Atom-probe tomography (APT) and first-principles calculations are employed to investigate the partitioning of Hf in the γ′ (L 12) /γ (fcc) phases in two multicomponent Ni-based superalloys. APT results indicate strong partitioning of Hf atoms to the γ (fcc) -phase. We perform first-principles calculations of the substitutional formation energy of Hf for a model γ (Ni) / γ′ (Ni3 Al) system indicating Hf partitioning to the γ′ -phase. Additional calculations of the Hf-Cr binding energy suggest, however, that Cr atoms, which partition to the γ -phase, have a strong attractive binding energy with Hf atoms, thus predicting a reversal of the Hf partitioning in favor of the γ -phase due to alloying with Cr.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)