Про механізм утворення оксидів алюмінію в залізовуглецевих розплавах: Processy litʹâ, 2021, Tom 143, №1, p.28-37

• Дата: 2021
• Автори: Бєлов, Б. Ф., Троцан, А. І., Карлікова*, Я. П., Рябчиков, І. В.
• Формат: Стаття
• Мова: Ukrainian
• Опубліковано: National Academy of Sciences of Ukraine, Physical-Technological Institute of Metals and Alloys of NAS of Ukraine 2021
• Теми: полігональна діаграма; оксиди алюмінію; квантово-механічні параметри; класифікація та структуризація
• Онлайн доступ: https://plit-periodical.org.ua/index.php/plit/article/view/47
• Назва журналу: Casting Processes

Received 11.11.2020 UDK 669.189:669.046.554 A polygonal diagram of the state of the Al-Al2O3 system in the entire range of concentrations of solid and liquid initial components was constructed using the graphical-analytical method. In contrast to the known one, this diagram shows a sequential series of aluminum oxides, including the primary phase Al2O, secondary intermediate phases AlO and Al3O4, which coexist with liquid aluminum, as well as the area of their separation. Based on the quantum-mechanical parameters of aluminum and oxygen, an analysis of the structural-chemical state of the oxides was carried out and a sequential series of intermediate phases between aluminum and corundum, which are formed in liquid and solid states, were established: Alliq. → Al2O (Al6O3)liq.4+: (Al12O6)sol.0 → AlO (Al4O4)liq.4+:(Al8O8)sol.0 → Al3O4 × (Al6O8)liq.2+: (Al12O16)sol.0 → Al2O3 (Al4O8)liq.4-: (Al16O24)sol.0. For the established intermediate phases of aluminum oxides, structural and chemical reactions of their formation, chemical and structural formulas, temperatures of their formation and melting are given. All lower oxides are formed in the solid state and coexist with liquid aluminum. Spinel AlO ∙ Al2O3 → (Al3O4) is formed at a monotectic temperature of 1900 0С. The sequence of formation of aluminum oxides depends on the number of particles and the relative packing density of polygonal and polyhedral cells of ion-molecular complexes of aluminum and oxygen ions. It is shown that under oxygen deficiency in a metal melt on the basis of lower aluminum oxides, full-valent oxysulfides (Al6O3S2)0 → (Al4O4S2)0 are formed, which exist at the temperatures of liquid steel, and (Al12S6)0, (Al8S8)0, which are present in the solid metal. In a deeply deoxidized metal, which contains sulfur and aluminum, aluminum sulfides of low and linear valence of the stoichiometric composition Al12S6 → Al8S8 → Al12S16 → Al16S24 are formed in the solid state, depending on the oxidation of the metal. The presented results supplement the known experimental data on the phase diagram of the Al-Al2O3 system and allow us to reveal the mechanism of the formation of nonmetallic inclusions during the deoxidation of steel with aluminum.