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P. Lang, T. Weisz, M.R. Ahmadi, E. Povoden-Karadeniz, A. Falahati, E. Kozeschnik:
"Thermo-kinetic simulation of the yield strength evolution of AA7075 during natural aging";
Advanced Materials Research, 922 (2014), 406 - 411.

The yield strength evolution in aluminum alloy 7075 is investigated during natural aging. The
thermo-kinetic simulation, capable of predicting nucleation, growth, coarsening and dissolution of
metastable and stable hardening precipitates in Al-Zn-Mg-Cu during natural aging, is outlined
briefly. A recent strengthening model for shearing and bypassing of precipitates by dislocations is
utilized to calculate the evolution of the macroscopic yield strength at room temperature. The
simulation accounts for vacancy-solute binding energies calculated with the help of first principles
simulations that influence the diffusivity of the system due to the presence of excess quenched-in
vacancies. These results provide predictions about the amount of excess vacancies trapped by solid
solution alloying elements and how the lifetime of vacancies changes due to attractive or repelling
binding forces between vacancies and different solid atoms in the aluminum matrix. In our
approach, we calculate the strength evolution after quenching due to interaction between
dislocations and changes in the microstructure by precipitation of different kinds of secondary
phases. The predicted evolution of yield strength is finally verified on experimental measurements.

simulation, natural aging, AA7075, excess quenched in vacancies, binding energy

http://dx.doi.org/10.4028/www.scientific.net/AMR.922.406