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Hot deformation and dynamic recrystallization (DRX) behavior of the Cu-Cr-Zr-Ag alloy were studied by hot compressive tests in the 650–950 °C temperature and 0.001–10 s−1 strain rate ranges using Gleeble-1500D thermomechanical simulator. The activation energy of deformation was determined as Q = 343.23 kJ/mol by the regression analysis. The critical conditions, including the critical strain and stress, for the occurrence of DRX were determined based on the alloy strain hardening rate. The critical strain related to the onset of DRX decreases with temperature. The ratios of the critical to peak stress and critical to peak strain were also identified as 0.91 and 0.49, respectively. The evolution of DRX microstructure strongly depends on the deformation conditions in terms of temperature and strain rate. Dislocation generation and multiplication are the main hot deformation mechanisms for the alloy. The addition of Ag can refine the grain and effectively improve the DRX of the Cu-Cr-Zr alloy. It can also inhibit the growth of the DRX grains at 950 °C deformation temperature, making the microstructure much more stable.

Hot deformation behavior of the Cu-Cr-Zr-Y alloy was studied by hot compressive tests in the 650–850 °C temperature and 0.001–10 s−1 strain rate ranges using the Gleeble-1500D thermo-mechanical simulator. The flow stress behavior and microstructure evolution were observed during the hot deformation process. The peak stress increases with decreasing temperature and increasing strain rate. The apparent activation energy for hot deformation of the alloy is 336 kJ/mol. Based on the dynamic material model, the processing maps for the alloy were obtained at 0.3, 0.4 and 0.5 strain. The evolution of dynamic recrystallization microstructure strongly depends on the deformation temperature and strain rate. Dynamic recovery is the main softening mechanism at low temperature and high strain rate. Dynamic recrystallization appears at high temperatures and low strain rates. The precipitates of chromium-rich particles were observed during hot deformation. The addition of Y can refine the grain and effectively improve the hot workability of the Cu-Cr-Zr alloy. According to the processing maps and microstructure observations, the optimal hot working parameters for the Cu-Cr-Zr-Y alloy are 800–850 °C temperature range and 0.01–1 s−1 strain rate range.

Hot deformation behavior of the Cu–Cr–Zr alloy was investigated using hot compressive tests in the temperature range of 650–850 °C and strain rate range of 0.001–10 s−1. The constitutive equation of the alloy based on the hyperbolic-sine equation was established to characterize the flow stress as a function of strain rate and deformation temperature. The critical conditions for the occurrence of dynamic recrystallization were determined based on the alloy strain hardening rate curves. Based on the dynamic material model, the processing maps at the strains of 0.3, 0.4 and 0.5 were obtained. When the true strain was 0.5, greater power dissipation efficiency was observed at 800–850 °C and under 0.001–0.1 s−1, with the peak efficiency of 47%. The evolution of DRX microstructure strongly depends on the deformation temperature and the strain rate. Based on the processing maps and microstructure evolution, the optimal hot working conditions for the Cu–Cr–Zr alloy are in the temperature range of 800–850 °C and the strain rate range of 0.001–0.1 s−1.

The hot deformation behavior of the Cu-Cr-Zr-Ag alloy has been investigated by hot compressive tests in the 650-950 °C temperature and 0.001-10 s−1 strain rate ranges using Gleeble-1500D thermo-mechanical simulator. The microstructure evolution of the alloy during deformation was characterized using optical and transmission electron microscopy. The flow stress decreases with the deformation temperature and increases with the strain rate. The apparent activation energy for hot deformation of the alloy was 343.23 kJ/mol. The constitutive equation of the alloy based on the hyperbolic-sine equation was established to characterize the flow stress as a function of the strain rate and the deformation temperature. The processing maps were established based on the dynamic material model. The optimal processing parameters for hot deformation of the Cu-Cr-Zr-Ag alloy are 900-950 °C and 0.001-0.1 s−1 strain rate. The evolution of DRX microstructure strongly depends on the deformation temperature and the strain rate.

To study the workability and to optimize the hot deformation processing parameters of the Cu-Cr-Zr-Y alloy, the strain hardening effect and dynamic softening behavior of the Cu-Cr-Zr-Y alloy were investigated. The flow stress increases with the strain rate and stress decreases with deformation temperature. The critical conditions, including the critical strain and stress for the occurrence of dynamic recrystallization, were determined based on the alloy strain hardening rate. The critical stress related to the onset of dynamic recrystallization decreases with temperature. The evolution of DRX microstructure strongly depends on the deformation temperature and the strain rate. Dynamic recrystallization appears at high temperatures and low strain rates. The addition of Y can refine the grain and effectively accelerate dynamic recrystallization. Dislocation generation and multiplication are the main hot deformation mechanisms for the alloy. The deformation temperature increase and the strain rate decrease can promote dynamic recrystallization of the alloy.

Hot deformation behavior of the Cu-2Ni-0.5Si-0.15Ag alloy was investigated by hot compression tests using the Gleeble-1500D thermo-simulator in the 873 K to 1073 K (600 °C to 800 °C) temperatures range with the 0.01 to 5 s−1 strain rate. The flow stress strongly depends on the deformation parameters, including temperature and strain rate. The flow stress decreases with the deformation temperature and increases with the strain rate. The constitutive relationship between the peak stress, the strain rate, and the deformation temperature can be described by the Zener–Hollomon Z parameter in the hyperbolic sine function with the hot deformation activation energy of 316 kJ/mol. The dynamic recrystallization (DRX) is one of the important softening mechanisms of the Cu-2Ni-0.5Si-0.15Ag alloy during hot deformation. The DRX behavior of the Cu-2Ni-0.5Si-0.15Ag alloy is strongly affected by the Z parameter. Lower Z parameter leads to more adequate DRX proceeding.

Hot deformation behavior of the Cu-Cr-Zr and Cu-Cr-Zr-Ce alloys was investigated by compressive tests using the Glee-ble-1500D thermomechanical simulator at 650-850 °C and 0.001-10 s−1 strain rate. The flow stress decreased with the deformation temperature at a given stain rate. However, the flow stress increased with the strain rate at the same deformation temperature. The constitutive equations for two kinds of alloys were obtained by correlating the flow stress, the strain rate and temperature using stepwise regression analysis. The addition of Ce can refine the grain and effectively accelerate dynamic recrystallization. The processing maps were established, based on the dynamic material model. Instability zones in the flow behavior can be easily recognized. Hot deformation optimal processing parameters were obtained in the range of this experiment. The hot deformation characteristics and microstructure were also analyzed by the processing maps. The addition of Ce can optimize hot workability of the Cu-Cr-Zr alloy.

Hot deformation behavior of two alloys, Cu–Zr and Cu–Zr–Y is studied by compression tests using the Gleeble-1500D thermo-mechanical simulator. Experiments are conducted at 550–900 °C temperature and 0.001–10 s−1 strain rate. The true stress–true strain curves are analyzed, and the results show that the flow stress strongly depends on the temperature and the strain rate. Furthermore, both alloys behave similarly when the flow stress increases with higher strain rate and lower temperature. Based on the dynamic material model, the processing maps are obtained at strains of 0.4 and 0.5. The optimal processing parameters for the Cu–Zr and Cu–Zr–Y alloys are determined. In addition, the constitutive equations for the alloys are established to characterize the flow stress as a function of strain rate and deformation temperature. Based on the microstructure evolution analysis, the results show that the addition of Y can effectively promote dynamic recrystallization. Moreover, the processability of the alloy can be optimized. Thermal deformation activation energy and the peak power dissipation efficiency for the alloys are obtained. It is observed that the addition of Y effectively improves thermal deformation activation energy and has considerable influence on the peak power dissipation efficiency.

Hot deformation behavior of Cu–Ni–Si and Cu–Ni–Si–Ag alloys is investigated using the Gleeble-1500D simulator in the 600–800 °C deformation temperature and 0.01–5 s−1 strain rate ranges. Dynamic recrystallization (DRX) mechanism is a feature of high temperature flow stress–strain curves of the alloy. Microstructure is observed by optical microscopy. Ag addition can refine the grains and accelerate dynamic recrystallization. Characteristic points of the flow stress curves, including critical strain for DRX initiation (ϵc), are determined by employing strain hardening rate analysis. Processing maps are developed and analyzed based on the dynamic material model (DMM). Ag addition can optimize the alloy processing workability.

Hot deformation behavior of the Cu-Cr-Zr-Nd alloy was studied by hot compressive tests in the temperature range of 650-950 °C and the strain rate range of 0.001-10 s(-1) using Gleeble-1500D thermo-mechanical simulator. The results showed that the flow stress is strongly dependent on the deformation temperature and the strain rate. With the increase of temperature or the decrease of strain rate, the flow stress significantly decreases. Hot activation energy of the alloy is about 404.84 kJ/mol and the constitutive equation of the alloy based on the hyperbolic-sine equation was established. Based on the dynamic material model, the processing map was established to optimize the deformation parameters. The optimal processing parameters for the Cu-Cr-Zr-Nd alloy hot working are in the temperature range of 900-950 °C and strain rate range of 0.1-1 s(-1). A full dynamic recrystallization structure with fine and homogeneous grain size can be obtained at optimal processing conditions. The microstructure of specimens deformed at different conditions was analyzed and connected with the processing map. The surface fracture was observed to identify instability conditions.