Effect of the Size of Al3(Sc,Zr) Precipitates on the Structure of Multi-Directionally Isothermally Forged Al-Mg-Sc-Zr Alloy
- Авторы: Sitdikov O.1, Avtokratova E.1, Mukhametdinova O.1, Garipova R.1,2, Markushev M.1
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Учреждения:
- Institute of Metals Superplasticity Problems
- Ufa State Aviation Technical University
- Выпуск: Том 118, № 12 (2017)
- Страницы: 1215-1224
- Раздел: Structure, Phase Transformations, and Diffusion
- URL: https://journals.rcsi.science/0031-918X/article/view/166919
- DOI: https://doi.org/10.1134/S0031918X17120122
- ID: 166919
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Аннотация
The effect of Al3(Sc,Zr) dispersoids on the evolution of the cast Al-Mg-Sc-Zr alloy structure under multi-directional isothermal forging (MIF) has been investigated. The alloy, which has an equiaxed grain structure with a grain size of ~25 μm and contains dispersoids 5–10 and 20–50 nm in size after onestage (at 360°C for 6 h) and two-stage (360°C for 6 h + 520°C for 1 h) annealing, respectively, was deformed at 325°C (~0.65 Tm) up to cumulative strains of e = 8.4. In the initial stages of MIF, new fine (sub)grains surrounded by low-angle and high-angle boundaries (HABs) were formed near the initial grain boundaries. With increasing strain, the volume fraction and misorientation of these crystallites increased, which led to the replacement of a coarse-grained structure with a fine-grained one with a grain size of ~1.5-2.0 μm. Dynamic recrystallization occurred in accordance to a continuous mechanism and was controlled by the interaction of lattice dislocations and/or (sub)grain boundaries with dispersoids that effectively inhibited the migration of boundaries, as well as the rearrangement of lattice dislocations and their annihilation. The particle size and the density of their distribution significantly affected the parameters of the evolved structure; in an alloy with smaller particles, a structure with a smaller grain size and a larger HAB fraction developed.
Об авторах
O. Sitdikov
Institute of Metals Superplasticity Problems
Автор, ответственный за переписку.
Email: sitdikov@nm.ru
Россия, Ufa, 450001
E. Avtokratova
Institute of Metals Superplasticity Problems
Email: sitdikov@nm.ru
Россия, Ufa, 450001
O. Mukhametdinova
Institute of Metals Superplasticity Problems
Email: sitdikov@nm.ru
Россия, Ufa, 450001
R. Garipova
Institute of Metals Superplasticity Problems; Ufa State Aviation Technical University
Email: sitdikov@nm.ru
Россия, Ufa, 450001; Ufa, 450000
M. Markushev
Institute of Metals Superplasticity Problems
Email: sitdikov@nm.ru
Россия, Ufa, 450001