中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 22 No. 7 July 2012 |
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Materials Science and Engineering of Ministry of Education,
Central South University, Changsha 410083, China）
Abstract:The hot deformation behavior of Al-Zn-Mg-0.25Sc-Zr alloy and its microstructural evolution were investigated by isothermal axisymmetric hot compression tests at temperatures from 340 to 500 °C and strain rates ranging from 0.001 to 10 s-1. The steady flow stress increased with increasing the strain rate or decreasing the deformation temperature, which can be described by a hyperbolic-sine constitutive equation with the deformation activation energy of 150.25 kJ/mol. The tendency of dynamic recrystallization enhanced at high deforming temperatures and low strain rates, which corresponded to low Z values. With decreasing Z value, the main softening mechanism of the alloy transformed from dynamic recovery to dynamic recrystallization, correspondingly, the subgrain size increased and the dislocation density decreased.
Key words: Al-Zn-Mg-Sc-Zr alloy; hot deformation; flow behavior; microstructural evolution
