Effects of ruthenium on phase separation in a model Ni-Al-Cr-Ru superalloy

Yang Zhou, Dieter Isheim, Gillian Hsieh, Ronald D. Noebe, David N. Seidman*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

15 Scopus citations

Abstract

The temporal evolution of a Ni-10.0Al-8.5Cr-2.0Ru (at.%) alloy aged at 1073 K was investigated using transmission electron microscopy (TEM) and atom-probe tomography. The γ′(L12)-precipitate morphology is spheroidal through 256 h of ageing as a result of adding Ru, which decreases the lattice parameter misfit between the γ′(L12)- and γ(f.c.c.)-phases. The addition of Ru accelerates the compositional evolution of the γ′(L12)- and γ(f.c.c.)-phases, which achieve their equilibrium compositions after 0.25 h. Initially, Ru accelerates the partitioning of Ni and Cr to the γ(f.c.c.)-phase, and the partitioning of Al to the γ′(L12)-phase, but after 0.25 h, Ru, which partitions to the γ(f.c.c.)-phase, decreases the partitioning of Ni and increases the partitioning of Al and Cr. The temporal evolution of the average radius, R(t), number density, volume fraction of the γ′(L12)-precipitates, and the supersaturations of Ni, Al, Cr, and Ru in the γ(f.c.c.)- and γ′(L12)-phases are compared in detail with predictions of coarsening models and PrecipiCalc simulations. Based on a spline function fitting procedure of the concentration profiles between the γ′(L12)- and γ(f.c.c.)-phases, it is demonstrated that the temporal evolution of the normalized interfacial width, δ/R(t) vs. R(t), of each element, decreases with increasing ageing time: δ is the interfacial width.

Original languageEnglish (US)
Pages (from-to)1326-1350
Number of pages25
JournalPhilosophical Magazine
Volume93
Issue number10-12
DOIs
StatePublished - Apr 1 2013

Keywords

  • Ni-Al-Cr-Ru alloy
  • atom-probe tomography
  • coarseniing kinetics
  • effects of Ru
  • transmission electron microscopy

ASJC Scopus subject areas

  • Condensed Matter Physics

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