Berlin 2024 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 3: Topical Session: Sustainable metallurgy

MM 3.9: Talk

Monday, March 18, 2024, 12:45–13:00, C 130

Segregation behavior in Ni-based superalloys — •Ahmed Abdelkawy, Mira Todorova, and Jörg Neugebauer — Max-Planck-Institut für Eisenforschung, Max-Planck-Str.1, 40470 Düsseldorf

Precipitation-hardened nickel-based superalloys are widely used in aerospace and oil and gas industries due to their high strength and corrosion resistance properties that are retained even at elevated temperatures. The exceptional high-temperature strength characteristics are due to the dispersion of intermetallic phases, such as γ′ (Ni3(Al, Ti)) and γ″ (Ni3Nb), within the γ (Ni) Matrix. The corrosion resistance is attributed to the presence of Cr, Nb, and Mo as solid solution within the matrix. The interplay between the matrix, the intermetallic phases, and the dispersed solid solution elements may influence the alloys’ properties but remains largely unexplored due to the complexity of the multicomponent nature of these systems. In this study, we examine the segregation behavior of the alloying elements into and around the intermetallic phases and its effect on the corrosion-resistant characteristics of the superalloys. Moreover, we systemically study the thermodynamic stability of the various defects and formed interfaces by constructing defect phase diagrams.

Keywords: Nickel; Superalloys; Solid interfaces; Defects; Phase diagrams