Investigation of Iron‐Aluminide‐Like Phase Composition in Complex Concentrated Fe ₃₂ Cu ₁₂ Ni ₁₁ Ti ₁₆ Al ₂₉ Alloy

Complex‐concentrated alloys based on the combination of the 3d transition elements and aluminum are promising candidates for future lightweight high‐temperature applications. However, the thermodynamically driven phase composition of these alloys has not been clearly understood, leading to conflicting results. In this work, investigations on the alloy are carried out with an emphasis on identifying the crystal structure(s). The microstructure and crystal structures are studied using a combination of scanning electron microscopy and X‐Ray diffraction. The alloy possesses a two‐phase microstructure with a Fe‐rich matrix and Cu‐rich precipitates after aging heat treatment. The matrix is found to possess the crystal structure in combination with precipitates, having a characteristic A2 structure. The phase fractions, precipitate size, and morphology are studied using quantitative microscopy. The thermodynamic origin of the phase composition is explained by using the results from binary and ternary subsystems and the Miedema's model for binary interactions. Finally, an overaging phenomenon in the studied alloy system is correlated in terms of microhardness measurements.