中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 26 No. 6 June 2016 |
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education,
Central South University, Changsha 410083, China;
3. School of Mechanical Engineering, Hunan Institute of Engineering, Xiangtan 411104, China;
4. Nonferrous Metal Oriented Advanced Structural Materials and
Manufacturing Cooperative Innovation Center, Central South University, Changsha 410083, China）
Abstract:The dynamic recrystallization behavior of 7085 aluminum alloy during hot compression at various temperatures (573-723 K) and strain rates (0.01-10 s-1) was studied by electron back scattered diffraction (EBSD), electro-probe microanalyzer (EPMA) and transmission electron microscopy (TEM). It is shown that dynamic recovery is the dominant softening mechanism at high Zener-Hollomon (Z) values, and dynamic recrystallization tends to appear at low Z values. Hot compression with ln Z=24.01 (723 K, 0.01 s-1) gives rise to the highest fraction of recrystallization of 10.2%. EBSD results show that the recrystallized grains are present near the original grain boundaries and exhibit similar orientation to the deformed grain. Strain-induced boundary migration is likely the mechanism for dynamic recrystallization. The low density of Al3Zr dispersoids near grain boundaries can make contribution to strain-induced boundary migration.
Key words: aluminum alloy; Zener-Hollomon parameter; dynamic recrystallization; strain-induced boundary migration; Al3Zr dispersoids
