Effect of heterogeneously distributed pre-existing dispersoids on the recrystallization behavior of a cold-rolled Al-Mn-Fe-Si alloy
It is well known that strong concurrent precipitation, mainly located along grain/subgrain boundaries, results in a coarse and elongated grain structure, and unusual sharp P {011} and/or M {113} texture components during annealing of supersaturated AA3xxx-series alloys. In this study, a supersaturated as-cast Al–Mn–Fe–Si alloy was annealed at three temperature–time paths after cold rolling and their effects on the softening behavior have been analyzed and compared in terms of final grain structure and texture. In particular, material conditions with dispersoids located along grain/sub-grain boundaries were produced prior to annealing. The effects of pre-existing dispersoids as well as dispersoids formed during annealing (concurrent precipitation), both of which are heterogeneously distributed along grain/sub-grain boundaries, on the recrystallization behavior of the deformed material were investigated and compared. The results clearly show that, due to their larger sizes, these pre-existing dispersoids do not significantly increase the strength of the P/M texture components as compared to the dispersoids formed during annealing, even though the former can still affect the grain structure. It can be concluded that sharp P/M textures develop when recrystallization takes place at low temperature where nucleation of other orientations, whether from particle stimulated nucleation (PSN) or other nucleation mechanisms are suppressed by concurrent precipitation.
Recrystallization behavior of a supersaturated Al–Mn alloy
The effect of concurrent precipitation on recrystallization behavior during the isothermal annealing of a supersaturated and deformed Al-Mn alloy was investigated. It is found that concurrent precipitation strongly affects the recrystallization behavior of this alloy. At low temperatures, concurrent precipitation retards recrystallization and results in large flat grains. The size of recrystallized grains decreases significantly with increasing temperature. The kinetics of recrystallization was determined by measurements of hardness. The JMAK exponent decreases from 3.0 to 0.8 as the annealing temperature increases from 371 °C to 427 °C. The activation energy for recrystallization of the alloy is about 456 kJ/mol. Concurrent precipitation enhances the activation energy for recrystallization of aluminum alloys.
Grain boundary energy and grain growth in Al films: Comparison of experiments and simulations
Abstract Relative free energies of 〈1 1 1〉 tilt boundaries in 1.7-μm-thick Al films were compared with boundary enthalpies obtained via molecular dynamics simulations. Grain growth studies in 25 and 100-nm-thick Al films were compared with simulations. The sources of the differences between experimental and simulational results are discussed.