MATHEMATICAL MODELING OF PRIMARY PHASES STABILITY DURING CRYSTALLIZATION OF Fe-C-Mn-Si-Ti-Al-N ALLOY
| Jazyk: | ukrajinština |
|---|---|
| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Математичне моделювання; № 2(45) (2021); 103-113 |
| ISSN: | 2519-8106 2519-8114 |
| Popis: | The crucial task of materials science is investigation, forecasting and mathematical modeling of the conditions of primary phases formation, the study of their thermodynamic stability and the structural transformations sequence in multicomponent alloys and steels. The object of this paper is to investigate the thermodynamic functions and thermodynamic stability of aluminum oxidesAl2O3and(Al, Ti)2(O, N)3, their dependence on temperaturewith accounting for the first degree of approximation of high-temperature expansion for thermodynamic potential of binary alloys, perform a comparative analysis. The structural properties of the Fe-Mn-Si-Ti-Al-N-C alloy are considered in this work. It is shown that under crystallization the formation of separate inclusions of aluminum oxidesAl2O3and (Al, Ti)2(O, N)3 occurs. For the first time, calculations of Gibbs energy, entropy, heat capacity are performed and their dependence on temperature is derived taking into account the contribution of the first degree of approximation for high-temperature expansion of thermodynamic potential of aluminum oxide Al2O3. It should be noted that the well-known methods for calculating the thermodynamic functions of the phases can be used only under equilibrium conditions and do not take into account fluctuation processes.The method proposed in this paper makes it possible to determine the temperature of formation of the Al2O3 phase, which coincides with data of other authors.The Gibbs energies for Al2O3 and (Al, Ti)2(O, N)3 phases are compared, and it is shown that the formation of (Al, Ti)2(O, N)3 oxide in the alloy is more energetically favorable, which is consistent with the experimental data. It is proved that the Al2O3 phase is thermodynamically stable over all the temperature range.The temperature dependence of determinant of thermodynamic stability of aluminum oxide (Al, Ti)2(O, N)3 has a distinct minimum at a temperature of 1423 K, which indicates that this phase loses its thermodynamic stability, decomposes and begins to form a new phase. Mathematical modeling of thermodynamic functions of phases provided in this work can be applied further to any alloys and steels. Після лиття в структурі сплавів Fe-C-Mn-Si-Ti-Al-N відбувається утворення дрібнодисперсних включень оксидів алюмінію Al2O3 та(Al, Ti)2(O, N)3. Порівняння енергій Гіббса фаз Al2O3 та (Al, Ti)2(O, N)3, показало, що більш енергетично вигідне в сплаві утворення оксиду (Al, Ti)2(O, N)3, що узгоджується з експериментальними даними. Показано, що фаза Al2O3 термодинамічно стійка на всьому температурному інтервалі, а фаза (Al, Ti)2(O, N)3 втрачає свою термодинамічну стійкість при температурі 1423 К. |
| Databáze: | OpenAIRE |
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