Effect of the Size of Al3(Sc,Zr) Precipitates on the Structure of Multi-Directionally Isothermally Forged Al-Mg-Sc-Zr Alloy
- Autores: Sitdikov O.1, Avtokratova E.1, Mukhametdinova O.1, Garipova R.1,2, Markushev M.1
-
Afiliações:
- Institute of Metals Superplasticity Problems
- Ufa State Aviation Technical University
- Edição: Volume 118, Nº 12 (2017)
- Páginas: 1215-1224
- Seção: Structure, Phase Transformations, and Diffusion
- URL: https://journals.rcsi.science/0031-918X/article/view/166919
- DOI: https://doi.org/10.1134/S0031918X17120122
- ID: 166919
Citar
Resumo
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.
Sobre autores
O. Sitdikov
Institute of Metals Superplasticity Problems
Autor responsável pela correspondência
Email: sitdikov@nm.ru
Rússia, Ufa, 450001
E. Avtokratova
Institute of Metals Superplasticity Problems
Email: sitdikov@nm.ru
Rússia, Ufa, 450001
O. Mukhametdinova
Institute of Metals Superplasticity Problems
Email: sitdikov@nm.ru
Rússia, Ufa, 450001
R. Garipova
Institute of Metals Superplasticity Problems; Ufa State Aviation Technical University
Email: sitdikov@nm.ru
Rússia, Ufa, 450001; Ufa, 450000
M. Markushev
Institute of Metals Superplasticity Problems
Email: sitdikov@nm.ru
Rússia, Ufa, 450001