Investigation on critical strain of dynamic recrystallization for 7A04 aluminum alloy

The thermal simulation compression tests of 7A04 aluminum alloy were conducted at 350-450 degree C with the strain rate of 0.01-10 s(-1) on the Gleeble thermal simulation test machine. Based on hyperbolic sine relations of peak stress, the thermal deformation activate energy Q of 7A04 aluminum alloy was determined. Based on Sellars model and work hardening rate theta , the critical strain constitutive model of dynamic recrystallization was established. The results show that comparisons between the simulated and experimental results are satisfactory and the constitutive model of critical strain could be used for indicating the beginning of dynamic recrystallization for 7A04 aluminum alloy.