National University of Science and Technology MISiS, Moscow, Russia:

N. A. Belov, Professor, Principal Researcher at the Department of Metal Forming, Doctor of Technical Sciences
N. O. Korotkova, Engineer at the Department of Metal Forming, Candidate of Technical Sciences, e-mail: kruglova.natalie@gmail.com
S. O. Cherkasov, Master’s Student at the Department of Metal Forming
A. A. Aksenov, Professor at the Department of Metal Forming1, Doctor of Technical Sciences

Through calculations and experiments, the authors of this paper conducted a comparative analysis of two alloys: Al – 1.5% Mn and Al – 1.5% Mn – 1.5% Cu — by comparing their physico-mechanical properties in different states during thermomechanical treatment. Thus, specific conductivity and hardness were determined for castings and rolled sheets reduced at ε = 80% both as cast or rolled and following multi-stage annealing in the temperature range of 200–600 ^oC. Addition of copper was found to contribute to the conductivity and hardness of both cast and deformed specimens after annealing due to Al₂₀Cu₂Mn₃ dispersoids formed in the structure. The size of the latter is ~100 nm. Two specimens in an as-deformed state were found to have a higher specific conductivity attributable to an accelerated breakdown of the (Al) solid solution amid high dislocation density due to high deformation rates. The authors carried out a quantitative analysis of the phase composition of the Al – 1.5% Mn and Al – 1.5% Mn – 1.5% Cu alloys in the temperature range of 200–600 ^oC. For deformed Al – Cu – Mn semi-products, the authors came up with a function enabling to calculate specific conductivity on the basis of phase composition parameters.
This research was funded under the Assignment No. 11.2072.2017/4.6 for the implementation of the following project: Developing a process to obtain deformed semi-products made of aluminium-matrix eutectic composites hardened with L1₂ phase nanoparticles without quenching.

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