The Structure and Mechanical Properties of Rolled Sheets of the Multicomponent Al–2.5Ca–2.5Mg Alloy Doped with Scandium and Zirconium

Abstract

Using the Al–2.5% Mg–1% Mn–0.4% Fe base alloy (wt %) as an example, the effects of calcium, scandium, and zirconium additives (at about 2.5, 0.1, and 0.2 wt %, respectively) on the strength of rolled sheets has been studied. Ingots of the alloy of the chosen composition and the hot and cold rolled sheets obtained from them were used as objects for the experimental study. Based on microstructural studies, it isshown that calcium binds iron into compact inclusions (presumably, into the Al10CaFe2 phases), which has a positive effect on the mechanical properties of the alloy, as well as on the technological plasticity during therolling operation. Zirconium and scandium additives make it possible to form thermally stable nanoparticles of the Al3(Zr, Sc)–L12 phase, which is favorable for maintaining a partially unrecrystallized structure in coldrolled sheets during annealing at least up to 400°C. Using the alloy of the selected composition as an example, the fundamental possibility for producing sheet products from cast (unhomogenized) ingots with the properties of thermally hardenable alloys of the AlSiMgMn and AlZn4.5Mg1.5Mn types without using quenching has been demonstrated.