Processability and structural evolution of round ingots of Al – 2 % Cu – 2 % Mn alloy during forming

Abstract

This paper looks at the processability of round ingots of Al – 2% Cu – 2% Mn alloy during pressing, radial-displacement rolling and drawing. As a result of pressing combined with cross rolling, 9 mm round bars were obtained, which were then rolled and drawn into 0.5 mm wire. The wire was examined in its initial state and after different regimes of annealing. The paper shows that the cast structure contains a small amount (<2 vol. %) of eutectic particles Al2Cu and Al15(Fe,Mn)3Si2, which ensures a good deformation plasticity at the relatively low temperature of 300 oC and enables to produce 15 mm pressed round bars with a 94% reduction. In spite of considerable strain hardening, the bars displayed high processability when subjected to cold radial-displacement rolling and drawing. Thus, a 0.5 mm wire could be obtained with a total reduction of 99%. Mn-bearing dispersoids partially formed during pressing, which prevent softening during annealing. It is shown that the best combination of strength and plasticity is achieved after annealing at 350 oC, which indicates a rather high heat resistance. This experimental alloy can potentially be used as a basis for developing wrought alloys designed to produce round ingots on a commercial scale. Such ingots require no homogenization and can be used to produce a variety of deformed semi-finished products offering an optimum combination of mechanical performance and heat resistance.This research was funded under Grant No. 20-19-00249 by the Russian Science Foundation.