Independent expert, Honored Scientist of the Russian Federation, Moscow, Russia

Yu. V. Levinsky, Professor, Doctor of Technical Sciences, levinsky35@mail.ru

D. Mendeleev University of Chemical Technology of Russia, Moscow, Russia

Е. V. Vershinina, Associate Professor, Candidate of Technical Sciences, kaver@yandex.ru

The state diagrams of binary systems in the temperature-composition coordinates, widely used in metal science and manufacturing, do not take into account the pressure factor, whereas the latter has a significant impact on the thermodynamics and kinetics of technological processes, properties and quality of the final product. For a more accurate understanding and forecasting of the process of alloys production and operation, it is necessary to take into account the pressure factor, i.e. to consider the behavior of the system in the “temperature – pressure – composition” coordinates. Adding another parameter transforms the two-dimensional state diagram into the three-dimensional one and increases the maximum number of phases in equilibrium for a two-component system to four. Three-dimensional p – T – x diagrams are not used in practice due to the complexity of their interpretation but they allow to represent the behavior of  the system in “temperature-pressure” coordinates, as well as depict various isobaric and isothermal sections. The article discusses the principles and rules for constructing the state diagrams of systems in coordinates p – T, as well as isobaric and isothermal sections. The state diagrams in the “temperature – pressure” coordinates, isobaric and isothermal sections are constructed for the two-component Co – Zn system, and the tetratectic parameters are determined, i.e. the values of temperature, pressure, and composition for the four-phase equilibria present in the system. Based on the studies of p – T – x diagrams of binary systems previously performed by one of the authors of this article, the temperature-barometric coordinates, as well as the compositions of 198 tetratectic points for 46 binary metal systems, have been determined. These results can be useful for industrial technologists and researchers in the field of materials science.

1. Levinsky Yu.V. Diagrams of the state of metals with gases. Moscow : Metallurgiya, 1975. 295 p.
2. Levinsky Yu.V., Lebedev M. P. P – T – x state diagrams of binary metal systems. Calculation and construction methods. Moscow : Nauchnyi mir, 2014. 199 p.
3. Zlomanov V. P., Avetisov I. Kh., Mozhevitina E. N. Physical chemistry of solids. P – T – x diagrams of phase equilibria: textbook. Moscow : RHTU im. D. I. Mendeleeva, 2019. 183 p.
4. Chuvildeev V. N., Levinsky Yu. V., Vershinina E. V. Fundamentals of the theory of sintering of metal powders. Moscow : Nauchnyi mir, 2020. 306 p.
5. Savich V. V., Oglezneva S. A. Powder metallurgy: current state and development prospects: monograph. Perm : Izd-vo Permskogo nats. issled. politekhn. un-ta, 2021. 694 p.
6. Lyakishev N. P. State diagrams of double metal systems. Guide book: in 3 volume. Moscow : Mashinostroeniye, 1996. 992 p.
7. Koo C. M., Sambyal P., Iqbal A., Shahzad F., Hong J. Two-Dimensional Materials for Electromagnetic Shielding. John Wiley & Sons, 2021. 224 p.
8. Iqbal A., Shahzad F., Hantanasirisakul K., Kim M. K. et al. Anomalous absorption of electromagnetic waves by 2D transition metal carbonitride Ti3CNTx(MXene). Science. 2020 . Vol. 369. Iss. 6502. pp. 446–450.
9. Karun Kaan Ölçen, Tuncay Dikici Evaluation of the shielding effectiveness of electrodeposited Zn – Ni, Zn – Co, Ni – Co, and Zn – Ni – Co alloy coatings. J. Mater. Sci: Mater. Electron. 2024. Vol. 35. Article No. 1376.
10. Massalski T. B., Subramanian P. R., Okamoto H., Kacprzak L. Ed., Binary alloys phase diagrams. ASM, International, Material Park, Ohio, USA, 1990. 3589 p.
11. Mozeva A., Nenov D., Gidikova N. Determination of the activity of zinc in liquid cobalt and nickel alloys. Arch. Eisenhuettenwes. 1977. Vol. 48, Iss. 10, pp. 533–534. DOI: 10.1002/srin.197705060
12. Budorov S., Wassilew G, Mandadchieva L. The Thermodynamics of Cobalt–Zinc and Nickel–Zinc systems. Z. Metallkd. 1976. Iss. 67, Iss. 5. pp. 307–310.
13. Budorov S., Wassilew G. The thermodynamics of β and γ intermetallic compounds of Nickel–Zinc and Cobalt–Zinc systems. Z. Metallkd. 1977. Vol. 68, Iss. 12. pp. 795–798.
14. Alcock C. B., Itkin V. P., Horrigan M. K. Vapour pressure equations for the metallic elements: 298–2500K. Can. Metall. Quart. 1984. Vol. 23, Iss. 3. pp. 309–313.
15. Samir Abu Ali, Geyderikh V. A. Thermodynamic properties of solid Co – Zn alloys. Zhurnal fizicheskoy khimii. 1971. Vol. 45, Iss. 5. pp. 1248–1251.
16. Levinsky Y. Pressure dependent phase diagrams of binary alloys. Stuttgart: The Materials Information Society, 1997. 1830 p.