Physicochemical properties and creep strength of a single crystal of nickel-base superalloy containing rhenium and ruthenium

Abstract

Abstract The influence of alloying elements, including rhenium and ruthenium, on the physicochemical and structural parameters of single crystal nickel-base superalloys has been analyzed. The results were used in computer designing of a single crystal nickel-base superalloy containing rhenium and ruthenium. The optimized alloy composition, providing the best physicochemical properties and longest creep lifetime, contains 6 wt.% rhenium and 4 wt.% ruthenium. <001> single crystals of the designed superalloy were directionally solidified and investigated in as-cast, heat treated and creep deformed conditions. The investigations included: characterization of the superalloy microstructure, dendritic segregation of alloying elements, their partition between the γ- and γ′-phases etc. Creep rupture tests were performed in the temperature interval of 900 – 1 100 °C and included tests longer 1 000 h.