Hot Deformation Characteristics and Processing Map of Al-Li-Cu-Mg-Zn-Ag Alloy

To investigate the hot deformation characteristics of Al-Li-Cu-Mg-Zn-Ag alloy, isothermal hot compression tests were performed in a wide range of temperatures (300~500℃) and strain rates (0.001~10.000 s-1) on Gleeble1500. Processing maps at true strain of 0.1, 0.3 and 0.5 were built. Micrographs of the safety area and instability area at true strain of 0.5 were analyzed. True stress-true strain curves which included transitory stage and steady stage showed that flow stress increased with the increase of strain rate and the decrease of temperature. Processing maps showed that energy dissipation factors at true strain of 0.1, 0.3, 0.5 had the similar growth trend and reached the peak value at high temperature low strain rate area. The proportion of instability area rose with the increase of true strain and the deformation parameters of instability area at true strain of 0.5 were 300~480℃, 0.01~10.00 s-1. Micrographs showed that safety area contained structure of dynamic recovery with much less dynamic recrystallization and local plastic deformation occurred in instability area. Hot deformation parameters were suggested as 410~480℃, 0.003~0.100 s-1 when true strain was less than 0.5. © Editorial Office of Chinese Journal of Rare Metals. All right reserved.