Abstract: Hot deformation behavior of the Cu-0.5Cr-0.1Zr alloy at 600-750 ℃/0.001-1.0 s^-1 was studied by hot compression test. The results show that the high temperature flow stress, dynamic recrystallization critical values and dynamic recrystallization softening behavior of the Cu-0.5Cr-0.1Zr alloy were closely related to the deformation temperature and strain rate. The thermal activation energy Q and Zener-Hollomon parameter of the Cu-0.5Cr-0.1Zr alloy were calculated using the Arrhenius equation, which are 244.94 kJ/mol and Z=ε·exp(244.94×10³/RT), respectively. Also, the calculated results of the critical values of dynamic recrystallization by using three methods prove that the Poliak-Jonas criterion has the highest accuracy, and based on which the constitutive equation for the critical values of dynamic recrystallization was established. Furthermore, using the net softening effect η values of dynamic recrystallization, the softening behavior of dynamic recrystallization during hot deformation is discussed. Finally, the processing map of the Cu-0.5Cr-0.1Zr alloy is established, from which the best thermal processing parameter is determined to be 680-750 ℃ and 0.03-0.001 s^-1, and the relationship between power dissipation coefficient and dynamic recrystallized grain size is introduced in detail.

Key words: Cu-0.5Cr-0.1Zr alloy, hot deformation behavior, dynamic recrystallization critical condition, softening effect, hot processing map