Modeling the evolution of the structure and properties of alloys for an Al-Zn-Mg system in ageing

An investigation into and modeling of artificial ageing in alloys of an Al-Zn-Mg system are carried out. To determine the kinetic parameters of the dissociation of a supersaturated solid solution, methods of transmission electron microscopy, a measurement of electric resistance at heightened temperature, and differential scanning calorimetry are used. To describe the evolution of the structure in ageing, the Avrami equation and the ageing time dependence of the particle size are applied. A comparison between the computational and experimental values of particle sizes showed the sufficiently high accuracy of the model. Based on this, the yield strength for alloys of the system under consideration in the aged state was computed. The computational error was 11%, which is comparable with the error of the experimental determination of the yield strength.