Effect of Homogenization Treatment on Superplastic Properties of Aluminum Based Alloy with Minor Zr and Sc Additions

Abstract

Effect of one-step and two-step homogenization treatment on precipitation of Al3(Sc,Zr) dispersoids, grain structure after annealing of cold rolled sheets and superplastic behaviour of a novel Al-Mg based alloy were studied. Heterogeneous nucleation of Al3(Sc,Zr) phase on dislocations and subboundaries dominated at one-step annealing and both homogeneous and heterogeneous nucleation of Al3(Sc,Zr) were observed at two-step annealing modes. It was shown that two-step treatment mode provides high density of Al3(Sc,Zr) precipitates and 650 % of elongation at the constant strain rate of 10-2 s-1 in the studied alloy.