Physicochemical and technological features of creating metal-based high-superalloys

Abstract

The analysis of modern nickel-based superalloys evolution for casting single-crystal turbine blades was performed. The influence of rhenium as a new alloying element on the physicochemical, kinetic, and structural parameters of nickel-based superalloys and phase stability is discussed. The following experimental data are generalized: the coefficients of segregation and distribution of alloying elements in nickel-based superalloys γ- and γ-phases, the influence of alloying elements on the melting temperature, γ- and γ-phases crystal lattice parameters, diffusion rate of atoms and probability of topologically close-packed (TCP) phase formation. The principles of the balanced alloying and computerized design method for developing fourth-generation single-crystal nickel-based superalloys with high Re content (9-10 %) are considered. The role of high gradient directional solidification (200-220°C·cm-1) in producing single-crystal turbine blades of nickel-based superalloys with high Re content is discussed.