Effect of Alloying on the Microstructure, Phase Stability, Hardness, and Partitioning Behavior of a New Dual-Superlattice Nickel-Based Superalloy

Abstract A novel γ – ′– ″ dual-superlattice superalloy, with promising mechanical properties up to elevated temperatures was recently reported by Mignanelli et al . (in: Proceedings of the 9th International Symposium on Superalloy 718 & Derivatives: Energy, Aerospace, and Industrial Applications, pp 679–690, 2018). The present work employs state-of-the-art chemical spatial characterization techniques study effect systematic additions Mo, W, Fe variations in Nb Al contents have phase fraction, thermal stability, elemental partitioning, alloys from this system. Alloys were produced through arc melting followed heat treatment. Multi-scale hardness testing employed characterize their microstructure, properties. Alterations such or partitioning behavior then explained thermodynamic modeling. modest addition 1.8 at. pct Mo had a strong microstructure stability: it minimized microstructural coarsening during treatments while not significantly decreasing ′ solvus temperature. reduction 0.6 strongly reduced volume without affecting fraction. precipitate fraction led significant alloy hardness. Fe, added achieve better processability material cost, decreased temperature caused rapid treatments, 0.4 temperature, also 0.9 W but increased both fractions. These data will be invaluable optimize current design inform future efforts. Graphical