Effect of heterogeneously distributed pre-existing dispersoids on the recrystallization behavior of a cold-rolled Al-Mn-Fe-Si alloy

a r t i c l e i n f o 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} b566N and/or M {113} b110N 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. Aluminum AA3xxx-series alloys have moderate strength, good duc-tility and excellent corrosion resistance, a very typical application is the beverage can body, as well as in packaging, building and appliances' applications. These alloys contain Mn as their main alloying element, while other elements like Fe, Si, Mg and Cu often are added to improve their mechanical properties. Most of the Fe content forms intermetallic constituent particles during solidification, while the majority of Mn content remains in solid solution, resulting in supersaturation of the solid solution. The supersaturated Mn will precipitate as fine Mn-bearing dispersoids during subsequent thermo-mechanical processing steps [1–3], thus change the microchemistry of the alloy [4]. The effect of fine dispersoids on the softening behavior of aluminum alloys during isothermal annealing has been extensively studied [4–8]. There are mainly two types of dispersoids involved during the annealing of deformed aluminum alloys. The first type belongs to the fine disper-soids present before annealing, often referred to as pre-existing disper-soids, this type of dispersoids is usually formed during homogenization and/or hot deformation and they are mostly randomly distributed. The other type is the dispersoids that …