The flow stress behavior and microstructure of semi-solid 7050 aluminum alloy during hot compression deformation process were investigated on the Gleeble-3500 thermal-mechanical simulator at the deformation temperature of 420

4

65 ℃ and strain rate of 0.001

0

.1 s-1.The results show that the flow stress is increased sharply to reach the peak value with increasing in strain at the initial stage

and then tends to be constant

and it is increased with the strain rate increase while it is decreased with rising the deformation temperature.The flow stress can be described by a constitutive equation in hyperbolic sine function.The deformation activation energy is evaluated by linear regression analysis to construct the constitutive equation on flow stress of the alloy during hot compression.With increasing in temperature and decreasing in strain rate

the elongated grains in the deformed alloy is grown.The main softening mechanism of the deformed alloy during hot compression deformation exhibits dynamic recystallization.