Особливості тиксоформінгу високоміцного алюмінієвого сплаву ВАЛ10 в умовах імпульсного пресування

• Дата: 2023
• Автори: Головаченко, В. П., Пригунова, А. Г., Шеневідько, Л. К., Ісайчева, Н. П., Кошелєв, М. В., Вернидуб, А. Г.
• Формат: Стаття
• Мова: Ukrainian
• Опубліковано: National Academy of Sciences of Ukraine, Physical-Technological Institute of Metals and Alloys of NAS of Ukraine 2023
• Теми: високоміцний алюмінієвий сплав ВАЛ10; ультратонкостінна форма; роторна обробка; тиксоформінг; мікроструктура; механічні властивості
• Онлайн доступ: https://plit-periodical.org.ua/index.php/plit/article/view/features-thyxophorming-high-strength-aluminum-alloy-val10-condit
• Назва журналу: Casting Processes

Physico-Technological Institute of Metals and Alloys of the NAS of Ukraine (Kyiv, Ukraine) UDK 669.715:66.067 The work provides for the study of the possibilities of manufacturing high-quality castings of different thicknesses from high-strength aluminum casting alloy VAL10 (AM4,5Kd) in extreme conditions of pulse thixoforming. As a result of the carried out researches features of thixoforming in the course of manufacturing of cast samples which design has thermal knots which cause occurrence of hot cracks are defined. It is established that the solid globular phase of the metal suspension practically does not form a framework, which, in turn, avoids the formation of hot cracks. The choice of modes of heating the workpieces and their subsequent thixoforming in the pseudo-solid state was made according to the data of differential thermal analysis (DTA), based on the constructed dependence "temperature - liquid phase fraction". Using ultrathin-thin sealed molds made of aluminum foil with a thickness of 300 μm, the peculiarities of the formation of the microstructure of castings with a diameter of 15 mm obtained from the liquid state of the melt VAL10, which were hardened in water, were investigated. It is shown that the casting temperature of 700 0C and 660 0C, cooling rate (3.1–6.2 0C/s) in combination with the simultaneous use of rotary treatment of aluminum melt significantly affect the morphology and size of dendrites of solid copper solution in aluminum (α-phases). In particular, at a casting temperature of 700 0C and a cooling rate of 6.2 0C/s in the castings is formed atypical for the alloy dendritic structure of the α-phase. Reducing the cooling rate to 3.1 0C/s under the conditions of rotary treatment dramatically changes the curing process and leads to the formation of a globular fine-grained structure of the α-phase. In the process of thixoforming, the temperature of the mold was maintained at the level of 310–320 0C. The amount of liquid phase in the pseudo-solid workpieces was 40 %. The velocity of the metal inlet into the cavity of the mold was about 50 m/s The metal suspension was highly liquid and completely filled the cavity (0.2 mm x 100 mm) along the mold connector. The obtained samples are characterized by the absence of cracks, and their mechanical properties after heat treatment according to the T6 regime were: σв = 410 MPa, δ = 5 %.   References  1 Zakharov A. M. (1980). Industrial alloys of non-ferrous metals. Phase composition and structural components. Moscow. [in Russian]. 2 Aristova N. A., Kolobnev I. F. (1977). Heat treatment of cast aluminum alloys. Moscow: Metallurgy. 144 p. [in Russian]. 3 Non-ferrous metals and alloys. Composite metallic materials / Ed. I. N. Friedlander: Encyclopedia. M.: Mashinostroenie, 2001. Vol. 2–3. 880 p. [in Russian]. 4 Wang Q., PANG C., Liv., He J. Effect High Magnetic Fields on the Distribution of Solute Elements in Al-alloys / Proc. 5-th Inst. Symp. On Electromagnetic Processing of Materials. Sendai: Japan, ISIJ. P. 387–390. 5 Bochvar S. G. (2012). Study of regularities and development of technological principles of out-of-furnace modification of the structure of aluminum alloy ingots using acoustic cavitation: Abstract thesis for the degree of Dr. Science (Engin.): spec. 05.16.09 "Materials Science". Moscow, 2012. 50 p. [in Russian].6 Golovachenko V. P., Borisov G. P., Duka V. M., Vernidub A. G. (2012). Casting of non-ferrous metals and alloys from metal foil. Casting processes. No. 2, pp. 40–44. [in Russian].7 Patent UA 94861C2. Method of casting blanks / Golovachenko V. P., Borisov G. P., Vernidub AG, Duka V. M. Publ. 2011. Bull. № 9. [in Ukrainian].8 Golovachenko V. P., Borisov G. P., and Vernidub A. G. (2014). Effect of temperature and rotary treatment on hot brittleness of high-strength aluminum alloy VAL10. Casting processes. No.3. P. 65–69. [in Russian].9 Semenov B. I., Kushtarov K. M. (2010). Production of metal products in solid liquid state. New industrial technologies: textbook. Benefit. Moscow: Publishing house of MSTU named by N. E. Bauman. 223 p. [in Russian].