Effect of Scandium on Recrystallization of Aluminum and its Alloys

Abstract

For the last 15 years about 15 commercial Sc-bearing aluminum alloys have been developed in Russia. The main purpose of making scandium addition to aluminum alloys is an improvement in strength properties due to retention of a nonrecrystallized structure in heat-treated semiproducts. Scandium is the most effective element-antirecrystallizer for aluminum alloys and it is superior to other well-known additions-antirecrystallizers (zirconium, chromium, manganese). Making a small scandium addition results in a dramatic increase in a recrystallization temperature of wrought semiproducts (even in the case of cold-rolled sheets), which exceeds a heating temperature for quenching and annealing. As a result, all semiproducts retain a nonrecrystallized structure after heat treatment. The present paper covers experimental data showing the effect of scandium on recrystallization of aluminum and its alloys.