Elevated temperature compression deformation behavior of commercial pure Zr combined with the constitutive equation and processing map

The compression deformation behavior of commercial pure zirconium at elevated temperature is systematically investigated at different conditions. The corresponding deformation mechanism of pure Zr is clarified for analyzed flow stress, work hardening rate, activation energy, and microstructure. A modified Arrhenius-type equation is proposed for future numerical simulation, which shows a good relativity between the theoretical and experimental data. The apparent deformation activation energy is 209 kJ mol${}^{-1}$, indicating that a cross-slip of dominant dislocation mechanism controls the deformation process. Established based on the dynamic material model (DDM), processing maps indicate that the optimum processing conditions are 700–900 °C at 0.1–0.14 s${}^{-1}$ and 905–950 °C at 3–20 s${}^{-1}$ with the high efficiency of power dissipation. Microstructure examination reveals that the main restoration mechanism in the safe domain is related to dynamic recrystallization and the unstable regional microstructure results in the flow localization and cracking behavior. (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)