Siberian Federal University, Krasnoyarsk, Russia¹ ; RPC of Magnetic Hydrodynamics Ltd., Krasnoyarsk, Russia²:

V. N. Timofeev, Head of the Department of Electrotechnology and Electrical Engineering¹, Director², Doctor of Technical Sciences

M. M. Motkov, Senior Researcher¹, Project Leader²

RPC of Magnetic Hydrodynamics Ltd., Krasnoyarsk, Russia:

G. P. Usynina, Principal Materials Scientist, e-mail: galina@usynina.ru

All-Russian Institute of Light Alloys, Moscow, Russia:
V. V. Zakharov, Head of the Laboratory of Physical Metallurgy and Aluminium Alloys Technology, Doctor of Technical Sciences

This paper describes the results of an attempt to develop a new Al – Zr – Hf-base alloy, which, compared with the well-known ATsE alloy (0.2–0.45% Zr), is doped with hafnium and which nevertheless has a lower total concentration of zirconium and hafnium (0.3%) and because of this a lower cost. Combined doping with zirconium and hafnium in the 1:1 proportion resulted in the production of ingots cast at a high cooling rate (103 ^oC/sec) and having the structure of a solid solution of zirconium and hafnium in aluminium. Particles of Al₃(Zr_1-xHf_x) intermetallics that get separated as the solid solution breaks down ensure a high heat resistance of Al – 0.15 Zr – 0.15 Hf wire. The process used for making long-length drawing billets (which involves casting into an electromagnetic mould followed by highintensity deformation in the Conform unit) ensured high processability resulting in the production of fine 0.5 mm wire. Several different regimes of final annealing were tested and a two-stage regime (400 ^oC/2 h + 300 ^oC/10 h) was selected that ensured an acceptable level of mechanical properties (σ_в = 153–176 MPa, σ_0.2 = 130–140 MPa, σ = 12–15 %) and the specific electrical resistivity equal to 0.02955–0.02970 Ohm·mm²/m. As the diffusivity of hafnium in aluminium is higher than that of zirconium, no long soaking times were required for the final annealing of Al – 0.15 Zr – 0.15 Hf wire. Like it is with the wire made of the well-known ATsE alloy (aluminium-zirconium). The breakdown time of the solid solution of zirconium and hafnium was times shorter than that of the solid solution of zirconium in aluminium. The obtained 0.5 mm wire made of Al – 0.15 Zr – 0.15 Hf was successfully tested at OKB KP (Special Design Bureau of the Cable Industry).
Support for this research was provided under Grant No. 22-19-00128 by the Russian Science Foundation, https://rscf.ru/project/22-19-00128/.

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