National University of Science and Technology “MISiS”, Moscow, Russia.

N. A. Belov, Professor of a Chair of Casting Technologies and Art Material Treatment, e-mail: nikolay-belov@yandex.ru
P. K. Shurkin, Post-Graduate Student of a Chair of Metall Forming, e-mail: pa.shurkin@yandex.ru

National University of Science and Technology “MISiS”¹, Moscow, Russia. ; A. A. Baikov Institute of Metallurgy and Materials Science², Moscow, Russia:
T. K. Akopyan, Researcher of a Chair^1,2, e-mail: nemiroffandtor@ya.ru

There was carried out the experimental investigation of deformation capacity of high-strength econimically alloyed aluminium alloy (Al – Zn – Mg – Ni – Fe system). Calculation methods defined the critical temperatures and forecasted the structural changes in the process of thermaldeformation treatment. A cross-section flat ingot was obtained in a nearly working like environment. This ingot had passed through the whole operation cycle with obtaining of hot-rolled sheet (5.5 mm thickness) and sheet iron (0.5 mm thickness) with the reduction degrees of 86% and 90% respectively. Microstructural investigations show that iron and nickel are joint into the eutectic-formed Al9FeNi phase on all stages, and non-equilibrium phases after air cooling are isolated as fine-disperse particles, having no influence on technological plasticity. The structure of sheet iron is a “natural composite” type, where the compact evenly distributed eutectic aluminides (1–2 μm) are the reinforcing function. Reinforcing thermal treatment according to the modes T and T1 obtained the competitive indicators of mechanical properties: in particular, the tensile strength was 481 and 580 MPa, respectively. This system alloy can also be successfully obtained in the form of pressed bars (confirmed by the investigations of the samples, given by the industrial partner RUSAL). The pressed bars have high plasticity (over 14%) in T1 mode. Both as a result of rolling and pressing, the difference between the tensile strength and yield stress in T and T1 modes is over 200 MPa, which tells about the possibility of regulation of the properties by the selection of thermal treatment modes.

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