Modeling of whole process of ageing precipitation and strengthening in Al-Cu-Mg-Ag alloys with high Cu-to-Mg mass ratio

A physically based numerical model to predict the microstructure evolution and yield strength of high Cu-to-Mg mass ratio Al-Cu-Mg-Ag alloys during the whole ageing process was developed. A thermodynamically-based precipitation model, employing the classical nucleation and growth theories, was adapted to deal with the precipitation kinetics (evolution of radius and volume fraction of precipitates for Ω phase) of aged Al-Cu-Mg-Ag alloys. The model gives an estimation of the precipitation kinetics (evolution of radius and density of precipitates for both θ' and Ω phases) of the alloy. The strengthening model based on Orowan mechanism was deduced. The microstructural development and strength predictions of the model are generally in good agreement with the experimental data.