Empress Catherine II Saint Petersburg Mining University, Saint Petersburg, Russia
K. Yu. Shakhnazarov, Professor at the Department of Materials Science and Technology of Art Products, Doctor of Technical Sciences, e-mail: Shakhnazarov_KYu@pers.spmi.ru
S. A. Vologzhanina, Professor at the Department of Materials Science and Technology of Art Products, Doctor of Technical Sciences, e-mail: vologzhanina_sa@pers.spmi.ru
R. M. Khuznakhmetov, Postgraduate Student of the Department of Materials Science and Technology of Art Products, e-mail: s225045@stud.spmi.ru

Given the fact that identifying the cause-and-effect mechanisms behind abnormal properties in materials is of enormous importance for science and practical sphere, the authors of this paper propose an approach that allows to establish the relationship between the changing electrical properties and the nanoparticles of intermediate phases forming in non-ferrous metal alloys. A K_Δ criterion is proposed that allows to evaluate a possible formation of nanoparticles of chemical compounds (intermediate phases) which significantly influence transformations in the fine structure. This helps relate the extremums on the curves of electrical properties (such as electric conductivity, specific electrical resistance, electrical resistivity, temperature coefficient of electrical resistance, thermoelectromotive force), which can hardly be explained, to the phase equilibrium diagrams of commercial non-ferrous alloys. It becomes possible to consider the phase equilibrium diagram taking into account the developed K_Δ criterion, which allows to predict the formation of nanoparticles of intermediate phases and, as a consequence, changes in electrical properties in the systems (Pt – Ag, Al – Fe, Bi – Pb, Al – Zr, Cu – Zn) of non-ferrous alloys. The developed K_Δ criterion enables to determine the causes of: maximum electrical resistivity and its temperature coefficient of silver-platinum alloys; unchangeable electrical resistivity in the concentration range (24–32%(at.) Fe) of aluminium-iron alloys; the spike in conductivity and absolute maximum of thermoelectromotive force of bismuth-lead alloys; maximum specific resisti vity of aluminium-zirconium alloys; unchangeable conductivity and temperature coefficient of electrical resistance of copper-zinc alloys.

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