Modeling of isothermal recovery and recrystallization kinetics by means of hardness measurements

Recovery and recrystallization, which may happen during annealing of materials, are very important technological processes through which many properties of the material can be changed. Hence, reliable and efficient modeling of the softening process is vital. Hardness can be used as a simple and cheap measure to model the softening processes. In the present study, the isothermal recovery and recrystallization kinetics of a commercial purity aluminum alloy AA1050 is experimentally modeled using hardness test at four temperatures from 285 °C to 400 °C after cold rolling to various reductions. In order to achieve more accurate analysis, hardness data points are increased and a statistical method is used. The isothermal recovery and recrystallization kinetics are described by a logarithmic and the Johnson‐Mehl‐Avrami‐Kolmagorov relationships, respectively. It is found that hardness measurements can be performed as a parameter to quantify recovery and recrystallization kinetics. The constants of models and the activation energies for both processes are calculated in the different conditions. These constant parameters are dependent to the temperature. Also, the activation energies of recovery and recrystallization rise as these transformations proceed.