Abstract
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.
Original language | English (US) |
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Article number | 161909 |
Journal | Applied Physics Letters |
Volume | 95 |
Issue number | 16 |
DOIs | |
State | Published - 2009 |
Funding
The research was supported by MEANS II AFOSR Grant No. FA9550-05-1-0089. We acknowledge partial support from the National Science Foundation (DMR-0804610) for Z.M. and from the Marie Curie IOF (CEC FP7) for Y.A. Dr. L. Graham and Prof. T. Pollock are kindly thanked for supplying alloys. The LEAP tomograph was purchased with funding from the NSF-MRI and ONR-DURIP programs. The authors acknowledge Dr. C. Booth-Morrison for helpful discussions and Dr. D. Isheim for managing NUCAPT.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)