The flow stress characteristics of the commercial Al-Zn-Mg-Cu-Zr alloy were analyzed by isothermal compression at 300

4

50℃ and strain rate of 0.01

1

0 s-1 with the Gleeble-1500 hot simulator. The results reveal that the flow stress is controlled by strain rate and deformation temperature

where the flow stress is increased with increasing in strain rate and it is decreased with increasing in temperature. The flow stress is firstly increased to a peak value and then tends to be constant at strain rates less than 10 s-1 with increasing in strain

showing dynamic recovery

while it is decreased after a peak value with the increase of strain at astrain rate of 10 s-1 and deformation temperature higher than 350℃

exhibiting partial dynamic re-crystallization. The strain hardening exponent n and deformation activation energy Q were calculated by linear regression method. And the flow stress constitutive equation of the alloy during hot deformation is presented.