The life-time of structural vacancies in the presence of solute trapping

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 is directly proportional to the concentration of vacancies. We present a physical modelling framework, where we simulate the evolution of excess vacancies on the example of Al-alloys during simplified time-temperature treatments. Interaction energies between solute atoms and vacancies are evaluated by first-principle analysis. Assuming that the escape of vacancies from existing traps is dependent on temperature and binding energies, we explore the life-time of non-equilibrium vacancies and the natural and artificial aging response of Al alloys. The predictions of the model are finally compared to experimental data.