Abstract
Isothermal hot compression experiments were carried out using the Gleeble-1500D thermal mechanical simulator. The flow
stress of the Cu-1%Zr and Cu-1%Zr-0.15%Y alloys was studied at hot deformation temperature of 550°C, 650°C, 750°C, 850°C,
900°C and the strain rate of 0.001 s–1, 0.01 s–1, 0.1 s–1, 1 s–1, 10 s–1. Hot deformation activation energy and constitutive equations
for two kinds of alloys with and without yttrium addition were obtained by correlating the flow stress, strain rate and deformation
temperature. The reasons for the change of hot deformation activation energy of the two alloys were analyzed. Dynamic recrystallization
microstructure evolution for the two kinds of alloys during hot compression deformation was analyzed by optical and
transmission electron microscopy. Cu-1%Zr and Cu-1%Zr-0.15%Y alloys exhibit similar behavior of hot compression deformation.
Typical dynamic recovery occurs during the 550-750°C deformation temperature, while dynamic recrystallization (DRX) occurs
during the 850-900°C deformation temperature. High Zr content and the addition of Y significantly improved Cu-1%Zr alloy hot
deformation activation energy. Compared with hot deformation activation energy of pure copper, hot deformation activation energy
of the Cu-1%Zr and Cu-1%Zr-0.15%Y alloys is increased by 54% and 81%, respectively. Compared with hot deformation activation
energy of the Cu-1%Zr alloy, it increased by 18% with the addition of Y. The addition of yttrium refines grain, advances the
dynamic recrystallization critical strain point and improves dynamic recrystallization.
Go to article