Effect of Complex Alloying on the Phase Composition and Thermal Characteristics of Al–Fe–Si Aluminum Alloys

This study presents a comprehensive analysis of phase formation in Al–Fe–Si aluminum alloys with the addition of ten industrially significant alloying elements (Mg, Cu, Ni, Mn, Cr, Zn, Ti, Zr, V, Be), performed using thermodynamic modeling via the Thermo-Calc software package. Phase formation was investigated and compared in a commercial alloy (Al98–Fe1–Si1) and an intermetallic alloy (Al60–Fe33–Si7) under both individual and synergistic alloying conditions. The thermal characteristics (liquidus, solidus, and α- and β-transformations) and phase constituents were analyzed across a broad temperature range (0–1200 °C). It was found that the alloying elements exert diverse effects on phase stability and alloy structure, with intermetallic systems exhibiting greater thermal stability. Particular attention was given to the formation of the matrix phase and the influence of synergistic alloying on phase equilibria and the potential emergence of new stable compounds. The results provide a basis for targeted alloy design, including the use of secondary aluminum, to develop materials with tailored properties for transportation and mechanical engineering applications.