Temporal evolution of nanostructures in a model nickel-base superalloy: Experiments and simulations

Chantai K. Sudbrack*, Kevin E. Yoon, Zugang Mao, Ronald D. Noebe, Dieter Isheim, David N. Seidman

*Corresponding author for this work

Research output: Contribution to conferencePaperpeer-review

14 Scopus citations


The temporal evolution of the nanostructure of a model Ni-base superalloy (Ni-5.2 at.% Al-14,2 at.% Cr) is studied experimentally employing three-dimensional atom-probe (3DAP) microscopy in conjunction with kinetic Monte Carlo (KMC) simulations at 600°C. It is demonstrated that not only can the mean compositions of individual γ' (Ni3Al with the L12 structure) precipitates be measured but the Ni, Al, and Cr concentration profiles within the precipitates can also be determined for precipitates with a mean radius (〈r〉) as small as 0.85 nm. The three asymptotic time dependencies of the Lifshitz-Slyzov-Wagner (LSW) theory of coarsening (Ostwald ripening) are measured and found to deviate from its theoretical predictions; possible explanations for these discrepancies are discussed. At 0.25 hr. there is 3DAP microscope evidence for the presence of precipitates of another nickel-rich phase, ≈"Ni3Cr" (Ni3Cr1-xAlx), which exhibits short-range order (SRO) and that is metastable with respect to Ni3Al. This metastable phase is also found by KMC simulations and has the composition Ni3Cr1-xAlx, which is Ni-2.91 at.% Al-21.98 at.% Cr at 16 hours. Our results demonstrate that the decomposition of the primary γ (FCC) phase results in the concurrent formation of an ordered phase and a disordered phase by 0.25 hours.

Original languageEnglish (US)
Number of pages8
StatePublished - 2003
EventElectron Microscopy: Its Role in Materials Science - San Diego, CA, United States
Duration: Mar 2 2003Mar 6 2003


OtherElectron Microscopy: Its Role in Materials Science
Country/TerritoryUnited States
CitySan Diego, CA

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Metals and Alloys


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