The Effects Of Homogenization Treatments On The Recrystallization Behavior Of Al-1.2Mn Alloy

Among the 3xxx series of alloys, Al-1.2Mn foil is commonly used as current collector within lithium ion battery because of its high strength and conductivity. This foil is fabricated generally by casting –homogenization- hot rolling- cold rolling-intermediate annealing- foil rolling. It is necessary to control the grain structures during intermediate annealing process because the structure greatly affects the surface topography of foil. Different homogenization procedures were performed for Al-1.2Mn alloy lead to different concentration of Mn in solid solution, which result in two kinds of recrystallization grain structure during annealing. The effect of different homogenization conditions on recrystalization behavior of Al-1.2Mn alloy sheet during intermediate annealing process was investigated.① The article studied the effects of two-step homogenization(620 ℃/10 h + 440 ℃ /12 h) and one-step homogenization(620 ℃ /10 h) on the following recrystallization firstly. The results indicate that the recrystalization temperature of alloy treated by two-step homogenization is lower than that of the sample treated by one-step homogenization. As the dispersoids precipitated during one step homogenization have strong pinning on grain boundary, the recrystalization grain structure has significant differences compared to that of two-step homogenization.② In order to investigated the interaction between precipitation and recrystallization during annealing of Al-1.2Mn alloy further, another two homogenization treatments(440 ℃ /12 h+620 ℃ /10 h、440 ℃ /12 h) and the as-cast state were added based on two-step and one-step homogenization. It was observed that if the precipitation occurred prior to recrystallization, the size of dispersoid was small and precipitated on grain boundary preferentially, Because of the strong pinning effect on grain boundary migration, the grains grew to elongated state. In contrast, when recrystallization took place prior to precipitation, recrystallization was little affected by concurrent precipitation of Mn-bearing dispersoids, which lead to a fine-grained structure.③The samples with homogenization at 620 ℃ for 10 h and 440℃ for 12 h displayed different evolution of the growth kinetics and texture.