中國有色金屬學報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 33 No. 3 March 2023 |
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metal Materials Science and Engineering of Hunan Province, Central South University, Changsha 410083, China;
3. Applied Materials Science, Department of Engineering Science, Uppsala University, Uppsala 75121, Sweden）
Abstract:The deformation behavior and microstructure characteristics of Al-6.00Mg, Al-6.00Mg-0.10Zr and Al-6.00Mg-0.25Sc-0.10Zr (wt.%) alloys were investigated by hot compression tests and electron microscopy methods. The results show that after deforming under the maximum processing efficiency condition (673 K, 0.01 s-1), dislocation densities of Al-6.00Mg, Al-6.00Mg-0.10Zr and Al-6.00Mg-0.25Sc-0.10Zr alloys are 2.68×1016, 8.93×1016 and 6.1×1017 m-2, respectively. Their dynamic recrystallization fractions are 19.8%, 15.0% and 12.7%, respectively. Kernel average misorientation (KAM) analyses indicate that dislocation accumulation near grain boundaries is enhanced by adding Zr or Sc+Zr. Besides, the established hot processing maps, based on the dynamic material model (DMM), reveal that the addition of Zr or Sc+Zr can reduce the range of low-temperature unstable domain but expand the unstable domain at high temperatures and high strains. The experimental results further verify that under the testing deformation condition, only the Al-6.00Mg-0.25Sc-0.10Zr alloy cracks at 773 K and 1 s-1.
Key words: Al-Mg alloys; Sc; Zr; hot deformation; dislocation density; dynamic recrystallization
