The kinetics of dynamic recrystallization of Cu–0.4Mg alloy

To investigate the dynamic recrystallization (DRX) behaviors of Cu–0.4Mg alloy, compression experiments with height reduction of 60% were performed in the temperature range of 500–800 °C and the strain rate range of 0.005–10 s−1 on a Gleeble-1500 thermo-mechanical simulator. The constitutive relationship between peak stress, strain rate and deformation temperature for Cu–0.4Mg alloy is established by means of the conventional hyperbolic sine equation and the activity energy of hot deformation is determined as 213.8 kJ/mol. The critical strain for DRX initiation is identified from the conventional strain hardening rate curves, and can be described as a function of Zener–Hollomon parameter (Z). The DRX kinetics model of Cu–0.4Mg alloy is established by further analysis of true stress–strain curves and by examination of microstructure. The complete DRX grain size is a power law function of Z with an exponent of −0.1949.