Flow Stress Behavior and Microstructural Evolution of a High-Alloying Al–Zn–Mg–Cu Alloy

The flow behavior of a high-alloying Al–Zn–Mg–Cu alloy was studied by compression tests with the temperature range of 300–440 °C and the strain rates range of 0.001–1 s−1, and the corresponding microstructural evolution was observed. Results show flow stress curves exhibit the peak value at a critical strain, and the peak stress decreases with increasing of deformation temperatures. Numerous precipitated particles with a small size and high-density dislocations should be responsible for the high flow stress. Dynamic recovery is the main way of flow softening while dynamic coarsening of precipitated particles and dynamic recrystallization also play a role in flow softening under low-temperature and high-temperature conditions, respectively. The continuous dynamic recrystallization is the major mechanism for dynamic recrystallization behavior.