Influence of strain rate on hot deformation behavior and recrystallization behavior under isothermal compression of Al-Zn-Mg-Cu alloy

Abstract

An Al-Zn-Mg-Cu alloy was isothermal compressed at temperatures ranging from 300 °C to 450 °C with strain rates ranging from 10−5 s−1 to 10 s−1 to study its deformation and recrystallization behaviors. The evolution of grain structure during the isothermal compression demonstrated that sub-grains found in grain interiors of those deformed with high strain rates from 10−2 s−1 to 10 s−1, were mainly the results of continuous dynamic recrystallization (CDRX), while many recrystallized grains formed at grain boundaries of those deformed with low strain rates from 10−5s−1 to 10−3s−1, were largely believed to be the result of discontinuous dynamic recrystallization (DDRX). Furthermore, two totally different constitutive equations as the result of different dynamic recrystallization mechanisms were proposed.