution as sinfluenced by the precipitates.