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P. Lang, Y.V. Shan, E. Kozeschnik:
"The life-time of structural vacancies in the presence of solute trapping";
Talk: ICAA14, Trondheim, Norway; 2014-06-15 - 2014-06-19.

Vacancies are the simplest type of lattice defect. However, they play a major role in the kinetics of diffusional processes, such as solid-state precipitation, where mass transport directly depends on the concentration of vacancies. We present a physical modelling framework, where we simulate the evolution of excess vacancies on the example of different Al-alloys during various time-temperature treatments. Interaction energies between solute atoms and vacancies as well as solute clusters and vacancies are evaluated by first-principle analysis. Our thermo-kinetic model is based on the postulate that attractive interaction between solutes and vacancies results in trapping. Assuming that the escape of vacancies from existing traps is dependent on temperature and binding energies, we found that the life time of non-equilibrium vacancies is highly controlling the aging response of Al alloys. The predictions of the model are finally compared to experimental data.