Структура литого композиційного матеріалу системи [Al – FeCr], отриманого з використанням дисперснонаповненої моделі, що газифікується

• Дата: 2023
• Автори: Небожак, І. А., Дерев’янко, О. В.
• Формат: Стаття
• Мова: Українська
• Опубліковано: Physico-technological Institute of Metals and Alloys 2023
• Теми: армування; армуюча фаза; газмодель; гідро- та газодинаміка ЛГМ-процесу; інтерметалід FeCr; композитний виливок; композиційне зміцнення; ЛГМ-процес; ЛКМ системи [Al – FeCr]; ливарна форма; ливарний Al-сплав марки АК12; литий зразок; математична обробка; матричний розплав; мікроструктура; нульмірний; параметри трибоструктури
• Онлайн доступ: https://www.metalsandcasting.com/index.php/mcu/article/view/53
• Назва журналу: Metal and Casting of Ukraine

On the example of an isotropic cast composite material on base of [Al – FeCr] system, obtained with using of cast aluminum alloy (type AK12 DSTU 2839:1994), the effectiveness of its composite hardening in the “cavity” of a casting mold during casting according to gasified models. For this the microstructure of cast specimens was investigated uniformly at 6 horizons and the parameters of the tribostructure of composite olives in height were determined also. The results of metallographic analysis of the experimental castings showed that the structure of zero-dimensional cast composite material of the system [Al – FeCr] changes along of height in the cast samples. In particular, it was found that the morphology of eutectic and other precipitates and inclusions of this structural components in obtained material, that is, the metal matrix (cast aluminum alloy AK12) and the reinforcing phase (intermetallic FeCr – σ-phase), is practically the same along the height of the cast sample. The basis of the eutectic, which prevails in the structure, is a solid solution of the alloy components in Al, against which there are needle-shaped Si crystals of various dispersion. Sometimes primary Si crystals are encountered. The dominant place in the microstructure is occupied by inclusions of intermetallic compound FeCr, which are located in the form of cloud-like crystals clusters with irregular shape of various sizes. The topography of eutectic and other precipitates and inclusions in each of the templates is the same height of the experimental casting. The analysis of the results of the studies showed that between the specific number of inclusions of the reinforcing phase in the structure of the test composite and their dispersion there is a pronounced functional relationship, that is, the average dispersion and the specific number of inclusions of the reinforcing phase change depending along of height in the composite casting – the dispersity of the σ-phase from below the top gradually rises, but the specific number of its inclusions is systematically increasing. For comparison, a metallographic analysis of the control casting material was carried out, which made it possible to find out that the morphology of eutectic and other precipitates and inclusions along the height of the cast sample in all templates is almost the same. The experimental results showed that dendrites of an a-solid solution on Al based and needle-shaped crystals of double siliceous eutectic (a + Si), as well as skeletal precipitates of light gray color of a complex ferromanganese phase AlCuMnFe are observed in the field of metallographic sections (it is also possible to form such a phase as AlSiMnFe). Mathematical processing of an array of numerical experimental data made it possible to derive empirical equations that analytically describe functional dependencies, discussed above.