ТЕХНОЛОГІЧНІ ОСОБЛИВОСТІ ВИГОТОВЛЕННЯ СПЛАВУ АК7ч, ЗМІЦНЕНОГО ЦИРКОНІЄМ, УВЕДЕНИМ ІЗ ТЕТРАФТОРИДУ ЦИРКОНІЮ: Procesi littâ, 2023, Vol 2 (152), 16-23

• Дата: 2023
• Автори: Іванченко, Д. В., Ямшинський, М. М.
• Формат: Стаття
• Мова: Ukrainian
• Опубліковано: National Academy of Sciences of Ukraine, Physical-Technological Institute of Metals and Alloys of NAS of Ukraine 2023
• Теми: алюмінієві сплави; цирконій; тетрафторид цирконію; модифікування
• Онлайн доступ: https://plit-periodical.org.ua/index.php/plit/article/view/59
• Назва журналу: Casting Processes

The paper considers the important features of the technology of strengthening AK7ch aluminum alloy with zirconium introduced with its tetrafluoride. The choice of a complex flux containing zirconium tetrafluoride in its composition is justified. It is indicated that in order to recover zirconium from its tetrafluoride in the aluminum melt, it is first of all necessary to ensure the formation of sodium or potassium fluorozirconate in the strengthening mixture. The mechanism of recovery of zirconium from tetrafluoride is presented. Technological recommendations for obtaining AK7ch alloy are given. It has been established that the complex flux intended to the alloy, which is modified, must  be injected into liquid aluminum before the introduction of other alloying elements, namely silicon and magnesium. The maximum appropriate temperature for injecting zirconium into the aluminum melt from the complex flux is indicated. The maximum amount of zirconium that was recovered is 0.4%. The microstructure and mechanical properties of an alloy strengthened by zirconium from its tetrafluoride, which was injected into the alloy in the amount from 0.8 to 1.2%, were studied. As a result of the modification of aluminum alloy AK7ch with zirconium, the grains of silicon solution in aluminum (α-phase) are grind. No other structural changes are observed. The value of tensile strength and relative elongation of the alloy increases by 1.3 and 1.7 times, respectively.   References Gokhshtein M.B (1973). On the classification of modifiers and modifications. Non-ferrous metals. 5. 72–74 [іn Russian]. Azhazha V.M. (1998) Zirconium and its alloys: production technology, areas of application. Kharkov: NSC KIPT. 90 [іn Russian]. Moskvitin V.I. (2012) Thermodynamic principles of aluminothermal reduction of zirconium from ZrO2 in chloride-fluoride salt melts. Non-ferrous metals, 4, 43–46 [in Russian]. Timothy J. Lynch (2022) Determination of Speciation and Local Structure of NaCl–SrCl2 and LiF–ZrF4 Molten Salts. Phys. Chem. B. 126. 7. 1539–1550. Williams D.F. (2006) Assessment of candidate molten salt coolants for the advanced hightemperature reactor (AHTR). Tennessee: Oak Ridge. 86. Thoma R.E. (1965) The Condensed System LiF–NaF–ZrF4–Phase Equilibria and Crystallographic Data. Journal of chemical and engineering data, 3, 219–230. Belov N.A. (2003) Influence of zirconium on the structure and mechanical properties of microalloyed alloys of the Al–Fe–Si system. Izvestiya vuzov. Series: Non-ferrous metallurgy, 4, 54–60 [in Russian]. Gasik M.I. (1999) Theory and technology of electrometallurgy of ferroalloys: A textbook for students of higher educational institutions studying in the specialty «Metallurgy of ferrous metals and alloys». Moscow: SP Internet Engineering, 764 [in Russian]. Litynska L. (2006) TEM and HREM study of Al3Zr precipitates in an Al–Mg–Si–Zr alloy. Journal of Microscopy, Vol. 223, 182–184. Belov N. A. (2007) Phase composition and structure of silumins: Reference. Moscow: MISIS, 283 [in Russian].